The present invention relates to novel derivatives of general formula (I) ##STR1##

in which

• R3 is a (1-6C)alkyl, aryl, aryl(1-6C)alkyl, heteroaryl, heteroaryl(1-6C)alkyl, aryl or heteroaryl fused to a (1-10C) cycloalkyl, heterocycle, heterocycloalkyl, cycloalkyl, adamantyl, polycycloalkyl, alkenyl, alkynyl, CONR1R2, COOR1, SO₂R1, C(NH)R1 or C(NH)NR1 radical;
• R5, R6 and R7 are, independently of one another, chosen from the following radicals: halogen, CN, NO₂, NH₂, OH, OR8, COOH, C(O)OR8, —O—C(O)R8, NR8R9, NHC(O)R8, C(O)NR8R9, NHC(S)R8, C(S)NR8R9, SR8, S(O)R8, SO₂R8, NHSO₂R8, SO₂NR8R9, —O—SO₂R8, —SO₂—O—R8, trifluoromethyl, trifluoromethoxy, (1-6C)alkyl, (1-6C)alkoxy, aryl, aryl(1-6C)alkyl, heteroaryl, heteroaryl(1-6C)alkyl, heterocycle, cycloalkyl, alkenyl, alkynyl, adamantyl or polycycloalkyl.