these compounds have been compared with those of phosphorus(II1) chloride, methanol, the chloro-

fluorophosphines, and other similar compounds. RECEIVED APRIL 7, 1950

[CONTRIBl:TION FROM THE DEPARTMENT OF CHEMISTRY, USIVBRSITY OF NOTRE DAME]

The Preparation and Properties of Some Thienyl Butenols'" I<y (>PORGF 'I. G i i I r T m l h lvr) F?, T , m R~xror;

li-hen a-t hienylmagnesi urn 1 m i 1 lit1 e wa5 ;t I - lowed to react with butadiene nmnoxide there was obtained a hutend ( I ) which was teiitatively as- sumed to be I-(ct-thieriy1)-buten-%-01-1. This assumption was based on the preparatioii by Senieniuk and Jenkins' of a series of butenols (to which was assigned the general structure of R --- CH2---CH=CH-CH20H (XI) by the reaction of various Grignard reagents with butadiene monox- id?.

N - - h f g S + CH, - CH -CH-CH, ---+

Thev favored the reaction course AJ,

OhfgX I HLO + Hi

K---CH?-cH---CH=CH, - ------+ I3 -

12 - CI-Iz-CHOH -CH=CHz --+ K--CI12--CH=CH--CH20H (S)

3s an explanation of the formation of (X) rather than the expected R-CH2-CHOH-CH=CH2. They did not exclude however, the possibility of * ' 1,A-addition" of the Grignard reagent to butadi- ene oxide. Evidence for assigning the general structure (X) to this series of compounds rested solely on the identification, by physical constants of the product obtained from the reaction of 11 I et hylmagnesium b romi d e with butadiene mot 1 - oxide as penten-2-01-1. The possibility that iso- meric products3 might result from the reaction of (;rignard reagents with butadiene monoxide made it desirable to cunfirni the tentative structure as- signed to (I). Confirmation was obtained in the following manner,

I-( cr-Thienyl) -buten-3-ol-2 (I I) and 1 - (a-thi- enyl)-buten-3-ol-l (III)* were prepared by the re- action of a-thienylsodium with butadiene monox-

(la) Abstracted in part from the dissertation presented to the Graduate School of the University of Notre Dame bv Ceorne T Gmitter.

i lb) General 'lire Research Fellow 194fi 1949. Present ?ddress Velsicol Corporation, Chicago, Illinois.

C2) Semeniuk and Jenkins, J . A n Phnrrii 4ssnc, .5cz Ed , 97, 118 (1948).

, 3 ) Since the conipletion of our tnvesttgation, Gaylord and Beckcr (J. Org. Chcm., 16, 305 (1960)) have reported the formation of 141- naphthyl)-buten-3-01-2 when butadiene oxide reacted with l-naph- thylmagnesium bromide Jenkins and Semeniuk,* on the other hand, report having obtained otily I-( l-naphthyl)-hiiten-2-ol-4 from the same reaction.

(4) Isobutylene oxide and styrene oxide have been reported by Henry (Compl. f r n d . , 146, 21 (19907)) and Tiffeneau and Foumeati tb id . , 146, 647 (1908)) t o reart %I> isobutyraldehyde and phenyl- uxtafdebyde, respectively, with Grignard reagents. (111) was syn- thesized to exclude the possibility tha t butadiene monoxide had re rcred with a-thirnrlni3jinP.ium bromide in d 4mi ln r farhiori

ide arid allyliiiagnesiuni hroniide with ?-thiophene aldehyde respectively. Alttempts to synthesize (11) by 'tn alteniate route, the reaction of a-thi- enylmethylmagnesiuni chloride with acrolein and the Barbier modification5 of this method yielded. as the only isolable product,6 sym-di-(a-thienylj- ethane.

A comparison of the physical constants of (It with those of IT and I11 indicated (I) is not identi- cal with either compound, a fact which was fur- ther confirmed by the difference in melting points of the corresponding 3,3-dinitrobenzoatesa XI- though the three hutenols (I), (TI) and (111) un- derwent cleavage on ozonizationi indicating the presence of an olefinic linkage8 in their structures. formaldehyde (isolated as a 2,4-dinitrophenylhy-- drazane J was obtained as an ozonization product only in the case of (11) and (111) but not in the case of (I) a fact indicating that the olefinic link- age in (I) is not terminally located. Failure to obtain acetaldehyde as an ozonization product of (I) was considered to exclude the possibility that (1) possessed the structure Th-CH(0H)-- CH=CH---CH3 which could conceivably result if butadiene monoxide rearranged to crotonalde- hyde which then underwent a normal reaction with the Grignard reagent.

Dehydration of t r j , (TI) and (111) yielded ail unsaturated intermediate (Ivj which, without further purification9 was converted in each case to the same maleic anhydride addition compound ! Vj according to the Diels-Alder method. lo

If the possibility of migration of a thiophene ring from its original position on the butene chain during dehydration is excluded, then the dehydra- tion product (IV) must be 1-(a-thienylj-butadi- ene-l,3, the maleic anhydride addition compound (Vi, X(m-thienyl\- 14-tetrahydrophthalic anhy-

ciride, the carlxm skeleton of (I), Th--C-&--C-C

arid the origirial butenols must differ only in the

" I , i l l 1

(,?) 13arhier, Compl rcnd., 148, 110 (1899). (8) Delaby (CoinP1 r e n d , 194, 1248 (1932)) reported tha t the

reaction of benzylmagnesium bromide with acrolein gave only a 6% yield of benzylvinylcarbinol

' i) Thiophene under identical conditions was not oxidized. 8) Attempts to establish the presence of an olefinic linkage in

compounds (I), (11) and (111) hy catalytic hydrogenation were unsuccessful.

(9) The tendency for a-thienyl butadienes t o polymerize was so pronounced tha t attempts t o purify these compounds by distillation m vaczio and at temperature- as low a? 40-.50° led to their extensive polymerization.

The compounds failed to add hydrogen.

'IO) Dirls, Alder ani1 Priri, B o , 62, 2081 (1429).

Oct., 1950 PREPARATION OF SOME THIENYL BUTENOLS 4587

/O\ Th-MgBr + CHz-CH-CH=CH2 + Th-CH=CH-CHzOH

(1) /9 1 -HzO

Th--Sa + CH*-CH-CH=CH2 + Th-CHz-CH(OH)-CH=CH2 ---+> Th-CH=CH-CH=CH8

! (11)

(111) Th-CHO + CH2=CH-CHzMgBr --f Th-CH(OH)-CHz-CH=CH2

Th Th I S a I

CHa-C(0H)CECH ----f CHs-C(OH)CH=CHz + CH2=C(Th)-CH=CH2 (11s.) "a

(VI)

/ 8 I! ThMgBr + CH,-C-CH=CH~

(YII) f

(VIII)

maleic anhydride

position of the hydroxyl group and the olefinic linkage.

To establish the fact that no migration of the thiophene ring had occurred during dehydra- tion a-thienylmethylethynylcarbinol(V1) was pre- pared by the reaction of sodium acetylide with 2- acetylthiophene in liquid ammonia. Compound (VI) was then reduced by a solution of sodium in liquid ammonia to 2-( a-thienyl)-butenS-ol-2 (VII). Confirmation of the structure of (VI11 was afforded by its alternate synthesis from a- thienylinagnesium bromide and methyl vinyl ke- tone. The butenol (VII) was dehydrated to an intermediate (VIII) which, without further puri- fication, was converted t o a maleic addition com- pound (IX). This addition compound (IX) on the basis of mixed melting point and analysis, proved to be isomeric with s-(a-thienyl)- A4-tet- rahydrophthalic anhydride (V) . Compound (IX) must, therefore, be 4-(a-thienyl)- A4-tetra- hydrophthalic anhydride and the dehydration product (VIII) from which it was obtained, 2- (a-thieny1)-butadiene-1,3.

The principal product obtained by the reaction of a-thienylmagnesium bromide with butadiene monoxide is, therefore, 4-(a-thienyl)-buten-2-01-1, a conclusion in conformity with the observations of Semeniuk and Jenkins.* According to the mechanism favored by these authors. 3 -(a-thi- enyl)-buten-3-01-2 (11) should be an intermediate which undergoes allylic rearrangement in the for- mation of (I). Compound (11), however, was found to be stable during hydrolysis of the reac- tion mixture. Compound (I), therefore, must have resulted from l,.l-addition of the Grignard reagent to butadiene monoxide rather than from rearrangement of (11).

Experimental 4-(a-Thienyl) -buten-2-01-1 (I). -To a solution of a-

thierrylmagriesiurn bromidc prepared from 135 g. (0.83

mole) of a-bromothiophene and 20 g. (0.83 gram-atom) of magnesium in 200 ml. of anhydrous ether (cooled in an ice- bath) was added with vigorous stirring, over a period of one and one-half hours, 52 g. (0.75 mole) of butadiene monoxide dissolved in an equal volume of anhydrous ether. After standing for seven hours under an atmosphere of dry nitrogen the reaction mixture was hydrolyzed by pouring it into a mixture of ice and water made slightly acidic with dilute hydrochloric acid. The aqueous portion of the hydrolysate was extracted with ether, the extract added to the organic portion of the hydrolysate and the combined solutions washed first with aqueous bicarbonate, then with saturated brine, and finally dried over anhydrous magne- sium sulfate.

The ether was removed by distillatioii and the residue on careful fractionation under reduced pressure yielded 40 g. (2670) of (I) , b. p. 85-86" ( 2 nim.)," XZ5D 1.5561, dZ6r 1.117.

Calcd. for CaHloOS: C, 62.34; Ii, 6.49; S, 20.77. Found: C, 61.77; H, 6.46; S, 21.42.

The 3,5-dinitrobenzoate of (I) was prepared in the fol- lowing manner. To a mixture of 1.0 ml. of (I) and 3.0 ml. of anhydrous pyridine was added 0.5 g. of 3,5-dinitro- benzoyl chloride and the mixture then heated on a steam- bath for ten minutes. After cooling the reaction mixture was poured with stirring into cold water, the resulting precipitate allowed to settle, and the supernatant liquid decanted. The residue was washed with a few milliliters of 5% sodium bicarbonate solution, filtered and, on re- crystallization from absolute methanol, melted a t 74.5- 7 5 O .

A n d . Calcd. for CljHI2X%0&: C, 51.72; H, 3.46; S, 8.04; S, 9.19. Found: C, 62.11; H, 3.44; S, 7 . T ; s, 9.11.

1 -(a-Thienyl) -buten-3-01-2 (11) .--a-Thienylsodiuni was prepared from 50 g. (2.17 gram atoms) of sodium and 118 g. (1.0 mole) of a-chlorothiophene in 600 nil. of benzene according to the procedure of Schick and €iartough.12tL To this mixture, maintained under a nitrogen atmosphere were added, with vigorous stirring, 70 g. (1.0 mole) of butadiene monoxide in 100 ml. of anhydrous benzene a t such a rate that the reaction mixture was held a t gentle reflux. Stirring was continued until it had cooled to room temperature and the mixture was then poured into ice and water. The hydrolysate was acidified with dilute hydro- chloric acid and the aqueous portion extracted with lwr i -

(11) All boiling points and melting point.; unrorrecterl (12) All analyses by hficro Tecii. f.aIJorxtori?\, Skokir, l l l i~~ois . (12a) Schick and Hartough, Tms J O U R N A L , T O , 28fj (lW3).

/c!iL. T h combined benzene eatr'ict and orgaiiic yor- tioii of the hydrolyzate were washed with aqueous sodium bicarbonate, brine, and fixally dried over auhydrou, magnesium sulfate. After removal of the bciizene by dis- tillation under a nitrogen atmosphere, fractionation of the rcsidue under reduced pressure yielded 25 g. (16 zc:1 of

J n u l . Calctl. for CsEIl~OS: C, 62.31; 11, 6 . ~ ; S, 20.7'7. Found: C, 62.08; I f , 6.56; S, 18.14.

Preparation of the 3,5-dinitrobeuzoate of (11) accordiug to the method previously indicated for the 3,5-dinitro- benzoate of (1) yielded a compound which, on recrystalli- ?Ition from absolute methanol, melted a t 89-90'.

I l l . b. p. 80-81' 12 mrn.), N'SD 1.5468, d264 1.106

9 33 I

l-ia-Thienyl) -buten-3-ol-l ,111) .---'To ,A liter of an ether solution of allylinagnesium bromide prepared from

f4.0 gram :ttoms) of magnesium and 145 g. (1.2 of allyl bromide according to the method of Gilman

wly with vigorous agita- ) of a-thiophenealdehydc ether. Throughout the

,tdditiori of the aldchvtii the reaction mixture 'u ab cooled ni an ice-bath.

The reaction mixture M '3s then hydrolyzed and treated .itcording to the procedure outlined in the preparation of (1) Aftel removal of ether by distillation, fractionation of the reaction product under rcduced pressure yielded 0 5 g. (GI?,) of IIII), h. p. 76-77" r - 0 tnln ) , )t% 15441, tElbJ 3.108.

.lncii. Calcd. for C&&S: C , ti2.34; 11, tj:Ly; S, 31.77 Found: C, 61.65; H, 6.40; S, 20.95.

Preparation of the 3,5-dinitrobenzo:itc of (111) accord- ing to the method of Marvel and Waltonil yielded a yellon crystalline compound, m. p. 54-55".

alnul. Cdlcd. for CI,HI~N#.~~S: C, 51.72; H, 3.45; s, 8.04; S, Found: C, SI.58; 11, 3.67; S, 8.03; s, 9.06. Z-(~~-Thienyl)-butyn-3-01-2 (VI) .-Three grain atonis

(117.3 g.) of potassium was converted15 to potassium amide in 1500 ml. of liquid ammonia contained in a three- liter three-necked flask equipped with a mechanical stirrer, liquid ammonia condenser, and protected from atmospheric iii015t~tre :md carbon dioxide by ti wcla lirnc filled drying t 01% t r . The mixture, cooled to - 50°, was then saturated II iih dry acetylene for n period of forty minutes after which ethcr nere added I O i g. (0.85 mole) of 2-ncetylthiophenc tli~solved in 100 ml. of anhydrous ether. The reaction mixture was stirred vigorously, held a t -5U", and kept saturated with acetylene throughout the xldrtion of the ketone arid for five hours thereafter. It VAS then neu- tralized by addition of excess ammonium chloride , the mimonia removed by evaporation, and the residue hy- iirolyzed. The aqueous portion of the acidified hydroly-

ti' W.IS extracted with ether and the ether extract, com- net! with the organic portion of the hydrolyzate wa\ isticti with aqueous sodium bicarbonate, brim, and

( 1 1 let1 over anhydrous magnesium sulfate. Removal of t I i c cther by distillation folloived by fractionation of the i I >i(lui undcr rcduced pressurc yielded 38.8 g. (307$) of 1 I ).If h. p 70 71 5" (2 mm.) ; T I ~ O D 1.5556; dZo4 1.1518.

. l 7 1 u I . Cnlcd. for C8€IsOS: C, 63.15; 11, 5 . 2 7 ; S, 31 .OX. I'ouitci: C, 02.03; H , 5.44; S, 21.33.

2 -(a -Thienyl) -buten-3-ol-2 (VII) .-A. Methyl-a - t hwiiylethyriylcarbinol (T'I), 20 g. (0.13 mole), was re- iluced by sodium in liquid ammonia according to the inethod of Campbell and Eby.17 The crude product was -____.

' 13) Gilman and McClumphy, Bull soc chrm , 48, 1322 (1928)

,16) Vaughn Vogt and Nieuuland, THIS JOZIHNAL, 56, 2120 14) Marvel and Walton, J OVE C h o n , 1, 88 (1942).

IC)%&) 113) I'hi. rcet\it m c c~~r!~iiioI which darhrtis rathcr rapidly on ex

I O-lll < t 0 11&11t LII 1 I l T I u l i i r d i n irtrlttion of s t r '1, ~ l l o q u l l l o r t r

1 - Cir~i,!,cII in</ 1 ) I \ l i i ' i 11 t n k i 63, .!iIi l l + i ' q

i r e d from traces 01 thc uuteduced acetylenic carbiuol by extractiug its ether solution with Tollens reagent, after which it was washed with brine and dried. The ether was removed by evaporation under reduced pressure and thc

tion, likewise under reduced pressure, of ' \ * I l ) , h 1) fiij-ti;" 2 mni , V A ' D

B. -To .t solution of a-thieiiyliiiagxresiurii bromide 111 400 nil. of ether prepared from 163 g (1.0 mole) of a- i)rornothiophene and 24.3 g. [ i grmi atom) of nidgnesiuni were added slowly .tiid in dropbbise fashion a solution of 54.5 g. (0.79 mole) of methyl vinyl ketone in 200 ml. of .inhydrous ether. Duririg this addition the reaction mix- ture was vigorously stirred and cooled. The reaction mix- t u x was then hydrolyzed ant1 treated according to the procedure outlined in the preparation of ( I ) . Aftcr re- moval of ether hy distillation under reduced pressure, fractionation of the reaction product under reduced prts- wre yielded 7.0 g. (4.60/o) of (YII), b. y. 66-68" (2 mm.i ;

The portions of (1'11) obtained from proce- dures (A) aiid (I3) were combined and redistilled undei wduced pressure, 1) 1) 66-67' (2 mrii ) ; n2% 1.5430, d2!, 1 .Oi1

i l ) i o / . Calcd. for CsHloOS: C, 632.34; H, f5 W . h , 2IJ.77'. Found: C, 62.50; H, 6.45; S, 20.65.

Ozonization.-Three-gram samples of ( I ) , (XI) and (Il l) dissolved in 80 ml. of low-boiling ligroin were ozonized 'it 0' and the ozonide decomposed accordiug to the method of n'hitmore m d Church.lY lkcomposition of the ozonides of (11) ,tiid (111) yielded as one of the product5 formal- dehyde, isolated 3s 2,4-clinitrophenylhydrazone, m. p

Thc identity of this compound mas further con- firmed by mixed melting point with an authentic sample, the 2,44initrophenyihydrazone of formaldehyde. No for- ination of formaldehyde 2,4-di1iitrophenylhydrazorlc YI a\ observed when the ozonide of (I) was decomposed.

* Dehydration of Buteno1s.--A 10-g. sample of the butenol to be dehydrated was mixed with an equal weight of an- hydrous potassium acid sulfate together with a trace of hydroquinone and introduced into a 50-ml. Claisen flask attached to a receiver cooled in a bath of Dry Ice-acetone The flask was then heated to 80" over a period of one-half hour and kept a t 80-90' for one hour in the case of (J'II) or heated to 100" over one-half hour and kept a t 100-1 10 e in the cases of (11) and (111). A pressure of 2 mm. u a i triaintained i i i the apparatus throughout the period of heating and the nuterial collected in the receiver consisted of a mixture of ice and approximately 1-2 g. of :tn organic iiibst,tnce which was imniediately separated from the ice, dried over anhydrous magnesium sulfate, and without further purification* converted to the corresponding tetra- hydrophthalic anhydride derivative.

Dehydration of (I) mas carried out in the manner just described for (VII) except that pulverized potassium hy- droxide pellets were wed inqtead of anhydrous potassium acid sulfate.

j-(a-Thienyl) -Ar-tetrahydrophthalic Anhydride (V) . A solution of 2 g. of maleic anhydride and 3 g. of I - (a - thienyl) -hutadiene-l,3 (IV) , obtained by the dehydration of ( 1 and dissolved in 20 id . of anhydrous benzene, was heated for three hours a t YO3. The product whlch c i y c - t,tlli& from thc reaction mixture on cooling, was filtered, .tnd after four recrystdizations from A mixt ur'c of benzent itid low-t)oiling ligroin, yielded 0 17 g . of ;I. colorlesi coni- pound \.], 111. p. 101)-10lo.

.1nd Calcd for C121110OJS. C, 61 53; 11, 4 5, S, 13.63 Found C , 61.06; 13, 4.44, S, 13.80.

it'hexi the products obtained by the dehydration of (11) and (111) were derivatized according to the same procedure, crystalline compounds were obtained whose identity with ( V j was established by absence of depression in their mixed melting points with (Y) .

1 -(a-Thienyl) -1,4,4a,9a-tetrahydroanthraquinone and I-(n-Thienyl)-anthraquinone.-A mixture of 2 g. of 1,4-

hoquinoue m c l 2 g. of I-(a-thienyl) -butadiene-1 ,X- ~ 1 i i hcatcrl i i i I i tc im-~~. i th for two hours Thc

1.5438.

I <'hiir</i 7 1 , ) 54, i1U l c i 3 2

Oct., 1950 REARRANGEMENT OF N-DIPHENYLMETHYL-0-TOLUIDINE 4,580

product after six recrystallizations from 96% ethanol Depression of the melting point of a mixture of (V) and yielded 0.6 g. of 1-(a-thienyl) -1,4,4a,ga-tetrahydroanthra- (IX) conlirmed the lack of identity between them. quinone, m.p. 159-160'.

Oxygen was bubbled through a solution of 0.5 g. of the Achowledgment*-The authors wish to ac- 1-(a-thienyl) -tetrahydroanthraquinone dissolved in 25 knowledge the assistance of Dr. K. N. Campbell ml. of 0.2 iV alcoholic sodium hydroxide until the solution during the portions of the investigation con- changed from red to colorless and an almost quantitative yield of 1-( a-thienyl) -anthraquinone had precipitated therefrom. It crystallized from 95% ethanol as yellow Ernest needles, m. D. 175.5-176.5'.

cerne;i with ~zonization and to D ~ ~ . e. c. price, and G* F* Hennion for their advice

and interest. Anal: Calcd. for C18H1002S: C, 74.48; H, 2.90; S,

11.03. Found: C, 74.22; H,3.78; S, 11.08. Summary 4- (~Thienyl ) -d4-tetrahydrophthalic Anhydride (IX) .- A series of a-thienyl substituted butenols has

One gram of 2-(~-thienyl)-butadiene-1,3 (VI111 obtained been prepared, characterized, and their dehydra- by the dehydration of (VII) was converted to (IX) ac-

colorless crystalline compound which after four recrys- the reaction of a-thienylmagnesium bromide with tallizations from a benzene-low boiling ligroin mixture butadiene monoxide has been identified as 4-( cy- melted a t 112-113'. thienyl)-buten-2-ol-l formed by 1,4-addition.

d n d . Calcd. for CIZHIOO~S: C, 61.53; H, 4.27; S, 13.63. Found: C, 61.52; H, 4.25; S, 13.71. XOTRE DME, INDIASA RECEIVED JANUARY 13, 1950

cording to the method previously indicated, yielding a tion products studied* The product Obtained

[CONTRIBUTION FROM THE DEPARTMENT OF CHEMISTRY OF THE UNIVERSITY OF NEW HAMPSHIRE]

Rearrangement of N-Diphenylmethyl-o-toluidine BY H. A. IDDLES AND W. L. HARTOP, JR.

In earlier studies concerning the rearrangement with diphenylcarbinol in acetic acid medium led of the triphenylmethyl ether of o-cresol and of N- to the production of a mixture of products. These triphenylmethyl-o-toluidine, as well as in the could be separated by the precipitation of the SUI- related direct introduction of the triphenylmethyl fate salt of a mono-substituted product I11 and radical into the para position of either o-cresol or the recovery of an ether-soluble fraction which was of o-toluidine, the enGance of only one triphenylrnethyl radical has been observed.' In extending these observations, the less highly substituted diphenylmethyl ether of o-cresol was rearranged; the conditions were determined lead- ing to the direct introduction of one and two radicals into the nucleus and the orientation of the products was established by direct syntheses.

The elucidation of these struc- tures has now been utilized in inter- preting the analogous introduction of the diphenylmethyl radical into o-toluidine and in extending the earlier work of Busch and Rinck3 who prepared N-diphenylrnethyl- o-toluidine I1 from benzylidene- o-toluidine and phenylmagnesium bromide and found that this mate- rial, when heated with a-toluidine hydrochloride in a sealed tube a t

I in presence of o-cresol

HOAc HCIL

I V VI 210°, rearranged to give a product which they postulated to be 2-methyl-4-diphenyl- methyl aniline 111.

proved to be the disubstituted product IV. Each of these free amines was diazotized and converted

. . . (3) Busch and Rinck, Lcci.., 38, 17Gl (l!l05) cresol seriesg