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peaks a t mass-to-charge ratios of 112 (CBFI), 93 (CzFd, 74 (C3FZ)j 69 (CF3), 52 (CZFZ)and 31 (CF).' Compounds such as perfluoroethylene and perfluorocyclobutane show CF? peaks,8 but tetrafluoroallene gave an unusually high value a t
1'01. 78
and barium hydroxide were equally effective in bringing about the desired elimination ; refluxing I1 in anhydrous pyridine was somewhat less
an.
.Sddition of chlorine to tetrafluoroallene gave 1,2,2,3-tetrachloro-1,1,3,3-tetrafluoropropane, a liquid with the same b.p., refractive index and infrared spectrum as an authentic sample. Tetrafluoroallene polymerized even a t low temperatures; a t room temperature under pressure polymerization occurred in a few hours to yield first a liquid and then a white solid. The polymerization is being studied.
satisfactory. The concentration of the solution in which the degradation was carried out decidedly affected the yield of desired product. Thus, when a solution of I1 (66.5 mg.) and sodium bicarbonate (42.0 mg.) in 50 ml. of water was heated on a (7) A modified We9tlnghouse Model L V mash spectrometer was steam-bath for two hours, a 45y0 yield of I was used W e wish t o t h a n k Mr R o b e r t D Vanselow for t h i s spectroobtained. However, when I1 (3.33 g.) and barium gram hydroxide (2.20 g.) were dissolved in 50 ml. of ( 8 ) "Catalog of Mass Spectral Data," National Bureau of Standards, Americdn Petroleum I n s t i t u t e Research Project 44, spectra 361 a n d water and heated for two hours, only 24y0 of y112 tropolone formed. Precipitation of the barium DEPARTMENT OF CHEMISTRY ion by addition of Dry Ice followed by concentraUYIVERSITY OF CAIJFORSIA THOMAS L. JACOBS tion of the solution to a volume of 3 to 5 ml., gave Los ANGEIES 24, CALIFORSIA RONALD S. BAUER rise to I in 20% yield. After recrystallization, the RECEIVED JDLY 23, 1936 product, m.p. 211-212", showed infrared maxima (Nujol) a t 6.10, 6.26, 6.60, 7.78 and 8.23 p ; its ultraviolet spectrum showed Xpd;," 360 mp A CONVENIENT SYNTHESIS OF r-TROPOLONE (4.33), 227 mp (4.31) and 336 mp (4.22), Sir: 228 mp (4.20). These properties are in good The theoretical significance of tropone and the agreement with those reported earlier for three isomeric tropolones (monohydroxytropones) Acknowledgment.-The authors are deeply inhas directed much effort toward the synthesis of debted to the Research corporation for the support these compounds. Tropone, tropolone and p- of this research through a Frank Gardner Cottrell tropolone have been known for some time.' Re- grant. cently, Nozoe and co-workers succeeded in prepar( 5 ) American Viscose Corporation Fellow, s u m m e r 195G ing y-tropolone (I) for the first time by acid DEPARTMENT O F CHEMISTRY hydrolysis of 4-bromotropone, a by-product ob- CORNELL UNIVERSITY J. MEINWALD tained in 5-1070 yield from the bromination of ITHACA, 0. L. CH.4PM.4NK XEWYORK cycloheptanone.2 In the same year, Johnson RECEIVED AUGCST 15, 1956 and co-workers reported an alternate synthesis starting from 3,6-dimethoxycycloheptatrienecarboxylic acid, obtained in quite low yield from hydro- THE REACTION OF AZOBENZENE AND CARBON quinone dimethyl ether and diazoacetic ester. MONOXIDE As a part of a general study of the elimination Sir : reactions of bicyclic quaternary salts, we have Previously we have shown that Schiff bases investigated the base degradation of teloidinone react with carbon monoxide in the presence of methobromide (11), in the hope of developing a cobalt octacarbonyl to yield phtha1imidines.l convenient route to y-tropolone (I) We have now found that azobenzene reacts simiTeloidinone, prepared by a Robinson "bio- larly with one molecule of carbon monoxide (150 ~ynthesis,"~ gave 11, m.p. 218-219" (dec.), in atmospheres pressure in all cases) to form indazoalmost quantitative yield when treated with lone, I, a t 190" and with two molecules of carbon excess methyl bromide in ethanol a t room tem- monoxide a t 230" to yield 3-phenyl-2,4-dioxoperature. The degradation was carried out by dissolving I1 and two equivalents of base in distilled water and heating the solution on the steam- A/"\,- n co bath. The formation of I was followed by periodically removing aliquots from the reaction mixture and measuring the intensity of the 360 mp absorption band exhibited by y-tropolone in 0.1 N sodium h y d r o ~ i d e . ~ JX variety of bases were found t o produce I in yields of 457&. Sodium bicarbonate (1) For a n excellent rex-iew see P . L,Pauson, Chem. Reus., 65, 9 (1055). (2) T. Nozoe, 1.. M u k a i , Y . Ikegama a n d T. Toda, Chem. and Ind., 66 ( 1 9 5 5 ) . (3) R. S. Coffey, R. B. Johns a n d A. W. Johnson, { b i d . , 658 (1955). ( I ) J . C. Sheehan a n d B . LI. Bloom, THIS JOURNAL, 74, 3825
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