Reactivity of α‐acylated β‐enamino ketones and esters: Synthesis of pyrazoles

Abstract

Abstract The reactivity of the enamino compounds 4‐amino‐3‐phenylamino(thio)carbonyl‐3‐penten‐2‐one 1 and 2 and ethyl 3‐amino‐2‐phenylamino(thio)carbonyl‐2‐butyrate 7 and 8 was studied using the reaction with hydrazine hydrate and hydrazine hydrochloride to evaluate the 1,3 electrophilic center of the compounds by the formation of the pyrazole rings. The pyrazoles 3, 4, 5, 9, 11 and 13 were obtained depending on the reaction conditions employed.