Organic fluorine compounds. Part XXXIX. Reactions of α-fluoro-β-keto-esters

Abstract

Ethyl 2,4-difluoroacetoacetate, ethyl ethoxalylfluoroacetate and the analogous benzyl ester gave the normal Wittig reaction with triethyl phosphonoacetate, whilst ethyl formylfluoroacetate gave a dimer of diethyl 4-fluoroprop-1-ene-1,3-dicarboxylate. Treatment of the sodio-enolate of ethyl formylfluoroacetate with acid chlorides gives 3-acyloxy-2-fluoroacrylates. The acyloxy-group of these compounds can be replaced easily by aromatic amines, and, furthermore, they can be employed for the synthesis of pyrimidines, e.g., 5-fluorouracil.