This invention relates to a compound of the formula: ##STR1##

or a pharmaceutically acceptable salt thereof, wherein A and R¹ are each an optionally substituted 5 to 6-membered heteroaryl, wherein the heteroaryl is optionally fused to a carbocyclic ring or 5 to 6-heteroaryl; R² is NH₂; R³ and R⁴ are each hydrogen, halo, (C₁-C₄)alkyl optionally substituted with halo and the like; and X¹ to X⁴ are each hydrogen, halo, hydroxy, (C₁-C₄)alkyl optionally substituted with halo and the like. These compounds have COX-2 inhibiting activity and thus useful for treating or preventing inflammation or other COX-2 related diseases.