Abstract: A compound of the formula (I) wherein A is O, S, CHR1 or NR2, R1 and R2 are H, lower alkyl, X1 and X2 are H, halogen, nitro, cyano, etc., Y1 is H, lower alkyl, Z1 and Z2 are H, halogen, cyano, hydroxy, lower alkyl, etc., and n is an integer of 2 to 4, a pharmaceutically acceptable salt thereof, a process for preparing the same, a pharmaceutical composition containing the same as an active ingredient, and an intermediate therefor. The compounds (I) of the present invention show a potent PDE IV inhibitory activity as well as an excellent bronchodilating activity, and hence, they are widely useful as a PDE IV inhibitor in the treatment or prophylaxis of allergic inflammatory diseases or organ inflammatory diseases, especially in the treatment or prophylaxis of pulmonary diseases accompanied by airway obstruction such as asthma.