[ C O S T R I B C T I O N FROM THE DEP.4RThIEXT O F CHEMISTRY, POLYTECHNIC INSTITUTE O F
Azo Compounds.
BROOKLYN]
XXVII. Synthesis of a-Alkyl and a,a-Dialkylbenzylazoalkanes and Intermediate Hydrazines and Hydrazonesl HI7 C .
rr. O V E R R E R G E R .IND AADOI.PII V . D I ( ~ I l r l , I ~ ) ’ R~:crirvcuJUXE 23, 1058
The reaction of phen~~lrnagncsiurn bromide or pheiiyllithium on acetaldehyde aziiie, acetone azine, diethyl ketazine and methyl isobutyl ketazine gave the corresponding mo~io-l,2-additionproducts, a-phenylethyl, a-cumyl, a,a-diethylbenzyland cu,cu-tnethylisobutylbenzylhydrazone, respectively, of the parent carbonyl. Distillation of t h e reaction mixture obtained Kith cycloliexanone azine gave apparently hydrocarbon decomposition products. The pure free bases, a-phenylethylhydrazine and a-cutnylhydraziiie were obtained by hydrolysis of the respective hydrazones. Condensation of a-phenylethylhydrazine with acetone gave acetone or-phen~-leth~-lhydrazone.The four azo compounds, a-phenylethylazoisopropane, ~-cumylazoisopropane, ~,a-diethylbenzylazo-3-peiitatieand a,a-1iietliylisobutylbenzylazo-2-(4-methylpentane) were obtained by the oxidation o f thcir respective hydrazines which iii turn were obtained by the hydrogenation of the corresponding hvdrazones.
In the course of a study of thc decomposition of aliphatic type azo compounds, a number of unsymmetrical benzylazoalkanes were required, This paper describes the preparation of the benzylazo alkanes of the structure shown in IV. A lntcr paper will describe their decomposition. R
R
R “ IVd; R = R ” ~=C&, R’ = H Although symmetrical linear aliphatic azo conipounds where the azo linkage is attached to primary or secondary aliphatic radicals are reasonably well k n ~ w n ~ ~ , unsymmetrical ~ , ~ ~ , ~ , ~linear , ~ aliphatic azo compounds are quite r a ~ e ,isopropyl~,~ azomethane being the only one reported on which decomposition studies have been carried out. As far as is known, no unsymmetrical aliphatic benzyl-type azo compound had been previously re, ~ ported in the literature. Wieland, et ~ l .reported that the attempted preparation of benzylazotriphenylmethane led primarily to the decomposition product, asymmetrical tetraphenylethane. Cohen and Wang’O have reported an attempt to synthesize diphenylmethane, obtaining a mixture of hydrazones. The isomerization of azo compounds to the more stable hydrazone isonierI1 in the presence of acids or base^^,^^^.'^ is known. IVhen the It’
(1) This is t h e 27th in a series of papers concerned with t h e preparation a n d decomposition of azo compounds. For t h e previous paper it1 this series, see C . G. Overberger, I. Tashlick, lf. Bernstein and R. G . Hiskey, THIS J O U R N A L , 80, 0660 (1938). (2) T h i s paper comprises a portion of a thesis presented by Adolph V. DiGiulio in partial fulfillment of the reqiiirements for t h e degree of Doctor of Philosophy i n the Graduate Sclinol of the I’nly-technic Inslitiite of Brooklyn. ( 3 ) (a) €1. C. R:rln.;pcrger, T i m JIJVRN?T., 49, 912 ( 1 9 2 i ) ; (11) 50, 714 (1028). (4) (a) S. G. Cohen. S. J. Groszos and I). B. Sparrow, i b i d . , 74,3947 (1950); (b) S. G. Cohen and C. 1.1. Wang, ibid.,77, 2457 (1925). (5) W. A. Schulze and H. L. Lochte, ibid.,48, 1030 (1026). (0) G. Fodor and P. Szarvas, Be?., 76B. 334 (1943). (7) L. D. Garrick, G. W. Drake a n d H. L. Lochte, T H I S J O U R N A L , 58. 100 (1930). (8) H . C . Rarnsperger, ibid., 51, 2134 (1929). (9) H . Wieland, A. Hintermaier and I. Dennstedt, A7177.,462, 1 (1027). (10) S. G. Cohen and C. H. Wang, THISJ O U R N A L , 77. 31328 (1955). (1 1 ) G . E. K. Branch and M, Calvin, “ T h e Theory of Organic Chemistry,” Prentice-Hall, Inc., S e w York, N. Y., 1941, p. 288. (12) H . L. Lochte, \V. A . S o y e s and J. K . Bailey, T m s J O U R N A L , 44, 2556 (1022). (13) K. A . ‘f.ripale and 1’. V Usachev, 1,Rziss. P h y s . - C h e m . So
