2580
W. E. BACHMANN AND N. L. WENDLER
wt., 204.26.
It'ound: C, 94.06; H, 5.95; mol. wt. (Rast), 215. The product did not depress the melting point of a sample of diphenyl~juccindene-10, m. p. 205.4-207.8", prepared essentially according to Brand and Muller4; the final reduction of 9,12-dichlorodiphenyIsuccindadiene-9,12 was conducted with zinc dust in refluxing acetic acid solution (37% yield of crystallized product; found: C, 94.02; H , 6.00; absorption spectrum in ethanol: max. 310 mp, log E 4.iX). From the more soluble fraction there was obtained 60 m g . of 1,Z,5,6-dibenzcyclooctatetraene in the form of cdorless crystals, in. p . iO6.8-1O8.Io. A crystallographic exainination20 indicated acicular crystals showing parallel and 45" extinction and probably monoclinic; they are biaxial positive with (Y near /3 = 1.678, y > 1.76, moderate 2 v. Anal. Calcd. for C16H12: C, 94.07; H, 5.92; mol. wt., 204.26. Found: C, 94.05; H , 5.90; mol. wt. (Rast), 212. The hydrocarhon gave distinct melting point depressions when mixed with diphenylsuccindane and with dihydroanthracene. The substance readily decolorizes permanganate solution and a solution of bromine in carbou tetrachloride. Solutions in benzene are fluorescent. The hydrocarbon apparently does not form a picrate. Other Decarboxylation Experiments.-Several further trials were made in an endeavor to improve the yield of the desired product and to determine how the by-product arises. In an experiment conducted as just described but with rigid control of the temperature to 260-265", dibenzcyclooctatetraene was the sole product but the yield was no better. Decarboxylation of 200 mg. of diacid with freshly reduced copper powder in quinoline solution a t 225-245" (forty-five minutes) affordedD26 mg. (19%) of dibenzcycloiictatetraene, ni. p . 106-108 ; the hydrocarbon was obtained in about the same yield when the reaction was conducted in a scaled tube a t 285 ', and no diphenylsuccindene was detected in either instance. Decarboxylation in quinaldine a t 240-250" gave similar results (16% yield of material nicltitig a t 100-103"). Trials in a subliming apparatuij with rcduced copper or with basic copper carbonate as catalyst resulted in the formation of both isotners ill low yields. The best results were obtained with copprr chromite catalyst as follows. A mixture of 1 g. of the diacid with 2 g. of copper chromite catalyst 39KAF, layercd with 1 g. of catalyst, was placed in a 25-cc. flask coiincctcd by a
Vol. 68
ground-glass joint and a right-angle tube to a receiving flask cooled in a dry ice-bath. Moderate suction was applied to the system and the temperature of the reaction mixture was raised to 260-300Ofor one hour. A crystalline product that collected in the receiver was crystallized from alcohol and afforded 150 mg. (22%) of colorless needles of 1,2,5,6-dibenzcyclo6ctatetraene, m. p. 107.2-108.8". Decidedly less satisfactory results were obtained with the same catalyst and a solution of the diacid in 2,6dimethylquinoline or in 1,6-dimethylnaphthalene. 1,2,5,6-Dibenzcycl08ctadiene-l,5.-Dibenzcyclooctatetraene (76 rng.) was hydrogenated in absolute alcohol (30 cc.) in the presence of Adams catalyst (100 mg.) at a pressure of 2300 Ib. (five hours). When the filtered solution was concentrated and diluted with a few drops of water the product separated in colorless, rectangular crystals, m. p. 106-109°; yield 50 mg. (65%). Recrystallization fro," ligroin (30-60 ") raised the melting point Mixtures with the starting material and to 108.5-110 with diphenylsuccindane showed definite depressions in melting point. A mixture with a sample of the known sdibenzcyclooctadieneb that became available after the completion of this work melted at 108.5-110". Anal. Calcd. for C1eH1(: C, 92.24; I T , 7.75; mol. wt., 208.29. Found: C, 91.88; H, 8.00; mol. wt. (Rast), 197. Diphenylsuccindane .18-This hydrocarbon was prepared for purposes of comparison, both by the hydrogenation of diphenylsuccindene-10, as reported by Brand and Muller,4 and by the Clemmcnsen-Martin reduction of diphenylsuccindanedione-9,12; the yield from 3.8 g. of diketone was 2.7 g. (80%) ; m. p . 102.8-104".
.
Summary 1,2,5,~-Dibenzcyclooctatetracne has been syn,
thesized from o-phthalaldehyde and o-phenylenediacetonitrile and found to be chemically reactive. The spectra of the hydrocarbon and two of its derivatives show evidence of a t most only partial conjugation between the benzene rings and the free double bonds, and i t is concluded that the eight-membered ring is noli-planar and hence incapable of full resonance stabilization. (18) Roser, Ann., 247, 153 (1888). CAMBRIDGE, MASSACIiUSEri S
RECEIVED JULY 31, 1946
[CONTRIBUTION FROM THE CHEMISTRY LABORATORY O F THE Ui$IVERSITP O F MICHIGAN]
Synthesis of l-Keto-~~~J~~-dodecahydrophenanthrene, cis-9-Methyl-l-decalone, and other Cyclic Ketones BY W. E. BACHMANN AND N. L. WENDLER' The unsaturated hydroxy ester I was prepared from 1-decalone, zinc and methyl y-bromocrotona t e 2 In order to avoid the formation of a dienic ester,3 the Kcforniatsky reaction was carried out ( I ) From the Ph.D. dissertation of N. L. Wendler, 1944. (2) Ziegler, el al. [ A n n . , 551, 80, 120 (194211 describe a n elegant method of preparing methyl y-bromocrotonate a n d its application in the Reformatsky reaction. See also Schmid a n d Karrer. Hclu. Chim. Acto, 29, 573 (1946). (3) Fuson a n d his co-workers [Fuson, Arnold a n d Cooke, THIS JOURNAL, 60. 2272 (1938): Fuson a n d Southwick, ibid., 66, 679 (19441 I, who made the important discovery t h a t methyl r-iodocrotonate can be used in the Reformatsky reaction. prcpared the dieuicester rather t h a n the hydroxy ester from the reactiurr with cyclohexaisone it] I)oiliug benzene. See also Cook atid Schoental. J. Chem. Soc.. 289 (1945).
in a mixture of equal volumes of ether and benzene a t about 60'. The unsaturated hydroxy ester was reduced catalytically over h n e y nickel in methanol, and the product was dehydrated and hydrolyLed to what is probably y-( A' "octahydro-1-naphthyl)-butyric acid (11). A sample of this acid was readily dehydrogenated t o the known HO
C c rPsiijti w i l l 1,c reported in a future cun~tnuuicat I 011.
( 2 ) Cook iiuil I,JIVT~UCI.. J . C h r v i .SOL...817 (1937). (til J u l t n s ~ ~ u '1'111s , I U I I K N . ~ I . , 66, 1317 (1943).
added to ice and dilute acetic acid, and the product was separated from the aqueous solution by means of ether. The ether solution was washed successively with 1% amrnoniuin hydrosidc, water and saturated salt solution and then dried. The oily product containing I, which renmined after evaporation of the solvent, was dissolved i:i (7) Bachmann and K. C. Edgertun, ; b i d , 62, 2220 (l94IJ)
2582
W. E. BACHMANN AND N. L. WENDLER
Vol. 68
50 cc. of ethanol and hydrogenated in the presence of 5 g. methanol was removed a n d the residue was heated for two of Raney nickel at 30 pounds pressure in the course of hours with 100 cc. of 20% potassium hydroxide solution. fifteen minutes. The product obtained by evaporation of The cooled solution was diluted with a n equal volume of the solvent after separation of the catalyst by centrifuga- water, extracted with ether, a n d then acidified. The tion was heated with 18 g. of potassium acid sulfate a t resulting unsaturated dibasic acid (V or isomer) which was 160" for one hour. The product from this treatment was collected as a n oil resisted all attempts t o induce crystalsaponified by refluxing with a solution of 25 g . of potassium lization. It was hydrogenated in 50 cc. of acetic acid in hydroxide in 250 cc. of 50Yo ethanol for three hours. The the presence of 0.2 g. of platinum oxide catalyst. The resulting acid ((11)was purified by evaporative distillation acetic acid was removed under reduced pressure and water at l15-:120° (0.05 mm.); yield of colorless oil, 3-3.5 g . was added to the residual oil; after several weeks in a reAnal. Calcd. for C14H2202:C, 75.67; H, 10.00. frigerator the saturated dibasic acid (VI) solidified; weight, 5.5 g. This crude acid was used in subsequent Found: C, 75.59; H, 10.01. The unsaturated acid readily decolorizes bromine in operations. A sample of the acid after recrystallization carbon tetrachloride and slowly reduces dilute aqueous from dilute methanol and then from ether-petroleum ether potassium permanganate. Dehydrogenation of a sample (Norit).formed colorless crystals; m. p. 109-112". Anal. Calcd. for C12H200d: C, 63.16; H, 8.77. by heating with four equivalents of sulfur afforded the Found: C, 63.42; H, 9.05. known y-1-naphthylbutyric acid; ni. p . 105-107". 1-Keto-A4asl['s-dodecahydrophenanthrene (IIIa) .-The cis-9-Methyl-1 -decalone (VII) .-Four grams of the aforementioned unsaturated acid was converted into its crude acid (VI) was converted into the dimethyl ester by sodium salt by means of a solution of sodium methoxide in means of diazomethane and the ester was evaporatively methanol. The methanol was removed by evaporation, distilled a t 105-110" (0.05 mm.). The colorless liquid and the sodium salt Jvas added to a solution of 3 g . of diester was dissolved in 75 cc. of dry benzene and added to oxalyl chloride in 25 cc. of benzene. After two hours of a flask containing anhydrous sodium methoxide, prepared refluxing, the mixture was filtered and the benzene was from 0.8 g. of sodium. The mixture was refluxed in a evaporated under reduced pressure. The resulting a c i t nitrogen atmosphere for three hours on a steam bath, then chloride in 15 cc. of carbon disulfide was chilled to -10 cooled and acidified with dilute acetic acid. Thc organic and treated with a solution of 3 cc. of anhydrous stannic solution was washed with sodium bicarbonate solution chloride in 25 cc. of carbon disulfide according to the pro- until neutral and then dried. Evaporation of the solvent After one hour a t - l o " , cedure of Cook. and as a liquid. left the 2-carbomethoxy-9-methyl-1-decalone the mixture w a s allowed to stand a t room temperature for The compound failed to give a color with ferric chloride. two hours and was then poured onto ice and water. The The 6-ketoester was refluxed with a mixture of 50 cc. of carbon disulfid~was evaporated, the product was extracted concentrated hydrochloric acid and 50 cc. of acetic acid for with ether, and the ether solution was washed with dilute twelve hours in a system provided with a mercury trap. alkali in order to remove unchangcd acid. The oil which The mixture was diluted with two volumes of water, remained after the removal of the ether was refluxed with saturated with salt and extracted several times with ether. 15 cc. of dimethylaniline for three hours; ether was added The ether extract was washed with sodium bicarbonate to the cooled mixture and the dimethylaniline was removed solution, dried and evaporated. The residual 9-methyl-lwith aqueous acid. Evaporative distillation of the prod- decalone was evaporatively distilled a t 80" (0.0;m m . ) ; uct at 120-130" (0.05 mm.) yielded the ketone I I I a as a yield, 2.5 g. (nZ5 1.4845). After regeneration from its colorless oil. .A solution of 0.5 g . of the ketone, 1.5 g. of semicarbazone the ketone had n2$ 1.4922 (reported, semicarbazide hydrochloride, and 5 cc. of pyridine in 25 cc. 1.4897j and 1.49036). The melting points of the semiof methanol was refluxed. The semicarbazone was carbazone (m. p. 228-229"), oxime (m. p . 108-109') and obtained crystalline by trituration with methanol; from 2,4-dinitrophenylhydrazone (in. p. 159-160") checked the this solvent it crystallized ixi colorless needles; m. p . 225' values reported previously for these derivatives of cis-9dec . methyl-1-decalone. Mixed melting points of these deAnal. Calcd. for C1+ONS: C, 68.97; I t , 8.81. rivatives with samples kindly sent us by D r . W . S . Johnson showed no depression. Our lower melting form of the Found: C, 68.95; H , 8.17. The 2,4-dinitrophenylhydrazonewas prepared in 1)oiliiig oxime was transformed to the higher iwltiiig form (m. p. 114.5-115.5') by seeding with a sampl.: of U r . Johnson's ethanol containing a drop of sulfuric acid; i t crystallized higher melting form. from ethanol in brilliant red needles; m. p. 215-216". y-(3,4-Dihydro-l -naphthyl) -bityric Acid (VIII) .-The A n d . Calcd. for C20HzaOaN4: C, 62.50; H, 6.25. Reformatsky reaction between iL3 g. of 1-tetralone and Found: C, 62.28; H, 6.56. methyl 7-bromocrotonate was carried out as described for 7-2-Methyl-.2-carboxycyclohexanebutyric Acid (VI) .--A I. The hydroxy ester after catalytic hydrogenation ITas mixture of 10 g . of zinc, 8.5 g. of 2-methyl-2-carborneth- dehydrated with 18 g . of potassium acid sulfate a t 160" oxycyclohexanone, 9 g. of methyl y-bromocrotonate, and (one hour). The product was separated from the salt and a little iodine was refluxed in 50 cc. of a 1:l mixture of refluxed for two hours with 10 g . of potassium hydroxide in ether and benzeiie; reaction set in within one-half hour as 100 cc. of 50% ethanol. A n equal volume of water was shown tiy the separation of a yellow solid. Further addi- added, the solution was extracted with ether, and the tions of zinc a:id hroinoester were made and the reaction aqueous solution was acidified. The desired acid precipiwas carried out as described for the preparation of 11. tated as an oil which gradually solidified. After recrystalHydrogenatioii of the Reformatsky product (IV) was lization from ether-petroleum ether i t melted a t 85--86"; carried out in 50 cc. of mrthanol with 5 g. of Raney nickel yield, 5.5 g. (50%). I t decolorizes instantly a solution of at 30 pounds pressure. Removal of the catalyst and hromine in carbon tetrachloride and reduces aquenus eSaporation of the solvent a t 50" afforded the saturated potassium permanganate. Reformatsky eljter a s a n oil. .lnal. Calcd. for C14Hi602: C, 77.74; H, 7.40. Pure thionyl chloride (6.5 cc.) was added dropwise with swirling to a solution of the product in 40 cc. of anhydrous Found: C, 77.87; H, 7.48. Dehydrogenation of a sample of the above unsaturated ether and 15 cc. of pyridine which had been chilled to 0-5'. After one hour at room temperature the mixture was acid with one equivalent of sulfur gave the known y - l poured onto ice water and the product was taken up in naphthylbutyric acid; m . p. 107-109° alone and when ether. The ethereal extract was washed with dilute hydro- mixed with a n authentic specimen of the compound. Cyclization of y-(3,4-Dihydro-l -naphthyl) -butyric Acid. chloric acid, \< ith sodium bicarbonate solution and with water. The o.il which remained after evaporation of the 1-Keto-l,2,3,4,9, IO-hexahydrophenanthrene (IX) .-One gram of tlir acid iva4 converted into its sodium salt I)y dried solution was refluxed for ten hours with a solution of iiicaii> of w d i u n i iiirthoxide as described previously, alld 10 g. of potaqsium hydruxidr i n 100 cc. of methanol; thc I.__. ....- . t h r salt was trtated with a solution of 1 g. of oxalyl chloride )SI Cumjk a n d I L a n r r n ~ r ,J . Clirirt >w., 11337 (193.5). in 10 cc. oE hrnzcnr. T h e acid chloride in 10 a ' . of carboll
Dec., 1946
2583
SYNTHESIS OF CYCLIC KETONES
disulfide was treated with 1 cc. of stannic chloride in 10 a vertical air condenser during the course of one hour. cc. of carbon disulfide a t -10" for one hour and at room This operation with isopvpyl alcohol was repeated. The temperature for two hours. The product was isolated a n d reaction mixture was treated with cold dilute sulfuric acid, heated with 0.5 cc. of dimethylaniline in the manner de- the product was extracted with ether, and the ether soluscribed previously. Evaporative distillation under re- tion was washed successively with dilute aqueous ammonia duced pressure followed by crystallization of the distillate and with water. Evaporation of the ether yielded 3 g. of from ether-petroleum etheroyielded 0.2-0.3 g. of colorless carbinol ester as a n oil. A sample on catalytic dehydraneedles of IX; r r i . p . 48-49 . Usually it was necessary to tion and dehydrogenation with palladium on charcoal a t purify the ketone through its oxime in order to obtain it 300" afforded the known y-2-naphthylbutyric acid; m . p . crystallinc. The unsaturated ketone is readily susceptible 95-96 alone and when mixed with a n authentic specimen. t o photochemical oxidation. A mixture of 2 g. of the carbinol ester and 5 g. of potasAnal. Calcd. for C I ~ H ~ ~C, O : 84.81; H , 7.12. sium acid sulfate was heated a t 160" in a n oil-bath for one hour. The product obtained by ether extraction was Found: C, 81.42; H, 7.05. The oxime crystallized from aqueous alcohol in stout, saponified by refluxing with a n excess of 10% aqueous potassium hydroxide in 50% ethanol solution for three colorless needles; m . p . 140.5-141.5' cor. hours. The hydrolysate, after addition of water and exAnal. Calcd. for ClaHljON: C, 78.76; H, 7.09; S , traction of neutral material with ether, was acidified, and 6.56. Found: C, 78.74; H, 7.09; X, 6.07. the precipitated acid was recrystallized from petroleum Dehydrogc.nation of a sample of the unsaturated ketone ether. The colorless needles of y-(3,4-dihydro-2with one tquivalent of sulfur a t about 250" yielded l-keto- naphthyl)-butyric acid melted a t 70-71 '; yield, 1.3 g . 1,2,3,4-tctraliytl~-opl~eria11threr1e which had the correct Anal. Calcd. for ClaHloO2: C, 77.77; IT, 7.411. analysis and ineltiiig point atid tnelted unchanged when Found: C, 77.55; H, 7.27. mixed with an autheiitic specimen of the compouiid. The 4-Keto-l,2,3,4,9,10-hexahydrophenanthrene(XIIa) . osiines of 1hi. coiiipounds were also identical. The acid chloride from 0.6 g. of the acid X I a was prepared y - (1 -Keto -1,2 3,4-tetrahydro -2 -naphthyl) -butyric 'Acid from its sodium salt and oxalyl chloride by the procedure (Xa).-Dry sodium elhoxidc, prepared from 4.6 g. of sodium and 60 cc. of ethanol followed by removal of the described for IIIa. A solution of the acid chloride in 1 0 cc. of carbon disulfide was added dropxise with swirling to excess alcohol in i'acvo a t loo", was suspended in 100 cc. of dry benzene iii ail atmosphcre of nitrogen; t o the cooled a solution of 5 cc. of stannic chloride in 10 cc. of carbon disulfide at - 10"; a dark complex precipitated gradually suspension a solution of 14.6 g. of 1-tetralone and 29.2 g. of diethyl oxalate in 35 cc. of benzene was added with during the addition and became green. After one hour at - 10' and twelve hours in a refrigerator (or two hours a t swirling. After eight hours at room temperature, the mixture was pocred onto ice-water, neutral material was room temperature), the mixture was poured into a mixture ice, ether and hydrochloric acid. The ether solution extracted with ether, and the glyoxalate was precipitated of from the aqueous solution with hydrochloric acid. The was washed with dilute alkali and with water and then ethyl 1-keto-1, L',3,4-tetrahydronaphthalene-2-glyoxalate evaporated. The residual oil, which slow-ly gave off was recrystallized from ethanol; yield, 17 g. (70%); hydrogen chloride when warm, was heated f i t h 10 cc. of dimethylaniline for three hours. After the removal of the i n . p. 44-45" (rcported,g 48"). A mixtiire of 17 g. of the glyoxalate and 10 g. of pow- dimethylaniline and its salt with dilute acid, the product dered soft glass 'was heated in a n oil-bath with stirring at was evaporatively distilled in a high vacuum. The u n 155-160". After the evolution of carbon monoxide was saturated cyclic ketone slowly solidified on standing; complete (fifteen tninutes), the ethyl l-keto-1,2,3,4-tetra- i t crystallized from ether-petroleum ethcr in colorless hydro-2-naphthoate was separated from thc glass hy means iieedles; m . p. 4.5"; yield, 0.2-0.3 g . Anal. Calcd. for CIIIIIIO: %.XI; H, 7.12. of ether a n d dis1.illcd under reduccd pressure; b. p. 123125" (0.05 nun.); yicld, 16 g. ('30%). The keto ester Found: C, 84.XO; H , 7.21. crystallized on chilling; i n . p . 34-33" (r?ported,Y34"). The oxime was rccrystallized from ethanol: i n . p . 1x7The addition of 7.5 g. of the keto ester in 50 cc. of 188". anhydrous ethariol to a solution of sodium ethoxide preA n d . Calcd. for C14H1SOr\j: C, 78.76; H, 7.09. pared from 11.9 g . of sodium arid 23 cc. of ethanol resulted Found: C, 78.69; H, 7.09. in the depositioii of the insolul~lesodio derivative. T o the A sample of the 4-ketohexahydrophenanthrcneon desuspension was added 7.5 g. of y-brotnobutyronitrile in 30 cc. of ethanol a n l l the mixture was refluxed 011 a steam-bath hydrogenation with one equivalent of sulfur yielded 4keto-1,2,3,4-tetrahydrophenanthrene; m . p. 64-66 O alone for twelve hour:,. The excess alcohol was removed in a current 01: air, v a t c r was added, and the product was ex- and when mixed with known material. Methyl 1-Keto-5 -methoxy-l,Z,3,4-tetrahydronaphthaltracted n i t h etlier. Distillation of the product a t 180" (40 g.) was (0.2 mtn.) yielded 8 g . of y-(l-keto-2-carhethoxy-1,2,3,4- ene-2-glyoxalate .-5-Methoxy-l-tetraloneIO tetrahydro-2-naphthyl) -butyronitrile as a colorless oil. glyoxalated by the method employed on 1-tetralone in 500 Five grarns of this cstcr nitrile was hydrolyzed and de- cc. of benzene with 50 g. of dimethyl oxalate and the carboxylated by boiling for tu.eiity-four hours with a mix- anhydrous sodium methoxide prepared from 10.8 g. of ture of 3 1 cc. of acetic acid and 50 cc. of concmtrated sodium. The glyoxalate obtained by acidification of the hydrochlcric acid. The solvrnts were rcmoved under aqueous solution of the sodium salt crystallized from inethanol in pale yellow needles; yield, 55.4 g . (93%); reduced pressure a u t i the residu:il acid was purified through I n . p. 102-103". carbonat? extractiuii from cthcr solution. The keto acid Anal. Calcd. for C14H1406: C, 64.11; H , 5 ~ 4 . (Xa) obtairicd oil acidificatioii vi-ystallizcd from ether-Found: C, 64.24; H, 5.57. petroleum rther in colorless ric~edlrs; 111. p . A4 65"; yield, .'-3.5 i g. (70 is:&). Methyl l-Keto-5-methoxy-1,2,3,4-tetrahydro-2of 60 g. of the glyoxalate .lna/. Calcd for CllIilhOa: C, 72.41; H , 6.90. naphthoate.-Decarbonylation in the presence of 55 g. of powdered glass at 160-175' was Found: C , 72.20; H, 7.21). complete in twenty minutes. The keto ester which was y-(3,4-Dihydro-2-naphthyl)-butyric Acid (XIa) .--A solutioii of 3 g . of the aforementioned keto acid was isolated by ether extraction was sufficiently pure for the treated with an ethcr solution of diazomethane, and the next step. In a small run the product from 2.36 g. of methyl ester vva s purified by cvaporative distillation a t glyoxalate was evaporatively distilled under reduced pres140" (O.O:? r n r n . ) . The mcthvl estcr (3.5 9.) was refluxed sure and recrystallized from ether-petroleum ether; yield with a solutioti of 12 g. of aluiuiriuni isopropoxide in 40 cc. 1.85 g. 190%) ; in. p . 68-69", .4md. Calcd. for C13H~101: C, 66.6ti; €-I, 5.98. of toluene arid 1 IN. of isupropyl alcohol for four hours; then Fourid: C , M.:;H , 5.94. 4 0 c c . of i.;npr
