Process for the preparation of novel therapeutically useful dihydroindole derivatives

摘要

The invention relates to a process for the preparation of compounds of the formula I and the preparation of physiologically acceptable salts thereof <IMAGE> wherein R1 and R2 are each independently an alkyl or alkenyl group having up to 6 carbon atoms and which may be substituted, a cycloalkyl or cycloalkenyl group having 5 to 7 carbon atoms, an aryl or partially hydrogenated aryl group or a 5 to 7 or 8 to 10 membered monocyclic or bicyclic, heterocyclic group consisting of 1 or 2 S or O atoms and/or up to 4 N atoms and which may be substituted, or R1 is hydrogen and R2 is as defined above, and R4 is hydrogen, alkyl having 1 to 6 carbon atoms, alkenyl having 2 to 6 carbon atoms or aralkyl having 7 to 14 carbon atoms. These compounds have hypotensive properties.