2,3-disubstituted pyridine derivatives, process for the preparation thereof, drug compositions containing the same and intermediates for the preparation

Abstract From the Canadian patent

Compounds represented by general formula (I) (wherein A is O S, CHR1 or NR2; , R1 and R2 are each H or lower alkyl; X1 and X2 are each H halogeno, nitro, cyano or the like; Y1 is H or lower alkyl; Z1 and Z2 are each H halogeno, cyano, hydroxy, lower alkyl or the like; and n is an integer of 2 to 4) and , physiologically acceptable salts thereof; a process for the preparation of both; drug compositions containing the same as the active ingredient; and intermediates for the preparation. The compounds (I) exhibit potent PDE IV inhibiting and excellent bronchodilating activities and are therefore useful , as PDE IV inhibitors and as therapeutic and preventive drugs for various allergic …