This invention relates to a compound of the formula: ##STR1## or a pharmaceutically acceptable salt thereof, wherein A and R.sup.1 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; R.sup.2 is (C.sub.1 -C.sub.4)alkyl optionally substituted with halo, amino or an alkyl amino; R.sup.3 and R.sup.4 are each hydrogen, halo, (C.sub.1 -C.sub.4)alkyl optionally substituted with halo and the like; and X.sup.1 to X.sup.4 are each hydrogen, halo, hydroxy, (C.sub.1 -C.sub.4)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.