Synthesis of benzo-, pyrido-, thieno- and imidazo-fused N-hydroxy-4-oxopyrimidine-2-carboxylic acid derivatives

N-Hydroxy-4-oxoquinazoline-2-carboxamide derivatives (cyclic hydroxamic acids) and related pyrido- and thieno-substituted analogues, as well as a N-hydroxyhypoxanthine-2-carboxamide were synthesised for the first time, by means of a four-step sequence that involves a smooth reaction of aminohydroxamates with methyl trimethoxyacetate. Other strategies were unsuccessful.