Aniline derivatives possessing an inhibitory effect of nitric oxide synthase

A compound represented by the formula (1) or a possible stereoisomer or an optically active form of the compound or a pharmaceutically acceptable salt thereof:

• (where
• R1 is SR6 or NR7R8;
• R6 is an optionally substituted straight-chained or branched alkyl group having 1-6 carbon atoms or a straight-chained or branched alkenyl group having 2-6 carbon atoms;
• R7 is a hydrogen atom, a straight-chained or branched alkyl group having 1-6 carbon atoms, a cyclic alkyl group having 3-8 carbon atoms, a straight-chained or branched alkenyl group having 2-6 carbon atoms, a straight-chained or branched alkynyl group having 3-6 carbon atoms, a straight-chained or branched alkoxy group having 1-6 carbon atoms, or a nitro group;
• R8 is a hydrogen atom or a straight-chained or branched alkyl group having 1-6 carbon atoms;
• R2 is a hydrogen atom, a straight-chained or branched alkyl group having 1-6 carbon atoms, an alkoxycarbonyl group of which the alkyl portion is a straight-chained or branched alkyl group having 1-6 carbon atoms or a carboxyl group, or may combine with R3 to form a 3- to 8-membered ring;
• R3 is a hydrogen atom or a straight-chained or branched alkyl group having 1-6 carbon atoms, or may combine with R2 to form a 3- to 8-membered ring;
• R4 is a hydrogen atom, a straight-chained or branched alkyl group having 1-6 carbon atoms, an alkoxycarbonyl group of which the alkyl portion is a straight-chained or branched alkyl group having 1-6 carbon atoms, an optionally substituted acyl group having 1-8 carbon atoms or an amidino group that may be substituted on the nitrogen atom with a straight-chained or branched alkyl group having 1-6 carbon atoms or a cyclic alkyl group having 3-8 carbon atoms or a nitro group, or may combine with R5 to form a 3- to 8-membered ring;
• carbon atoms, or an optionally substituted cyclic alkyl group having 3-6 carbon atoms, an acyl group having 1-8 carbon atoms, an alkoxycarbonyl group of which the alkyl portion is a straight-chained or branched alkyl group having 1-6 carbon atoms, or Y5 and Y6 may combine together to form a 3- to 8-membered ring;
• R5 is a hydrogen atom, a straight-chained or branched alkyl group having 1-6 carbon atoms, an alkoxycarbonyl group of which the alkyl portion is a straight-chained or branched alkyl group having 1-6 carbon atoms, an alkoxycabonylamino group of which the alkyl portion is a straight-chained or branched alkyl group having 1-6 carbon atoms or an amino group, or may combine with R4 to form a 3- to 8-membered ring;
• Y1, Y2, Y3 and Y4 which may be the same or different are each a hydrogen atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a straight-chained or branched alkyl group having 1-6 carbon atoms that may be substituted by 1-3 halogen atoms, a cyclic alkyl group having 3-6 carbon atoms that may be substituted by 1-3 halogen atoms, a straight-chained or branched alkenyl group having 2-6 carbon atoms, a straight-chained or branched alkynyl group having 2-6 carbon atoms, an optionally substituted straight-chained or branched alkoxy group having 1-6 carbon atoms, a straight-chained or branched alkylthio group having 1-6 carbon atoms, NY5Y6 or COY7;
• where Y5 and Y6 which may be the same or different are each a hydrogen atom, an optionally substituted straight-chained or branched alkyl group having 1-6
• Y7 is a hydrogen atom, a hydroxyl group, a straight-chained or branched alkyl group having 1-6 carbon atoms or a cyclic alkyl group having 3-6 carbon atoms, an alkoxy group of which the alkyl portion is a straight-chained or branched alkyl group having 1-6 carbon atoms or NY5Y6;
• where Y5 and Y6 which may be the same or different are each a hydrogen atom, a straight-chained or branched alkyl group having 1-6 carbon atoms or a cyclic alkyl group having 3-6 carbon atoms;
• and
• n and m are each an integer of 0 or 1, with the proviso that
• 2-benzyloxycarbonylamino-3-(4-(N′-nitro)guanidinophenyl)propionic acid,
• 2-t-butoxycarbonylamino-3-(4-(N′-nitro)guanidinophenyl)propionic acid,
• 2-amino-3-(4-(N′-nitro)guanidinophenyl)propionic acid,
• 2-amino-3-(4-guanidinophenyl)propionic acid, and
• an optically active form thereof are excluded and with the further proviso that when R1 is NR7R8, then R2 is neither a carboxyl group nor an ester thereof, and with the further proviso that R7, R8, R2, R3, R4, R5, Y1, Y2, Y3 and Y4 are not all hydrogen when m and n are O.