Acetamidoxime: A Useful Reagent for Constructing Heterocyclic Compounds

Acetamidoxime (1) is a useful reagent for constructing heterocyclic compounds by the condensation-cyclization reactions with carbonyl compounds such as carboxylic acids and acid chlorides. For example, an ester 2 is formed by the condensation reaction of the hydroxy group of 1 with the carboxylic acid, followed by the intramolecular cycloaddition of the amino group of 2 to the carbonyl group to give the heterocycle 3. The formed 1,2,4-oxadiazole derivative acts as a bioisostere of the ester and amide groups. Therefore, 1 is expected to be used for the formation of heterocyclic compounds aimed for drug discovery.