SYN'tfiES OF ALLtYLTHlOPlf U<;S , DlTHIALKAN~ AND :tBIACYCLOHF~!IE D~IVAl'lVES OF' KlfO\~N STHUC'l'U.lE THESIS SUBMl'.t'T~:O l PAHTIAL FUL lLL · T OF THE 11E~UI l&iiEtfTS FOrt TJle DEGREE OF IIAOTE3 0 SCI... CE IN CHBMISTttY I N THE GRAOUA.~.E DIVISION OF TEXAS \YO~N ' 3 UNIW.:HS I TY DEP !iTl4~'::NT OF C li~M I ST!{Y BY :.LARTBA CHUN- L l BSIU, B. S . DENTON , T.ax.AS JUlff~ . 1 960 ABSTH CT .Hsiu, Martha Chun-Li. Synt~'lasis £!. ~ oro:18 Alkvl thiophen~t~~, Dit hia.lkanes, ~ ~­ cyclohcxo..nos 2!_ Known St:ructur9. Dir~ c t c by Dr. Rober"& W. Higgins, Juno, 1960. Sub.tli +-ted f'or aster of Science Degree. Soma tli4G ago the s r.aff of the Department of Cho:.nis try at ,~,ex&s \!o. w1 1 c Uni'leraity beoau.te interested i.n de termining the atruc~u r.~tJ o:f ot•ganio suLfur com:.>onnds i n petroleum. The method e!Jt)loyed wae an indirect one in that the prop..:rti as or e n t?ounde of know!'l struct uz-e , synthesized by a ccepted procedures, wer19 co::apared with the p.roport1"s of ,u,..e !!Ul!'ur compounds iso­ la tad fro:a pot.:ooleum fr11ctions . In the event all the properties i n vestigated were "&he swne, it could be coneludod t hat tha structures or the t'lio compounds we.:-e 1dont1c a.l. lnt e~ost as a1rectad toward t hose s ulfur constitu­ ent:! in pstroleu.."'! for cany reasons. Firstly 6 there wns a pur~ly ncado:ale 1nte1•est in that one is naturally curious about the cno.mi. co.l ns.turn or all natural p:'oducts. In this particular case it was felt that further knoT;ledge on the structure of the co s t i r.uo...lts in petroleura r:ould a lso !!hod some light on t ho origi n of this ~st i::tporto.nt natura.l rQ­ s ource. Secondly, the petroleum industry is vi tally interested 1 2 in the nature of these sul .fur constituents in petroleum .for e oono:nic reasons. Thirdly, t)roparation o~ a.ad itional sulf'ur co.:tpourds v:olll contribute a great deal t o t he fundamental knowled:a oJ" or ganic f'ull'ur chemistry. lt lo a well- known .fact t hat the sulfur comnoL.mds in .oetrol au;-!1 , particularly t he l .. e£1ned products obtainar !;nero­ fro,!, are obnoxious a.na dett'i.ll6ntal. fhe problt:.': 13 further co~>licatcd bec~use of t he dlrfi c ~ ltlcs aaaocinted ~ith the r'fJ:'l"lV:ll 0 C t J:e g'llr~Ur' Co.npol onts du.C'i . g Cl18 .re_"'ining processes • Ar.; .., 1e ttor )r f::1ct, in the past m1.1.ny of cho o:l fielus which had a hl;h sul.:'u"' co~tent waro by-passed. .no .. eva;·, ·,ti tl1 the inc :r~·J~ sed uses or pe-;roleUL'l in our higt.l.r .nechanizod civili­ zn't'!.on ~ it !a nocoss!'lry to ur.llizo all ~inda of patrolouro .flBlds, mr ~:;n tho:Je v.hich preEwnt problema. It is bcliovod b:,. man:) authorities on pctroloum .re~ini!l; that :nore efficient letl'ous of rg;novlnp, the ha~--mfu l .eul fur impuPi tios could be achieved 11' th~ cLemical structure of' tho sulfur cons ti tuants were known. Consequently tho major objective of this l nvastlgution was to 'Jrepare s. series or o rganic sul rur oo rn~ounds of' k."lown st,'uoture to serve as refer­ ence stu.ndards in tha identification of sulfur compounJ~ 1Rolated from potrolou.n. The :f'irat t:rpos o r eulf'ur CO!:t:>Ound s prepure l~ in the Texas \. o~an' s Un1 versi t1 laboratories woro thiophene der-i v ­ ativaa. Interest wag initiaL!.. .; focuoa,1 oa t l1is type atl"ucture because 't!Wl:f earlier investigators had obtained evidenc e that so:no st""uctu.l.. tH of thls t ;:rpc wer•o _)r&s~nt ln petrole\1!!1. 0!' course, onLy a ver.·y few of tha many thousands or possiole s true t·--1res C"J'tld be raado ln the cou.rao of c.!.m.e l.nol vod i n t!-1-Ls -:.•ono·~rch wo!"~ . ~'ho compounds of this t y p13 preparod in e. hin;i~ d!l.J; !'P.~ o.f j)'ll"'lt:~ by this lnv&sti :fitor ncre 2-1>:-o-Jyl­ th:!.,")) h.One, 2- pontyl thio;.>hone. ·~-prop '1- 2-isoaeyl thlo.Jhone and ?.- ~J~nt, ; l - 5- hexy l thiophene. So;no a :;tontion was dil.. eoted towaPd effoctlnt-.:; u syn­ thosin o f t L t icy cl ohexan~ and 1 ts c.l.'::,:;l dc~ .... iv<.lt iven. lt \'.na ant lc.t )n.'Cod i. h a t: .nany of the hic her boiling sul~u..:-> cons ._.i.. tu­ ent:=t ::! .~ 1P.troleum , ,.e~e cyclic :in nature 02, ~"~von pol:rcycl!c .. ThorofOPf', ~Jf;tho•is wero sought to ?~:·opare, at firet, some or she sir:n? l<$!'!;; o.r the thiacyclohoxano r!o.!'ivativos. .!any prt>b­ l"> .. ts ~-:e:rc ')JlOOUnt~recl . 1i'l:lincyc lohOX:tne ~md its 1-lllOt h l d oriva tivA 'h'f'ro prepa:-ecl but unfortunatol;;; noi the..:· in n high dc Lo.;l"e~"' of purity nor in h"'cd yields. This synth etic problem nE>qds further 1nvescigation. 111hcn di.fficulty vws c:'lcounterec in the ;> r'3puratio:'l ot: t!:.iac;olohexane, it was deemed l't'iao to t'vllow a sideline th 'l t presented itself during the sys1the~is o.f chi o.cyclohoxane. An 1nternedlf\t6 i n the at,te.il;:>teo. prOptirat.lo.u o£ ch1aoyclohexane by one ~.)ro ced u:>'J wsa 1 , 5- di thlaponttme. '.~.:.is compou.::1d '< · ag rE*adily all.. y lated .lth n- pro;Jyl bromide to yield a dithiallume, na:11ely, 4,10- dithi ntridocane. Anotr·r-1" i.ithialknnf'! pre;.H!::'c<l ~· as 4 , 7- dith.iudocane. 4 All the compounds produced were lnilestl gatod in the rexr..s 'No.rtl-! ri t s Uni vor>.,i ty i C~"'Obiolog i cal '{osearch Laboratory. The .. e roesul ts will oG compiled lilld Jr esr,nted in a saparate t r. esi s. ACKliOWLEDGMENTS In acknowledging her deep sense of obligation to them, the au thor 1 ants to thank all members of the raoul ty and ad­ ministr ation of Texas Woman's University who have assisted her in the pursuit of the Master of Science degree . She is p ar­ ticularly graterul to Dr . Robert W. Higgins, who directed this research problem with encourae;ernent and enthusiasm during the pas t two years. In the preparati on of this thesis, the author wishes to extend her appreciation to Dr. Hobert W. Hi ggins and Dr. Helen A. Ludeman for their s uggestions and assistance. The author furthermore w1 shes to express her sincere gratitude to The Robert A. \Y eleh Foundation of Houston , Texas , !'or a generous grant to t he Dopartment of Chemistry of Texas \•J oman's University which m.ade t his work pos s ible. 111 TABLE OF' COlt~ENTS Page I . INT10:>UCTION • • . .. 1 II. EISTOHICAL • . 5 A. Alkylthiophenee . 5 B. Thi a c y clohexane and Derivati ves • . .. 13 C. Di thialkanes . 18 III. DISCUSSION • • • • . 20 A. Prepa ration of 2-Alkyl- and 2 , 5-Dialkyl- thiophenes • • • • • • • • • • • • • 20 B. Thiac y clohexa.ne and Its Derivatives . 22 1. Problems associated wi th preparation of thiacyclohexane • . • • • • • • • • . 22 2. Synthesis of i ntermediate products in the preparation or alkylthia- cycl ohexa.nes • • . • . • • • • 25 3 . Preparation of 4- ethy lthiacyclo- hexane . , . • • 2 7 0 • .Preparation of D1 thialkanes • • • • • • 27 1. Synthesis of alpha, omega di thiols • 2 7 IV. EXPERIMENTAL • . 29 A. Preparation of 2-Alkylth iophenes . 29 I. Synthesis of 2- propylthiophene • 29 a. Acylation of t h iophene with propionic anhydride • 29 b . olff-Kishner reduction of 2- propanoylthiophene 2 9 1v 2. Synthesis or 2- Arnylthio~hene . 30 a. Preparation or n-butyl cyanide . • . 30 b. Preparo.t1 on o£ n- valeric acid ... 31 c. Preparation or n-vale.ryl chloride 31 d. Preparation of 2-pentanoylthiophene . • 32 e. Wo1ff-Kishner reduction of' 2-pentanoylthiophene •• . 32 B. Preparation of 2, 5-Dialkylthiophenes . .. 33 1. Synthesis of 2-Propyl-5-ieoamyl­ thiophene • • • • • • • . • • . 33 a. Preparation of' 2-propyl - 5-iso- valerythlophene • . • • . • . 33 b. \Uol.ff-Kishnor reduction of' 2 - propyl- 5-isovalcrythiophene • • • • . 34 2. Preparation of' 2-Amyl-5-hexyl- thiophene • . • • • • • • • • • • . 35 a. Synthesis of' 2-amyl-5- hexanoylthiophene • • • • • • • • • • 35 b. \ o1ff- Kishner reduction of 2-amyl- 5-he.xanoylthiophene • . 35 C. Synthesis of Thiacyclohexane and Der1 v a.tives • • • • • • • • • • . 36 1. Preparation of Thiacyclohexane • . 36 2 . Preparation of 4-Methylthiacyclo- hexane . 37 3 . Preparation of Intermediates in the Synthesis of A1kylth1aeyclohexanes . • • 37 a.. Synthesis of diethyl 3,3-dimetbyl glutarate • . • . 37 b. Preparation of' 3 ,3-dimethyl 1,5- pentanedlol • . • • . • • • • • • • . 38 c. Preparation of 3 , 3-dimethyl 1,5- dibromopentane • • • . • . • . 39 v d. Preparation o£ 1- i odo-5-chloropcntone . 39 e . Synthesifl of di thialkanes • 40 1 . Synthesis of Alksnedithiols • . 40 a . Preparation of: 1,2-ethanedi thiol 40 b . Preparation of 1 , 5- pentanedithlol ••.• 41 2 . Alkyl ation o£ Alkanedi thiols • . • • • • . • 42 a .