zolyl; R.sup.20 is hydrogen; and A is furanyl orthienyl, in which said furanyl is optionally substituted with a chloro or bromo.A ninth embodiment of the first aspect of the present invention is a compound of the third embodiment of the first aspect wherein: R.sup.2 is selected from the group consisting of hydrogen, fluoro or methoxy; R.sup.5 is --C(O)NR.sup.9 R.sup.10 ;R.sup.15 and R.sup.19 are e