A STUDY 9? “me FRAGMENTATEON AND REDUCTEGN 0? SOME NONvBRANCHED 'I‘ER’E‘IARY CMRBINOLS m THE PRESENCE OF mummy? CHLORm ‘f‘hasés 5101‘ 111a Degree of MS. MECHICAN STATE COLLEGE. Robez‘i V; Smith 1947' THFSiS :1“. ‘ "f {“1 I, . ' .3.“ 31.1.1313 w¢1 - Univcrgity i 1 '= “is J THESIS flfl KM 51/19/50? « at wry-v1; t‘_ 2. .4 '~ 7 2’ I". 1’ a s l A J," 1 .. ,ky.ufih..i.z_:!:v. $3.2),I...‘ .... . u. .. .u I--. . .. Lit?! f .w.\vL. A STUDY OF THE FPJLGHFII~ITATION A111) REDUCTION OF 503-; I‘iOIL-BRMFCHED TERTIMU ()ARBINOIS IN THE PRESENCE OF ALUMI NU}! CHLORIDE by ROBERT v. 523m A T193518 Suhaitted to the Graham School of Elohim State Collego of Agricultm and Applied Science in partial fulfilmt of tbs requruaentu for the demo of EASTER OF SCIENCE Department of Chafiatry 19h? LOW” hummmuwm 331666 TABLE OF CONT EI‘QTS mum-.0000... IWdOOODOOOOOO Wed 0.0.01.0. W - Part I Preparation 0! Alcohol: a Continuation Apparatus . O O O O I C Coxflensnuon, Separation and Fractionation Maul «- m II Canaan-mum with Ileana truncation and Remit: Mimic-coco... Sunny mm.......-. Page 17 31 33 39 1o IflTRODUCTI ON Extonsivestuiylnsbeenmedeinthspsstonths coxflmstionoftertinryslcoholswithbonseneandplnmls inthoprssenoe orslmimmohloride. 'mogrestershsro of thisvorkmustbecx'editedtoDr.R.C.Hustonufloo§ writers in this laboratory, In the early part of this tork the investigators were more coma-nod with the formation of the direct condensation prodmts W the interest in unputtawyammbemconcermdnmmamdyorm degroo of fragmentation and remnant produced when reaction conditions and molar qthitios of the reactants mvu'iedzsndpe‘msrilythenbrmomngonthoosrbon stonsdjeosnttometvdrmcorbonminomssd. Also inflamkotfiustonumdFriedanenn(1),lhetonu1dJeoh- “(2),sndflnstmendfmgtm(3)snsppumtrodmtien or'ptfllingout'offlnmgonoftlnflooholmroportod, however no explanation for this was offered. Itmflmepurposooffllisinvostigetiontosmdyond compsrethorrsgnentotionooomingmnon-bmnohed ternary alcohols, Loo. alcohols with primary silky]. group- ings sttsohed to the max-owl carbon were condensed with bum in the presence of Humorous almimm chloride. Alsoflnpurpossotthisinvestigetionnstostulythl sppsrentmductimorthsdcommmtekuphoodm'ing the reaction. 2o IIISTORI CAL The history of the conienaetion of alcohols with benzene in the presence of slmnimnn chloride had its begin- tring back in 1897 when Net (h) prepared dipherwlmethsne from the cordeneetion of benzyl alcohol with benzene in the presence of anhydrous elmimm chloride. Repeating this . work in 1916, Huston and Friedm (5) reported other pro- ducts formed during the reaction. Also in 1918 Huston and Friedmaxm (l) condensed meflwlpherwlcarbiml and ethyl- phemrlcarbinol. From these reactions were obtained, in approximately ten percent yields, etm'lbenzene and propyl- beneene reepectively, in addition to the expected conden-i notion product. he apparent reduction or ‘pulling out“ oftheoxygenottheslcoholtofomthesewtylnryl fordrocsrbons was left unexplained. Huston and Seger (6) in 1926 condensed noflwl, ethyl, propyl and iscpropyl, butyl, ieobntyl, and isoamyl alcohols at room tempereture mingono-Mli'moleofelmflnmnohloridetomnoleofflu olcolwl. These alcohols did not give the expected alkyl benzene. Inl933xmtonondnm (7) found moon-comm eetion of triplwvlcqébiml, triphemrlmeflmne res obtained, rather then the expected tetrephexvlmetlum. Huston end Goodemoot (a) have shown that claim chloride slkyletee by mermelcoholonlymumieestreinedcerbon 3. attached to the W group. Huston, Fox and Binder (9) found that straight-chain csrbinols, such as dimethyl-n— butylcerbinol, no fllyletlwl-n-propylcarbimle end trio thylc- carbinol condense more readily than branched-chain cerbinols togivetheecrpectedmcylbensene. Theyeocpldinedtlmt the letter carbinols have s larger tendency to form unsatu- rated compounds and tertiary elkyl chlorides. Tzukernnik (10) found that satm-stod primary aliphatic alcohols do not condense, simple secondary alcohols give e 25-30 percent yield of the secondary slkyl benzene, while tertiary butyl alcohol gives a 60-70 percent yield of Wetfnrlphenylmsth- one. Norris and Imp-ohm (11) showed that in the condense- tion of alkyl halides with benzene the polyencyleted Indra- cerbone Immedweredetermined toelsrgeenctentbythemole ratio or the benzene and slmimn chloride used. They obtained a great variety or derivatives when the ratio used mleeetlmnonetoomofchlorideendbemm,ehiloths chief product use the synnetriosl trielkyleted derivative. They obtained mesitylene m the condensstion of methanol and benzene or m-xylene end else sym-Methylbenzene from ethanol and benzene. Huston end others (12), (9) found iron the comlenssuon of the tertiary alcohols from butyl through the octyle that flmmleratio otelcoholtoslmimmchlorideisons teens- half respectively for the aptinnm production of the corres- ponding mono slkyl benzene. h. Many secondary sloohols have been condensed with ben- sensbyKayesndothers (13)endfl1ey£oundthatingemrsl, more alxnnimm chloride than 0.3 moles per one-halt mole of alcohol decmased the yields of the mono slkyl benzenes. Theyelsoreportedttmttheedditionotdrymlgesthrouglh out the addition of the slcohol to the reaction mix increased the yields. Huston and Hughes (3) mpOrted the isolstion of sec-butylbensem from the condensation of 3- phenyl-J-pentenol. Also Huston and Jackson (2) reported the isolation of iSOprOpylbemene and eeo-butylbensene from the condensations of dipherwlisopropylcsrbinol and diphemrl-n sec-butylcsrbinol with phenol respectively. They were first thought to result from the breakdown (with hydrogenation) of the condensstion products under the influence of almimn chloride. however, when p—twdroxytriphervlisopmpylmetlm was dissolved in ligroin and trested with aluminum chloride, no isopmpylbenzene could be isolated. Instead l,l-diphenylp 2-netlvlplr-propem was found along with phenol. They can-- cltuiedrranthisthattheeec-alkylbennemwesfomsd during the process of condensation and not by decomposition of the condensation product. The lurdrogen donor was not detemined. HustonendBarrett (1h) showedintheirmrkonthe condensation of the dehydration product of tertiary butylp csrbinol that the reaction was greatly aided by the addition of "Cl. However, they found that the condensation of the S. alkene did not give the chloride of the alcohol as a pro- duct isolated at the end of the reaction as was the case with the condensation of the alcohol 1mm. They also dmaonstrated that the formation of split products by mix- ing tertiary heptylbensene with alumimm chloride indicates reversibility of the alkylation reaction. Other workers (15) have demonstrated this, especially with tertiary elkyl MPE- Van Dyke (16) using a gas trap and nitruneter apparatus, found danetmrlation to be pronounced in the condensation of the more highly branched alcohols. In the condensation of 2, 2, 3-trineflnrlp3-pentanol, four percent of methyl chlor- ide was isolated and identified. 6. TE [EURETICAL Experimental evidence has shown that the alkyhtion of benzene with alcohol in the presence of anhydms almimzn chloride is closely related to the alkylation sith alkenes and alliyl halides, as both have been isolated in the reaction, and they also give good yields of the slkyl- benzene. The formation of alkenes during the reaction has been used to propose a mechanism whereby rearrangement takes place of the alkyl groups or certain primary and secondary- alcohols. In connection with this ucxenne and Saws (1?) proposedanechanism onthe basis oi‘theabove type rearrange- menu. Using boron trifluoride as a catalyst they have isolated mall wants of the elkenee and their polymers Iran the products of the reaction. e-cxIZ-cnz-on £3... R-CH-cne R-Clecnz 4- 0686 —, R—CH(CélIs)-C}13 Time the condensation of a primary alcohol leads to a secondary alkyl benzene. Onthebasisofdityletiontaungplacetmtlntomr. tion of the alkyl halide as an intermediate, Tanker-uni); (10) has proposed a mechanism for tertiary alcohols. ‘b-CSHnOH 4- A1013 -———> t-CSHJJQAIC12 + H01 7. 05810 4- HC]. -——-» b-CSHIICI “0591101 + c6116 M» t-csnucéss + 1161 The isolation of alkenes and alkyl halides has been offered as experimental evidence of the above type reactions. Evolution of [El during the reaction was elqnlained by the formation of the aluminum chloride-alcohol complex With subsequent elimination of the me. He also preposed this type of mechanism for the condensation of secondary alcohols, although he found no chlorides or alkenes as by- products. This mohanism, however, does not explain the rearranged products found by heart (18) from his work on the condensation of some secondary alcohols with benzene in the presence of anhydrous almimm chloride. Several ionic meclmxisms have been preposed by various workers in this field, all involving a catsnoid attack on the ring. However only the theory of Price (19) will be mentioned. Wertyporoch and Firla (20) have demonstrated by con- ductance studies the formation of an ionic complex between elumimna chloride and alkyl halide. .. 9.1 i .. <21 ,_ R329 4- 4.1301: R + ( 3;: 13.101) Cl . Cl Ulich and Heyne (21) have measured the equilibrium for the formation of certain of the catalyst-alkyd halide com- plexss postulated by hertypomch and in addition, found 8. that the rate of alkylstion was directly proportional to the concentration of this catalys tp-ell-tyl halide complex. This type of complex can also be shown using oxygen containing cmpounds such as alcohols, others, esters, etc. Cl C1 R30: + A1301: R:0:Al:Cl"_’4—-— R"+(IIOA1013)' H C1 Cl This again shows the formation of the electron defici- ent carbonima ion. The attack on the benzene ring then pro- coeds analogous to halogenation whereby the carbonium ion completes its octet by association with a pair of electrons from a double bond of the aromatic nucleus. R30 4- 0 dens ——+ @042 + H" The reaction becomes a little more complex in the case m R is more highly branched, “particularly in the case of tertiary alcohols. This has been evidenced by the iso- lation of by—products such as tertiarybutylbensene in some cases. This, of course, strongly indicates a fragmentation and t reaction as indicated by the following ennple: ..\ (SH-$13 r§§3 ‘CH 3- <~\——e 3«CH CH 4- CHZKZ ‘xéfl CH3; Mf 3H3 3—, H3 32 \a‘ / h~-u~—.--’ The shift of the methyl group to the positive carbon atom with subsequent colonies of the carbon to carbon bond as indicated accounts for the isolation of tertiaxybutyl- bensem frqn the condensation of this alcohol. This of 9. course is in accordance with women's (22) views on mole- cular rearrangements. 10. EXPERBEEEJTM - PART I I. Preparation of Alcohols The following tertiary alcohols were selected on the basis of non-branching on the carbon chain adjacent to the hydroaqu carbon. The last carbinol (D), being an exception, was prepared in order to canpare the effect of branching on the/3, carbon stun. A. lr-E‘Unrlr-h—heptanol B. WoWI-h-heptaml C. 3—Ethyl-3-hemnol D. 2,h,lr-Trinethyl-2-pentanol Part A. h-Ethyl-lu-heptanol 93H Cl! -C -C uglg CH “CH III”! This alcohol was prepared by the use of the Grignard. reaction, by the addition of propionic acid to propyl mag- nesiun bromide, followed by hydrolysis of the resulting addi- tion compound. The procedure for the preparation of the alcohol from a Grignard reagent and an organic acid was fol- lowed according to Bailey's work in this laboratory with slight modification (23)- Ths Grignard Ias prepared by plac— ing 116.8 grams (6 moles) of magnesim turnings in a five liter three-neck flask equipped with a glycerine sealed mech- anical stirrer, reflux condenser, and dropping funnel. The cordenser and dropping forms]. were closed with calcium chlor- ids drying tubes. The reaction was started by running into the flask about 10-15 ml of a 1:1 mixture of anhydrous ether and propyl bromide. The ether was dried over freshly cut sodium and redistilled. The propyl bromide was dried over anhydrous calcium chloride and redistilled, that portion boiling between 70-72% being collected. After the above portion was added, the reaction flask was left to stand for about two minutes to allow the reaction to start. After the reaction started, which was indicated by the reaction of the magnesim in contact with the bromide, five hundred ml of azdwdrous other was added through the tap of the condenser, the mechanical stirrer started, and the mainder of the propyl bromide other solution (737.hg branide; 6 moles) added at such a rate as to keep the reaction under control. Ex- ternalcoolingwasusedinordertoincreasethsratecf addition. Anhydrous other was added throughout the reaction, or 330 Isl/mole of Grignard. After the addition of the bromide res completed the reaction mixture was allowed to stand, with stirring for a. period of two hours. The Grignard reagent was then titrated according to the method described by Gilman, Wilkenson, Fischel, and Meyers (21;). The calculated amount of Grignard was five and one tenth moles, or an eighty five percent yield. On this basis 126 grams (1.? moles) freshly distilled pro- picnic acid in anhydrous other (We per mole of acid) were added at the rate of one drop per second. After the addition was complete the mixture was then allowed to stand for a period of two hours with stirring. Five hundred ml. of ankwdrous, thiephene free, benzene as then added and the ether distilled off on the steam bath. The addition can- pound was then allowed to reflux, with stirring for a period of two hours, and then stand ovemight. The purpose of the addition of the benzene was to allow the addition compound to reflux at a higher temperature, which was found by Bailey (23) to increase the yield of the alcohol as much as 17% in the case of 2-nethyl-3-etlnrl-3-pentsnol. The addition pro- duct was then hydrolyzed with ice and enough 131 We ' acid to dissolve the basic magnesium salts. The benzene layer was separated and the water layer extracted three times with benzene. The combined benzene layers were washed with 10 percent sodium carbonate solution until basic to litmus, and then with distilled water. The bensem-alcohol ‘ was then dried over anhydrous sodium sulfate for a period of twenty four hours; then the benzene removed through a peeked column and the alcohol collected over a two degree range at reduced pressure. Yield: 60:: BP16 I 78-8006 1397“,: Ira-180°C ago 8 1.14.332 Bio 3 00831.50 This alcohol was prepared by Tschebotsrew and Ssigew (25), Hales (26), and Stas (27). Physical constants obtained checked with those of Stas in which he prepared the alcohol fran the reaction of dipropyl ketone and ethyl magnesim bron- ide. Part B. 1r}..:ethyl-4H1eptanol Ciij-CE-Iz-dC-Hz- §:3-Cllz-Cllé0113 This alcohol was prepared by the use of the Grignard reaction by the addition of ethyl acetate to propyl magnes- iun bromide. The one procedure was used as Just described for the preparation of lr-ethyl-lr-heptanol. The ethyl acet- ate ms dried over axmydmus calcium chloride and redistil— led, collecting that portion boiling between 76-78°C/7hOmn. Yield: 52% 8P7”: 159-16100 8P1: I 62-61100 111230 I 1.h2h2 nfi" : 0.8252 This alcohol was prepared by Gortalow and Saigew (28); and Noise (26). The latter used the sme method of prepara- tion as the author. Part C . 3-Efl1yl-3-hexsnol II CHB-CHZ-g; -CH2-CIIZ—C}13 This alcohol was prepared by the use of the Grignard reaction by the addition of n-butyric acid to ethyl magnes- ium bromide. The same procedure was used as Just described for the preparation of the previous two alcohols. The n- butyric acid was dried over anhydrous sodium sulfate and mdistilled, collecting that portion boiling between 163- 165°C/750mm. Yield: 50‘): ESP-71m: 159-16100 3912 1 57-5900 n50 8 1.1616 Bio : 0.8370 This alcohol was prepared by Masses (29), Butlerow (30), Clarke and Riegel (31), Halse (26), and Bailey (23). The author prepared the alcohol in this laboratory by the same method as Bailey. Part D. 2 ,h,h-Trimethyl~2-pentanol egg-c @334“: The alcohol was prepared by the method of Butlerow (32) with slight modifications. ‘Iwo parts by volume of a quant- ity of like volumes of concentrated sulfuric acid and Inter were mixed with one part by volume of tertiary butyl alcohol (8 moles). This mixture was placed in a five liter round bottom flask fitted with a reflux comerser and refluxed on 15. a steam bath for a period of tsenty four hours. Two layers appeared which were separated, and the top oily layer was washed several times with water and then dried over anhydr- ous calcium chloride. This organic layer was then further dried by refluxing over freshly cut sodim. This also took out any uncondensed alcohol in the formation of an alcohol- ats. The product was then fractionally distilled, and that portion boiling between 102-th%/756 m. was saved as di- isobutylene. Into the diisobutylene was passed gaseous hydrogen iodide at 10°C, generated in the following manner. Enoughiodimandredphosphoruewasohm‘gedinathree liter three-neck round bottom flask to produce eight moles oi‘hydrogeniodide. Anmessofiodiaewasused, thepro- portion being approximately twenty to one. Also a small amount of sea sandwas added. Attached to the generatorwas a drapping funnel charged with water and a gas train con-- sisting ofaseries ofU-tubes filledwithglassbeads, red phosphorusandwaterc The endofthe trainlsdintoaliter three-nech, round bottom flask containing the diisobutylene, undelivexyuibebeingplaoedomm.ebovethesurfaoeot the liquid. A mechanical stirrer and gas absorption appara- tus was also connected to this flask. The hydrogen iodide wasgmeratedbyfirstfusingtheiodineandredphosphorus inthcgenorcmr,mnumnuimthcmterfmww ingfunnelto dropataveryslowrate. Thediisobutylene was stirred vigorously during tne addition. we audition 16. was complete when the diieobutylene was completely sahmated. The resulting iodide was washed with water until all excess hydrogen iodide was rescued. The product was then placed in a three liter three-mob, round bottcsn flask equipped with a mechanical stirrer. To this was then added in small portions the calculated amount of moist silver oxide with vigorous stirring at 10°C. The silver oxide was prepared by dissolv- ing the required amount of silver nitrate in the least amount of water and then adding the required amount (slight mess to insure complete precipitation) or concentrated sodium hydroxide solution. The resulting mixture was allowed to warm to room temperature and the excess liquid removed by vacuum distillation. The mning liquid was then remved from the silver iodide by a centrifuge. The organic War was then separated from the water layer and the latter extrac - Ited three times with ether. The combimd organic layers were then washed with ten percent sodium carbonate solution and driedoveramydrouseodim sulfate. Theetherwas movedat atmospheric pressure and the alcohol distilled in a packed column under reduced pressure. field: 25% 813733: lhh°C ”15 x 50-52% “1230 I Lid-’90 nfiS : 0.8212 17. The Condensation Apparatus The apparatus used for the condensations of the various alcohols was essentially the sane as that devised by Van Dylna (16) in this laboratory with a few minor modifications. Figure 1 shows a diagram of the apparatus in general, and the various parts will be pointed out and listed below. A - A three-neck, round bottom flash the size generally used being 1 liter. B - Dropping funnel with inner sealed tube for equali- zing the pressure in order to keep out moisture and forming an air tight systen. C - liechanical stirrer consisting of an electric motor and a glycerine sealed glass stirrer. D - Carbon dioxide generator systan consisting of a vacuum bottle for the solid carbon dioxide, a wash bottle consisting of concentrated sulfuric acid and a mommy safety valve. E.- A side-arm delivery tube to which is attached a thorn- ometer and reflux condenser. F - Two way stop cock in order to bypass the ice-salt cooled trap. G - Ioo-salt cooled trap to condense the vapors of the volatileliquids, such as benzene and alcohol. H-Twowayetop cockinordertobypass the carbon dioxide-acetone cooled trap, leading to the nitro- meter. I- L- n... 18. Carbon dioxide—acetone cooled trap to condense any substance not boiling lower than -80°C. One way stop cock operated in conjunction with stop cocks F and H. Tide was closed when L was adjusted to bypass the trap. Hercury trap to prevent back pressure due to the cooling down of the system towards the end of the reaction. Safety bottle Gas nitronetcr containing 50 percent C.P. potassium hydroxide for dissolving the carbon dioxide only. The nitronetor was of 300 :11. capacity with a die-- neter of 25 mm in the vertical sections and 10 mm in the curved section. mercury was placed in the base to seal the potassium hydroxide from trap L. I-Iitrometer leveling bulb consisting of a 250 m1. separatory fimnel. Nmmlwfl 19. III Condensation, Separation and Fractionation The alcohols prepared as described were condensed with benzene in the presence of anhydrous aluminm chloride. The general method employed as to control of temperature, quantity, and addition of reactants was that used by several other workers, in this laboratory, studying the framentation of branched, tertiary alcohols. It was established by Huston and Friedazaxm (1) that the proportion of benzene to alcohol was about 5 moles to 1 respectively, in order to obtain the nam'nm yield of the expected alkyl benzene con— densation product. In all of the condensations this proport- ion was used, vmile the proportion of anhydrous aluminum chloride was varied in the condensation of h—nethyl-h- hep- tanol. The results of this variation will be imicatcd in Table A. As the procedure for all of the condensations, separations and fmctionations carried out was essentially the same for all four alcohols only one particular condensation will be described here. Thirty grams (0.23 moles) of C.P. anhydrous aluminum chloride was placed in the reaction flask along with 351 grams (Ins moles) of anhydrous unophom-rreo benzene. The benzene-alumimm chloride mixture was heated to reflux, with stirring in order to drive out any dissolved amend then was allowed to cool to room temperature. Large amounts of gaseous hydrochloric acid were produced at this time and the almimxn chloride suspension took on a light brown to red color. 20. After allowing the mix to cool to room temperature the system was swept out with carbon dioxide until nicrobubbles appeared in the nitrometer. The alcohol was then added, with stirring, at the rate of appromately one drop per second. The initial temperature was 28°C rising to 36°C after one third of the alcohol had been added. it this point it was necessary to use external cooling in order to maintain this temperature. Gaseous evolution usually took place during the addition of the first one third of the alcoh- ol and back pressure was noticed after amuroximately one half of the alcohol was added. This back pressure was due to the heat of the reaction subsiding and the apparent cessation of any gaseous pmiucts. At the end of the addin- tion the temperature dropped to 335°C. Stirring was con- tinned for a period of two hours and then the reaction was allowed to stand for twenty four hours before hydrolysis. At this time any gas which formed in the nitroneter was transferred to gas bumttes and analyzed. Amy volatile liq- uids found in the traps were distilled for purification, their boiling point determined and then sealed. There was only one case of any liquid being found in the gas traps and that was Specifically isobutans from the condensation of 2,14,};- trimetlvl-z-pentanol. Gas caught in the tdtrometer in each condensation was trmsferrod to gas burettes and tested for condensibility by passing it back all forth through a condensing tube innersed fl. ‘r‘\:1.. .I 21 in solid carbon dioxide and scetone. Gases collected from the condensation of the non-branch alcohols did not condense, burn nor support combustion. Gas collected in the nitro- meter from the condensation of 2,h,h-trmstmrl-2-pentsnol condensed and was identified as isobutam. The hydrolysis of the reaction conpourxi was accom- plished by the addition of small pieces of ice directly to the reaction flask with stirring until the temperature began to drop. Then 100 ml. of chilled, distilled eater was added in 50 ml. portions. No acid was used in the hydro- Maia, as the addition of the water dissolved the basic salts, si‘ter considerable stirring took place. The organic layer use then separated from the aqueous 1m, the letter washed three times with 25 ml. portions of hem, and the combined extracts plus the original organic layer was dried over anhydrous sodium sulfate. The color of the solution from the various cordensstions varied from light ormge to dark menish yellow, all having sn epslssoent tinge. All distilletions werecsrried out. by s 60 cm. belies peeked colmnn of 15 theoretical plates. The heed on the calm was designed for distillation under reduced presents with s take of! for permitting reflux. Thus it was possible to sllowthevspors toccmetoequilibrimbefore scutsss node. The solvent in esch case was distilled off st atmos— pheric pressm'e. During this period of the distillation s carbon dioxide-acetone trap was connected between the head 22. of the colunn and the vacuum safety flask. This was for the purpose of condensing cry low boiling liquids which might have been dissolved in the solvent, and was particu- larly helpful in condensing s sizeeble portion of isobut- ens from the 2,h,h-trimethy1—2-pentsnol condensation. It as found in new cases by workers in this laboratory (16) that it was necessary to remove the elkyl chloride frac- tion before distillation was continued beyond the low boiling fractions. The author had no apparent difficulty in this respect, 1.0., chloride contamination of higher fractions, emept in the case of the 2,h,h-trimethyl-2- psntsnol condensation. In this partied!” case it was nec- essary to remove the elkyl chloride as it contaminated the higher boiling frsctiom. This ms accomplished by reflux- ing the combined frections with en equal volmne of fifty percent elcoholic potassium Imiroxide for 3 period or fonrto sixhours. Theorgmic layer-was then sepsrsted fromttnraterlsyersmthe tomesshed three times sith wall portions of water. The organic layer use then dried over snlvdrous potassius carbonate. Upon distille- tion the higher fractions were tournd free from chloride. In commotion with the distinction of the condensation products of Ms particular elcohol it was else necessary to treat the higher fractions shove the elkyl chloride sith e five percent brondne in carbon tetrschloride solu- tion to runove the mahzrstion which contaminated the 23. higher boiling fractions to a mall extent. After treata- ing with the bromine solution it was found that the unsat- uration was completely removed from these higher boiling fractions on redistillstion. In order to purify each frsction it was necessary to use a sinner colunn of the some type, as the hold up was too great in the larger column. It was found that upon he or three repeated distillations fractions could be obtained sufficiently pure for the detemxinstion of physi- cal constants. Perth. .. The comiensation of h—ethyl-dp-heptanol with benzene in the presence of anhydrous almi- mm chloride. Fraction I h—ethylheptam Teslvsto firteengrems otthe saturatedlvdrocarbon per mole of alcohol condensed was isolated. It was con- taminated to a small degree with the unsaturated Isidro- carbon, asses tobe emcted. Haeverat‘terthiswas moved by shaking with cidlled concentrated sulfuric acid the main fraction gave a negative test for umaturation and chloride. is no derivative could be prepared it was identified by its physical constants, which checked with the literature (33). Yield: 10% W719: 137-13800 2h. ego . 1.10% “£0 3 007260 ufi' 8 Cale. h3.78 Obs. h3.58 Fraction II h—chloro-lr-eflwlheptmm This fraction gave a heavy chloride test with alcoholic silver nitrate reagent. The physical constants checked with those reported in the literature (26). Yield: 27% 231313 a 6h—67°c nfi? I l.h380 of) 3 0.8815 LER I Cale Q 118 .61], Obs . ’48 0’40 Fraction III h-GthyL-h-phenylheptene This fraction» being the expected condensation,pro- duct, was obtained in good yields. The physical constants checked with those reported in the literature (31;). Yield: 37% 831 I! 89°C 113° n 1.h89a Dip I 0.3690 MR 3 Gale. 67.89 Obe. 67.87 VFrection IV Terry residue Yield: 10% he» Data for the calculation ot.mcleculer’rerrection was taken fran.Shriner end Fueon, 'Identification of Organic Compounds“. 25. Part B - The condensation of h—metlnrl-Ji—heptsnol with benzene in the presence of army-drone elmimm chloride. Fraction I h-eetlwlheptane Seven to ten grams of the saturated hydrocarbon per mole of alcohol condensed was isolated depending on the amount of anhydrous aluminum chloride used. From table one it can be seen that from changing the quantity of the almi- mmchloridefrononei'ourthtoonehali’moleincreeseetm yield of the hydrocarbon. eppzozdmetely three percent. The same treatment for moral of traces of unsaturation was employed as in Fraction I, Part A. The physical constants checked with the Literature (33). Yield: 10% prhgt 116-11700 ”go 8 1.3980 of? a 0.70M; ”R I Cale. 39.16 ObSe 9.06 Fraction II lechlomfivlheptm This fraction gm e heavy chloride test with alcoho- lic silver nitrate reagent. The physical constants check with those reported in the literature (26). Yield: 17% BF“ : Sta-61°C “I230 : 1.2015 26. Dfio I 0.8688 “R ' Cale. 1:11.02 Obs. M027 Emotion II; Iroiefllyl-lpphenylhepmte This fraction, being the expected condensation pro- (hint, we obtained in good yields. The physical constants checked with those reported in the literature (at). It Iillbenoticedfron‘l‘eble I thattheuseof onehali‘nole quantities of anhydrous aluminum chloride as compared to one quarter mole per mole of alcohol decreased the chloride traction approximately seventy percent, and increased the yield of the mooted alkyl benzene about fifty percent. Yield: . 148% ml 3 73-7110C 2150 3 1.13930 Dfio I 0.872? “n 3 Cole. 63.27 Obs. 63.26 Fraction IV Terry Residue Iield: 11% Part C . The comation of 3-et1nr1—3-hexanol with benzene in the presence of exmydrcms almi- mm chloride. Fraction]: Union-n ThiemctionwaeieohtedinlO-JZ percent yieldsnnd mfounitobeanoctemaccordingtoitenoleculer 27. refraction. However, the physical constants did not check with the expected paraffin hydrocarbon, 3—ethylhexenee Isomerism was expected, but a thorough check of the lit- ereture showed that its constants agreed only with those for WWI-haptanee To obtain this isomer of course would mean e lengthening of the chain, which is highly ' improbable. It was not possible et this time to take the absorption spectra. in the infra. red on this hydrocarbone Therefore its absolute identity remains unknown. Yield: 10-12% 3P7“): us-n6°c 131230 I 103980 {£0 3 007052 Mn I C810. 39016 Obse 39.02 Fraction II 3-chloro-3-ettnrlhenne ‘ This fraction gave at heavy chloride test with elcoholic silver nitrate reagent. The physical constants checked with those reported in the literature (35). Yield: 12.5% B?“ a Sta-52°C ngo : 1.13321 Bio a 0.8695 ME I Cele. W02 Oboe 1:13.20 Fraction III Wl-J-phewlrmne This fraction being the expected condensation pro- duct, was obatined in good yields. The physical constants checked udth those reported in the literature (3h). Yield: 1‘03 WI 8 73-7600 ngo : 1.11931: nfio : 0.878!» MB 3 Cale. 63.27 Obs. 62.89 fraction IV Terry Residue Yield: 10% Part D - The condensation of 2,h,h-trimethyl-2~ pentanol with hormone in the presence of alxmimm chloride. Fraction I Isobutane This motion was condensed in the carbon dioxide- acetone trap (hiring the condensation. Also an equal quantity was recovered in the carbon dioxide-acetone trap dining the removal of the solvent by distillttion. These portions were combined (total of. 5 grams) and distilled several times, until the boiling point became constant. The boiling point temperature was recorded by an Amohuts thereunder. The refractive indent of the isobutene was taken on an ordinary Abbe type refractometere Acetone cooled by solid carbon dioxide was forced back and forth fllroughflneprlmeineuchammmrastokeepthetmpera- ture as steady no possible at 45°C. scum me kept from 29. untopand'bottomprimsuri‘acesbyseeling inapiece of anknrdrous calcium chloride with small plates of glass and ordimry stop cock grease. This method worked quite satie- factorily for this particular determination. Yield: M65 397%: -lO-(-8)°C 115.25 3 1e3513 Fraction II 2,13,13-trixaetlvlp2-pentene This particular fraction was isolated in a very small mount. It gave an unsaturation test with 5 percent brat- ine in carbon tetrachloride. Yield: 1% B1103: 112-113°C “D20 8 1.15152 Bio I O. 7215 HR ’ c310 Q 38 969 0b8 e 38 e 89 Erection III 2-met1wl-2-phenylpropane This faction was isolated in rather large mounts, as was expected from the work of others in this laboratory on the study of the tragzmteteon of branched tertiary alcohols when condensed with benzene in the presence of anhydrous almimm chloride. The physical constants cracked with those reported in the literature (at). Yield: 20% 897333 169-170°G 30. ago 3 1.11918 1820 I 0.8656 MB 8 Cale o Idle 79 Obs o I the 921 D Fraction IV 2.1;,h-trimetml-v2-phergvlpentane Due to the lpparent fragmentation of the alcohol curing the condensation, the yield of the expected conden- sation product was reduced considerably. The physical constants checked with those reported in the Intel-ammo (3h). Yield: 11:5 8P1 : 66—6806 n30 .- 1.1.935 Bio I 0.8812 MR 3 C810. 63.27 (Ibo. 62.72 {reactionl Terry Residue Yield: 65% 8oz no.3 3: “S the; 3 m6 2.0 ngonnaéafioa. 0.3 33.: a 8% m2 .226 own 8% no.2 63 m3 8mm.” om: $5 2.6 ”gaging-Aggy hated“ Beige 3. So: u 3.2 e: 8&6 0% 232 3.3 “an new $34 om: m6 m6 Emailing! manna? Hagen .13 33» m 3383: 33H 33» 533 n 5 .8 33» .8395 838k £33 g 163 285m 33 8.3: dang Candacovcoo 30m.— Sfiofio 3:528 .35an H 393. .38... H Ema . gcalgenq mm. an an I town-Hag e an .n mum: :flelguggw ufi qua-Hoe.” no!" 33 0 Own Agata...“ Silo”: eikm “36 «33 cm: m6 8.0 $55.33..“ 0.: a.” 938nm g DOG-H {@903an 3:3 mntmm 834503 tabfiealu ”aw 8-H 33» u 8.3 a: «mafia own .82 no.2 m3 “Qua 8R4 om: m6 :26 Edna-n 0243 95mm 92 33» u use; a 33» 3%» Sang 5 3o 33» 83g coyote confiscate? «.82 oflflaoeaoo 338m 853 $3 8.2020 355 38 dog 3.3: 8.32 “83.30 31. WHAL - PM II I. Condensation with Heat-no In order to seek further information as to the mech- sides or the reduction of the alcohol when condensed with benzene in the presence of enmdrous eltmimm chloride, e similar condensation was carried out using nomel hexene, es s solvent in this case, in place of bsnsenee The condensation was carried out as explsined in mm Part I, with the emeption or the substitution of freshly distilled n-hexsne for bensenee Also e simple carbon dioxide-ecstane trap was substituted for the elebor- ete systan used in the previous condensetions. This trap lead directly off or the‘top or the reflux condemer. . After the addition of the dcohol was canplete the alumina: chloride famed A solid ball, acting similar to the dehydration of an alcohol with phosphorous pmtcsdne. The hydrolysis, drying and distillstion we carried out in the nsuel tamer. Upon distillation of the reaction mix- ture, it was found that epprometely seventy five percent of the totel fractions hed an index of "fraction slightly below that of the estimated twdrocerbon 3—ethyntuenee time each cut gave e positive test for chloride end - maturation. The chloride no removed by the eddition of aqueous silver nimte end ”gusting the silver chloride by tasting on the stm bath with frequent agitation. 32. The musturation was moved by the addition of 5 percent bromine in carbon tetrachloride. The distillstion of this failed to give any of the saturated hydrocarbon, 3-ethylp hem. Me is analogous to the results obtained by match and Jackson (2). 33. DISCUSSION The purpose of this investigation was two-fold: to detsmine the extent of fragmentation, if." any, when nonf- branched tertiary alcohols were condensed with benzene in the presence of anhydrous almdmm chloride; and also to show that reduction of the alcohol occurs during the reaction and the study of its mechanism. It was clearly shownintheexperimentalpartthatbrancIdngonthehydro- xyl carbon in the case of 2,11,11-trimet1wl-2—pentanol greatly emlsnced the fragmentation, as compared to the other non- branched alcohols where no fragmentation was found. This is in accordance with other workers in this laboratory (11;) and (16), who found that the yield of these fragments was greeteras thebrenching onthe hydroxyl carbonwas increased. In consideration of the molecular structure of the thme non-branched alcohols it would hardly be expected that any fragmentation or rearmngmnent would mosesuily taheplaceasthsyellareofareletivelylowenergy level, and the chance of weakening any bond by electron cementx‘atioztwould notbevery great, aswould be the case of a highly branched alcohol. In the case of the condenser- tion of 3-efl1yl-3-hexenol the expected ”titrated kwdm- carbon, 3-etrnrlhuene, was not obtained, which at first thought, indicated a rammt or possibly a dunethyl- eticn. Hot-ever, after a thorough check or the literature was made, the only paraffin hydrocarbon whose pMsical 31h constants checked was h—nethylheptsne. For the formation of this hydrocarbon, of course, would mean a lengthening of the chain, which is highly improbable. As there was not any way to analyze this fraction, except possibly by infra red absorption, its identity was not determined. In con- motion with this, h—ethylhexane was synthesized in the laboratory by the dehydration of the corresponding ter- tiary alcohol, and subsequent reduction of the olefin. The ' physical constants checked with those found in the litera- ture. The ionic moisnian of Price (19) has undoubtedly gained the most favor. On the basis of his theory, the car- bonium ion is formed either from the alcohol, the chloride, the alkene, or the 8.11qu benzene. The electron deficient cation then receives its pair from the double bond of the benzene ring. This, of course, is analogous to halogenation in which the electron deficient carboniuu ion 02"), which may he aryl or allqu, reacts like the halogen cation to cmnplete its octet by association with a pair of electrons from a double bond of the armatic nucleus. Showing the formation of the carboniun ion from the alcohol, the ‘ reaction proceeds in the following mar. 11 H 91g g; } CHfCHz 120H 1. A1613 ——-» cn3-caz‘ + ammo]; 35'. \——» Guyana-0112 Hassle-I‘m3 1m q: 0113-0122-032-4- CH2—0212-0H3 g2 22 :2 ORB-Clifgrg1:+ EOE —-» 0213-02124 :33" -—. 0113-012? 0—0 + H'- Ext; 0113 0% In the case of a highly branched alcohol such as 2,h,h trimethyl-Z-pentsnol the mechanism is a little more complex with the formation or split ban-products. The reaction proceeds in the follaling manner. H3 (ma-g? 3-CHzc§:: c-OH + A1813 —» C113 %3 H3~C112-§HB + A1(OH)C13 CH3 CH2 cu 3—c -cu2-c .. no]. —-; Chloride :3 0:3 If“: CZBHZ :33 The cormtration of electrons around the neo carbon atom maltsintheleakeningoftheoarbontocarhonbomiwithth formation of the tertiary butyl carboniun ion and isobutene. CI! 3m 9H2 mfg. c312 (3:: _._., and 2 + wim .m CH3 The tertiary butyl carbonims ion immediately hooks up with the benzene nucleus to form the clkyl benzene. From the experimental evidence obtained, it would appear that the 180- butsne is immediately reduced to isobutane, although the mechanism of this reduction is not yet clear. Mdence or the reductdOn of alcohols during condens- ation with benzene and phenol has been reported by Ihzston and Moderation (1), Huston and Hughes (3), and Huston and Jackson (2). However, as was previously stated, no explana- tion was offered as to the mechanim of this reaction. In the action or flicyl chloride on benzene in the pres- ence of dwinum chloride 2:13ka and Zuber (37) claims that by varying the conditions 3 fraction may be obtained which consists principally of n-pmpylbenzene. According to Heuitssscu and Isacesou (38) the formation of n-propyl- benzene is due to the use of aluminum chloride which has been poisoned by addition of water. They state that the catalyst is so weakened that it effects deln'drogenstion of c sinmlteneouely formed dilvdrosnflzrscene, and e subsequent reduction or the primarily formed 93-chlompr0pyl) benzene is thereby obtained: 2H CéllSCIizcmlcrI 3 ——-; 06HSCHZCH20H3 +1'Cl 37. Thomas (39) states that reduction of compounds contain- ing Mdrogen acceptors confims the evolution of hydrogen effected by action of elminum chloride on aromatic com- pounds. From (1:0) showed that when nitrobenzene was boiled with benzene and elumimm chloride there was formed, in addition to much resinous matter, on 8.5 percent yield of p—axdmhipherwl. Kliegel and Huber (hi) showed that, in connection with this, since the same compound is formed from phony). hydroxylmine and benzene in the presence of aluminm chloride, the Wynne may be seemed to be on intemuecflste product in the reaction of bensem. hmemr and Binapfl (ha) demonstrated the dehydro- gemting effect of aluminum chloride in benzene by conversion of nobemem into p-mimbipimrw‘l in 70-80 percent yields. MM and Polosov (10) showed that 31mm chloride is instrumental in condensing hydrocarbons with the evolu- tion of hydrogen. Its usefulness for this purpose arises from its activity es 1 cleavage catalyst and as e dem'dro- genoting condensation catalyst. mamas (39) states that it not only cracks the lurdrocefiaone into unsaturated compounds which are hydrogen-acceptors, but it also induces the pro- (Motion of hydrogm by promoting demrdrogeneting condensa- tions. According to Orlov (M1) when enmdrous elmimm chloride is used as catalyser the hydrogenation can take place even without the external action of compressed twdro- 8M. 33- From the above evidence and in visitor the fact that both Jackson (2) and the author were unable to obtain any reduction of the alcohol when benzene nae replaced by e saturated paraffin morocarbon in the presence of environs elumimm chloride, it has been shown that in order for em reduction to take place, the presence or en aromatic nucleus such as bensene is necessery. The reduction undoubtedly takes place by the oddities of hydrogen to the etlwlenic link- ego formed by the simple dehydrating action of the olmmm chloride. Evidence to support this lies in the facts pro- duced by other workers (16) and the presence of the unsatu- rated hydrocarbon fraction mixed with the saturated hydro- carbon in all three condensetione of the non-branched ter- tiary alcohols. It is possible that some reduction of tin elkene frection from the condensation of the highly branched elcohol 2,h,h~trineflwl~2-pentanol took place, however, this fraction was isolated in such wall amounts that it no immiscible to detect any 2,2,h-trmet1wl penteneo Evidence of reduction in this condensation, however, was shown by the isolation of isobutene. 39. sum or 1. Thnenon—branchedtertiaryalcorwlsandonetdghly branched tertiary alcohol were condensed nith benzene in the presence of ants/drone aluminum chloride. 2. Wtetion or rearrangement was not indicated in the non-branched alcohols as compared to the branched alcohol 2,h,h trimethyl-Z-pentenol. 3. In the condensation of lr-nethyl—lr-heptanol it was found that increasing the preportion of anhydrous aluminum chlor- ide from one third to one half mole per mole of alcohol increased the alkyl benzene fraction approximately fifty percent. h. Reduction was shown to take place during the condense- tion reaction as evidenced by the isolation of the paraffin radiocarbon traction in the case of the non-branched alcohols end isobutane from 2,h,h himsfivlnzdpentanol. 5. Although no mechanism for this reduction has been pro- posed, it has been sheen from the reaction of 3-ethyl-3- bexsnol with almimm chloride in n-hexane that the preeeme of an aromatic nucleus is may. 1. 2. 3. S. 6. 7. 8. 9. 10. 11. 12. 13. 1h. 15. 16. 17. 18. 19. 20. Huston end Friedsmsrm, Huston and Jackson, Huston and Hughes, Nor. BIBLIOGRAPHY J. Am. Chan. 800.. 93.786 Pb.D. M8, Mich. State C0110, 1mm, Ann., mun m Friedman), J. AID. Chem. 50°C, Huston end Sager, mutton end Davis, ‘ Huston end Goodmt, Huston, Fox and Binder, mum, Harris end Ingrsham, Huston end Heieh, Huston, Guile, Schulatd. Huston and Keys, . Huston end Esterdshl, Huston end Curtis, Huston end Barrett, m... ' Huston end VanDyke, Mcfieme and Son, Huston end Km, Price, Winch end Firle, ibid., (19h0). 32g, 255— 13, 2527 yg, 1955 5.5. T110818, HiChe State 0011., Skids, J. Org. Chen” (1932.) 2, 251 J. Gen. Cham.(u.s.s.n.), 55117.76h,767 J. Am. Chm. 300., J. Am. Chm. 50°C, 92,1221 gem end Wesson, J.0rg.Chem., _6_, 252 Ph.D. Thesis, Eich. State 0011., Reg. Thesis, Mich. Stats 0011., ibid., (19h1). Hess 1110813, “Che State 0011., J. M Chem» 1311.1). MB, 141611. Stats. 0011.. Jo Me Chem. We, (2) 92,161 22,. hm Ph.D. Thesis, Mich. State 0011., Chan. Rue, Ann., _2_9,m. 599, 287 (1918). (192:0) . (1892). (1916); (1926). (1933). (1931;). (1938). (1935) . (1938). (1936). (19h1). (191s). (1910). (191.1). (19142). (1911:). (19th). (1937). (191:2). (19111). (1933). 21. 22. 23. 21:. 25. 26. 27. 28. 29. 30. 31. 32. 33. 3h. 35. 36. 3?. 38. 39. 1.0. 1.2. 113. Ids. Ulich end Heyne, Z. Elektrochsm., _h_].._, 509 mm", Je All]. Chem. 503., 2” 3271} Huston end Bailey, 3.1.8. Thesis, hich. State (3011., 611mm, mkenson, Fischel, end Meyers J. Am. Chem. Soc., 3.5., 150 Tschebotsrew and 5313615.). pr. 2 22, 198) Hales, J. pr. 2 £32, 1156) Stan, . Bl. Soc. chick, Belg., Gortelmr end Saigon, J. pr. 2 22, 203) liesson, Coupt. ranch, $33, 1.8!; But)”, 3. 29.635) 615 Clarke end Riegel, J. Am. Chem. Soc., 2% 677 fixtleroe, Ann” ‘ 3382, 53 Francis, Industriel and Eng. Chem, 25, 1.1.6 Egloff, 'Pivsicel Constants of Hydrocarbons”, Vol III, Reinhold Publishing Corp., New York City, N.Y., 191.6. hontegne, A. ch. 10 Q, 111 Grease, J. Am. Chem. Soc., 52, 2739 Wispek end Zuber, J. Chem. Soc., Ab... 211 Reuitsesou end Isecescu,Ber., 9g, 1100-1103 man-a, 'Arflvdrous Aluminum Chloride in Organic Che-Ilium". p 659 Round, J. Chem Soc. Abe., .73, (I), 68 megs]. end Huber, J. m. Soc. Ab... 11g. 835 PM end Bimpfl, C.A., L6, 11:03 Axum end Poloeov, 0.1., 3;, 1.309 ‘Orlav, 0.1., Q, 217). (1935). (1932). (192lh) e (1923).. 2;, 383; e. 1927 I, 715) (1901). (1911). (1877). (1910). (1937). (1883). (1933). (1897). (1920). 6 175 034 I I I II III I III I | II III .Il‘lll II II I I|| I II III | I. l I | ll 93 03 I mung“)