Jan. 20, 1954
NOTES
Semicarbazone.-Recrystallized froin ca. 80% ethanol, the semicarbazone melted a t 184-1%" (cor.). Anal. Calcd. for CI8HS3S30Si: X, 12.92. Found: S , 13.09. m-Bromophenyltrimethylsilane.-m-Bromophenyltrimethylsilane was prepared by an adaptation of a procedure of Gilman and Melvin.18 n-Butyllithium'3 (0.132 mole) was added to a stirred solution of m-dibromobenzene in 100 ml. of ether over a ten-minute period. Occasional application of an ice-bath was necessary in order t o prevent excessive refluxing. When all the butyllithium had been added, stirring was continued a t room temperature for an ndditional 25 minutes. T o this reaction misture was then added a solution of 14.1 g. (0.13 mole) of trimethylchlorosilane and 50 ml. of ether over a 10-minute period. Stirring was continued for two hours a t room temperature and refluxing for an additional half hour. The reaction mixture was then hydrolyzed with dilute hydrochloric acid. The ethereal layer was separated, washed once with water, separated, and then dried over Drierite. After the ether had been stripped off, the residue was distilled t o yield 5.1
g. (17%) of a material boiling a t 96-97' (5 niin.), ? z ~ ~ 1.5290. Anal. Calcd. for CgH13BrSi: Si, 12.24. Found: Si, 12.1. p-Tolyl m-Trimethylsilylphenyl Ketone.-Two grams (0.0088 mole) of m-bromophenyltrimethylsilane in 30 ml. of ether was refluxed with 0.26 g. (0.011 g. atom) of magnesium turnings for four hours. This Grignard reagent was filtered under nitrogen, and to the filtrate was added 0.59 g. (0.00.5mole) of p-tolunitrilein 10 ml. of ether. Refluxingwas continued for four more hours, themixture was hydrolyzed and worked up as in the preparation of P-tolyl fi-trimethylsilylphenyl ketone. Distillation of the residue a t 0.5 mrn. yielded 1.1 g. (82%) of material boiling a t 130-131". This fraction was taken u p i n warm ethanol and refrigerated. There was obtained a crystalline material melting a t 40-42'. Recrystallization yielded a product melting at 43-44', A mixed m . p . with the ketone prepared through the FriedelCrafts reaction was not depressed. LAFAYETTE, IND.
603
NOTES The Isolation of trans-3,5-Dimethoxystilbene from Tall Oil B Y HANSALBRECHT A N D EDWARD H. SHEERS RECEIVED SEPTEMBER 2, 1953
3.5-Dimethoxvstilbene has been isolated from several natural sources1'*and ErdtmanIChas shown by a study of their ultraviolet spectra that 3,S-dihydroxystilbene and its methyl ethers occur naturally only in the trans form. I n the course of some work on the unsaponifiable constituents of tall oil fatty acids, there was obtained by batch vacuum refractionation of unsaponifiables extracted from commercial tall oil fractionation heads,3 a fraction boiling a t 203-208' (4 mm.) which showed a strong absorption near 300 mp. From this fraction 3,5dimethoxystilbene was isolated as its picrate and identified by its physical properties and those of several of its derivatives and by oxidation to benzaldehyde, benzoic acid and 3,5-dimethoxybenzoi~acid. 3,5-Dimethoxystilbene shows strong absorption a t 300 mp.4 Since only one other unsaponifiable fraction (b.p. 170-171" a t 4 mm.) showed an appreciable absorption in this region, and since the absorption of that fraction was such that k300 = '/z(kzso k320) (approximately), where k is the specific absorptivity, i t was assumed that a linear background absorption should give satisfactory values for trans-3,5-dimethoxystilbenecontent. Therefore. the formula
+
YGtrans-3,5-Dimethoxystilbene =
100
K3w
- 0.5(Kzsd+
ksza)
38.5
(1) (a) H. E r d t m a n , Svensk Pappersfidn., 46,226 (1943); (b) Saensk Kern. T i d . , 56, 95 (1944); ( c ) ibid., 56, 134 (1944). (2) R. F. B. Cox, THISJOURNAL, 62, 3512 (1940). (3) Arizona Chemical Co., 30 Rockefeller Plaza, New York 20, N. Y. ( 4 ) Spectrum t u he published in Agplbed Specluoscopy, Vol. 8 .
was derived from k values obtained with pure 3,5 dimethoxystilbene (&SO = 7S.S; k300 = 119; k320 = 82.2) and used to determine the trans-3,5-dimethoxystilbene content of crude and distilled tall oil and of tall oil rosin. The quantity of trans-3,5-dimethoxystilbene present in the unsaponifiables of crude and distilled tall oil is appreciable (cf. Table I). It is interesting to note that tall oil rosin,5 unlike wood and gum rosins, contains no detectable amounts of trans-3,5dimethoxystilbene. TABLEI t r U n s - 3 , 5 - D I ~ ~ E T H O X 1 S T I L B E N CONTEST E OF
TALLOIL
AND
TALLOIL DISTILLATION PRODUCTS R Ivans-3,6-Dimethox~.stilbene
I n unsaponifiables
Crude tall oil5 Distilled tall oil5 Tall oil rosin6 a
7.4 18.0 Not detecteda
I n product
0.54 .32 ..
linsaponifiables in product,
o/o 7.3 1.8
5.0
Estimated lower limit of detection, 0.02%
Experimental Ultraviolet absorption spectra were obtained using a Beckman spectrophotometer, Model DUV, and a Cary automatic recording spectrophotometer, Model 11. Isolation of trans-3,5-Dimethoxystilbene.-An unsaponifiable fraction from tall oil, boiling a t 203-208" (4mm.) and weighing 0.597 g. in ethanol was treated with a saturated ethanolic picric acid solution. The yellow picrate which crystallized immediately was collected after standing overnight, 0.633 g., m.p. 109-llOo, unchanged on recrystallization from ethanol. The picrate was cleaved by partition between benzene and dilute ammonia. The residue from the benzene solution solidified after standing two days, m.p. 55". After two recrystallizations from ethanol, large colorless needles melting a t 57" were obtained; boiling point 206" (3.8mm.), n Z 5(supercooled ~ melt) 1.5600. ( 5 ) Tall Oil Rosin, a s defined under t h e Naval Stores Act (Kegulations for t h e Administration a n d Enforcement of t h e Naval Stores Act, Feb. 8, 1952,paragraph? 160.2 and 180.305.)
D
NOTES
604 Anal. Calcd. for C16H1602:
c, 79.97;
H, 6.7.
\Tal. i f 3
Found:
led onljp to highly colored solutions and intractable tars. \?'e have therefore investigated other apI t s 1,3,5-trinitrobenzene complex, yellow iieedles from proaches which might be expected to yield Y-bronioxqueous ethaiiol, melted at 122' (reported 121--122",2 122perinaphthene (I)or its equivalent. As described in 123'Ib). tvczns-x,x-Dibromo-3,5-dimethoxystilbene,white needles the Experimental section, we have converted 01from ethanol, m.p. 134.5-135.0O (reported 135-136"6), was methylnaphthalene to 3-bromoperinaphthanol-i prepared as described by Erdtman.6 (111). I t was hoped that this alcohol could be dePotassium Permanganate Oxidation.-trans-3,5-Dimethhydrated in the usual fashion to give 8-bromoperiosystilbene ( 3 g.) was refluxed for two hours with neutral naphthene (IV). In view of recent experiments on potassium permanganate in acetone. The manganese dioxide was dissolved by treating with sodium bisulfite and the isomerization of perinaphthene derivatives," sulfuric acid and a colorless precipitate (1.7 9.) was collected, it would be expected that solutions containing tlisolved in dilute sodium hydroxide and reprecipitated with either 11' or I would give the same tautomeric mixdilute hydrochloric acid. The acid thus obtained was reture of compounds and therefore a synthesis of IV crystallized from water to yield colorless needles of 3,5-diinethoxybenzoic acid, m.p. 184-185'. would be equivalent to a synthesis of I. However, .lnal. Calcd. for CsHl"04: C, 59.33; H, 5.33; neut. all attempts to conyert :hbromoperinaphthanol-T equiv., 182.2. Found: C , 29.27, 59.38; H , 5 . 5 6 , 5.54; to IV were unsuccessful. Highly colored amoiiieul. equiv., 184, 183. phous solids were formed much as in the previous The acid filtrate \vas concentrated and estracted with attempts to synthesize I. .'llthough the lack of ether; from this extract, a second acid, identified as benzoic stability of bromoperinaphthene (I or IV) niay 11c xcid. m . p . 120°, neut. equiv. 124 after crystallization from lvater, n a s obtained by alkaline extraction. The neutral related to the high reactivity of the allylic halogell, fraction, 0.07 g . , oil, yielded a 2,4-dinitrophenylhydrazone attempts to stabilize the product through the forof n1.p. 233-237' corresponding t o t h a t of benzaldehyde. rnatiori of complex salts were also unsuccessful. We wish to thank Dr. Julius A. Kuck and Dr. Robert C. Hirt of these laboratories for the microanalyses and ultraviolet spectra, respectively. C,7Y..il, 79.61: H, 6.78,B.X.
(6) H. Erdtman and G. Erdtman. B o . , 74B,5 (1841).
AMERICASCYANAMID COMPANY STAMFORD, CONNECTICUT
B Y \' BOEKELHEIUE A \ D MARTISG O L U M A ~ ~ RECEIVED AULL~ST 21, 19Ki
The two most important factors in the stabilization of long-lived radicals, such as triphenylmethyl, .Ire generally considered to be the added resonance stabilization of the radical over that of its dimer .t11(1 the steric hindrance which lowers the strength o f the bond foriried during dimerization. It would 1 ) highly ~ desirable to study these factors independtLntly of' each other a i d i t was with this purpose in mind that we recently investigated the preparation .mcl bromination of perinaphthene. I t was hoped that 0-bromoperinaphthene ( I ) \.r.ould result and this could then be converted by standard procedures to the perinaphthenyl radical JI. Because of its high degree of symmetry the Iwrinaphthenyl radical should be highly stabilized by resonance, although there should be little or no steric hindrance to its dimerization. Thus, if the perinaphthenyl radical could be prepared, its Iroperties would serve as an indication of the importance of resonance stabilization for long-lived mdical5
q" I
I
I1
Unforttinately, attempts to obtain 9-bronioperinaphthene by the bromination of perinaphthene 11) Beaunit \7111\ Preductoral Fellow, 1951 1932. ( 2 ) V Borkrlheide and C. Larrabre. T H I s JOURNAL,73, 1.245 (IY.50)
Br IL.
13r 111
A Synthesis of 3-Bromoperinaphthanol-7
Experimental"
3-Bromoperinaphthanone-7.-This was prepared froin amethylnaphthalene in an over-all yield of 32yo. The four steps employed it1 this conversion can be summarized acl follows: (1) a-iiiethylIlal)hthalene was brominated following the procedure of kla>,t.r : t i i d Sicglitz6 and gave l-rnethyl-4Ixotnonaphthalerie a s ;I pale yellow oil ( b . p . 152-154' a t 12 111111., picrate, i i i . ~ . 1 % - 127') iii 76yo yivltl. (2) T h c 11hot obromiria t i o n of 1- I net hyl-4-broni oriap h t h d r n c* \v; t i carried out accor(ling t o tliv pent.r;il procedure indicated b y \\'isliceiius7 arid afforded l-brorno11iethyl-4-bro11~onaphtl~~1Irwe as white crystals, m , p . t02--104°, i n 46% yield. This 50 carried out using T-brorr~oiuccit~irr~itic. de :is reagents, hut the latter method is less convenient than the direct photobromination and the yield of the desired product is essentially the same. ( 3 ) The conversion of 1-bromomethyl-4-bromonaphthalene to ~-(4-bromo-l-naphthyl)-propionic acid by alkylation with malonic ester followed by alkaline hydrolysis w a s carried out following the procedure described by Fieser and Gates' for the preparation of p-( 1-naphthgl)-propionic acid. The acid \vas obtained in 96% yield as white crystals, tn.1). 14ti.5-14X0.6 (4) The cyclization of p-(4-bromo-l-naphthyl)-propionic. acid was accomplished by means of anhydrous hydrogen fluoride following the procedure of Fieser and Gates for the preparation of perinaphthanone-7.8 From 1 0 . 0 g. of fi-(4-brorno-l-liaphthyl)-propionic acid, there was obtained 8.8 g. (94%) of 8-bromoperinaphthanone-7 as pale yellow crystals, 111.p. 96-97', after recrystallizatioii from cyclohexane. Anal. Calcd. for C13H90Br:C,59.79; H , 3.47. Found: C , 59.99; H, 3.47. The oxime of 3-bromoperinaphtharlot~e-7was obtained, after recrystallization from ethanol, :is light yellow needles, m.p. 192-193O dec. - - ..
_- ..
( : 3 ) V . Boekelheide and C. Larrabee, ibid., 73, 1240 (1960). (4) V . Boekelheide and hl. Goldman, J. Org. Chem., in press.
(0) Analyses by S f i s Claire King. All melting points corrected. ( t i l F . >layer and A. Sieglitz, Ber., 66, 1835 (1922). (7) W. Wislicenus, ibid.. 49, 2822 (1816). ( 8 ) L. F . Fieser and RI. D. Gates, THISJOURNAL. 63, 2335 (1940).
