rogen atom to which they bond to form a pyrrolidine ring, a piperidine ring, a hexahydroazepine ring, a morpholine ring, a thiomorpholine ring, or a piperazine ring having optionally a lower alkyl or benzyl substituent on the other nitrogen atom); --CO--R7 (A-2) (in which R7 is a hydrogen atom, a lower alkyl group, a lower alkoxy group, a lower alkoxycarbonyl group, a lower alkyl group being subst