6-subtituted-7-heteroquinoxalinecarboxylic acid derivatives and addition salts thereof and processes for the preparation of both

A 6-substituted-7-heteroquinoxalinecarboxylic acid derivative represented by the formula (1):

• wherein
• A denotes a single bond or methylene (CH2),
• Y denotes a nitrogen atom or ═CH—,
• V denotes a single bond or methylene (CH2),
• T denotes a hydroxyl group, amino group, lower alkoxycarbonyl group, carboxyl group, aldehyde group, the formula (2):
• wherein
• X denotes an oxygen atom or sulfur atom,
• R denotes an aralkyl group, phenyl group, naphthyl group, 5- or 6-membered heterocycle which may have one or more substituents, 5- or 6-membered heterocycle having a benzene ring fused thereto which may have one or more substituents on the benzene ring or the heterocycle, lower alkyl group which may be substituted with halogen atom, or cycloalkyl group, or the formula (3):
• wherein
• X denotes an oxygen atom or sulfur atom,
• R denotes an aralkyl group, phenyl group, naphthyl group, 5- or 6-membered heterocycle which may have one or more substituents, 5- or 6-membered heterocycle having a benzene ring fused thereto which may have one or more substituents on the benzene ring or the heterocycle, lower alkyl group which may be substituted with halogen atom, or cycloalkyl group,
• Q denotes a halogen atom, lower alkyl group or lower alkoxy group, and
• R1 denotes a hydroxyl group or lower alkoxy group,
• or an addition salt thereof.