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ABSTRACT

NUCLEAR MAGMLTIC RLSCNANCL STUDIES OF HYDRAZUNLS

by Carol Elizabeth Usborne

The nuclear magnetic resonance spectra of thirteen hydra-
zones were examined to determine configurations, conformations,
syn/anti ratios and solvent effects.

The assignment of configurations was based on two points.
Sterically it is resonable to expect that configuration I should

be thermodynamically'more stable than II when H1 is smaller

N- N\-\ N-N“
u z \\ 2
C C

/ \

R7” R' R\/ \R1

I TL

than R2. Secondly, due to steriospecific association of benzene
with the substrate the chemical shift of gig protons to higher
magnetic fields is greater than that of the trans protons.
Using these two principles it was possible to make configura-
tional assignments to the syn and anti isomers of various hydra-
zones. For example, in all cases the cis aldehydic proton of
aldehydic hydrazones is found to resonate at lower magnetic
fields than the trans aldehydic proton.

From the spin-spin coupling constants it was possible to

determine which conformations were the more stable for the

hydrazones. For example, the coupling constant for syn pro-

Carol Elisabeth Osborne

pioxmLiehyde hydrazone Ji‘fi‘ioc. 5.52 c.p.s.. while for syn
18Waleruldehyd0 mtua‘m Jh’n - 5e60 copes. Th1. 11111-
' (X

cates that for the syn aldehydic hydrasenee conformation III
N — NH N - NH

2 2
“w QM
K H H, H
II ISL
becomes more stable than malformation IV as the H group in-
creases in size. Conformation III involvee a trans coupling
and e genera coupling and conformation IV the gauche couplings.
Since Jt > 48 confomltiun III would have the larger coupling
constant.
The relationship between conformations and chmical sidfte
was also .miuillfid. It was found that a proton in the plane

of the carborr-Mtregen bond is shielded with respect. to a
proton above or below the plane.

THE

k."

hUCL.;i.e-x:{ game-TIC iikSQiSé-RCL STUDIRS

L F Ii? .Li'ri.-’xl.¢1.££:.3

{Ty

Carol Llizabeth beborne

Submitted to
fiichigan State University
in partial fulfillment of the requirements
for the degree of

mast-.3 b? SCILi’éCb

Department of Chsa'xiatry

1962.

I ‘: t'f'v' Y) I i)"e._.~ 'fgfi‘.u
’1L“.I‘."J‘ dfidu‘ ““.3 Q

I would like to capress my appreciation
to Dr. G. J. Kirahatsos for his patient guidance

in directing the research for this thesis and for
his assistance during the preparation of the thesis.

ii

Introduction . . . . . .

Results and Discussion .
Chemical Shifts . . .
Solvent Effects . . .

Coupling Constants . .

TABLE OF LtfiTLfiTS

Confbrmations of the syn Isomers . . . . .

Conformations of the anti Isomers . . . .

Half-hidths . . . . .
AnisotroFic Lffects of

Syn/Anti Ratios . . .

Experiment 31 e e e e e e
Apparatus e 0 e e e e
Reaction Procedure . .

N.M.fi. Speflra e e e 0

Bibliography.....................oo

the Carbon-Nitrogen

iii

Double Bond

page

\0 \fl km

10

1O

11:3? CF I‘.‘.Bll;i

page
Table I ,.
(”165116111 «Jilin: 0f hydréxiOMS 1“ le e e e e e e e e e A

Table II
Spinpdpin Coupling Constants of fiydrasones . . . . . 13

Table III
Conformer Farcentages of Syn Aldehydio hydrasonee . . 19

Table IV
A; F9 Values for the Conformatione of’Eyn
Aldehydic ifydrazones e e e e e e e e e e e e e e e e 2.

.1

fable V
Halfaridthe of oc-methyl F'rutons and
fildelu’dici‘wtutw.................. 2)

Table VI
Chemical Shifts, in 0.3.8., of the
Syn $1.66}!de W :1)?“ 86130118 fiyiu‘aZOiwae e e e e e e e 27

Table V11
syn/Anti Composition of Hydrazones; Seat. . . . . . . 29

iv

1.1.}? U? 1" 161.. 3

page

Figure ‘e

h.u.r. st-ectrum of acetone hydrazone with

55:18.11 amount or 875133 present. e e e e e e e e e e e e e 6
Figure 2.

Il.m.r. erectrwn of acetone mnirasone with

confiidfirablo aging :Jmtiente e e e e e e e e e e e e e e e 7
Figure 3

R.m.r. spectrua of acetaldem'de hydrazoue showing

Peaks 333%“ to L3. “103. Of the Gilli-ire e e e e e e e e e 8
Figure 1..

.ffect of diluticn on the chancel shifts of

QCOtham’dX-‘fizbnaeeeeeeeeeeeeeeeeeeee 1'
Figure 50

:..m.r. spectrum of acetone )wdrazone 2 mole )3
inbenzerze........................12

Figaro 6.
R.m.r. Spectrum of butanone hydrazone. . . . . . . . . . it
Figure 7.

fi.m.r. sgectrum of diethylacetaldehyde hydrazone. . . . . 16

Figure 6.

t-i.m.r. effectru'a cf isupentamne hydrazone. . . . . . . . 21
Figure 9. .

;£.m.r. spectrum of proniozuldehyde tgv'drazone,

small triglet downfieln is from mine. . . . . . . . . . 22

ILTXCDUCTICH

huclear magnetic resozmnce spectroscoyy has been a Very
useful method for studying problem arising from restricted
rotation about a caroon—xdtrogen double bond. The hydrogens
in the neighborhood of the anisotropic group serve as a probe

for detecting asymmetry around the double bond; 3.5. I and II.

N—N N-
“ ”2 u NHZ
C C
/ \ / \
R2 R. K R2

Many workers have used n.m.r. to study the isomers of
compounds containing a carbon-nitrogen double bond. In 1958,
Phillips (1) showed the existence of syn-anti isomers of ali-
phatic eldoximes. Later Lustig observed separate peaks for
the syn-anti isomers of ketoxiznes in the presence of aromatic
solvents (2). Studies of 2,A-dirdtmphexarlm'drazones sud
semicarbasones were made by Karabatsos, Graham and Vane (3}-
Karabateoe and Taller (MS) made similar studies of nitroc-
amines, phen} lha'drasonee and p—tolylhydrasoms.

The purpose of this research was to study by n.m.r. con-
tigurational end conformational isdnerisa of rgdz-azones; 3.5;.
syn and anti assignaents to isomers, syn/anti ratios, and
conformations of the wall groups attached to the carbon-
nitrogen double bond.

The assignaent of configurations is based on steric

considerations. For emuple, the ratio 111/ l V should increase

2

when 31 is kept constant and R2 is changed from ethyl to

iaOprOle.

N"NH _
u 7* w NHL
//C\\ C\
R1 R‘ R\/ R2
III N

Throughout the thesis the isomer with the amino group
cis to the smaller 8 group will be regarded as the eyn
isomer. The hydrogens of the R groups are numbered as
indicated in V and are designated as cie or trans to the

amino group.

N~NH
\\ 1
C.

/ \
C“C H
I n
H

fi H

i-ilfi‘fiilffi 33M) {‘31 3C! H35 1"} :‘u’

Chemic;.=‘ M

Table I summarizes the chemical shifts of several hydra-
zones. The more intense signals were assigned to the con-
figuration with the smallest group cis to the amino group.
In new instance. seine was present in the l'zroduct or was
formiw from hydrasone es the egectrs were taken. Figure 1
shows the spectrum of e freshly distilled sample of acetone
hydrssone with a wall mount of urine present. After let-
ting the acetone hydrnsone sit at room temperature for a few
hours the spectrum was taken again showing evidence of more
azine, as seen in figure 2. In order to confirm the hydrw—
zone peaks a null amount of the corresgomling aldehyde or
ketom was added to the Mdrasone smugzale after the spectra
were run end the sample was reoem'nined to see which peeks
decreased in intensity.

The aldehydic hydrazones dimerize at room temperature

(reaction one) to give crystalline 3,6-dialkylhexahydro—

Z /C\ —-> /C c/ (1)
K H H \NH-NH/ \R

s-totrazine (6). Figure 3 shows the spectrum of sootulde-
hyde hydrezone with peaks which presumably are those of the
diner. Imediately after this spectrum was run the sample

crystallized in the n.m.r. tube.

 

 

 

 

 

 

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Fran Table I it can be seen that Oi-methyl protons
always appear at higher fields when cie to the amino group
than when trans. In contrast, the aldehydic proton, H1,
and 15-methyl protons resonate at lower fields when cis
than when trans. Although in only a few cases could cie
<1~methylene protons be detected, it appears that they are
deahielded (lower fields) with respect to trans ¢lqmethy-
lone protons. It was not possible to detect the resonance

of the cie CX-methine protons.

Solvent Effects

The effect of solvent on the chemical shifts can also
be seen by looking at Table I. The solutions shown in Table
I are all 10% hydrazone - 90; solvent, by volume. In carbon
tetrachloride there in little effect on the chemical shift-
for either the eyn or the anti isomers. But when benzene
1e need ee the solvent the cie hydrogens are shifted up-
field more than the trane hydrogena. A hydrogen bonded

complex of conformation VI explains this behavior. Since

5
N/ ”\u

RA ‘0

EL

8‘ is closer to the center of the benzene ring than R2
A1}(cie) > A1} (trans). The behavior of hydraaonee in benzene

is similar to that of other compounds of the type R1320nNZ

(3.1¢.7).

Figure I. shows the effect of dilution studies on ace-
tone hydrazone. Curve I, which is concave upward, represents
the cis Ot-methyl hydrogens of acetone hydrasone in benzene.
Curve II, also concave upward with a slight shift towards
lower magnetic fields with low concentrations of the solvent,
is the trans Oi-methg'l hydrogens in benzene. Curve III is
the cis (It-methyl hydrogens in carbon tetrachloride and Curve
IV the trans Mnethyl hydrogens in carbon tetrachloride.

The chemical shifts in carbon tetrachloride are quite imaensi-

tive to dilution.

Coupling Constants

Table II swamarizes the coupling constants, accurate to
$0.05 c.p.s., between H, and the cat-protons of the aldehydic
hydrazones. The probe temyerature was maintained at about

36' .

Confomatioqg g; 3.333 m Iscmerg

flaw instrumental methods have shown that the stable con-
formation of a tetrahedral carbon bonded to a trigonal carbon
has a single bond eclipsing the double bani (8-22). If VII
is the conformation of acetaldehyde hydrazone, then its coupling
constant may be expressed as:
Jim - (2...!g + JtVB

where J 8 is the gauche coupling and Jt the trans coupling.

 

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SpinPSpin Coupling Constants of

Table II

Hydrazones

 

 

 

 

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F
\ 9 -- ‘
\ C = N~ MHZ J°lvent Juido‘(cepe 30)
R1// cis trans
1 II . - ‘ .CI } - . ' .
P, H R2 LH‘ h3 Jest 5 52 5 L5
“.1 - H d2 . CHZi-fyr “Bat; 5.60 I he93
001“ 5.50
Benzene 5.53
it, - H R2 - cazcéhs heat 5.77 5.07
COIL 5.77
R1 '3 H R2 '- CH2t~I$u EtUH 6.23 5.35
R1 - H R2 - 1‘?!‘ limit 5.18 7018
- . - ‘i .2"; A” 'j o I .1-
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Ho

N—NHZ N—MHZ N-NHZ N—uuz
H K R K H K “ k
/, H , H , H / u
H H H’ H R” H “’ R

YE YE Dim 11a

If VIII and 1X3 are energetically equivalent than the

coupling constant for a monosubstituted aldehydlc lwdrnzonc
should be the some as that for acetaldehyde hydrazone (5.1.0
c.y.a.}. however, the substitution of an alkyl group prob—
ably decreases the coupling by about 0.1.43.7 c.p.s. per alkyl

substituent (23—25;. (For example, is 8.0 c.p.a.

JCi€301t.-1*-
(X - h), 7.26 c.p.s. (I - CH3) and 6.8 c.p.a. for isobutane.)
From steric considerations one would oxyact IX to ho more
favorable than VIII, in which case the coupling constant of
monosubstituted ucetaldehyde hydrazono would be larger than
that of ncetaldohyde hydrazonn aince Jt>'JE. Also, as R gets
larger JH1HGLSh°uld get larger because more of the compound
would be in conformation IX. From the data it can be con—
cluded that this is the case; 3.3. J“le for methylacetulcie-
hyde hydrazone 13 5.52 c.p.a., for leoprcyylacetaldehydc hydra-
zona 5.60 c.p.a., and for‘tybutylncotaldehydo hydrazono 6.23
c.p.a.

Fbr the disubatituted aldehydic hydrazonea there are
three possible confonnationa with a single bond (C u h) eclip-

aing the carbon-nitrogen double bond. As the R groups get

larger'moro of the compound should be in conformation 1 rather

than XI and the coupling constant should increase. The data

15

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16

indicate that this is true, confonnation 1 is more otable

N—NHz N-Nuz N~-NHZ
n R a
KKH ,,\(IKH 6N1
R/ R R R R H

X Xian XML

than conformation XI. For exaarle, when both It groups are

methyl J - 5.18 c.r\.s.; when they are iBOprogryls J - 6.58 c.p.s.
If it is assumed that t—butylacetaldem/de hydrazone

exists solely in conformation 1:4 then its couyling constant

may be expressed as:

.33 + at
J may. + correction - ”'15“
where the correction factor arises from the substitution of
an alkyl group for a hydrogen. By using the above e. pression
and the one previously given for J 2,‘ ho; of acetaldchydo hydra-
‘1

zone it is possible to calculate J and Jt' than 0.3 per

3
allql oubstituent is used as the correction factor J8 - 3.11.
c.p.o., Jt - 9.92 c.p.s.; with 0.5 as the correction J3 - 2.71.
c.p.a., Jt -- 10.72 c.p.e.; using 0.7, JE '- 2.31. c.p.n., at c:
11.52 c.p.a. These values are camitrable to those which Bothner—
By found for olefins; Jg '3 3.7 c.p.s., Jt - 11.5 c.p.s. (10}.
The values calculated for J g and Jt may then be used
to determine the percentages of the different conformers. For
the monoaubstituted acetaldehyde hydrazones the expression

for determinirg the percentages of than two is:

X(JE-.L + Jt) 1
Jm. + correction - n. + (1 - x)J,.
I .GXIEO ‘ b

 

17

where x is the amount of the compound in conformation 1X8 +
11b, and (1 - x) the amount in conformation VIII. Table III
shows the percentages obtained by this method.

For the disubstituted acetaldehyde hydrazones the expres-
sion for calculating the amounts of conformers X and Ma + .21},
is:

J; + 2(correction) - th + (1 - x)Jg

inexp,
where x is the amount of conformer X and (1 - x) the amount
of conformer XIfl + 1111,. The percentages thus obtained for
the different conformations of the disubstituted acetaldehyde
hydrazonee are also shown in Table III.

The percentages of different conformations at equili-

brium may then be used to find A Po, the standard free enera'

N - N112 N -NH2
11
{Kn K: VM
(4/ H T__ //
11‘ a

\—X 13/2

change between the two conformations. The expression for
A F0 is:

a 9° - -RTan
or

A F° :- -H‘l‘lnT’5./_—23E

The values found for A F0 are shown in Table IV.

18

Table III

Conformer Percentages of Syn Aldehydic Hydrazones

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

19

 

 

 

 

 

Monosubstituted Conformation
aldehydic hydrazonee
Compound N-N“ N-NH
R. H 'K 7. R K Z
__ R”< H / H
C a N MHz, l4 R’ \\
R1 1X3 + be VIII
Correction per alkyl substituent
03 05 07 03 05 07
R1 - H 122 a CHZCH3 79% 82% 85% 21% 18% 15%
R1 - H 122 .. 01121-1» 82% 81.15 8673 18% 16% 111%
R1 = H R2 -= 011206115 8672; 89% 9076 111% 11% 10%
Disubstituted Conformation
aldehydic hydrazones
Canpound N-NVA2 N-NHZ
R1 H \\\ $1 K\
\\C==N-NR /’ H ’ H
/ 2 R K H’ K
R; X. x13 ‘1' Mb
Correction per alkyl eubstituent
03 05 07 03 05 07
R1 '3 H R2 ‘ i-Pl‘ 39% ((3% [+61% 61% 57% 514%
R1 = H R2 " CH(E’0)2 56% 57% 59,3 W 113% M73
R1 - H R2 -= CH(i-Pr)360% 61% 61% 1.0% 39% 39%

 

o
A? Values for the Confomations of $yn Aldemrdic Hydrazonee

Table IV

 

R1

Q:

N‘NHZ

A F0 cal. mole.

1

 

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It can be observed from Table II that for the nonoeub-
stituted aldeh1dic hydrazones the trans coupling constant in
each case is less than the cis coupling constant; 3.3.

{11101 I1-5. 6;) c.p.s. for thee syn fora of isopro; ylacetaldehyde
hydrazone and for the anti fem Jfi‘fiq' [”93 c.p.8. This
would soon to irxiicate that for the anti monosubstituted acet-

eldehyde hydrazones conformation MI is more stable than con-

fonnation XIII, since conformation III has two gauche couplings

Q )“Q )QZ

XE - XIII X11

whereas XIII has one gauche am one trans coupling. Conforma-
tion XIV would have approximately the same coupling constant
as XIII and would not explain the decrease.

Another explanation for the decrease could be that the
more stable confom1tion for the anti forms of the nonosubsti-

tuted acetaldemrde WMWB is conformation 1V. This seems
11—11112

:1

unreasonable since there would be considerable steric inter-
action between the alkyl group and the amino group- in this

conformation.

then the disubstituted anti aldehydic twdrazones are
compared with the syn disubstituted aldehydic hydrazonee it
can be seen that they have much larger coupling constants;
3.5. JHIH -= 6.32 c.p.e. for diethylacetaldehyde hydrazonee

in the syn form, while for the anti form JHIH =- 8.10 c.p.e.
N—NHI

J“
R

XXL

Conformation XVI then is the more stable conformation for

the anti disubstituted acetaldehyde hydrazonee.

Half-Widths

Table V shows the half-widths of the aldehydic protons,
H1, and the OK-methyl protons of several hydrazones. They
were measured in an effort to determine if coupling was occur-
ing with the protonexof the amino group. Although some of the
half-widths are larger than would be expected for no coupling,
there are no specific trends. From these data it is impossible
to make arw definite statements regarding coupling between
the amino protons and the (Ia-methyl protons or the aldehydic

protons, "1’ of these hydrazonee.

Anisotronig ngectg 2; the Cgbon-Ritgogen Double 13013
It was sham from the coupling constants that for the

Table V

half-21111111111 o1: (la-methyl Protons and ddshydic i-"rotons

 

half—tidth of

Cit-CH1, (c. p. 3.)
J

Half-.k1idth of

H1 (c.?.3.)

 

 

cis trans cie trans
R, - 1,113 112 - (3114,9113 1.20 1.0
R1 1- 0213 R2. - t-Bu .50
11,, - 13113 :12 - (2112136215 .70 .70
a, - 11 112 - (:11a .55 .70 .71 1.10
:11 - 11 112 - 1.1120113 .71. no?
a, .. s 11.2 =- (Mai-Fr .63 .93
R, - H. 11.2 - 01221126115 .51. .97
a, - 11 a2 -- Glut-Bu 1 .110 .95
a, - 11‘ .112 - casing .65 .70
“a. . '11 R2 - CHM-Pfiz .E9 .71;
R. - H R2 -= i-Pr .61 -7’8

 

 

 

eyn—kwdrszones, when R is changed from methyl to isogmoyyl to
t—butyl, conformation II is more stable than conformation VIII.
Similarly for the disubstituted acetaldem-de hydrssones, con-
formation 1’. becomes more stable than conformation ll as the
11 groups increase in size.

Table VI shows what this change in confonaation does
to the chanical shifts. The chemical shifts, accurate to g
i 1 c.p.s., are expressed in c.p.s. downfield from tetramethyl
silsne (0 c.p.e.). From the table it can be seen that as the

oe-proton spends more time in the plane of the carbon—nitrogen

 

double bond the resonance shirts to higher magnetic fields;
3.5. the on—methine proton of dimethylscotaldehyde hydrasone
resonates at 11.0 e.p.s., whereas the“ OK-methine proton of
dilaopropylacstaldehyde hydrazone resonates at 90.6 6.1). e.
That is, e proton in the plane of the carbon-nitrogen double
bond is shielded with respect to one above or below the plam.
This behavior is opposite to that generally accepted for
carbonyl compounds (26).

The difference between ”11(3) and flaw) may be due to

N - NH

”wk
,1 11
“D

the enisotromr of the carbon-nitrogen double bond or hyper-

1

conjugation which can occur with protons in position (3),

but not in position (A).

Table VI
Chemical Shifts, in 0.9.6., of the

riyn Aldefurde and 1311 hetone hydrogen“

 

~NHL

\nzaz

R R v («.253) 11(oc-C5‘ig) 11 (cc-031‘)

 

:11 - h 21,, - at; 101.5
:5. J

k, " H 33.2 '- ““2. IL. 1:65
:11 C H 3%,. " CH 1—? 193.1

4 a“.
:u, - h ;;,._ - Chit-Eu“ we. 5

‘ fi
32 ,z --'-. p.‘ ’3‘
e51 - xi “2 I. ‘I“{£CO.15 {not
H, - H :17. u {.t1(.£6),' m0

- H .. (325(4) 11?

“I 2 2
h -1z is; - Stu-Er), 90.5
J - "“5 - ’ ‘ u'
n. th L3. b“? 1&8
-.I .: .». ! Hf: r- ‘

1 - (J33 is“: . L}.z‘.d(3 14E)

'7 -x: ,e' .53.! .~~ 1'- cm.
33.1 H LL} “.2 I \,.12\.6.!5 $46.5
24;, -= $531.2 - (Jay-#02 11.3.5

 

. o
3.11 s‘gectra are neat solutions run at. 00 i--2c am 36:

except thoee indented by 11*, the latter were run in nun-i.

 

This behavior has also been denonetrated for carbonyl

ccmpomtis and other carbonyl derivatives (27).

Syn/Anti m

The percentages of the syn and anti isomers of various
hydrszones are shown in Table VII. The values were determined
from integration of peak areas and are accurate to i 53%. In t“
1111 cases the disu‘ostitutal aldehyde m'drazonee and the age: - |
disu‘c-etituted ketone hydrazones show a larger percentage of syn

leaner than em! of the monosubstituted hydrazones. It is

 

interesting to note that for the disubetituted eccteldehyde
hydraeones the percentage of the anti form increases es R
changes from methyl to ethyl to isoprowl. It would seen from

eteric considerations, that the trend would be the other way.

28

Table VII

‘/
Syn/Anti Canposition of Hydrazones; heat

 

 

R\

\ C -N ~NH2 '

Z
T? . ~
"‘ ' P“ 32 ' m 77.8: 22.2%
RI "‘ 3"“ a2 "' 1?? 93.1.3 6.9;;
“1 " -' ”:2 " 02"2965‘15 75.55 (1.5::
a, - rs. 5:2 - t-Bu 100.5
R1 " H “2 " 1-3? 90.7,: 9.3;;
H, II H H2 .- C.‘i(i-;t)2* 26,9; 13.1);
. .. ., . . a . , ,. ,
ti, -- H the '- Ch(i-Pr)2 83.1,» 16..»
R1 " H R:2 "' CHJE-Bu)‘ 72.55 27.526

‘ Sons )3th present

fl- Value may be slightly in error due to small
asine peak underneath the cis proton reek.

29

 

30
EATERIAEfiTRL

A: ratus

The reactions were carried out in a 100 ml. round bottom
flask equipped with a condenser. To the tap of the condenser
was added s small separatory funnel for the addition of the

aldehyde or ketone. 1f

Reaction Procedure

A 1. gram sample (3.88 ml. or 0.08 moles) of 100% hydra-

 

sine hydrate, 5 ml. of ethyl alcohol, end 15.3 a. (0.10 moles)
of barium oxide were placed in e 100 ml. round bottom flask
and cooled to 0° with an.ice bath. To the magnetically'stirred
solution was added, over s period of s half hour, e solution
containing A.53 g. (.078.moles or 5.73 ale.) of acetone in

5 ml. of ethyl alcohol. After the addition was completed the
reaction was allowed to stir for 10 minutes. The reaction
.mixture was then cooled and shaken with ether. After filtra-
tion the ether-hydrasone mixture was distilled under vacuum.
The material boiling frail 115-1 20° was collected.

The above procedure was followed for the other compounds
with variations in time and reaction temperature. For example,
all ketone hydrasone derivatives, except acetone hydrazone,
were allowed to stir for three hours at room temperature after

addition of the ketone.

m Staectrn

A Varian.A—60 n.m.r. spectrometer Operating at approxi-
mately 36° was used to obtain all spectra. The undeganeed
samples were run in thindwalled A-éO sample tubes. Tetra-
methylsilane'was uaed as an internal reference standard
( T - 10.00). rrhe chemical shifts were measured from sweep
widths of 500 c.p.s. and 250 c.p.e. Spinpspin coupling were fl

obtained from a sweep width of 50 c.p.e.

 

 

31

1.

2.

3.

A.

6.

7.

10.

32

BI BHOGILRPHY

h.D. Phillips, Annals of the N.Y. Academy of Sciences,

19, Article a, 817-831 (1957).
a. Lustig, J. Phys. Chem., 62, A91 (1961).

G.J. Karabatsos, J.D. Graham, F.A. Vane, J. Am. Chem. Soc.. 1

fig, 753 (1962).

G.J. Karabatsos, R.A. Taller, ibid., g2, 3624 (1963).

 

R.A. Taller, A.S. Thesis, Michigan State University, 1963.

Th. Kaufflman, G. Ruckelhauss, Jutta Schulz, Angewandte

Chemie, 3, No. 1, 63 (196A).

G.J. Karabatsos, R.A. Taller, F.M. Vane, J. Am. Chem. Soc.,

52, 2326 (1963).

S. fiizushima, T. Shimanouchi, T. Miyazawa, I. Ichishima,
K. Kuratani, I. Nakagawa and N. Shido, J. Chem. Phys.,

g1, 815 (1953).

I. Nakagawa, I. Ichishima, K. Kuratani, T. Miyazawa,

T. Shimanouchi and s. Hizushima, ibid., go, 1720 (1952).

S. Mizushima, T. Shimanouchi, I, Ichishima, T. Miyazawa,
I. Nakagawa and T. flraki, J. Am. Chem. Soc., Zfi,

2038 (1956).

11, A. i‘iiyahe, I. Iiikntaaha, T. i'iiy.:.z;n.a, I. Ickisixliua, T. CJI'iia'Zzu-

”°“°“1 “n“ 3° i13U9kima. “RefitrOCEim. note. 1‘. 161 (1338).

12. 11. Coming and 15.5. Harding, E-ec. Trev. China 25,. 957 (3955).

13. Pub. Kills, Cd... Lin an; 1.1:. 9.113011, J. Chem. 3139., 56,

1695 (1957).
11.. 3.3%. iic'rsci‘iauch and L.C. 'z'riaher, 11.14,, 1.5:: 7.31: (11,513}.
15. .i.J. elhrahma and Jr}. Fans-1e, i-Zol. 11:33.. 3,. LC? (19-60.

16. ,3, \. {fot1;n1.-1~-E-‘tg, C. hair-{50.1131 and is. Gunther, J. i313.

Chem. hoe” Lg, 2713 (19(45):

1?. “I31 LOth 3‘1"”17 {Nu Cr. reaJSX‘“"-'Olill, iL’iQe' Q’ ‘3‘ {11361}.

18. 31.... mthnuwi-‘y and 1:. t'i-unthcr, Disc. Karadggy 30¢” 3.3.

13? (1902).

19. (mi. ‘ehipple, J.i-. ('miustein ani (1.... riotllure, J. a.

3£11 (1960}.

Chat}. QOCe, E,

20. 12.3. L’hipple, J. Che-1.1. 'hys., :11, 11.139 (3561).

2,1, 1...). harm-xii, 13.1.. Carroll, and J.: . (eluillory. tetrahedron

Letters, 13.. 7V). (19013.)-

;2, c, ‘mers .3311 J.;..1.1-. Creutzbaréi, rec. Trev. Lhifii. Ii.

:31 (19:6).

I‘M . . ,.

(.2. :1. -.. {omen-Mil and ii. .311opp:..rd, men. day. 500., nor. 5.,

£69, 385 (1962;.

_ fin.

 

24.

25.

26.

D.R. hhitman, L. Onsager, M. Saunders, and H.E. Dubb,

J. Chm. Pkwse, 2, 67 (1960).
J.S. ‘riaugh and 11,11, Dobbs, 1mm, 31, 1235 (1959).

L.M. Jackman, "Applications of Nuclear Magnetic Resonance
Spectroscopy in Organic Chemistry", Pergamon Press,

New York, 1959, p. 122.

Private Communication, G.J. Karabatsos and N. Hsi

 

9111181111 M

 

 

 

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