Aryl Alkanehydrazonates and Their Thio Analogs. Synthesis of Some 2-Alkyl Derivatives of 4H-1,3,4-Benzoxadiazines and 4H-1,3,4-Benzothiadiazines

Abstract

Abstract Synthesis of some p-nitrophenyl alkanethiohydr azonates, RC(SC6H4NO2-p)=NNHC6H3BrNO2(2, 4−), and p-nitrophenyl alkanehydrazonates, RC(OC6H4NO2p=NNHC6H3BrNO2(2,4−) is described. Upon treatment with triethylamine in ethanol at reflux the thiohydrazonates give directly 2-alkyl-4-(p-nitrophenyl)-7-nitro-4H-1,3,4-benzothiadiazines, whereas the hydrazonates yield the hydrazides, RCONHN(C6H4NO2-p)C6H3BrNO2(2,4−). The latter hydrazides can be cyclized, under stronger basic conditions, into 2-alkyl-4-(p-nitrophenyl)-7-nitro-4H-1,3,4-benzoxadiazines by displacement of the 2-bromine atom.