Abstract
The condensation of substituted carbohydrazides 1a-e with a series of electron-poor compounds such as dimethylbut-2-ynediolate (2), 1,4-diphenylbut-2-yne-1,4-dione (3), 1,4-diphenylbut-2-ene-1,4-dione (4), and diethyl diazene-1,2-dicarboxylate (5) gave the derivatives of 1,3,4-oxadiazepine, 1,3,4-oxadiazinylacetate, (1,3,4-oxadiazolylidene) ethanone, dibenzoylpyrazole and tetrazolecarboxylate. The reaction mechanisms described the products formation are discussed.