FIELD: chemistry.SUBSTANCE: present invention relates to a piperidine derivative of general formula (I),where R1 denotes hydrogen or a substitute selected from the following (b)-(i): b) acrylic acid (including alkyl ester and hydroxyalkyl amide), (c) ureide, (d) alkenyl, (e) aminoalkyl which can be substituted with alkyl carbonyl or aminocarbonyl, (f) carbonyl alkyl, substituted with hydroxy, alkoxy or hydroxyalkylamino, (g) carbonyl, substituted with hydroxy, morpholino, alkoxy, hydroxyalkyl aminoalkoxy or cyclohexyloxy carbonyloxyalkoxy, (h) carbonylamino, substituted with alkyl or alkoxy, (i) aminocarbonyl which can be substituted with one or two substitutes selected from amino, hydroxy, alkoxy, alkenyl and alkyl (which can be substituted with halogen, thiol, piperidino, amino, alkoxy, alkoxycarbonyl, aminocarbonyl or one or two hydroxy)； R2 denotes hydrogen or a substitute selected from the following (j)-(r): (j) cyano, (k) acrylic acid, (l) alkyl, substituted with hydroxy or piperidino, (m) carbonyl alkyl, substituted with hydroxy, alkoxy (which can be substituted with cyclohexyloxy carbonyloxy) or hydroxyalkylamino, (n) carbonyl, substituted with hydroxy or alkoxy, (o) carbonyl alkoxy, substituted with alkoxy, (p) carbonyl alkyl sulphanyl, substituted with hydroxy or alkoxy, (q) alkoxy, (r) halogen； and R3 denotes hydrogen or a substitute selected from the following (s)-(w): (s) alkyl which can be substituted with carboxy, cyano, pyrrolidyl, piperidino, alkoxy, alkyl sulphanyl or one or two hydroxy, (t) carbonyl, substituted with alkyl or alkoxy, (u) carbonyl alkoxyalkyl, substituted with hydroxy or alkoxy, (v) carbonyl alkyl, substituted with alkyl, alkoxy or alkylphenyl, (w) aminoalkyl, substituted with aminocarbonyl or alkane sulphonyl, where one of said R1 and R2 denotes a substitute other than hydrogen, A is unsubstituted or is an oxo, B denotes carbon or oxygen, one of X and Y denotes carbon and the other denotes sulphur, the dotted line denotes a single
