| abstract |
The purpose is to provide selective PDE IV inhibitors which have a potent anti-asthmatic profile with excellent safety. A compound of the formula (1): <CHEM> wherein: A is an unsubstituted or optionally substituted 5 or 6 membered heteroaryl group or a fused benzene ring in which any of the above-defined heteroaryl groups is fused to a benzene ring, B is carbon or nitrogen, R<1> is hydrogen, lower alkyl, trifluoromethyl, hydroxyl, lower alkoxy, a residue derived from a carboxylic acid or a derivative thereof, amino, or an amino nitrogen-containing group, R<2> is hydrogen, halogen, cyano, nitro, lower alkylthio, lower alkylsulfinyl, lower alkylsulfonyl, trifluoromethyl, hydroxyl, lower alkoxy, a residue derived from a carboxylic acid or a derivative thereof, amino, or an amino nitrogen-containing group, and m is an integer of from 1 to 8, both inclusive; or a pharmaceutically acceptable salt thereof possesses selective PDE IV inhibition and is useful as a pharmaceutical drug, preferably an anti-asthmatic, etc. |