4-quinolinone derivative or salt thereof

摘要

PCT No. PCT/JP95/01118 Sec. 371 Date Dec. 9, 1996 Sec. 102(e) Date Dec. 9, 1996 PCT Filed Jun. 6, 1995 PCT Pub. No. WO95/33726 PCT Pub. Date Dec. 14, 1995This invention relates to a 4-quinolinone derivative represented by the following general formula (1): <IMAGE> (1) wherein R1 and R2 mean individually H, halogen, cyano, or lower alkyl, lower alkylsulfonyl, lower alkylsulfinyl, lower alkylthio or lower alkoxy which may be substituted by halogen, or phenylsulfonyl, phenylsulfinyl or phenylthio which may have a substituent; and R3 and R4 denote individually H, lower alkyl or cycloalkyl which may be substituted by halogen, or pyridyl, furanyl or phenyl which may have a substituent, or R3 and R4 may form a 4-, 5- or 6-membered heterocyclic ring, or a salt thereof, and an intermediate useful for the preparation thereof, and besides a medicinal composition comprising this compound as an active ingredient. The compound (1) or the salt thereof has an excellent potassium channel-activating effect and is useful as, for example, a prophylactic and therapeutic agent for diseases of circulatory and bronchial systems.