Pyrido (2,3-B) pyrazine derivatives

摘要

PCT No. PCT/JP96/03666 Sec. 371 Date Jun. 19, 1998 Sec. 102(e) Date Jun. 19, 1998 PCT Filed Dec. 13, 1996 PCT Pub. No. WO97/24355 PCT Pub. Date Jul. 10, 1997A compound of the formula: wherein R1 is pyridyl(lower)alkyl, N-oxidopyridyl(lower)alkyl or imidazolyl(lower)alkyl, R2 is aminophenyl, [protected amino]phenyl, [[[halophenyl](lower)alkenoyl]amino]phenyl, [[pyridyl(lower)alkenoyl]amino]phenyl, [[[N-oxidopyridyl](lower)alkenoyl]amino]phenyl, [[[protected aminopyridyl](lower)alkenoyl]amino]phenyl, [thiazolylcarbonylamino]phenyl which may have pyridyl, naphthyl having lower alkoxy and halogen, [dihalophenyl](lower)alkenyl, [N-oxidopyridyl](lower)alkenyl, [aminopyridyl](lower)alkenyl, [protected aminopyridyl](lower)alkenyl, [carboxypyridyl](lower)alkenyl, [protected carboxypyridyl](lower)alkenyl, [[pyridyl(lower)alkenyl]pyridyl](lower)alkenyl, [[carboxy(lower)alkenyl]pyridyl](lower)alkenyl, [[protected carboxy(lower)alkenyl]pyridyl](lower)alkenyl, [pyridyl(lower)alkenyl]pyridyl, lower alkylbenzothiazolyl or [halopyridylcarbonyl]amino, with proviso that when R2 is [[4-pyridyl(lower)alkenoyl]amino]phenyl, aminophenyl, [lower alkanoylamino]phenyl or [dihalophenyl](lower)alkenyl, then R1 is N-oxidopyridyl(lower)alkyl or imidazolyl(lower)alkyl, and a pharmaceutically acceptable salt thereof, which is useful as a medicament.