Aminophenylphosphonic acid compounds

A compound selected from the group consisting of those of formula (I):

• ##STR17## in which:
• R.sub.1, R.sub.2, which may be identical or different, represent hydrogen, halogen, linear or branched (C.sub.1 -C.sub.6) alkyl, linear or branched (C.sub.1 -C.sub.6) alkoxy, nitro, or trihalomethyl,
• X represents CO, SO.sub.2, or CH.sub.2,
• A.sub.1 represents selected from the group consisting of those linear or branched (C.sub.1 -C.sub.20) alkylene chain containing 0 to 6 double bonds and in which one or more --CH.sub.2 -- groups of the chain are optionally replaced by any one of the following groups:
• phenylene, substituted or unsubstituted,
• naphthylene, substituted or unsubstituted,
• anthracenylene, substituted or unsubstituted,
• (C.sub.3 -C.sub.7) cycloalkylene, ##STR18## in which A.sub.3 represents --(CH.sub.2).sub.m in which m represents 0, 1 or 2, --(CH.dbd.CH)--, or SO.sub.2, ##STR19## in which Z represents O, S, or NR.sub.5 in which R.sub.5 represents hydrogen or linear or branched (C.sub.1 -C.sub.6)alkyl, ##STR20## in which q or q', which may be identical or different, represent 0, 1 or 2, ##STR21## in which Z is as defined above, A.sub.2 represents:
• --(CH.sub.2).sub.n -- in which n is 0, 1, 2, or 3,
• or --CH.dbd.CH--,
• R.sub.3, R.sub.4, which may be identical or different, represent hydrogen or linear or branched (C.sub.1 -C.sub.6) alkyl,
• its isomers and its addition salts with a pharmaceutically-acceptable acid or base, the term "substituted" meaning that the relevant group is substituted with one or more halogen atoms or linear or branched (C.sub.1 -C.sub.6) alkoxy, hydroxyl, nitro, cyano, or amino (optionally substituted with one or more linear or branched (C.sub.1 -C.sub.6) alkyl groups) groups.