A compound represented by Formula I, or a polymorph, ester, tautomer,
enantiomer, diastereomer, pharmaceutically acceptable salt or prodrug
thereof, ##STR00001## Wherein R.sup.1 is halogen, --OR.sup.11,
--SR.sup.11 or lower alkyl; R.sup.2 is --NHR.sup.8; R.sup.4 is
--CHR.sup.12--, --C(O)--, --C(S)--, --S(O)-- or --S.sub.2--; and R.sup.5
is aryl, heteroaryl, alicyclic, or heterocyclic, wherein the aryl group
is substituted with 4 to 5 substituents, the heteroaryl group is
substituted with 3 to 5 substituents, the alicyclic group is substituted
with 3 to 5 substituents, and the heterocyclic group is substituted with
3 to 5 substituents.