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LThile the n.m.r. spectrum of 10,10-dimethy1-9-methylene-9,l0-dihydroanthracene (I) sho~vs the geminal methyl group absorption as a sharp singlet the spectrum of the dibrorno derivative, 10,10-dimethy1-9-dibromomethylene-9,10-dihydroanthracene (11) shows the methyl absorptions as two sharp well-separated peaks a t room temperature which coalesce a t 91". 10,10-Dimethyl-9-phenylbromomethylene-9,10-dihydroanthracene (111), and the methyl ester (V) of IV show a broad geminal methyl spectrum a t room temperature which separates to a doublet a t lower temperatures and sharpens to a singlet a t higher temperatures. Rate constants for the first-order processes responsible for the change in spectrum of 11, 111, and V have been calculated a t the coalescence temperatures t o be 57 (364' K), 35 (305' K ) , and 61 (300" K) sec-I, respectively. The AH*'s were used to extrapolate the rates to 305' to give values of 1, 40, and 100 sec-I, respectively. The process being studied is inferred to be the equilibrium between two boat conformations of the center ring in the dihydroanthracene system, rapid interconversion leading to identical environments for the two methyl groups.A comparison with the geometrically similar o,o'-disubstituted biphenyl racemization gives support for this explanation. A number of compounds with a proton and one substituent on the methylene carbon atom of I (substituents: bromine, chlorine, phenyl, carboxy, carbomethoxy, phenylmercapto) and also 10,10-dimethy1-9-phenylcarbomethoxymethylene-9,10-dihydroanthracene (XII) showedasingle methyl absorption a t room temperature. The methylspectruln of the mono bromo compound VI did not broaden a t temperatures down to 246' K.

A series of C-amino-1,2,4-triazoles, substituted with methyl, dimethylamino, methoxy, and methylthio groups, was prepared from the appropriate JV-cyanoazomethines and either hydrazine or methylhydrazine (eq 1). C-Azido-1,2,4-triazoles were prepared from the corresponding amines by diazotization followed by reaction with azide ion. When these diazotization reactions were carried out, the C-amino-1,2,4-triazoles derived from methylhydrazine, unlike those derived from hydrazine, yielded varying quantities of products depending on the acidity of the reaction media. Ir and proton nmr spectra of the C-azido-1,2,4-triazoles in various solvents indicated that none of them participates in imidoyl azide-tetrazole tautomerism, even at -82°.