1,1,1-Trichloro-4,4-diethoxy-3-buten-2-one and its Trichloroacetylacetate Derivatives: Synthesis and Applications in Regiospecific Preparation of Azoles

Abstract

The synthesis of 1,1,1-trichloro-4,4-diethoxy-3-buten-2-one and three trichloroacetylacetate derivatives from the acylation reaction of respective trialkyl orthoacetates and orthopropionates with trichloroacetyl chloride in good yields, is reported. The title compounds were used for the regiospecific preparation of two isoxazoles and five pyrazoles in the cyclocondensation with hydroxylamine and hydrazines, respectively. The transformation of the trichloromethyl group under mild conditions into carboxylic groups is also described.