Compounds according to the formula: ##STR1## wherein: R.sub.1 and R.sub.2 are each independently selected from the group consisting of H, loweralkyl, aryl, alkylaryl, aminoalkyl, aminoaryl, halogen, oxyalkyl, oxyaryl, or oxyarylalkyl; R.sub.3 and R.sub.4 are each independently selected from the group consisting of H, loweralkyl, oxyalkyl, alkylaryl, aryl, oxyaryl, aminoalkyl, aminoaryl, or halogen; and X and Y are located in the para or meta positions and are each selected from the group consisting of H, loweralkyl, oxyalkyl, and ##STR2## wherein: each R.sub.5 is independently selected from the group consisting of H, loweralkyl, alkoxyalkyl, hydroxyalkyl, aminoalkyl, alkylaminoalkyl, cycloalkyl, aryl, or alkylaryl or two R.sub.5 groups together represent C.sub.2 to C.sub.10 alkyl, hydroxyalkyl, or alkylene; and R.sub.6 is H, hydroxy, loweralkyl, alkoxyalkyl, hydroxyalkyl, aminoalkyl, alkylamino, lkylarninoalkyl, cycloalkyl, hydroxycycloalkyl, alkoxycycloalkyl, aryl, or alkylaryl; or a pharmaceutically acceptable salt thereof, are disclosed. The compounds are useful for treating Pneumocystis carinii in a subject in need of such treatment.