Abstract: A compound of the formula: ##STR1## wherein X is arylene, heteroarylene, fused arylene, fused heteroarylene, or deleted; Y is sulfonyl, --O--, or deleted; R.sub.1 is aryl, heteroaryl, fused aryl, or fused heteroaryl; R.sub.2 is H, lower alkyl, lower alkoxy, halo, nitro, cyano, haloalkyl, hydroxyl, carboxyl, amido, amino, or aminoalkyl; or a salt thereof are disclosed. Also disclosed are a pharmaceutical composition which contains an excipient and an effective amount of a compound of the above formula and a method of treating cancer which involves the administration of an effective amount of such a compound to a patient in need thereof.