Benzofuranylimidazole derivatives, a process for their preparation and therapeutical compositions containing the same

Process for the preparation of benzofuranylimidazole derivatives of the formula ( 1) ##STR9## wherein R.sub.1 represents a hydrogen atom, and

• R.sub.2 represents a hydrogen atom, a halogen atom, an alkyl group having from 1 to 6 carbon atoms or an alkoxy group having from 1 to 5 carbon atoms;
• or a therapeutically acceptable salt of such a derivative, the process comprising the following successive steps:
• reacting a compound of formula (2) ##STR10## wherein R represents an alkyl group having from 1 to 4 carbon atoms and HX represents an acid, with, at least, one molar equivalent of an aminoacetaldehyde dialkyl acetal, in a polar solvent, for 1 to 24 hours, at a temperature of from -5.degree. C. to the boiling point of the reaction mixture thereby obtaining a compound of the formula (3) ##STR11## wherein R' and R" represent, each, an alkyl group having from 1 to 4 carbon atoms, and
• cyclizing, in an aqueous acidic medium, for 1 to 24 hours, at a temperature of from 15.degree. to 80.degree. C., the compound of the formula (3), said cyclizing resulting in compounds of the formula (1).