Pyrrolopyridine derivative and use thereof

A compound represented by the formula

• wherein Ring A represents a pyridine ring which may have one or two C1-4 alkly groups, X represents a nitrile group, Y represents —CH═CH— or —(CH2)2, R1 represents (1) a C5-7 cycloalkyl group optionally fused with a benzene ring, (2) a C7-19 aralkyl group, (3) a 5- or 6-membered heterocyclic ring-C1-4 alkyl group or (4) a C6-14 aryloxy-C1-4 alkyl group, each of which may have 1 to 4 substituents selected from a halogen atom, a C1-4 alkyl group, a mono-, di- or tri-halogeno-C1-4 alkyl group and a C1-4 alkoxy group, and one of R2 and R3 is a hydrogen atom or a C1-4 alkyl group, and the other is a C6-14 aryl group, a C7-19 aralkyl group, a C3-10 cycloalkyl group, a tetrahydropyranyl group, a pyranyl group or a pyridyil group or a C1-6 alkyl group, each of which may have 1 to 4 substituents selected from a halogen atom, a C1-4 alkyl group, a mono-, di- or tri- halogeno-C1-4 alkyl group, a C1-4 alkoxy group, a C1-4 alkoxy-carbonyl group, a cyano group, a C1-4 alkyl-carbonylamino group and a hydroxyl group or a salt thereof.