“h..-

 

' .13. n; 9.9:; “4855:.“ 1y:
I- .- q.. . :
" "ay ii -28.” irwlda

L‘t’“, ‘! ut ‘Qi h 0" WHO: 0:5, 3,: .“r; , {.‘Y
' a -. 2' 7 " -. M.“ 3 .s -\v r" .‘f‘
s A fill fit $J“.:.' L '3 § 853‘ “’3 g x;-

‘ifiasia ‘Im 12% ill-args'm a}? M. 53.
MILC‘HmAN $1635 iin‘f'EifiEiHW‘

“\a‘Vaysm €3,432?th Efiwgerfii‘ariui

'3 was
s w 3'

3 E E
Ask

Z}

sns a. \ I.
TEE ' 177*L'/4R‘z

I w"
. .' . a . "‘ \rl.-A'
Piili'lu'lll‘ ;¢_‘ _

Universitj

,4
_ . E
b d-

.’,.___,.—-._......_..¢<

D ‘
-.‘I I
. ."ll. ” ’
. ‘ ‘ '
.‘. v

E‘_‘.Q‘ Lt'luilfil.l\“:4" “it, Illy J
... v 1.1...

A flVW SYETVESIS OF TKIGPVETE A30

Tiilifi-{I‘APEITI-J37 TE T1: lOLS

9y

WAYVE L. FREDERICK

A TRESIS

Submitted to the College of Science and Arts
of Nichigan State University of Agriculture
and Applied Science in partial fulfillment

of the requirements for the degree of

MASTER OF SCIEVCE

Department of Chemistry

1959

ACKEUHLEIXS‘LENT

The author wishes to express his appreciation
to Professor Robert D. Schuetz for his guidance
and counsel throughout the course of this work.
The author is also grateful to his wife for her
support and understanding during the course of
this work.

11

t.

I . .J
.. o. .
i.
., ml .
1 I.
.
.c 1‘
.-
.
r
x.
-
.
a.
.
.
. ,\
s
I
{
ry .

‘0

I
O
u

VITA

Wayne L. Frederick

Data and Place of Birth: November 27, 1932, in Aitken, Minnesota

Education: Central Michigan College, Mt. Pleasant, Michigan
l950-l954. Bachelor of Science, Cum Laude, 1954
Michigan State University, East Lansing, Michigan
1954-1959

Honor Society: The Society of the Sigma Xi.

iii

7-!

to

HEW SYNTHESIS OF TWIDPHEEE AND

TEIA‘!API1'THE‘£E TH IOLS

BY

WAYNE L. FREDERICK

AV ABSTRACT

Submitted to the College of Science and Arts
' of Michigan State University of Agriculture
and Applied Science in partial fulfillment
of the requirements for the degree of

1 MASTER OF SCIENCE 1

Department of Chemistry

Year 1959

Approved ch (”YD R/(M. (ii-
/ /

. ABSTRACT

The present investigation was undertaken to determine whether
and in what manner a two step synthesis involving the Friedel-Craft
Reaction of 2,4-dinitr0phenyisulienyl chloride with an aromatic nucleus
followed by basic cleavage of the resulting sulfide to obtain aryl
mercaptans could be extended to heterocyclic compounds, particularly
to the preparation of thiOphene and thianaphthene thiols. The reaction

sequence can be illustrated by the following equations, using thiOphene

as a specific example.

n02

N02 ’
II II + c1 31-91) II II s. N0 + HCl
8 ozn S s~3 § 2

CH
0 3

no; ‘ ‘ . . N02
U: l .3; mm . ._ U a
s 5'. £02 '2: “f V7 ’ ~ N02

The thiols, 2-th10phenethiol, Somethyl-Z-thiOphenethiol,

 

2,5-dimethyl-3-th10phenethiol, and 2-methyl-3-thianaphthenethiol were
prepared and isolated as their mercuric or mercuric chloride salts.
Two mercaptans, 2-thiOphenethiol, and 5-methyl-2—thiOphenethiol, were
prepared and isolated as pure heterOCyclic mercaptans.

The thiol derivatives, 2-piperidinoethyl-Z-thienyl sulfide

hydrochloride and 3-methyl-2-thienyl methyl sulfide were prepared

m I

of he

preps:

ter

in

he a

l

I! one

without isolating the intermediate mercaptans to show the utility of
the synthetic sequence of reactions in the preparation of derivatives
of heterocyclic mercaptans,

The heterocyclic mercaptan, Z-thianaphthenethlol was also ,
prepared by a reaction in which prOpylene sulfide was desulfurized by
interaction with 2-thianaphthyllithium. This is the first example of
the extension of this method, which was originally develOped with J

aromatic compounds, to prepare heterocvclic mercaptans,_

 

 

vi

’x
/ ‘k‘
a ”—4-.— --“ { ‘ “
.' l
a!
. z; s
I
‘. A
\\ / \v’-"

5
. ,1
L I), ’1,
' f1
\ I \.t‘

nZTRCCuC
14131”:le
313C}. 5311
EXPFR 1315 1

Propa:

TABLE OF COflTENTS

. Page

IhTRODUCTloflooooronrOOOOOOOOOIIOOOOOOOOOoOOOOee0.0000000000000000...
HISTORICALQOObOOOOOOeoeoeDeappeeOOOOboCIOOeeeeeoeeeeeeeo000.000.0000
DISCUSSIONO;OOOOOeee00000000000000.000000.0000000000000000.000006000

EXPFR‘MEHTALOOOeOeooceeeoeeeOOboedoeeeeeeeeereeeeeeeeeeOOIcOOOOOOcOe

PrOplration 0' Bi. (2,4-dinitr0phenyi) 013Ulfid.eececeeeeeeeeoeie

Preparation of 2 ,4-Dinitrophenyisulfenyl Chloride.....u..........

a r~ ' Full I bl.‘ -l- -a- «t‘lh

Preparation of 2- hiophenealdehyde...............................
Preparation of 2-& ethylthiOphene....................e....i.;.;...
Preparation of 2,5.oxn5thyitn1apaona...............§.............
Preparation of Z-Methylthianaphthene.so8....;£.s.....ooo...o.o...
Preparation of Prepylene Sulfide........................v........
Preparation of 2,4-Dinitrophenyl-2-thienyi Sulfide...........a...
Preparation of 5-Hethyl-2-thienyi (2,4-dinitrophenyl) Sulfide....
Preparation of 3-Methyl-2-thienyl (2,4-dinitrophenyl) Sulfide:.:.

..................

Preparation of 2 ,5~Dimethyl-3-thienyl (2, 4-dinitrophenyl)

SUlfidOeeeeee:eeeeeeeeeeeeeeeeeeeeeeeIeeeeeeeeeeeeeeeeeeeeeeee

Attempted Preparation of 2,b-Dichloro-3-thienyl-2,4-dinitro-

phOnYI SUIfidOeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

Preparation 0' Thianaphthyi-2,4-dinitraphenyi SlllfidCeeeeeeeeeeee

Preparation of 2-Methyl-3-thianaphthyl-2,4-dinitrophenyl

SUlfid.OOOOOOOOOOOOOOOOOOOOOOOOO00000000000eeoeooeeeeeeeeeare.

PrOparation 0f 2'Th10phCHCth101eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
pTCPCrCtion a, 5‘M0thY1‘2'th10ph0nOth1010eeeeeeeeeeeeeeeeeeeeeeee

Attempted Preparation of 2,5-Dimethyl-3-thiophenethiol...o.......

vii

13
i3
i4
_16
17
'18
~19
2O
21
24

26
27

28

30

32

35

‘ , . . ' 13:50? c
, 7 Prepare
E .. a . a a a , ‘ ' -‘ Attrpi

'. r . _, w. A_ , . .‘ ‘ ' . Attwpl

’ a v a . a e , '- ,' Preparl

sm‘um

e

. _ Prear.
:...n,.,s-‘ I, Art (p1‘tev‘i.h . 3 I-VSIQ{\"' .0 un- 00“. '

'5.”-
.

 

’3
, . , ~_ . t ‘ . -
f ; a. -, ~ ,, - .7 Pro
‘f L . . I. . . ‘ . p ,A n a 4 .. . , ' L l ‘ . ‘-, ‘ . ' , ' par
. ‘ I v
E
.r r: .v u»; . 7‘ . .: .- Pre a“
f .r. p " '5 2 ' I . ‘1 . .' :~ fl 0 p '. n ‘ . .- . | . u ' .~ ‘ I ,. e . n .
Chi
‘ C
. ‘ ,. r ' v‘ . o".
. a 8 >4 1 I _ . A. . be - . , e .1 l I . 7 . ‘4 ‘ 1' g u a ‘ / o
¢
- 1 o ' _ . ,-‘
» t ’ ‘ . ~. ‘ I;. y . ' I
- a , , - I n r u r r a A ‘ e ‘V . . . L \ ‘ ‘ ' ' ' J . A *‘ ‘ - .
¢ 0
' I Q a
a a l . ' . .
‘ , 'p ‘ ' - a. _ I ) . _ 'V ._ , ‘ ‘
~ -- ‘I' . br'e‘et‘«i‘A-4'-ce~..x - . .‘..» ... . - t ., -. ,,l .. '
' l
u C
A - 2': ‘tx “j '. q ) -- i . .- . a. ‘
\mv‘ see-13" v.<.vy. rngangsj‘ .‘ A - g ,1 I ope
- '—\ o. - u g
‘s ‘L‘ak-b.‘c»ul1‘«e'—£a&-.l-U~ -.e -_‘ '-'| -" Prep?
ch
.v . _ . . — . ‘ .7 ‘1
.; 1- ' . a r ‘ .
’pit.)f4§i--x\$.a - I .. . L _.
I ‘ ‘ - ‘ f.‘ 1 ' "V 'r . ‘ V.‘ .a ‘ .2 1. \ 'l. . ' -' “ , A
t I l ‘ ' - r l l ‘ , ‘1 .' A‘ A.
. “q
n ‘ ‘ . n . .. ,- - prQP“
. ,: . ‘ I a o“ _ .I‘. '«n . r . ‘
t “ ' ‘ ¢ I - . . A - .. .
.
Shfiijs
‘ , ‘ . . P .!. Q. r, :— vir‘qY‘
. . . . '. .— .‘. . ... - V
. [I V s t ‘ . i
x _ I . . ‘ y _. e b
-\. _-
. 4.5.1-1‘56.)lev‘PJl'i'Ia‘DOOO"!s..l~sitl‘i.‘tg~¢"b~Ganttflne.‘~'- - qt~\
“)- I
‘5‘I-ii': ll
: - ~ - ' ‘ ' ‘
" ~‘ ‘ 9. ‘ e .. ' l' . O ' ‘ , . a f' a '“x‘ .
' .1 ~ ‘ v _ . ‘ A
A . ‘
JA‘---'—'-'~‘.'~v‘a'I-..‘n 'e G'rfixn‘»Ja~4eC-be’et .eemos'I o . _"'
e n I A I . Q
7 ' ‘ .1, '. a . \ . ‘e-‘l _ o
. . u . l y . - u‘. .v ‘ \ I I t ‘v K ‘ t ' _. .
.. .
‘ - - ‘ ' v s n . ‘ - -. _
’ « ' , D ‘ l ' ‘. V n- l .l. , a
l. '
aar'»e"e: .‘I- a«.. u-«J’o\’¢o- tea-sieve" .e.-~ees¢'~li~;ia.I1-e~'
( ' l ’_ .
- ‘ ._ . .
:‘i'C-“s- >""p.<90.b>.g ‘, .t,~.',lc.el ' . ~ ' ~ .. -‘ l. .
3 ,- . ' , , . - y , .-,
. .. t.
\i' i"'l'-I.— :\ e-‘-q.' ;. V w 1' ‘ .4 .‘
.. v . - ' ' ‘ , . ‘ {L , __ .. -
1‘n9.leel*.h ‘~ ‘_ lg ~ _
. .
. T

TABLE OF CONTENTS - Continued Page
Preparation of 2-Thianaphthenethiol............................. 36
Attempted Preparation of 2-Hethyl-3-thianaphthenethiol.......... 38
Attempted Preparation of 2,2'oDithienyl Disulfide............... 39
Preparation of 2-Thienyl Hercury Mercaptide..................... 40
Preparation of 2-Thiephenemercaptomercuric Chloride............. 41
Preparation of 5-Hethyl-2-thiOphenemercaptomercuric Chloride.... 42

Preparation of 2,5-Dimethyl-3-thiOphenemercaptomercuric

Chlorid.00000000000000000000000.coo-oooooeoe000000000...eeeoo 43

Preparation of 2-Methyl-3-thianaphthyl Mercury Mercaptide....... 44

Recovery of 2-Th10phenethiol from 2-Thiephenemercaptomercuric

Ch10r1d0000000000eeeooeeeoeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee 45

Preparation of 3-nethyl-2-thienyl Pethyl Sulfide................ 46

Preparation of 2-Thienyl-2-piperidinoethyl Sulfide Hydro-

chlorid.O...OOOOOOCOOOOCOOOOOOOOOOOIOODOD...OOOOOOOOOOOQOOOOO 47

Preparation of 2-Thienyl (2,4-dinitr0phenyl) Disulfide.......... 49

Preparation of 2,4-Dinitr0phenyl Sulfide Derivatives of Thiols.. 49

SU:MRYOCOOOCOOCCOOOOOOOOOOOOOOOCOOOOOO.0.0.0.0....OOIOOOOOOOOOOOOO 52

REFEREEJCESOOCOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOUOOOOOOOOOOO.0.0.0.0.... 53

viii

1
..
I‘
01
“.nn
.4
. \
"o

9
I.
as.
"4

P

ed}.

em.
|
at).
.y“
‘
~-5‘
J
" ‘I,
.90!
I've

‘p

i if
,‘ V .
J "J
I ( 6
g
I e 3
a
- I 2'
A 2 a

Or (I
a

'~

, e
v ' '
I.

I ' ’
‘

‘ I‘
I U .-

a.

f‘
.
'1
I
A e D
.
. .
‘ Q h
r 1".
" .'
.i..« ‘.
O
.
J O 0
'¢
4 u‘
I .

~F'iI5e‘

O

I

Q. C

$

0.01

U

.

V, - r
, |

..r

‘

.l D Q
n, .
.

,-
m‘» ‘1
U C. O

t

.

v
‘ J 1'

f

.

.
i
.e
.-
9.138
f...
1'.

t-el

III.OOM9

O

4

.- 0.1
A:
‘ .
i ‘1
0‘
‘~ 4
I‘
‘I
.-.
v
.-
. . ,
I «l
'3
..|
..
. .
l
-‘o0..
.§
1‘ IV
.
.‘ a~
-“ |
V
*Kllem
I
‘ ‘4... -
. “ .'
o- O

non-.9

.awy§.P

’4‘
.

J.

\ | n

«-
'-v
.7.

. 3.5

'f

P

A

6 O

,z

-1‘.

\u.

TALE

II

III

‘4

TABLE
. I
II

III

LIST OF TABLES
Page
Thieny1-2,4-Dinitrophenyl Suifidee............................ 6
Thianaphthy1-2,4-DinitrOphenyl Suifidee....................... 8

Mercury Derivatives Of “110150.000eeeeeeeeeeeeeeeeeeeeeeeeeeee 11

ix

CO!

‘8.

IHTRODUCTION

The present study was undertaken to determine the feasibility
of preparing thiOphene and thianaphthene thiols via preparation and
subsequent basic hydrolysis of thienyi and thianaphthyl (2,4-dinitr0phenyl)
sulfides. This sequence of reactions was reported to give good yields
of easily purified products when applied to the synthesis of a series of
thiOphenols (17). The intermediate sulfides were prepared by reaction
of the sulfur heterocyclice‘uith 2,4-dinitr0phenyleulfenyl chloride
under Friedel-Crafts acylation conditions.

Previously-reported methods for the preparation of thiophene
and thianaphthene thiols usually had rather limited applicability and
did not, in general, give good yields. it was hOped that a more general
method, giving better yields of pure products could be deveiOped. It
was found convenient to isolate most of the thiols prepared in the

course of this investigation as their mercury or mercuric chloride

.alt.e

31::

HISTORICAL

Relatively few thiophene and thianaphthene thiols have been
reported in the literature. At present, six thiophenethiols and six
thianaphthenethiols are known. The general methods used in obtaining
these heterocyclic mercaptans can be best illustrated by several
specific syntheses. Schuetz and Houff (7) prepared 2-thi0phenethiol
by the zinc dust-sulfuric acid reduction of 2-thiOphenesulfonyl chloride.

The latter material was obtained by the chlorosulfonation of thiOphene.

[.5 '2150 c1 Z“ "20 [I 0 SH

‘3
Challenger and Iarrison (18) prepared 2 ethyl~3~th10phenethiol

by reducing thieno—3,2-b-thi0phene with metallic sodium in alcohol.

[::;:I:;::j alcohola E: 5:]::H5

Destructive distillation in vacuo of the tarry material produced
during the commercial production of thiophene from the dehydrogenation
and cyclization of butane with sulfur at 11000 F. produces 3-thi0phenethiol
(19) in yields of 30-40%.

Fawcett (20) prepared 2,5-dimethyl- 3-thiophenethiol by the lithium

aluminum hydride reduction of 2,5-dimethyl-3-th10phenesulfonyl chloride.

‘5

C’J

‘d

o
‘ .wh

2.

2.

tr

IC

sozm SH

[:T'::] LiAng [:i'::]
H3C| | l3 Ct er H38 I I CH3

5 5
This same investigator also prepared 5~(l‘-cyclohexenyl)-2-
thiophenethiol by the lithium aluminum hydride reduction of the

corr95ponding disulfide.

II II
0. s 5" 1.1M}:4 ll IISH
other 5 S
Caesar and Brenton (19) prepared 3-thiophenethiol by adding

sulfur to 3-thienylmagnesium iodide.

I ' M I
I. II + fig _E!§£4> II n g
5 other 5
" Mgr 3::ng H
II II + 5 ——-> II II _L"_> I' II
s s 5-

Heyd (21) prepared 2-thianaphthenethiol by adding sulfur to
2-thianaphthyllithium and acidifying the resulting lithium salt of

2-thianaphthenethiol.

s H“
03L: ——> GU —-> GU
S

Heyd (21) also obtained the isomeric 3-thianaphthenethiol by
treating S-thianaphthylmagnesium bromide with sulfur followed by

acid hydrolysis.

,I

‘r 5 la...-

l

‘1

A-“ 4
x

Illan'- «-¢

I‘<._~---—.-- .

. .n...,- .

a .e..-..-

i

'\
.
vp~~~v u“{

vll.‘

.S .___§€> S __fl___€> S

Kharasch (17) has recently introduced a new and somewhat novel
method for the synthesis of aryl mercaptans involving basic cleavage
of aryl-2, 4-dinitr0phenyl sulfides. - This prOCedure can be illustrated

by the following equations.

1, + AlCl 4 H01
02.0 "3—) QS'Q "02

0. H3
Q r “02 l. KOH, seen an
A? +
e 2. h+
$0 “02 NO'2

The present investigation dealt with the feasibility of developing

 

ES
a:

a similar reaction sequence for the preparation of thiOphene and thianaph-
thene thiols-

Bordwell (22) has reported a rather unique reaction of organe-
lithium compounds with thiiranes in which the sulfur is abstracted from
cyclic sulfides to yield lithium salts of mercaptans.

C4H9Li 4 cg-iacugpnz ._> c4ugssu + Civi3CH=CH2

4.
64319311 ——”-——> C4H9 SH
This desulfurization was successfully used to prepare

2-thianaphthenethiol in the present study.

l
of.

p...
(7

DISCUSSION

The necessary thienyl and thianaphthyl 2, 4-dinitr0phenyl sul-
fides were prepared by the interaction of 2, 4-dinitr0pheny1-sulfenyl
chloride with the heterocyclic nucleus in ethylene chloride as a reaction
media at its reflux temperature, using anhydrous stannic chloride as a
catalyst. This reaction is illustrated by the following equations,

using thiOphene as a specific example.

N02

8” 23c, SnCl4 [s ls- N02 + n31
(C::C1)2>

An excess of the-heterocyclic compound was employed to reduce its

 

 

loss through the formation of polymeric material. In tie case of 2,
5-dichlorothiophene, only a yellow material, which appeared to be poly-
meric, could be isolated. With alkylthiOphenes, the sulfide yields
ranged from 63% in the case of 3-methylthi0phene to 92% in the case of
2, 5-dimethylthiophene. Alkyl substitution, which left an Open alpha
position, activated the heterocyclic nucleus toward polymerization to a
greater degree than toward substitution. The thienyl-Z, 4-dinitrophenyi
sulfides, two of which are prepared here for the first time, and some
of their prOperties are summarized in Table I.

The thienaphthenes were less susceptible to polymerization by
the stannic chloride catalyst than the thiophenes. The thisnaphthenes,
on reaction with 2, 4-dinitrophenyl-sulfenyl chloride, took on just a

slight dark coloration and only a small amount of tarry material was

{.1 I:

y,”—

Iv

.m
n .J
I
( I
O

' in!

Q5

3

nfideaa

{3‘3

.aogouaw H>oonoonu .coauouumaavo>uoou no. acosaom an.

.maocuaun .ouxouw .>uouanon~a coewuououx xn woa>awc< Auv
uncannovo~ .a.e nauoaou Aug uuoolam any
oo- .o.a wauoaou adv gououosx Any

 

emoou ov.m No.0v

 

m
m: ,I4un:
oo.on nu.» v¢.ov «mVONZOazuao no Anvn.n-.n- u_ _

 

 

 

m
mp.~« om.u «m.¢¢ so.~u ~>.~ mn.vv «mvomzmzaao no n.ou~-o- __ ;
96
a a m on:
o>.- oo.~ oo.ev eo.~a as.“ an.vv «mvoazmzH u no no~ _ _
m
u - - o>.«~ m~.~ mn.~v wmvouzomouo om Any can = __
m x o m x mm assauom u used» 0 o.s .x 1:.Auvm

Auvvcsom accouon

vououzo~oo «cooked

 

~mxiAA___wvxra_ mmaomgam auzmzaoapuzuaov .u auumuzh
. a woman

I. . .o .I"

 

formed. The product obtained from thianaphthene melted over a wide
temperature range indicating it to be a mixture of the 2- and 3- sub-
stituted isomeric sulfides. The thianaphthyl-2, 4-dinitr0phenyl sulfides
and some of their properties are given in Table II.

In addition to stannic chloride, two other catalysts were inves-
tigated during the development of preparative methods for obtaining the
above mentioned sulfides. It was found that even when small amounts of
anhydrous aluminum chloride were employed at temperatures as low as ~250,
tar formation was excessive and very low yields of the products were
isolated. An attempt to employ anhydrous ferric chloride resulted in
extreme tar formation and identifiable product could not be isolated.
Anhydrous stannic chloride was found to be ineffective as a catalyst at
temperatures below the boiling point of ethylene chloride.

The heterocyclic 02, d-dinitrOphenyl sulfides could be cleaved
by methanolic potassium hydroxide, or sodium methoxide in methanol (1).
Since sodium methoxide offered no particular advantages and required
additional effort in its preparation, methanolic potassium hydroxide was

used throughout most of the work described here.

3 0CH3
U 1. KOH in CH3OH\ II II + @5502
I
S‘- 02 2. 14+ 5 SH N02

The sulfides were easily cleaved in approximately ten minutes at

 

the reflux temperature of methanol. The reaction time was kept as short
as possible since the initially formed mercaptide ion was found to decom-

pose during the remainder of the cleavage reaction and during the

|
e a
a
s
s

v‘.'~

I
a
n
O
a
a
Q
. . - o ‘

.Hnawv and semen asuunuo>ac3 eueum cmmmgodfi .euoenh .o .zm ap>om .0 any

I {

lul“

 

 

 

02 a H m m /
3 a . a. on |_ _
\
w I m A /
Eases“ .. ofldfl mm «263 _ . _ . _ .
. u . \
0 ed .3 3.; u f u o... .2 .. x

 

N02 0 mew mmnm “33m 4?"..me £09:”flatwoNlmzmH.;:&<Z<H Fr

02 HH 39:.

p...-

O.-

a .
a}. .\
.l. \ ‘ I . ‘
I)
2‘. I
t I
L. ..
s. ‘
II‘- ii i | yl‘ .
~ ..
-
—
.. I
s ’7, rs
\ / \\

subsequent solvent removal Operation. The cleavage step in the experi-
mental procedure was carried out in a nitrogen atmosphere and the
solvent was removed by vacuum distillation with minimum heating to
minimize decomposition and side reactions. The crude thiols also suf-
fared considerable decomposition during their vacuum distillation.

Employing a reaction period of an hour at the reflux temperature
of methanol and removing the major part of the methanol solvent at
atmospheric pressure, resulted in a 17% yield of 2-th10phenethiol.

Bis (2-thienyl) disulfide was isolated as a byproduct from the crude

2, 4-dinitroanisole, the latter being recovered by filtration of the
reaction mixture following the basic cleavage of the sulfide, and also
from the distillation residue remaining after the purification of the
mercaptan. Under similar experimental conditions, 5-methyl~2-th10phen-
ethiol was isolated in only a 1% yield, and 2,b-dimathyl-S-thiophanethiol
could not be isolated. In the latter case, however, a 90% yield of bis
(2,5-dimethyl-3-thienyl) disulfide was isolated from the crude 2,4-di-
nitroanisole which was removed by filtration of the reaction mixture
following the basic cleavage of the sulfide. When the basic cleavage
reaction period was reduced to twenty minutes and the solvent was
removed by vacuum distillation with minimum heating, the yield of
2-thiophenethiol isolated was increased to 48%.

The apparent decomposition of the thiols occurring during their
preparation and isolation suggested that the mildest experimental condi-
tions possible should be used during the basic cleavage of the inter-
mediate sulfides and that the thiols be isolated as mercuric or mercuric

chloride salts. When the heterocvclic-2,4-dinitrephenyl sulfides were

(.1

cleaved
and the
heatizg
19s for
previ ou

scan :1

of the
Iould h
tides a

prOCe'n:

b?PrGiL

'35 Obi.

II I]
l
s e

10

cleaved by methanolic potassium hydroxide, using short reaction periods,
and the methanol solvent was removed by vacuum distillation with minimum
heating, the yields of thiols, isolated as mercuric salts, ranged from
19$ for 2,5-dimethyl-3-thiophenethiol to 75% for 2-thiOphenethiol. The
previously undescribed merCUry salts and some of their properties are
summarized in Table III.

The isolation of satisfactory yields of the mercury derivatives
of the thiols indicated that the synthetic route used in their preparation
would be useful in obtaining thiol derivatives if the potassium mercap-
tides were used directly as obtained from the reaction mixture. Such a
procedure would avoid losses by decomposition during isolation and puri-
fication of the thiols.

Derivatives of two of the heterocyclic thiols were thus prepared by
treating the alkaline aqueous solution of the potassium mercaptide directly
with the appropriate alkyl halide after removal of the 2,4-dinitroanisole
byproduct. A 71% yield of 2-piperidinoethyl-Z-thienyl Sulfide hydrochloride

was obtained by this experimental procedure.

II Ills“? s CIGQC‘HQN: > _—" ~ Usmizm'fz‘fi‘ . >
s ‘

um]
[I 1' SCI" Cr? '— ‘ ‘ ?"CI
0 '2 '2 < >

The preparation of a second derivative, 3-methyl-2othienyl methyl

sulfide (32% yield), presented the possibility of either of two isomers or

 

 

MJGHIF EC mm>~h<>utma >K-Ufim~§

HHH m-J~Mh<..-u

I." «5..-
. .
I
l
5
A

11

.eoEuocmcooEuuw mo 0363 p333“ >383?!“ 0 89C panama A3

 

oznmeuzmao

 

 

 

 

 

om.nm on.~ om.em mm.nm «n.~ oo.mm mo cam-vaa
o: flwd
m~.o¢ an.” ue.u~ no.0e oe.a o~.- mmemezmu as om" .
23
33%:
-.mn H~.~ m~.o~ om.~n om.” oo.o~ oxaowmpzoo o” on~.n>~ .oac ,
Homxm
m
u n Homxm om:
v>.vn no.“ oo.e~ uo.en mm." ee.o~ mxao m and so an~.on~ .oou _ _
m
Homzm _ Ia
o~.hm an." oo.v~ Ha.>n om.o o>.m~ mzaoummxeu as va~.m>~ .oou ‘
m: m o a: m u
venom «cooked 253315 cavemen 33.90"— R Ba; .0 oi .:

 

39:; mo mm>Hh<>Hmmo 550:9.

H H H mqmfir

1...!»

. _ _ '1
I la (01“ .lnlv ! 1 11-..!04‘ u .‘v‘ I.-. t \ \ .cD. Vivi. ll. l'l'ov :‘II I .I. "uis: Q. .
a. . 5/. s .k . .
, ‘ . v- y
p a I
a 4 I
. .
a
I
J a
A .. I » ,
J. a "
ll
9!.
v i
s
l , ll . .
9» t .
y
.
I
\‘
. .
.
.. s
_ . .!
... _ _
d . ‘ . a
a
4
r
v
.4
.
. o.« ,1 . ..i

a...1.y|.r I131; 3,» ,
9‘

u

‘ , _....'

12

a mixture of isomers being formed. The 2.3-isomer was expected over

the 2.4-isomer.

no ' ‘
g3 2 a .' ($33 vac
' | ".5301 SnCl4 l' ' II | |
o .v _‘—‘>- ‘S'QNO E 13 HO
5 2 S “02 2 2-1.- 5 Q 2
. . N02
‘ 1. K0” 2. Hal 3 1. KCH 2. Sal

.an

7 53C
II ”1'55 ‘ ' 'll ‘ II N
s .313 -. ~ g . I 8 8C 3

The sulfida obtainad in the first stop malted sharply at 1206120.5°.~
indicating that a single isomer had bean obtained. An infrared spectrum
of tha methyl sulfida obtained in tho ascend step was coaparsd uith'
published spectra (23) of other 2,3-aubstitutad thiophanss and this
definitely indicated that tho 2,1-substitutad product had been obtained.

a \,
‘0
4')
~‘d
‘. -‘fr
,_.—
I
\‘1
r.
I
i

t‘\\
I
M
ii
/
r
1 .
n .7:

1
J

P: L,
f
\“‘ .‘

-n-

the pro]

were p14
1.5 l. 1
until t?
(1.5 9.
lion an‘

Wills}:

Placed 1
‘ien at!
iii ref]
lixture
'Odium c
Ilth 85C

"COW re

13

EXPERIMENTAL

Preparation of Bis (2,4-dinitrophenyl) Disulfide

\

402 eye

This compound was prepared using a procedure described for
the preparation of bis (o-nitrOphenyl) disulfida (24).

In a 3 1. round bottom flask fitted with a reflux condenser
were placed 360 g. (l. 5 moles) of crystalline sodium sulfide and
1.5 l. of ethanol. The reaction flask was heated on a steam bath
until the sulfide completely dissolved. Then the quantity 48 g.
(1.5 9. atoms) of powdered sulfur were added to the hot sulfide solu-
tion and heating was continued until the sulfur dissolved forming a
reddish colored solution of sodium disulfida. A solution containing
404 g. (2.0 moles) of 2,4—dinitrochlorobenzena dissolved in the minimum
amount of alcohol was prepared in a 5 1. three neck flask equipped with
a stirrer and a reflux condenser. The sodium disulfide solution was
added slowly to the 2,4-dinitrochlorobenzena solution through a funnel
placed in the top of the reflux condenser. The reaction mixture was
then stirred and heated on a steam bath, gently at first, and than at
its reflux temperature for two hours. After cooling, the reaction
mixture was vacuum filtered. The mixture of organic disulfida and
sodium chloride was transferred to a 2 l. beaker and well stirred
with 800 ml. of water to remove sodium chloride. The disulfide was

recovered by vacuum filtration and washed on the filter with 100-150 ml.

\J

of alcohol
{801’ yield

Literaturfi

A
(“Sulfide
neck fies
chlorine
Mpensii
oi Chlor
into the
resulted
filtered
Part of
t"if-"rat
Producg
Nsiiuaj
duct We:
from €331
Value, I
Chloflm

"Mm

14

of alcohol to remove 2,4-dinitrochlorobenzene. A 320 9. quantity
(80% yield) of the disulfide, decomposing above 240°, was obtained.

Literature value, d. 240-280" ('5).

Preparation of 2,4-Dinitr0phenylsulfenyl Chloride

N02

SCI
02::

A suspension of 40 9. (0.10 mole) of his (2,4odinitr0phenyl)
disulfide in 500 ml. of ethylene bromide was prepared in a l 1. three
neck flask equipped with a stirrer, reflux condenser, thermometer, and
chlorine gas inlet tube. A crystal of iodine was added to the stirred
suspension which was than heated to a temperature of l22-126°. A stream
of chlorine gas, dried by bubbling it through sulfuric acid, was passed
into the hot reaction mixture until a clear dark red colored solution
resulted, which required about ten hours. The solution was cooled and
filtered, using celite, to remove some insoluble eaterial. The major
part of the solvent was removed by vacuum distillation, keeping the
temperature below 80° to prevent decomposition of the product. The
product crystallized after prolonged cooling in an ice bath of the
residual syrupy liquid. A 38% yield of yellow colored crystalline pro-
duct was isolated by filtration. Following a single recrystallization
from carbon tetrachloride the product melted at 96-970. Literature
value, I. p. 97° (5). Several additional preparations of this sulfenyl
chloride, employing the procedure described above on a larger scale,

resulted in yields falling in the range of 50 to 60%.

 

.THE

Tu
chloride
catalyst.
(6.136 mu
Ithylene
dun:

. ‘0 :11. c

the flas

«'5
_.. _
.,
F

' luperat
a r i to the f
wlfurlc
' hours.
A Mite 1
‘ In the:
in I re!
“ch .43
and. p1
lion fr:

1

Chloridq
“Willi:
“mm
“d 619;
M reac-

'1Wen 1

15

Two additional preparations of 2,4edinitr0phenylsulfenyl
chloride were made, employing anhydrous aluminum chloride as the
catalyst. In a typical preparation, a slurry composed of 55 g.
(0.138 mole) of his (2,4-dinitr0phenyl) disulfide and l40 ml. of dry
ethylene chloride-was prepared in a 500 ml. three neck flask equipped
with a_st1rrer and a distillation head. The slurry was stirred while
40 ml. of solvent was distilled, the distillation head was removed and
the flask was protected with a drying tube while it cooled to room
temperature. One gram of freshly sublimed aluminum chloride was added
to the flask and chlorine gas, dried by bubbling it through concentrated
sulfuric acid, was passed into the stirred slurry for three and a half
hours.e The dark red colored reaction mixture was filtered through
celite to remove some dark colored insoluble material.‘ The filtrate
was thoroughly mixed with 200>nl oflanhydrous ethyl ether and set aside,
in a refrigerator, over night.. The dark red colored crystalline material
which separated was isolated by filtration to obtain a 36% yield of.a-
crude producthhich retained a slight red coloration after recrystalliza-
tion fromtcarbon tetrachloride, using norite.-

. Several attempts were made to prepare 2,4-dinitrophenyleulfenyl
chloride using fuming sulfuric acid as a catalyst, instead of anhydrous
aluminum chloride, in the_above described experimental procedure. The
reaction was reported to be complete in one hour by Kharaach, Buses,
and Gleason (6). In this investigation, however, no appreciable evidence
of reaction could be noted after periods of chlorination as long as

eleven hours.

THE

u.

> my
.é

'i

l ,

.23:-

. ‘ —‘
'7 ' .‘ 1
3.
‘ ‘ l

_‘ " z \
\oA Ia" .v‘

C I . .
n ‘ - 6

94’

,e
5.
.-
‘rfl .-
.a s u.

:4

(1.28 IN
1 1. fl:
(1.24 an
gently I
full st.
lixttre
ice, wi
ized wi
ution
The red
“News
Im wa
”"3 the
oil was

_' 60101

16

Preparation of 2-Thiophenea1dehyde

l {,u

 

 

 

To a mixture of 84 c. (1.0 mole) of thiOphene and 92 g.
(l.28 moles) of dimethylformemide, which was cooled and stirred in a
l l. flask fitted with a reflux condenser, was slowly added, l92 g.
(1.24 moles) of phosphorus oxychloride.a The reaction flask was heated
gently on a steam bath until the evolution of gas subsided and then at
full steam flow for an hour and a half. The dark red colored reaction
eixture was cooled in an ice bath and poured onto lOOO 9. of cracked
ice, with vigorous stirring. The aqueous mixture was partially neutral.
ized with a concentrated solution of sodium hydroxide and the neutrali-
zation was completed by adding small portions of solid sodium carbonate.
The red colored oil which separated was extracted into ether and the
aqueous phase was washed twice with ether. The combined ether extracts
were washed with water. dried in contact with anhydrous sodium sulfate,
and the ether was removed on a steam bath. The residual red colored
oil was vacuum distilled to obtain an 85% yield, 94.6 9.‘ (0.85 mole) of
.a colorless product boiling at 52-532/2-3 am. A boiling point or
44-459/l.l mm is reported for 2-thiophenealdehyde (l2). An additional
preparation, using the experimental procedure described above, on a

two mole scale gave an 84% yield of the heterocyclic aldehyde.

17

Preparation of 2-Hethylth10phene

as

A 3 1. three neck flask fitted with a thermometer and a
stirrer, and arranged for distillation, was charged with 94.6 g.
(0.85 moles of 2-thiOphenealdehyde, 168 ml. of hydrazine hydrate
(85%), and 672 ml. of ethylene glycol as a solvent. The stirred
reaction mixture was kept in the temperature range of 130-1600 for
forty five minutes while water and excess hydrazine were removed by
distillation. A small amount of water insoluble material was separ-
ated from the distillate and returned to the flask. The reaction
mixture was cooled below 600 s an efficient reflux condenser was sub-
stituted for the distillation head, and a 168 g. (3.0 moles) quantity
of potassium hydroxide was added to the flask. The stirred alkaline
mixture was again heated. A vigorous reaction was initiated when the
tempera ure of the reaction mixture reached 90-100o . When the initial
reaction had subsided t?.e mixture was heated at its reflux temperature
for an additional hour and the product was isolated by distillation.
The distillate was extracted with ether and the ether layer was washed
with dilute hydrochloric acid and dried in contact with anhydrous cal-
cium chloride. The drying agent was removed by filtration and the
ether was removed by distillation. Fractionation of the residual liquid
from metallic sodium resulted in an 80! yield of a colorless product
boiling at 109—llO°. The reported boiling point of 2-methylthiophene
is 112-1130 (13). An additional preparation of this material, using

the experimental procedure described above, resulted in an 82% yield

ceo

of the a}

II
condense
quantity
of 2,5—h
quan'itv
phcsphor
initiate
fine, 1
t0 main:
reactior
5°“! W
5? dim
h“m l
3“ 80d:
'ith in]
Yield 0

b‘po 13.

18

of the slkylthiophene.

Preparation of 2,5—Dimethylthiophene

NSC E: S IICH3

In a 3 1. three neck flask equipped with s stirrer. reflux
condenser, and a drapping funnel, was placed a 250 9. (1.12 moles)
quantity of phosphorus pentasulfide. A 300 §. (é.63 moles) quantity
of 2,5—hexsnedione was p lsced in the drapping funnel and a sufficient
quantity of it was added to the reaction flask to slurry the stirred
phosphorus pentasulfide. After the cyclization reaction had been
initiated by heating the reaction mixture mildly with a bunsen burner
flame, the ramaining 2, 5-hexanedione was added at s rate sufficient
to maintain the reaction mixture at its reflux temperature. The
reaction mixture was stirred at this temperature for an additional
hour after adding all the 2, 5-hexanedione. The product was isolated
by distilling it from the stirred reaction mixture until the residue
became very viscous. The crude product was extracted with 80 ml. of
3 H sodium hydroxide and washed with water. After drying it in contact
with anhydrous magnesium sulfate it was redistilled to isolate a 71%
yield of a colorless product boilino st 131-133o . Literature value,

beps 134.1350(14).

.THE

A t
funnel, ni
of anhydrc
reaction 1
wlution c
in 250 ml.
m stir-re
then fill-‘-
ehmed t?
m c0019:
“solved
Mod. 1
tml‘atm
“‘Phthene‘
Mfonate
napathyl 1
tm I,“ '
“Went“,
”Muted.
ch”rifle.

19

Preparation of 2-Methylthianaphthens

C343

A three liter three neck flask fitted with a stirrer, drapping
funnel, nitrogen inlet tube, and a thermometer was charged with 400 ml.
of anhydrous ether and 25 g. (3.6 molesl of lithium metal chips. The
reaction flask was cooled to .10° in a dry ice-isOprOpanol bath and a
solution of 247 g. (1.8 moles) of redistilled n-butyl bromide dissolved
in 250 ml. of dry ether was added during an hour. The reaction mixture
was stirred for two hours following the addition of the bromide and
then filtered under nitrogen through glass wool directly into a pre-
chilled three liter flask. The filtered solution of n-butyl lithium
was cooled to .10° and a solution of 215 g. (1.6 moles) of thianaphthene
dissolved in 200 ml. of dry ether was added during a forty five minute
period. The reaction mixture was stirred for an additional hour at a
temperature between -59 and ~10°, following the addition of the this-
naphthene. A solution containing 279 g. (1.5 moles) of methyl-p—toluene-
sulfonate dissolved in 150 ml. of dry ether was then added to the this-
naphthyl lithium solution during a one hour period. The reaction mix-
ture was stirred for an additional hour, then allowed to warm to room
temperature and poured onto 2000 g. of crushed ice. The ether layer was
separated, washed with water, and dried in contact with anhydrous calcium
chloride. The ether was removed on a steam bath and the residual syrupy

liquid was fractionated at reduced pressure in an 80 cm. jacketed

THE

IE

vigreau
It 5l-5
thianap

(10).

la! the
30 ml.
in an 1
”lane
lixture
ture.

' 9011;:
in 300
I‘oich ,
'isted
Dentanfi
"d the
distill

mg ml

vigreaux column. The fraction which boiled at 74-7é/2mm.. and melted

at bl-Szpafter distillation, corresponded to an 84% yield of 2-methyl-
thianephthene. Literature values, b. p. 73-74g/2mm. (9); m. p. 51.5-52o
(10).

Preparation of Prepylene Sulfide
G‘sqsfu

A l 1. three neck flask fitted with a stirrer and a thermometer
was charged with 80 g. (1.0 mole) of thiourea, 350 ml. of water. and
30 ml. of concentrated sulfuric acid. The stirred solution was cooled,
in an ice bath, to a temperature of 0-50 and 58 9. (1.0 wole) of pro.
pylene oxide was added to it during two hours. The cooled reaction
mixture was stirred for ten minutes and allowed to were to room tempera-
ture. .The temperature of the reaction mixture was kept below 25° and
a solution containing 106 g.-(l.0 sole) of sodium carbonate dissolved
in 300 ll. of water was added to it during a half hour. The oily product
which separated was extracted into pentane and the aqueous phase was
washed twice with additional quantities of pentane. The combined
pentane extracts were dried in contact with anhydrous calcium sulfate
and the pantane was removed by distillation. The residual liquid was
distilled to obtain a 60% yield of a colorless product boiling at 72-730.

The boiling point of propylene sulfide is reported to be '1'2h-‘7f’ao (15).

TH E

I'L.

tender.
(0. 21
of anh
The to
hours,
slow.

30 ml.
lith 1
layer
until

of 2C!
in UN;
resid;
bet a
'Xtre<
(c.04;

Liters

011..

21

Preparation of 2,4-Dinitrophenyl-2—thienyl Sulfide
N

as ”02

S

A 500 ml. three neck flask equipped with a stirrer and reflux
condenser was charged with 325 ml. of dry ethylene chloride, 12 9.
(0.051 mole) of 2,4-dinitr0phenyleulfenyl chloride, 40 g. (0.154 mole)
of anhydrous stannic chloride and 36 ml. (0.45 mole) of thiOphene.
The reaction mixture was stirred at its reflux temperature for two
hours, during which the evolution of hydrogen chloride had become quite
slow. The dark colored solution was cooled to room temperature and
30 ml. of ethanol was added to it. The reaction solution was extracted
with two 100 m1. portions oi dilute hydrochloric acid.7 The organic
layer was separated and concentrated by an air stream on a steam bath
until a viscous black residue remained. This solidified on the addition
of 200 ml. of ethanol. The crystalline mass was broken up and boiled
in the ethanol which was then decanted from it through a filter. The
residue was boiled in 150 ml. of additional ethanol which dissolved all
but a small amount of a black powdery material. The combined ethanol
extracts were treated with Morita A and evaporated to isolate 12.9 g.
(0.047 mole, 89% yield) of the crude sulfide melting at Ila-118.50.
Literature value, m.p. 119° (1).

Two additional preparations of 2,4-dinitrophenyl-2-thienyl sulfide
on a slightly smaller scale resulted in yields of 77% and 83%. In three
additional preparations on an approximately 0.25 mole scale the yields

decreased to 71%, 54%, and 60%, due to the formation of large amounts of

TH

f.
h-.-e--_14ai.

 

' _._..-__—._. - w...-

' ‘-—-°.

:3.

 

um

lltha
of th
did n
tire

ccnsi
obser

1n co:

ltirr1

0' I71]

flq'; 1

 

tarry_material which complicated isolation of the product._

While carrying out the above preparation it was noted that
although the reaction mixture began to darken immediately on addition
of the stannic chloride catalyst,‘the evolution of hydrogen chloride
did not become appreciable until the reaction mixture reached a tempera-
ture of approximately 75°. Further, the reaction mixture darkened
considerably during the removal of the solvent on a steam bath. These
observations prompted changes in the experimental procedure which_resu1ted
in considerably less tar formation and improved yields of the product.

In a typical modified preparation, a l 1. three neckflask,.
equipped with a stirrer and a reflux condenser was charged_with 400 m1.
of ethylene chloride, 20 g. (0.085 mole) of 2,4—dinitrophenylsulfenyl
chloride, and 13.4 g. (0.16 mole)_of thiophene. Afterfiheating the‘;
stirred reaction solution to a temperature of 65-700, 63.: g. (0.24 mole)
of anhydrous stannic chloride was added during five minutes and the
reaction mixture was then stirred at its reilux temperature for_an,
additional hour and a half., The stirred reaction mixture was cooled to.
room temperature, 25 al. of ethanol was added to it, and it was extracted
with two 200 ml. portions of dilute hydrochloric acid. _The organic layer
was separated, filtered, and transferred to a l l. f1ask.and the solvent
was removed by vacuum distillation on a water bath at 70°. ,The gray
residue was boiled in 400 ml. of ethanol and the solution was decanted
from the undissolved solid.. The residue was boiled in 150 ml. of addi-
tional ethanol and the solution was filtered to remove some insoluble

gray powder. The ethanol extracts were treated separately with Norite

.. . .‘ ..

v ‘ . . .I.
If ‘a
L .. ..
O a ,
. , . . A a. .
.‘v . .
. .. .,
.

t
‘ ' w
I I
. |« I 7
al-
a . .
.w 3
l. a
. .w
r r .,
n .
a e n n
. a 9,
. l
.
—
v .
.
‘ .
. .1
_
I
II;
n ,
a .
a
n a
.
v I ,
‘
w.
.
I
r .

and cooled to precipitate the product, which was collected on a filter.
The product which crystallized from the first ethanol extraction of the
Crude product was slightly brown in color while the crystalline material
obtained from the second extraction had a bright yellow color. The
combined ethanol filtrates were treated again with Morita and concen-
trated to yield an additional quantity of the crystalline product. The
total yield of product, melting at 1l8.5-ll9°, was 17.4 g. (73% yield).
A second preparation employing the same experimental procedure on a
0.106 mole scale resulted in an 80% yield of product.

Several attempts were made to prepare 2,4-dinitrophenyl-2-thienyl
sulfide using aluminum chloride as the catalyst. In a typical experiment,
a 500 ml. three neck flask equipped with a stirrer and a thermometer'was
charged with 100 ml. of dry ethylene chloride, 42 g. (0.05 mole) of
thiOphene, and 9.4 g. (0.04 mole) of 2,4-dinitrophenyisulfenyl chloride.
The reaction mixture was stirred at -10°, in an ice salt bath, and 12 g.
of anhydrous aluminum chloride was added during a period of twenty min-
utes. The reaction mixture turned red in color and became very viscous
and gummy. After a 5~10 minute period of stirring, 20 m1. of absolute
ethanol was carefully added to the reaction mixture and it was then
extracted with two 100 ml. portions of dilute hydrochloric acid. The
organic layer was separated and concentrated to a volume of approximately
:35 ml. by heating it under reduced pressure. The residual liquid was
poured into 100 m1. of petroleum ether (b.p. 60-900). The mixture was
boiled on a steam bath and the petroleum other solution was decanted

from a layer of tarry material which had separated. The tarry material

.31-

”1.

a."
V

 

24

was extracted with a second portion of boiling petroleum ether.
Concentration and cooling of the combined petroleum ether extracts
resulted in the precipitation of a very small amount of a yellow
crystalline material melting at 116°, after a single recrystallization
from ethanol. Additional preparations using as small a quantity as 5 g.
of anhydrous aluminum chloride catalyst and a reaction temperature in
the range -25 to 25° gave similar results.

A single preparation was carried out, using this same general
experimental procedure, with anhydrous ferric chloride as the catalyst.
Tar formation was excessive in this case and no product could be isolated.

An attempt was made to employ 8 g. of anhydrous stannic chloride
as a catalyst, using a reaction temperature of 0-50 in the above described
experimental procedure, but this also resulted in failure to obtain any

of the desired product.

Preparation of b—Hethyl-Z-thienyl (2,4-dlnitr0phenyl) Sulfide

”02

H30 U—S. “92

A solution containing 25 9. (0.106 mole) of 2,4-dinitr0phonyl-
sulfenyl chloride and 19.6 g. (0.20 mole) of 2-methylthi0phane dissolved
in 400 ml. of ethylene chloride was prepared in a l 1. three neck flask
equipped with a stirrer and a reflux condenser. This stirred solution
was heated to a temperature of 70-750 and 79 g. of anhydrous stannic
chloride were added to it during a five minute period. The reaction

mixture was then kept at its reflux temperature for an additional hour.

 

 

After cooling to room temperature, 25 ml. of ethanol was added to the
reaction 'mixtur. and it was extracted with two 200 ml. portions of
dilutcshydrochloric acid. The odor of hydrogen sulfide was detected
during the extractions. The organic layer was separated and the solvent
was removed under vacuum in a distillation flask on a water bath at 65° .
The brown residual solid was boiled in 250 ml. of 2bpr0panol and the
clear rad colored solution was decanted from an insoluble gummy residue.
The 2-propanol extract, on cooling, became cloudy immediately and a
quant ity of a dark red colored oil separated. This oil failed to
completely disco lve on addin.gr an adiitionai 50 ml. of 2-propanol and
boiling the solution. The errOpanol solution was decanted from the I
insoluble residue, which was discarded. The gunmy residue from the
reaction mixture was extracted with an additional 150 ml. of boiling
2-propanol, but only a small portion dissolved.: The combined 2vpropanol
extracts were treated  with horite and set aside in a refrigerator. A thin
layer of light brown colored crystalline material precipitated and then

J

a quantity of yellow colored crystals formed. The crystalline material

1;

was collected on a filter and washed with ethanol to isolate . 65%

.‘I E. (‘1

yield of a crude product melting at 99-101o . A single recrystallization
' i

from ethanol raised the nelting point to 102-1030 . Elemental analysis

if

9." the follwing rssults. Calc'd. for C11}!8N2O4o2l C, 44.58; H, 2.72;

S, 21. 64. Pounds C, 44.60; H, 2. 96s 3, 21.70.

gal

In two additional preparations of this compound in which the
.ofl"

stannic chloride catalyst was added at room temperature, prior to heating

the reaction mixture at  its reflux temperature, the yields decreased to

 

u

 

. ..
\ q
. In} 7
. A
U.
. s . ‘
.u ’. .
,,w . ‘ a. .
t.
‘ . ‘ \
‘
tv o u
‘ . .
.

... .v‘

» t...

J

“ '
"

ul

v a A
. aMC
‘
. .
O
.l
7 v
.3 a
o
I
.
I
_
.
o
.
.
.
i
C I
.
wl‘

 

44% and 48%. One additional preparation in which a reaction temperature
of 55-600 was used instead of the reflux temperature of the reaction

mixture resulted in a 42% yield of the desired product.

Preparation of 3-Hethyl-2-thienyl-2,4-dinitrophenyl Sulfide

(:33 2402
[' '13.:ch
5

A stirred solution containing 20 g. (0.085 mole) of 2,4-dinitro-
phenylsulfenyl chloride and 15.7 g. (0.16 mole) of 3~methylth10phene
dissolved in 350 ml. of ethylene chloride was heated to a temperature
of 75° in s 500 ml. three neck flask equipped with s stirrer and reflux
condenser. A 63.5 g. (0.24 mole) quantity of anhydrous stannic chloride
was added to the reaction mixture during a five minute period, after
which it was kept at its reflux temperature for an additional hour. The
dark colored, stirred reaction mixture was cooled in a water bath,
diluted with 30 ml. of ethanol, and extracted with two 150 ml. portions
of dilute hydrochloric acid. The organic layer was separated and the
solvent removed by vacuum distillation on a hater bath at‘s temperature
of 65°. The dark colored residual oil was extracted by boiling it in
250 ml. of isopropanol and decanting the alcohol solution from the tarry
residue. A quantity of a dark colored oil separated as the alcohol
solution cooled slightly. The solution was_boiled on a steam bath and
decanted, through e filter, from the undissolved material. Cooling
during filtration caused additional quantities of dark colored oil and

some crystalline material to collect on the filter. The filtrate was

 

 

27

treated with Morita and set aside in a refrigerator. The reaction
residue and the fluted filter paper were boiled in a mixture of 200 ml.
of ligroin (b.p. 60.900) and lo ml. of isOprOpanoi. The solution was
decanted from the undiseolved tarry residue, treated with Norite, and
set aside in a refrigerator. The yellow colored crystals which separ-
ated from both solutions were recovered by filtration to yield 15.9 g.
(63%) of a crude product. After two recrystallizations from isoprOpanol
(Morita A) the melting point of the product was 120.120.50. Elemental
analysis of the material gave the following results. Calc'd. for
011H3H20432, C, 44.58; H, 2.723 3, 21.64; Pounds C, 44.84; H, 2.893

3. 21.780

Preparation of 2,5—Dimethyl-3-thienyl (2,4—dinitrophenyl) Sulfide

”30- l l

.3 $302
5

A well stirred solution containing 20 g. (0.085 mole) of
2,4-dinitrophenylsulfenyl chloride and 19 9. (0.17 male) of 2,5-dimothyl-
thiOphene dissolved in 400 ml. of ethylene chloride was heated to a
temperature of 700 in a l 1. three neck flask equipped with a stirrer
and a reflux condenser. The quantity, 63.5 g. (0.24 mole) of anhydrous
stannic chloride was added to the solution during a five minute period
and the reaction mixture was kept at its reflux temperature for an
additional hour. Hydrogen chloride was evolved rapidly at the initial
stages of the reaction. The dark colored reaction mixture was stirred

and cooled in a water bath and 20 n1. of ethanol was added to it,

 

28

followed by an extraction with two 200 ml. portions of dilute hydro-
chloric acid. The organic layer was separated and the solvent was
removed by vacuum distillation in a water bath at a temperature of 65°.
The residual_solid-was extracted with 200 ml. of boiling 2-pr0panol

and the extract was treated with Morita and filtered. The remaining
yellow product was dissolved in boiling 2-propanol and the alcohol
solution was filtered to remove a small amount of insoluble matter.

The combined 2-pr0panol solutions were set aside in a refrigerators

and the crystalline product which separated was isolated by_filtration.
The yield was 24.4 g. (92%) of yellow colored crystals which melted at
lib-l15.5°. stcett (2) reported a melting point of 104.§-105° for
this compound. Elemental analysis gave the following resultsa

Calc'd. for C12H10N20432: C, 46.44; H, 3.25; 3, 20.66. Found: C, 46.67;
H, 3.46; 3. 20.54.

'In a second preparation of this sulfide the stannic chloride
catalyst was added_at room temperature, prior to heating the reaction
mixture at its reflux temperature, snd_the solvent was removed at
atmospheric pressure. The yield, in this case, decreased to 74%.

Attempted Preparation of 2,5-Dichloro-3-thienyl-2,4-dinitraphenyl
‘ Sulfide '-

“ lls-Q N02
Cl" i a: -Cl ”02 m ' .
i A 500 ml. three neck flask equipped with a stirrer and reflux_

condenser was charged with 250 ml. of ethylene chloride, 10 g. (0.043 mole)

 

. i 4. .. . e a . .
4
. . . e
(a n . §< . c J, p
r . . .1. .
.> . a p . , be If as (it. . .
3 \r a y.
a s a as . s . d . . I u
a ‘
. . e . x .a O , .. .. r
I. r
r . t t? 715 l e m 4 AM
at I . I . at I: e! a. ‘
. . a . . . H.A o a
l n I
s; r h i a v . v . . ‘.\ q
I . . O. .i p .
u c .e n .e\ \ c.
.e. . . l l uv . a .. .. V
.. as ~ ‘ e I . a
V —
.. . . c C A . . .
n ...i . V . ,n s Q
. i . _ H . . a e ,.. - . E
a i es... r a I a . .
i r s .a_ . I
are a. . c
s . fl I 1 §
i .
3 .
r . . . c _ I; . t v
t I .
i I . x , , ‘ n
e ~ I p .
w
. f . .a ‘ . .
deal-Vt; .
r . n A .r r A II! 4/. .
1 . y F ,
. . ¢ a . 1/
n
.
. . r
.. . d . . x .
. . u ’ . i — — x
1 . . _. x y ,
- _ '03 O
I . sniilvilsl
. e n a,
o . I . u
r I. ‘~ ‘
. n. e. . .\t\I/. ..._
u .v
p . \ I .
. \\ //l J.
‘ _ . -‘ . u
A . . . , _
a . x y
. .
. , . .. m . _ .
. . f. .\ u .
. I. .\\ .
, y e, . y
‘ ’1‘ ‘ r
. r h 1
s
.
. 4 . a
.
. 4 r
. .. . y a
T s . .
a. y
. a
y .. . .
’l.
e . 7., t
n . . . a ,
. t ”I v e
. p. a . A
, , a 4 x is
. .
i _ l
. , f V
4 . e
. . v ‘ . fl 1
. v ‘
h
. . . 2 .-

_bh. lush... ~..al.r..n.h'le I I: 1

 

of 2,4-dinitr0phenylsulfenyl chloride, 15 ml. of 2,5—dichloroth10phene,
and 33 g. of anhydrous stannic chloride. The reaction mixture was
stirred at its reflux temperature for three and a half hours. Hydrogen
chloride was slowly evolved throughout the reaction period. The stirred
reaction mixture was cooled to room temperature and 25 ml. of ethanol was
added to it. The dark colored reaction solution was then extracted with
three 100 ml. portions of dilute hydrochloric acid. The solvent was
removed from the organic layer by heating it in an air stream on a steam
bath. The dark colored residue was boiled in 150 ml. of ethanol and

the ethanol solution was decanted through a filter. The residue was
extracted with a second portion of boiling ethanol, but only a small
amount of the material dissolved. A yellow colored powdery material,
which decomposed above 120°, without melting, was isolated on treating
the combined ethanol extracts with charcoal and chilling the solution

in an ice bath. Apparently, the only product obtained in the above
reaction was a polymeric material. ’The desired sulfide is reported to
be a crystalline solid melting at 136.5-137° (16).

Preparation of Thianaphthyl-2,4-dinitrephenyl Sulfide

fie.

S i502

 

}

A stirred solution containing l0 9. (0.043 mole) of 2,4-dinitro-
phenylsulfenyl chloride and 8 g. (0.06 mole) of thianaphthene dissolved
in 250 ml. of ethylene chloride was heated to a temperature of 70° in a

500 ml. three neck flask equipped with a stirrer and a reflux condenser.

a ~n.
. .. . x. ‘ -- ..
‘ {A
e . n
l
A ‘ /
. .
15 a
e r . ..
. . ..
. 1
a (I Q
a. . e
,
v v
1, ‘e ..
a I.
J . x r.
.
.
x o ,. . .
. .
. .. . . .
,
3 ‘
. r If .\
I
1;
.\
.V
s,
.
f r. . .
\
,
1.
a _ i
.
r
I.
.
4
. ,
i

1.. 5:... .: .18.... .i! all. I w
u

.h 7....HWw1

 

30

A 33 g. (0.13 mole) quantity of anhydrous stannic chloride catalyst was
added, during a five minute period, to the reaction mixture which was then
stirred at its reflux temperature for an hour. The reaction mixture was
cooled to room temperature, in a water bath, and 15 ml. of ethanol was
added to it. The mixture was then extracted with two 100 ml. portions of
dilute hydrochloric acid. The organic layer was separated and the solvent
was removed by va¢uum distillation on a water bath at a temperature of
65°. The yellow colored solid residue was dissolved in hot benzene and
the solution was filtered to remove a small amount of insoluble matter.
The filtrate was diluted with an equal volume of isOpropanol, treated

with Eorite, and set aside to cool in a refrigerator. -The yellow colored
crystalline material which.separated was collected on a_filter and
recrystallized from isOpropanol containing a small amount of benzene..

A 58$ yield of product, melting in the temperature range 146-1520, was
obtained. Based on this melting point range, the product was judged to

be a mixture of the 2 and 3 substituted isomers.. The literature values
are: 2-thianaphthyl-2,4-dinitrephenyl sulfide, a.p..lS9-160° (3);

3-thianaphthyl-2,4edinitr0phenyl sulfide, m.p. 163-l64o (21)...:

Preparation of 2-Nethyl-3-thianaphthyl-2,4-dinitr0phenyl Sulfide
[-3. ”02
.3 F302

A 500 ml. three neck flask equipped with a stirrer and reflux

condenser was charged with 300 ml. of ethylene chloride, 10 g. (0.043 mole)

  

5.... o r- ... ’iw..t ii! , . 5.. I,- .sn'l.
.—

 

. ,o A
a
I I .
.
n." . l .
,
1‘
. .f I i .
s
v C
4 ~
1 r
r s
.. r
¢
. c
.
.
x
.
.
1
.
V.
.
,
_
.
k
v
.
4 . .i
.
. i
a
.
A
.
)
q,l.

knrr

a. .
t .
o
.4 s ‘ .
V.
.
l
o
. .
a
\
.\
t. a
‘D .
Q
.
C.
.
a a
.,
,
C
. .
.
.
I .v
.
.
.
b ._
.
e I
b
O u
4. v
1
.
d

\ w‘" M
r u A»- a.

’5.

31

of 2,4-dinitrophenylsulfenyl chloride, 8 g. (0.054 mole) of
2-methylthianaphthene, and 33 g. (0.13 mole) of anhydrous stannic

. chloride. The reaction mixture was stirred vigorously at its reflux
temperature for an hour. Hydrogen chloride was rapidly evolved during

the first half of the reaction period and the mixture took on a light

yellow-brown coloration. After cooling the reaction mixture to room
temperature, 15 ml. of ethanol was added to it and it was extraCted

with two 100 ml. portions of  dilute hydrochloric  acid. The organic

'1' 1

layer was separated and the solvent removed by vacuum distillation on

a water bath at a temperature of 70°. The  yellow colored residual

f . ’ 5

solid was dissolved in a boiling 2:1 ethanol-dioxane mixture, filtered,

fir

and set aside in a refrigerator. The crystalline material which

1.

separated was collected on a filter. The filtrate was concentrated to

approximately one fourth its volume and treated with Morita. Water

. t "V P

was added to the hot  solution until a yellow crystalline solid began

I J 2 I...

to separate, at which p oint the mixture was set aside in a refrigerator
to precipitate an add itional quantity of the crystalline product.

A combined yield of 75% of product, melting at 176° , was obtained. .
Heyd (4) reported a melting point of 179-18lo for this sulfide. Two

additional preparations of this compound gave yields of 73% and 76%

respectively.

\

It 1 s A «a lab,
- a .
a l . \a v .0 _
1 i a
.7. . . I .
‘ s!
m a. .
a -
. s I
~ I a
. .. . .L
y. .
s.
i .
he i
t 7 ‘
.
m.» r e w T. .
,_ . 5.. .

 

a
.pk .

. s. .. ..
a l. . .
.’ ‘l

- s
. a n-
a s
, g a \a
. . _
I u v
.... .
i .. s.
. v p
. 's‘ .
. F
.a a: .l a.
. r ‘
.o a . .
.O i
s a ..
. .
, .-
. u
e . a
_,
a l i
. c u. z‘
a
I a.
a . . .1.
s
b e. a
.. a
a _
.
.
4 1
.
a a.
y o
.
I
a ,
V. .\a
. .1
. .
x .
a ' 1
.
.
1
_
w a
1 a {\a
. .
. ._
, a
y
.
V _ t
. .
A
i
\L .
., .
an

Preparation of 2bThiophenethiol

To a solution of sodium methoxide prepared by allowing 5 g.
(0.22 9. atom) of sodium metal to react with 500 ml. of methanol was
added 29 g. (0.1 mole) of 2-thienyl-2,4—dinitrophenyl sulfide. The
stirred suspension was continuously flushed with nitrogen and held
at its reflux temperature for a half hour. ‘Approximately 260 ml. of
methanol was then distilled from the reaction mixture. The residual
liquid was poured onto cracked ice and the flask was rinsed with
sufficient water to bring the final volume to approximately 800 ml.
The resulting aqueous suspension was stirred for a few minutes and
filtered to remove a quantity of a red solid. The dark red colored
filtrate was acidified with lil sulfuric acid and steam distilled
until 400 ml. of distillate had been collected. The light yellow
colored distillate was extracted with two 50 ml. portions of ether.
The combined ether extracts were dried in contact with anhydrous
sodium sulfate, filtered to remove the drying agent, and concentrated
by distillation on a steam bath. The concentrated solution was trans-
ferred to a 50 ml. flask, using a small amount of ether, and the ether
was removed by distillation. The residual red colored oil was vacuum
distilled to isolate a 14% yield of a light yellow colored oil boiling
st 53-543/4-5 mm. Houff and Schuetz report a boiling point of 549/5 mm.

for 2-thi0phensthiol('7).

.---.——

A 2,4-dinitrophenyl sulfide derivative of the product was
prepared and faund to melt at 119° after a single recrystallization
from ethanol. Literature value, mp. 1190 (1).

Two additional preparations of 2-thiophenethiol, employing the
above experimental procedure, resulted in yields of 14% and 17%
respectively.

Small amounts of 2,2'vdithienyl disulfide were isolated from the
initial distillation residue and from the red colored precipitate
isolated after pouring the residue from the basic Cleavage onto ice.

The distillation residue was thoroughly washed'with warn*water and
recrystallized from aqueous ethanol to isolate a light yellow colored
crystalline material waiting at 57°. aChallenger, Hiller, and Gibson (8)
reported a melting point of 56° for 2,23-dithienyl disulfida.t The red
colored precipitate was recrystallized from methanol, using charcoal.

The yellow colored crystalline material melted at 88° and was assumed to
be 2,4-dinitroanisole. a melting point of av~ee° is reported (11.) for
2,4—dinitroenisole.' An additional quantity of this material was isolated
by adding ethanol to the filtrate, and concentrating it on‘s steam bath.
lecpropyl alcohol was added to the filtrate and it was again concentrated
and set aside in a refrigerator. A small quantity of yellow colored
crystalline material separated from solution. This melted at 42-440 and
was assumed to be impure 2 ,2'-dithi‘efinyl disulfide.

Several modifications of the experimental procedure described
.ebove effected a considerable increase in the yield of 2-thi0phenethiol

obtainable. In the modified -procedure., a solution containing 6 g.‘

I .
o
.. p
. .
at
'a
4 r
. ....
a .
A
i
. .. .
a. ..
..
~ .
o‘ ,
1
OJ
L
.I. .
t .
t .
. ..
’ e
. _ a. .
a
. a t. \
r, a
.
at
.
.. O
. .
.. .
a
a
.
. a
a.
Q r
I.
.

 

’11

.e
.3

.el.

 

V
.
r
.
(I ‘
. a
r
at
rt
.
.
b
.
x
I,
,.
.
.

34

(0.12 mole) of potassium hydroxide dissolved in 300 ml. of methanol
was prepared by warming the components in a 500 ml. three hock flask
while stirring the alkali methoxide solution with a stream of nitrogen.
A reflux condenser was attached to the flask and 17 g. (0.06 mole) of
2-thienyl-2,4-dinitrOphenyl sulfide were added to the reaction mixture,
which was then heated at its reflux temperature for twenty minutes in

a nitrogen atmosphere. The major share of the solvent was removed by
vacuum distillation on a water bath at 30-350. Care was necessary to
prevent severe bumping during the later stages of selvent removal. The
residue was poured onto cracked ice and the flask was rinsed with
sufficient water to bring the final volume to 400 ml. The aqueous
suspension was stirred until thoroughly chilled and then filtered to
remove a light orange colored solid, which was washed with water. The
filtrate was acidified with concentrated hydrochloric acid. The aqueous
phase was extracted with three portions of ether, which were combined
and dried in contact with anhydrous calcium chloride, and the ether
was removed by distillation on a steam bath. The residual dark red
colored oil was vacuum distilled to obtain a 48% yield of a light

yellow colored oil boiling at 30-329/1-2 mm.

Preparation of 5-Methyl-2-thiophenethiol

H3O l ' '39.
5

To a solution of sodium methoxide prepared by allowing 4.6 g.

(0.2l 9. atom) of sodium metal to react with 500 ml. of methanol in a

 

.
A s. . o
y . s c
. I
v
. s . . _ vL .
l . . O
..
. u n
i . c a A
b
s
l. -
. .. s
, . .
a A .
. .
J.
. y . . A
\ 1
L .
v
.
u.
u
x I l:
_
,—
. -
, V
x
a.
.
i ll! ’yu‘
m
. . c
r ‘ w ‘
i
_
‘
f
.
o
,-
s.
l
V r
c 0.2.... .. l2..fi.|lflat .r‘lfq 1
., .H .ts... 9...}—
.
.
D

 
 

one liter three neck flask equipped with a stirrer and a distilling head
was added 32 g. (0.103 mole) of 2,4»dinitrOphenyla5-methyl-2-thionyl
sulfide. The stirred reaction mixture was heated at its reflux tempera-
ture until the sulfide disappeared and then 260 ml. of methanol was
removed by distillation. The dark red colored solution was poured onto
ice and the flask was rinsed with sufficient water to bring the volume
to 800 ml. The aqueous suspension was stirred until thoroughly chilled
and filtered to remove s quantity of a red colored solid. The filtrate
was acidified with 1:1 concentrated sulfuric acid and extracted with two
33 ml. portions of ether. The combined ether extracts were dried in
contact with anhydrous magnesium sulfate, filtered, and the other
removed by distillation on a steam bath. The residual red colored oil
was vacuum distilled to isolate a 7% yield of a straw colored oil boiling
at 50-53°/3 m.

A 2,4-dinitr0phenyl sulfide derivative was prepared. It melted
at 103-103.5 as obtained directly from the reaction mixture. Two crys-
tallizations from ethanol raised its melting point to 105°. Elemental

analysis gave the following results. Calc'd for C n O S C, 44.58;

line 2 4 2;
H, 2.72; S, 2164. Found: C, 44.60; H, 2.96; 5, 21.70.

Attempted Preparation-of 2,5—Dimethvl-3-th10phenethiol
(Isolation of 2,5-Dimsthyl-3-thienyl Disulfide)

I ‘ 3H
n3c-[ s fl-cna

To a solution composed of 11.2 g. (0.2 mole) of potassium hydroxide

dissolved in 500 ml. of methanol contained in a l 1. three neck flask

 

36

fitted with s stirrer, distillation head, and a nitrogen inlet tube.

were added 30.6 9. (0.1 mole) of 2,5-dinothyl—S-thionylo2,4-dinitrophenyl
sulfide. The stirred reaction mixture was heated under s nitrogen
atmosphere until 300 oi. of nothsnol had been removed by distillation.
The dark rod colored residue was poured onto cracked ice and the flask
was rinsed with sufficient water to bring the volume of the mixture to
800 ml. An insoluble residue remained in the reaction flask. 'Tho
aqueous suspension was stirred in so ice bath until thoroughly chilled
and filtered through celite to remove s rod colored gummy solid. The
filtrate was acidified with concentrated hydrochloric acid but no
material, solid or oil, separated from solution and only s faint odor

of oercaptsn was detected. The red colored gummy precipitate was
extracted thoroughly with hot aqueous boss to remove 2,4-dinitrosnisole.
The slksli insoluble residue was equivalent to on 89% recovery of
2.5odimothyl-3-thienyl disulfids.' After recrystallisation from aqueous
ethanol the light yellow colored disulfido melted at 58.5-590. Elemental
analysis gave the following results.- Calc'd for C12H14S4s C, 50.31;

‘5

Preparation of 2-Thianaphthenethiol

~sn
s

A 500 ml. three neck flask fitted with a stirrer, dropping funnel.
nitrogen inlet tube, and a thermometer, was charged with 120 ml. of dry

other and 6.4 g. (0.90 9. atom) of lithium metal chips. The reaction

 

 

l C
1 v . . A .
A ‘ .. h x
. I
.
.
4 m _, . . r 5
HP ,-o . , ‘ . ‘ Q
I , . K
. , ‘ _ .
‘ I t?
’ .
fl . o v
. _ I
\ ,
.
a ,
..
v
. ‘ r
_
L L. v
Q‘
. \
‘
. .
.
n
w -
.
D
,.
v a
r
.
4 . .
. 4 r
.
I y
. o
.

 

 

3?

flask was cooled to ~100 in a dry ice-isopropanol bath and a solution
of 60 g. (0.44 mole) of redistilled n-butyl bromide dissolved in 60 mi.
of dry ether was added during a half hour. The reaction mixture was
stirred for an additional hour following the addition of the bromide
and then filtered under nitrogen through glass wool directly into a
precooled 500 ml. flask. The filtered solution of n-butyl lithium

was cooled to -100 and a solution of 48 9. (0.36 mole) of thianaphthene
dissolved in 25 ml. of ether was added during a fifteen minute period.
The reaction mixture was stirred for an additional half hour at a
temperature between -5° and ~10o and then it was allowed to warm to
room temperature. A solution containing 15 g. (0.22 mole) of
propylene sulfide dissolved in do ml. of dry ether was then added to
the thianaphthyl lithium solution during a fifteen einute period. he
increase in temperature was noted during the addition of the propylene
sulfide. The reaction mixture was stirred at its reflux temperature
for one hour, during which the color changed from blue through green

to light yellow. After being set aside overnight the reaction mixture
was poured into an equal volume of ice water. The aqueous layer was
separated and the other layer was extracted twice with 2 N potassium
hydroxide. The combined aqueous extracts were acidified with concentrated
hydrochloric acid. A quantity of yellow colored oil separated. This
was separated and the aqueous layer was extracted three times with
pentane. The combined pentane extracts were dried in contact with
anhydrous calcium sulfate and the pentane was removed by distillation

to isolate 13 g. (36% yield) of a yellow colored oil. An attempt to

 

 

JFMfleIJ 1.- a trellnll y
a . ,

 

38

purify the product by vacuum distillation was discontinued when the
material began to darken at a still head temperature of 160°/ 2 m.

A 2,4-dinitr0phenyl sulfide of the mercaptan was prepared and
it melted at 159° after recrystallization from a 131 methanol dioxane
mixture. Heyd (3) reports a melting point of 159-1600 for this
derivative of 2-thianaphthenethiol. Calculated for 614HBO4N252'

C, 50.59; H, 2.43; 8, 19.30. Found: C, 50.62; H, 2.51; 5, 19.46.
Attempted Preparation of 2-Methyl-3-thianaphthenethiol

SH

1

CH3

To a solution containing 7.8 9. (0.14 mole) of potassium
hydroxide dissolved in 370 ml. of a lzl methanol-dioxane mixture
contained in a 500 ml. three neck flask was added 25 g. (6.072 mole)
of 2-methyl-3-thianaphthyl-2,4;dinitrophenyl sulfide. A stream of
nitrogen was led into the reaction mixture and it was heated at its
reflux temperature for fifteen minutes. The major part of the solvent
was removed by vacuum distillation. The residue was poured onto cracked
ice and the flask was rinsed with sufficient water to bring the final
volume of the mixture to approximately 400 ml. The aqueous suspension
was stirred until thoroughly chilled and filtered to remove a quantity
of aired colored solid. A red colored solid precipitated from the
filtrate on acidification with concentrated hydrochloric acid. This

was extracted into other and the aqueous phase was washed twice with

 

other. The combined ether extracts were dried in contact with anhydrous
calcium chloride and the ether was removed by vacuum distillation.

Vacuum distillation of the residue yielded 4.3 g. of red oil, distilling
in the range 125.1753/2 mm.. which solidified as an orange colored solid.
This material melted in the range 90-1000. A considerable quantity of

a dark colored residue remained in the distillation flask. An attempt
-was made to prepare a 2,4-dinitrophenyl sulfide derivative but the product
obtained softened at 143° and melted above 1539 even after recrystallisa-
tion from methanol. A part of the product was found to be insoluble in
ethanol or aqueous base during the attempted derivative preparation. The
insoluble material melted at 153_154o after it was washed with water and
alcohol and dried. It was assumed to be the disulfide of the desired

thiOle

Attempted Preparation of 2,2'-Dithienyl Disulfide

A one liter three neck flask equipped with a stirrer, distillation
head, and an air inlet tube was charged with a solution containing 17.0 g.
(0.3 mole) of potassium hydroxide dissolved in 525 ml. of methanol, and
42.5 g. (0.15 mole) of 2-thienyl-2,4-dinitrophenyl sulfide.. The reaction
mixture was distilled, while flushing the syetem with a stream of air,
until 390 ml. of methanol had been collected. The stirred reaction

mixture was cooled in a water bath and 250 ml. of ether was added to it.

 

 

.‘ul.

L:
..
‘
t ...
'.1
.
x
I i. .\
pt- .
x a
u . it x,
/
v
‘
I
.
I
F O

A quantity of a brown colored precipitate which formed was removed by
filtration. The filtrate was extracted with two portions of cold

water and the organic layer was separated and evaporated on a steam

bath. The dark red colored aqueous extracts were discarded. The residue
was dissolved in hot ethanol and the solution was acidified with
concentrated hydrochloric acid. Treatment of the solution twice with
Norite failed to renove its dark red coloration. A dark red colored

oil separated on cooling the ethanol solution in a refrigerator overnight

and it was discarded.

Preparation of 2-Thienyl Mercury Mercsptide

. U“; Hg

2

To a warm solution containing 1.6 9. (0.014 mole) of 2-thiophenethiol
dissolved in 75 ml. of ethanol was added a solution containing 2.1 9.
(0.0065 mole) of mercuric acetate dissolved in 20 ml. of ethanol.

A yellow colored solid precipitated immediately. ‘ The mixture was stirred
and set aside in e refrigerator. The product was isolated by filtration
and washed with alcohol. A yield of 79% of e yellow colored solid in the
form of needles. which melted at 126° after s single recrystallisation
from ethanol. was obtained. Elemental analysis gave the following results.
Cslc'd. for C8H634Hgs C, 22.29; H, 1.40; Hg, 46.55. Found: C,22.42;

H, 1.58; Hg, 46.18.

J. I-
"I
_._

an. .15.!!!

 

 

41

Preparation of 2-Thiophenemercaptomercuric Chloride

“ ’ ll-Sth
S

A solution containing 4.8 g. (0.086 mole) of potassium hydroxide
dissolved in 250 ml. of wethanol was prepared by warning the components
in a 500 ml. three neck flask while stirring the methanol with a stream
of nitrogen. A reflux condenser was attached to the flask and 12 g.
(0.043 mole) of 2-thienyl-2,4~dinitrophenyl sulfide were added to the
potassium nethoxide solution. The resulting suspension was heated,
under nitrogen. at its reflux temperature for eight minutes after the
sulfide had dissolved and the reaction mixture had taken on a dark ,
coloration. The major part of the alcohol solvent was removed by vacuum
distillation on a water bath at a temperature of 30~35°. The residue
was washed from the reaction flask. onto crushed ice. with sufficient
water to give a final volume of approximately 400 ml. The resulting
aqueous suspension was stirred until thoroughly chilled and a yellow
selored solid was removed by filtration. The filtrate was acidified
with concentrated hydrochloric acid and then extracted three times with
other. The combined other extracts were concentrated on a steam bath
with simultaneous addition of 150 ml. of methanol. in portions. to
change solvents. A solution containing 16.3 g. (0.06 mole) of mercuric
Chloride dissolved in 50 ml. of methanol was added to the stirred
lethanol solution of the thiol. A precipitate formed immediately and

the suspension was set aside in a refrigerator. A 75% yield of product

 

a). r‘vw
.
'. a 1
UV .
—
I «m
.y
a.
. e

42

was isolated by filtration. After a single recrystallization from a 1:1
ethanol-ethyl acetate mixture the product was light yellow in color and
decomposed at 173-1740. Elemental analysis gave the following results.
Calculated for C4H332Cnga C, 13.70; H, 0.86; Pg, 57.11. Found: C, 14.06;

E, 1.52; Hg, 57.16.

Preparation of S-Methyl-Z-thiephenemarcaptomercuric Chloride

A solution containing 4.9 9. (0.0875 mole) of potassium hydroxide
dissolved in 250 ml. of methanol was prepared by warming the base and
the alcohol in a 500 ml. three neck flask while stirring the solution
with a stream of nitrogen gas. A reflux condenser was attached to the
flask and 13 g. (0.044 mole) of somethyl-2uthienyle2,4-dinltrOphenyl
sulfide were added to the alkali methoxide solution. The reaction
mixture was heated, under nitrogen, at its reflux temperature for twelve
minutes. The major part of the solvent was removed by vacuum distillation
on a water bath at a temperature of 30-350. The residue was poured onto
cracked ice and the flask was rinsed with sufficient water to bring the
final volume of the mixture to approximately 300 ml. The aqueous
suspension was stirred until thoroughly chilled and filtered to remove
a quantity of orange colored solid, which was washed with water. The
filtrate was acidified with concentrated hydrochloric acid and extracted

three times with ether. The combined other extracts were concentrated

It. ..

. .. . . ti“:

 

 

43

on a steam bath with simultaneous addition of 150 ml. of methanol,

in portions, to change solvents. A solution containing 16.3 g.

(0.06 mole) of mercuric chloride dissolved in 50 ml. of methanol was

dded to the stirred solution of the mercaptan. A bulky precipitate
formed and the suspension was set aside in a refrigerator. A 41%

yield of the product was isolated by filtration of the chilled solution.
After a single recrystallization from ethyl acetate-acetone the light
yellow colored product decomposed at 156-1570 on slow heating.

Elemental analysis gave the following results. Calculated for €5H582C1H9'
C, 16.44; H, 1.38; Hg, 54.92. Found: C, 16.60; H, 1.631 H9, 54.74.

Preparation of 2,S-Dimethyl-3-thiOphenemercaptomercuric
Chloride

SHgCl
H30. [' 1' a3
5

Employing the experimental procedures previously described for
the synthesis of thiOphenemercaptomercuric chlorides, 12 g. (0.039 mole)
of 2,5—dimethyl-3uthienyl-2,4-dinitropheny1 sulfide was cleaved in a
solution containing 4.8 g. (0.086 mole) of potassium hydroxide dissolved
in 250 ml. of methanol. A solution containing 14.4 g (0.053 mole) of
mercuric chloride dissolved in 35 ml. of methanol was added to the
methanol solution of the aerosptan to precipitate the" product. A 19%
yield of a light yellow-gray colored product, which decomposed at 175-176°

after a single recrystallization from a 1:1 ethyl acetate-ethanol mixture,

ans obtained. Elemental analysis gave the following results. Calculated

.. )t
a
t . l . 0.x . . a
a . t . .c. ..
A _
’
_ . . \ a a
s i I
.. r o
s i t
. .o t
.
p
c u
I; I. .
v i
.
. .. i _ .
W.
. U l l .
l o .
_
a
. .i
15.9
.
» Q‘ (I? I l s
., . I
u I .
. s
. s
m
. x
.
. t.
. A x a
. .J V ‘7. s .
. \ ,...
V
e . .. I
9
.
. ..
.
s .
.,
1 .
n ‘ u
I
O P
v
s. . .
. .
P
1.:
—
IX
0 V
r

gum , u, faflur..,: .é-F’ul‘oi

... .6.“

for C6H733 fig: C. 19.00; H, 1.86; fig, 52.8". Found: C, 19.23;

H, 2.11; H9, 53.11.

Preparation of 2-Methyl-3-thianaphthyl Mechry Mercaptide

S~
Hg
3
2

To a solution prepared from 2.8 g. (0.05 mole) of potassium

 

hydroxide and 150 ml. of 1:1 methanol-dioxane, which was contained

in a 500 ml. three neck flask fitted with a reflux condenser and a
nitrogen gas inlet tube, was added 8.9 o. (0.026molo) of 2-methyl-3-
thianaphthyl-(2,4-dinitr0phenyl) sulfide. The reaction mixture was
heated at its reflux temperature for fifteen minutes, while a stream

of nitrogen flushed the system. The major part of the solvent was
removed by vacuum distillation on a water bath at a temperature of 35°.
The residue was flushed from the reaction flack, onto ice, with
sufficient water to bring the final Volume of the mixture to approxi-
mately 400 ml. The aqueous suspension was stirred until thoroughly
chilled and filtered to remove an orange solid, which was washed with
water. .Tha filtrate was acidified with concentrated hydrochloric acid
and extracted three times with other. The combined ether extracts were
concentrated on a steam bath with simultaneous addition of 125 ml. of
methanol. in portions, to change solvents. A solution containing 3.5 g.
of mercuric chloride dissolved in 30 ml. of methanol was added, with

stirring, to the warm solution of the mercaptan. The mercaptide

 

precipitated immediately; the suspension was set aside in a refrigerator
to cool, and the product was collected on a filter. A 58% yield of a
light gray colored product, which melted with decomposition at 214-2160
after a single recrystallization from a 1:1 ethanol-ethyl acetate mixture,
was obtained. Elemental analysis gave the following results: Calc’d for
C18H14S4Hgt c, 38.66; H, 2.52, Hg, 35.88. Found: c, 37.85; H, 2.35;

Hg, 35.89.

Recovery of 2-Thi0phenethiol from 2-Thicphenemercaptomercuric
Chloride

A 2 9. quantity of 2-thiOphenemercaptomercuric chloride and 15 ml.
of concentrated hydrochloric acid were shaken together in a 100 ml.
separatory funnel for a few minutes. The slurry was extracted with a
portion of pentane, the latter being decanted from the aqueous layer.
An additional 3 m1. of concentrated hydrochloric acid was added and the
mixture was shaken with a second portion of pontane, which was decanted
and combined with the initial pentane extract. The aqueous phase was
again extracted with pentane. The combined pentane extracts were washed
with a snail portion of water and added to a solution of 1.1 g. (0.065 mole)
of 2,4-dinitrochlorobenzene dissolved in 20 ml. of alcohol. The mixture
was warmed on a steam bath until most of the pentane had evaporated.
The remaining solution was made alkaline by the addition of a concentrated

solution of potassium hydroxide to the heated solution. The alkaline

“or!" -‘-‘.i 1

7. Fl. P fife»: l I...‘:. l'fllc
A . . : .

 

3r;

46

solution took on a dark coloration and a precipitate formed after a

few minutes of heating. The mixture was extracted with a portion of
aqueous base to remove any 2,4-dinitrophenol. The alkali insoluble
residue was acidified with concentrated hydrochloric acid and dissolved
in hot isopropanol. The large yellow colored needles which precipitated
on cooling the solution melted at 119-1200, and represented a org
recovery of 2-th10phenethiol. Literature value, m.p. of 2-thienyl-

2,4-dinitr0phany1 sulfide, 119-119.5° (1).

 

Preparation of 3-Methyl-2-thienyl Methyl Sulfide

CH3
[[ - :fl~scu
s‘ 3

A solution containing 6.1 g. (0.11 mole) of potassium hydroxide
dissolved in 285 m1. of methanol was prepared by warming the base and
alcohol in a 500 ml. three neck flask while stirring the solution with
a stream of nitrogen. A reflux condenser was attached to the flask and
15.9 g. (0.054 mole) of 3-mothy1-2-thieny1-2,4-dinitrophenyl sulfide
were added to the alkali methoxide solution. The reaction mixture was
heated at its reflux temperature, under a nitrogen atmosphere, for
twelve minutes. The major part of the solvent uas removed by vacuum
distillation on a water bath at a temperature of 30-350. The residue
was poured onto cracked ice and the flask was rinsed with sufficient
water to bring the final volume of the mixture to approximately 300 ml.

The aqueous suspension was stirred until thoroughly chilled and filtered

 

.0..-
,—

n
I ‘
p
n.
r
. A‘ . .101... nil! :‘ $
. I . V> marl!!!

— ‘ 4r .

‘ —
. ful.

 

47

to remove an orange colored insoluble material.' The latter was washed
with water and the filtrate was transferred to a 500 ml. three neck

flask equipped with a stirrer, reflux condenser, and a dropping funnel.
The celution was warmed with an electric mantle and 6.1 g. (0.043 mole)
of methyl iodide were added during s half hour. The reaction mixture f,wnq
was stirred at its reflux temperature for an additional three and a

half hours. A red colored oil which separated on cooling the reaction

mixture was extracted into other and the aqueous layer was separated

and extracted twice with other. The combined other extracts were washed

 

with aqueous sodium hydr0xide followed by three washings with cold water.
The other solution was dried in contact with anhydrous calcium chloride
and the ether removed by distillation. The residual oil was fractionated
at reduced pressure to isolate a 32% yield of a light yellow colored oil
boiling at 67-689/6 mm. Elemental analysis of the product gave the
following results. Calc'd for C6H832' C, 49.95; H, 5.59; 3, 44.46.
Found: C, 50.09; P, 5.78; S, 44.63.

Preparation of 2-Thienyl-2-piperidinoethyl Sulfide
Hydrochlorlds

[' S B‘s-obsern 4 HCI

A solution composed of 5.6 g. (0.1 mole) of potassium hydroxide
dissolved in 275 ml. of methanol was prepared by warming the base and
the alcohol in a 500 ml. three neck flask while stirring the methanol

with a stream of nitrogen. A 14 g. (0.05 mole) quantity of 2-thienyl-

.TH!

['1

augqfiuv a Is 51!?

4 .
fear}

..

21%

,
.
.
_\l I
\ .r
\ .
\
.
II ‘
1 \
Ii.
O
‘1‘,
.
.4

2,4-dinitrophenyl sulfide was added to the alkali methoxide solution

and the resulting mixture was heated, under nitrogen, at its reflux
temperature for a ten minute period. The major part of the solvent

was removed by vacuum distillation on a water bath at a temperature of
30-350. The residue was poured onto ice and the flask was rinsed with
sufficient water to bring the final volume of the mixture to approxi-
mately 300 ml. The aqueous suspension was stirred until thoroughly
chilled and filtered to remove a quantity of orange colored solid. The
filtrate was transferred to a 500 ml. three neck flask fitted with a
stirrer, reflux condenser, and a drapping funnel. To the stirred,
refluxing filtrate was added, during a half hour period, a solution of
5.5 g. (0.03 mole) of 2-piperldinoethyl chloride hydrochloride dissolved
in 20 ml. of water. The reaction mixture was stirred at its reflux
temperature for an additional two hours following the addition of the
hydrochloride. A brown colored oil, which separated on cooling the
reaction mixture, was extracted into ether and the aqueous layer was
washed twice with ether. The combined ether extracts were washed once
with aqueous sodium hydroxide and twice with cold water. After drying

in contact with anhydrous magnesium sulfate the other solution of the
amine was cooled in ice water and treated with a gentle stream of hydrogen
chloride gas. The precipitate was collected on a filter and the filtrate
was again treated with hydrogen chloride to completely remove the amine.
An excess of hydrogen chloride caused the product to become quite
intractable. A 7th yield, 5.6 g. (0.021 mole), of a slightly red colored

crude product was obtained. After recrystallization from isOprOpanol,

 

49

0
using charcoal, the white crystalline product melted at 150-150.5 .
A melting point of 145-145.5° has been previously reported for this
compound (7). Calc'd. for cilalerszcis c, 50.07; H, 6.87; 3, 24.30.

Found: C, 49.98; H, 6.65; 8, 24.12.

Preparation of 2-Thienyl (2,4-dinitr0phenyl) Disulfide

$202
[I J] “S'S-Q 9532
5

To a solution containing 1 9. (0.0043 mole) of 2,4-dinitrophenyl

 

sulfenyl chloride dissolved in 10 ml. of carbon tetrachloride was added
1 9. (0.0086 mole) of authentic 2-th10phenethiol. The reaction mixture
was heated on a steam bath for ten minutes and the solvent was then
removed in an air stream. The residue was recrystallized from ethanol
(Morita) twice to obtain a yellow colored crystalline disulfide melting
at 57°. The above procedure was repeated using a sample of a research
preparation of 2-thi0phenethiol.t The resulting derivative melted at
56.5-570, and the mixed melting point of the two samples was 570.

Preparation of 2,4-Dlnitr0phenyl Sulfide Derivatives
of Thiols

A. 2—thienyl (2,4«dinitr0pheny1) sulfide

[\sjvs- N02

 

 

 

1;»‘3 I'VE-7|. talllf
,IL . .

m

Area-{l .

,uli
.

ill!

I

2': 1a.

An ethanolic solution of the sodium salt of 2-thiophenethiol was
prepared by treating 1.5 g. (0.013 mole) of the mercaptan, dissolved in
40 ml. of ethanol, with 0.52 g. (0.013 mole) of sodium hydroxide. The
stirred solution was heated on a steam bath and a solution containing
2.63 g. (0.013 mole) of 2,4-dinitrochlorobenzene dissolved in 10 ml. of
ethanol was added to it. The stirred reaction mixture was heated on a
steam bath for an additional ten minutes, filtered hot, and set aside to
cool at room temperature. .The yellow crvstalline sulfide which separated
melted'at 1190 after a single recrystallization fro: ethanol. Literature

“1“. .spe 119° (1).

a. 5-mothyl-2-thienyl (2,4-dinitr0phenyl) sulfide

~02
”3.0 LG...
3

To a solution containing 0.9 9. (0.0069 mole) of 5-methyl-2-
thiOphenethlol dissolved in 20 ml. of methanol was added 1 ml. (20 drops)
of 5N sodium hydroxide. The alkaline solution was stirred on a steam
bath and a solution containing 1.2 9. (0.0059 mole) of 2,4-dinitrochloro-
benzene dissolved in 15 ml. of methanol was added to it. The stirred
reaction mixture was heated for an additional twenty minutes and set aside,
at room temperature, overnight. The yellow crystalline sulfide which
separated melted at 1050 after being recrystallized twice from ethanol.
Elemental analysis gave the following results. Calc'd. for 511HBV20452'

C, 44.58; H, 2.72; N, 9.45; 5, 21.64. Found: C, 44.60; H, 2.96; N, 9.57;

5, 21.70.

 

 

I,»

fifil-ql. .3-

E 2.“ 2n ;

. r _ r e
. .. . 0
f1
, sen. I . .
.V. , )i u

his!!- .4

.0“. to
a! .
f,
r
x
x.
t
.. .f.
\.\ \‘w r p
\x x
a.
‘ s.
_ .w
. .k
.\
\tl \

 

.a}.

C. Z-thlanaphthyl (2,4-dinitr0phenyl) sulfide

 

This derivative of 2-thianephthenethiol was prepared employing
the experimental procedure described above in the preparation of
2-thienyl (2,4-dinitr0phenyl) sulfide. After recrystallization from a
1:1 methanol-dime mixture the yellow colored powdery Sulfide" melted
at 159°. Literature value, m.p. 159-1600 (3). Elemental analysis
gave the following results. Calcfd. for 01438“20452‘, C’ 50.59;

H, 2043’ 5, 19e30e FOUNdI C, 50e62; H, 2.51, S, 19e46e

51

 

 

 

_- . .~9

\;

M

h‘P-L a. .

_ «who; u

1.

2.

4.

5.

6.

SUI.L="~.‘.A RY

A two step synthesis involving the Friedel-Craft reaction of
2,4-dinitr0phenylsulfenyl chloride with a heterocyclic nucleus
followed by basic cleavage of the resulting sulfide was adapted

to the synthesis of thiOphene and thianaphthene thiols.

The previously unreported 5-methyl-2-thiophenethiol was prepared

and characterized.

The previously unreported 3-methyl-2-thienyl methyl sulfide

was prepared and characterized.

Two thiol derivatives, 5-methyl-2-thienyl-2,4-dinitrOphenyl
sulfide and 3-methyl-2-thienyl-2,4-dinitrophenyl sulfide, were

prepared for the first time and characterized.

Five previously unreported mercury mercaptide and mercaptOe

mercuric chloride derivatives were prepared and characterized.

The mercaptan, 2-thianaphthenethiol, was prepared by a method

not previously reported for-the synthesis of this compound.

 

.V

L”

1.

2.

3.
4.

5.

6.

8.

9.
10.
ll.
12.
l3.
14.
15.
16.
17.

18.

19.

20.

C.

R.
p.

C.
C.

N.

53

REFERENCES

M. Buess and N. Kharasch, J. Am. Chem. Soc., lg, 3529 (1950).

J. Fewcett, Ph. D. Thesis, Michigan State University, 1957,
227. g f

E. Heyd, Ph. D. Thesis, Michigan State University, 1956, p. 50.
E. Heyd, Ph. D. Thesis, Michigan State University, 1956, p. 51.

Kharasch, H. L. Wehrmeister, and H. Tigerman, J. Am. Chem. Soc.,

92, 1612 (1947).

N.

Kharasch, C. M. Buess, and G. I. Gleason, J. Am. Chem. Soc., 22,

1796 (1950).

W.

F.

H. Houff and R. D. Schuetz, J. Am. Chem. Soc., 22, 6316 (1953).

Challenger, 3. A. Miller, and G. M. Gibson, J. Chem. Soc., 769-71

(1948).

C.
D.
J.
E.
W.
C.
F.
R.
N.

F.

E. Heyd, Ph. D. Thesis, Michigan State University, 1956, p. 42.

A. Shirley and M. D. Cameron, J. Am. Chem. Soc., 13, 664 (1952).
Post and H. Mehrtens, Ber., g, l552, (1875).

Campaigne and W. L. Archer, J. Am. Chem. Soc., 12, 999 (1953).

J. King and F. F. Word, J. Org. Chem., 13, 638 (1949).

Peal, ner., lg, 2251 (1885).

G. Bordwell and H. M. Andersen, J. Am. Chem. Soc., 1;, 4959 (1953).
J. Fawcett, Ph. D. Thesis, Michigan State University, 1957, p. 228.
Kharasch, J. Org. Chem., 12, l704 (1954).

Challenger and J. 8. Harrison, J. Inst. Petroleum Technol., 2;,

135 (1935).

P.

D. Caesar and P. D. Brenton, Ind. Eng. Chem., 35, 122 (1952).

R. J. Fawcett, Ph. D. Thesis, Michigan State University, 1957, p. 92.

”415"" -‘~ .5”: 1a

A . .., .
0 $ 0 c. r. $ -
‘ t u
m. t p..
. ~
‘ C
V x
V o . ..
‘ 1| T
o
I.
u a. I .
O
x u a s .
O
..
. .
J.
.
I
. i—
.
‘
s.
. d O
’
T
r .4 3
if .

nasfladflfll-’ a”... ,3, . ..a.r

. ._ .p.‘

.1
IV
A

”i

~i

21.

22.

23.

24.

54

C. E. Heyd, Ph. D. Thesis, Michigan State University, 1956, p. 47-48.

F. G. Bordwell, H. M. Anderson, and B. Pitt, J. Am. Chem. Soc., 19,
1082 (1954).

H. D. Hartough, "ThiOphene and Its Derivatives," Interscience
Publishers, New York, 1952, p. 110.

H. Gilman and A. H. Blatt, "Organic Eyntheses," John Riley & Sons, Inc.
New York, 1941, 2nd ed., Collective Vol. I, p. 220.

 

. I
s cm — I i. .c
. T. D.
0 o . z. 0
I.
.
. O . . Ir. -
.. .v _
_. .
. ’ 1 .
a . « \“s s .. .
._ f. .A m. H .1
J a
y l . .J
P u 4 ' -.~
- . II
I
n.
, Ha.
-
1 .a
r
( .
V. 2
.
L
l 9"
\
.1 P
.
.. I
I
H
w
.
n,
..
w
.

 

«at... VET I?

le47‘ E12. .el...’ 5.2,...1...
a. .

erg?

 

“"3 '61

MARlS'GZ

 

 

 

 

1
1
1|.
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
11
1
1

3
9
2
1
3