Compounds having a naphthalene structure

A compound selected from those of formula (I):

• ##STR14## in which:
• A represents a ##STR15## group, R represents linear or branched lower alkyl,
• R.sub.1 represents hydrogen or linear or branched lower alkyl, and
• R.sub.2 represents
• hydrogen
• linear or branched lower alkyl, or cycloalkyl, in either case optionally substituted by a halogen atom, as well as, any diastereoisomers thereof, isomers, epimers and diastereoisomers and addition salts with a pharmaceutically-acceptable acid, is being understood that the terms lower alkyl, as used herein mean such a group having 1 to 6 carbon atoms inclusive and that cycloalkyl means such a group having 3 to 8 carbon atoms inclusive.