2662
COMhIUNICATIONS TO T H E
Vol. 79
EDITOR
with gas evolution, A,, 290 mp, log E 2.21, Amax 389 mp, log E 2.03. AnaZ. Calcd. for C17Hl&T2: C, 81.56; H, 7.25; N, 11.19. Found: C.81.51; H, 7.01; N, 11.23. Air oxidation of the crude hydrazine has also yielded the azo compound. The normal azo absorption found in acyclic azo compounds a t approximately 350 nip," has becri displaced t o 389 mp, presumably due to the cis configuration forced on the azo link in I, IZ = :i. Thermal decomposition of I, n = 3, in xylene solution at 100.2" gives first-order kinetics, half-lii'c 2.9 minutes, with a 94yo evolution of nitrogen ( 7 ) C. Overberger and 11,Lapkin, THISJ O U R N A L 77, , 4651 (1955). after 31 minutes. Decomposition of I in xylene a t SCHOOL OF SCIENCE CHI HUAWANG 80" gave a half-life of 27.1 minutes with oiily a BRANDEIS UNIVERSITY SHU-HSIHSIAO \VALTHAM 54, MASSACHUSETTS EUGENESAKLAD 71.5% evolution oi nitrogen. These decomposiSAULG. COHEN tion rates are over 100 times faster than the corresponding linear trans3 azo compounds. -4nalysis FEBRUARY 12, 1957 RECEIVED of products of the decomposition a t SO" indicates 290 the presence of the hydrazone 11, n = 3, A,, SEVEN- AND EIGHT-MEMBERED RING AZO COM- mp, log E 3.60. Analysis of the ultraviolet spectrum POUNDS of I , n = 3, has shown that I slowly isomerizes to Sir : the hydrazone IT, n = 3, in ethanol a t rootn temWe wish to report the synthesis and aecomposi- perature. tion of the azo compounds (I) The synthesis of the eight-membered ring azo compound I, n = 4, was carried out by preparing the appropriate cyclic azine by a modification of CtiHj-CH 'CH-GH~, n = 3,4 the method of Overberger and Lapkin,4 m.p. 136's=A-' 737", Xma,268mp, log €4.45. Anal. Calcd. for CIYDecomposition of these cyclic azo compounds HlsNz: C, 8 . 4 2 ; H, 6.92; X > 10.68; mol. wt., 262. should provide biradicals of the benzyl type. The Found: C, S2.64; H, 6.90; N, 10.13; iiinl. w t . preparation of the six-membered ring analog is also 281 (ebullioscopic in butanol). Quantitati\-e rcdescribed in this issue.' d method for the prep- duction of the aziiie followed by immediate osit1:iaration of the hydrazine precursor of I, n = 3, by tion with mercuric oxide yielded 575% of I, ?z = - 4 , reduction of the azine with lithium aluminum hy- 1n.p. SS-9O0, A,, 368 inp, log E 1.63. Anal. Calctl. dride has been reported previously.2 As a pre- for C1BH20N2: C, 81.77; H, 7.63; N, 10.60; mol. parative method, this procedure is unsatisfactory wt., 264. Found: C . 81.60; H, i . 4 i ; S ,10.7;;; owing to the formation of the hydrazone (11) mol. wt., 297 (ebullioscopic i i i butancil).~ 'The illfrared absorption for both I , ?z = 3,1,are almost identical, show n u hydrazone absorptions and COP firm the conclusions made from ultraviolet data. c~H~--cH' C-C6HSr 11 = 3 Acknowledgment.--1Ve wish to thank the Na\ NH--N / / tional Science Foundation for the support of :L A,,, 200 mp, log E 3.73, from incomplete reduction portion of this work, Grant NSF-1433. of the azine and from isomerization of the azo f;il S. ,.C Cclheii, 5 J ( ' , n > > z n ?nnd U. H S!>,trro!v, L b i L 7 2 , 39-47 compound obtained by autoxidation of the hydra- (19zn). 84j C . yl) d e r i v a t i v e (rf I , = 4 over lOyo palladium-on-charcoal followed by immediate oxidation of the crude hydrazine with I ) E P A R r M E S T O F CHEXISTRY C. G . OVERBBRGEK JOSEPH G . LOMB.4RDIKO ISSTITUTE01: mercuric oxide gives %.4y0 of I, n = 3, m.p. 115", POI,\-TECHSIC
azo compound7 has been reported, with ultraviolet absorption maximum and rate of decomposition quite similar t o those of the acyclic analogs,l the size of the ring apparently allowing the azo linkages to assume the trans configuration. Decomposition of 0.036 mole/l. of I in 3.46 moles/l. styrene in ethylbenzene a t 80" led t o polymerization of 8.5 molecules of styrene per molecule of I. Acknowledgment.-We are pleased to acknowledge generous support of this work by the National Science Foundation (NSFG575).
,
,l
(1) C . H. Wang, S. Hsiao. E. Saklad aud
7 9 , 2661 (19.573. ( 2 ) C. G. Overberger a n d
S G. Cohen, THISJ O U R -
NAL,
1.J.
Ilonagle, i b i d , 78, 4470 (1956).
BROOKLYS
IR~ISG TASHLICK
KICHARX BKOOKLYS 1, SEW YORK RECEIL-ED L \ I a R C r I 2, l < l c j i
(>. I 3 I S K E Y
