ES366092A1 - Procedure for preparing thiophene and furan derivatives. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Procedure for preparing thiophene and furan derivatives of the formula: **(See formula)** in which X is chosen from hydrogen, methyl and ethyl, chlorine and bromine radicals; Y is a phenyl radical that can be substituted by up to two chlorine atoms, bromine and fluorine; and Z means a group of the formula -CR1R2R3, in which R1 is chosen from hydrogen and the methyl and ethyl radicals; R2 is chosen from hydrogen and the methyl and ethyl radicals as well as the C2-6 alkoxycarbonyl, benzyloxycarbonyl and phenoxycarbonyl radicals; and R3 is a group chosen from those of the formula -CO2R4, -CONHR5 and -CONR6, in which R4 is chosen from hydrogen and the radicals alkyl, benzyl and phenyl C1-5, R5 is chosen from hydrogen and the hydroxy and amino radicals, as well as a C4-8 dialkyloaminoalkyl radical, and NR6 signifies the N-piperidino, N-morpholino and N-pyrrolidino radicals; and in which when R2 is a carboxyl radical R3 is also a carboxyl radical; B denoting both an oxygen and a sulfur atom; Y and Z being linked to non-adjacent carbon atoms of the heterocyclic nucleus; as well as non-toxic and pharmaceutically acceptable salts thereof; characterized by comprising reacting a compound of the formula: **(See formula)** in which B, X, Y and R1 have the meanings set out above, while R7 is chosen from hydrogen and the methyl and ethyl radicals; with an alkanol of the formula R4CH, in which R4 has the established meaning, in the presence of an acid chosen between sulfuric and hydrochloric, the latter being used only when B is an oxygen atom, obtaining a compound of the formula: **(See formula)** in which B, X, Y and R7 have the established meanings, while R4 particularly signifies a C1-5 alkyl radical. (Machine-translation by Google Translate, not legally binding)