h the proviso that when D is a BCH group, A is A4 or A13 and R3 is different from a (C1-C4) alkoxy radical, then R1 and R2 are not simultaneously a hydrogen atom; b) compounds of following formula (II): in which: R6 is a hydrogen atom or a (C1-C4) alkyl radical, R7 is chosen from a hydrogen atom, an alkyl radical which may be unsubstituted or substituted with a ???CN radical or with an amino group