Phenylalanine derivatives

A phenylalanine derivative of formula (1) or a pharmaceutically acceptable salt thereof:

• wherein X represents —O—, —O—SO2—, —NR1—, —NR1—C(═O)—, —NR1—SO2—, —NR1—C(═O)—NH—, —NR1—C(═S)—NH— or —C(═O)—, wherein R1 represents a hydrogen atom, a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a lower alkyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkyl group substituted with an aryl group or a lower alkyl group substituted with a heteroaryl group;
• Y represents N or CH;
• Z represents —C(═O)—, —S(═O)— or —SO2—;
• A represents a group of formula (2), a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, an aryl group, a heteroaryl group, a lower alkyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkyl group substituted with a group of general formula (2), a lower alkyl group substituted with an aryl group, a lower alkyl group substituted with a heteroaryl group, a lower alkenyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkenyl group substituted with an aryl group, a lower alkenyl group substituted with a heteroaryl group, a lower alkynyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkynyl group substituted with an aryl group or a lower alkynyl group substituted with a heteroaryl group:
• wherein R2, R3, R4, R5 and R6 may be the same or different from one another, and each represents a hydrogen atom, a halogen atom, a hydroxyl group, a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, an aryl group, a heteroaryl group, a lower alkyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkyl group substituted with an aryl group, a lower alkyl group substituted with a heteroaryl group, a lower alkoxyl group, a lower alkoxyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkoxyl group substituted with an aryl group, a lower alkoxyl group substituted with a heteroaryl group, a cycloalkyloxy group which may contain a hetero atom(s) in the ring thereof, an aryloxy group, a heteroaryloxy group, a hydroxy-lower alkyl group, a hydroxy-lower alkenyl group, a hydroxy-lower alkoxyl group, a halogeno-lower alkyl group, a halogeno-lower alkoxyl group, a halogeno-lower alkenyl group, a nitro group, a cyano group, a substituted or unsubstituted amino group, a carboxyl group, a lower alkyloxycarbonyl group, a substituted or unsubstituted carbamoyl group, a lower alkanoyl group, an aroyl group, a lower alkylthio group, a lower alkylsulfonyl group or a substituted or unsubstituted sulfamoyl group;
• B represents a hydroxyl group, a lower alkoxyl group or hydroxyamino group;
• G represents a hydrogen atom, a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a lower alkyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkyl group substituted with an aryl group or a lower alkyl group substituted with a heteroaryl group;
• D represents OR7, NR7R8, NHNR7R8, NR7NHR8, SR7 or R7, wherein R7 and R8 may be the same or different from each other and each represents a hydrogen atom, a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, an aryl group, a heteroaryl group, a lower alkyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkyl group substituted with an aryl group, a lower alkyl group substituted with a heteroaryl group, a lower alkenyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkenyl group substituted with an aryl group, a lower alkenyl group substituted with a heteroaryl group, a lower alkynyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkynyl group substituted with an aryl group, a lower alkynyl group substituted with a heteroaryl group, a halogeno-lower alkyl group, a halogeno-lower alkenyl group, a hydroxy-lower alkyl group, a hydroxy-lower alkenyl group or a substituted or unsubstituted amino-lower alkyl group, or R7 and R8 may be bonded together to form a ring which may contain one or two oxygen, nitrogen or sulfur atoms;
• and the substituent of the ring is a hydrogen atom, a halogen atom, hydroxyl group, a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, an aryl group, a heteroaryl group, a lower alkyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkyl group substituted with an aryl group, a lower alkyl group substituted with a heteroaryl group, a lower alkanoyl group, an aroyl group, a halogeno-lower alkanoyl group, a lower alkyloxy group, nitro group, cyano group, a substituted or unsubstituted amino group, carboxyl group, a lower alkoxycarbonyl group, a substituted or unsubstituted carbamoyl group, a lower alkylthio group, a lower alkylsulfonyl group or a substituted or unsubstituted sulfamoyl group;
• and
• E and E′ may be the same or different from each other and each represents a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkyloxy group or nitro group.