Synthesis of 1-(6-Methyl-2,4-Dioxo-1,2,3,4-Tetrahydro-3-Pyrimidinyl)Acetyl-4-Alkyl(Aryl)Thiosemicarbazides and their Heterocyclisation to 1,2,4-Triazoles and 1,3,4-Thiadiazoles †

Abstract

5-(6-Methyl-2,4-dioxo-1,2,3,4-tetrahydro-3-pyrimidinyl)methyl-1,3,4-oxadiazole-2-thione reacts with amines to give 1-(6-methyl-2,4-dioxo-1,2,3,4-tetrahydro-3-pyrimidinyl)acetyl-4-alkyl(aryl)thiosemicarbazides, which on treatment with base or acid undergo cyclisation to 4-alkyl-1,2,4-triazole-2-thiones or 4-amino-1,3,4-thiadiazoles, respectively.