DIMROTH REARRANGEMENT IN CONDENSED HETEROCYCLIC SYSTEMS

Abstract

This thesis includes three chapters, the first of which is a review on the Dimroth rearrangement in condensed heterocyclic systems. Chapter II is a discussion of the work carried out by the candidate. The main objective of the work is the synthesis of triazolopyrimidines and the deduction of the site of anellation of the triazole ring during their formation as well as the versatility of the Dimroth rearrangement with such types of heterocycles. The required starting materials were 5-cyano-2- hydrazino-6-phenyl-3,4-dihydropyrimidine-4-one (I) and its N-methyl derivative II. Reaction of I and II with formic acid gave 6-cyano-7-phenyl-1,2,4• triazolo[4,3-a]pyrimidin-5(8H)-one (III) and 6-cyano-8-methyl-5-phenyl• 1,2,4-triazolo[4,3-a]pyrimidin-7-one (IV), respectively. When the reaction was carried out in ethanol as a solvent, the fonnyl derivative V was obtained.