Synthesis of 1,2-Diazaphenalenes under Microwave

Abstract

1,2-Diazaphenalenes were prepared by condensation reactions of hydrazine with isophorone derivatives under various conditions: conventional heating in homogeneous solution and microwave activation either in homogeneous solution or in dry media. Microwave irradiation gave the best results with both enhancements in rates and yields. In many cases, decarboxylation of the heterocycles formed took place. When the reactions were carried out in dry media over K10 montmorillonite, dicondensation products were obtained beside the desired heterocycles. --H 2 0 Me Me 6 Scheme 3