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The condensation of ethyl 5hydrazino-3~methylpyrazole-4-carboxylate with various aldehydes and acid chlorides is outlined. The cyclisation of the resulting hydrazones and hydrazides, under oxidative and dehydrative conditions, respectively, gives ethyl 1 H-pyrazolo[3,2-c] -s-triazole-7-carboxylates. Hydrolysis of these esters followed by decarboxylation of the corresponding acids, gives 1 H-pyrazolo[3,2-c] -s-triazoles. Another method of synthesis of 1 H-pyrazolo[3,2-c] -s-triazoles, involves the condensation of S-methylisothiocarbohydrazide hydroiodide with p-oxo-esters. The synthesis of a range of azamethine dyes containing the pyrazolo[3,2-c] -s-triazole nucleus is described, and the absorption properties of these dyes are discussed.

Introduction.Thiele in his comprehensive study of the unsaturated compounds1 concludes that, as a rule, with a conjugate system of double bonds, more especially C = C -C = C and C = C -C = 0 addition takes place on the 1,4 position rather than on the 1,2 or 3,4 position. Subsequently it developed that Thiele's conclusions were not justified, for, as shown by Straus,2 *e. g., the addition of bromine on the system C = C -C = C takes place on both the 1,2 and 1,4 positions. Staudinger* has shown conjugate system, C = C -C = O. W. J. Hale, of the University of Michigan, has by letter taken issue with Bailey and Moore as to the constitution of their CeHsCH = N -N = 1 "Die Ketene," p. 2 (1912).2 Ann., 336, 95 (1907).

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The condensation of 1.3-dialkylbarbituric acids with ethyl orthoacetate gives 7H-pyrano[2,3-d]pyrimidines. The structures of these dyes were confirmed by their reactions. The preparation and light absorptions of several nonionic trinuclear dyes containing the pyrano[2,3-d]pydmidine nucleus are discussed.