Sulfonamides and derivatives thereof that modulate the activity of endothelin

A compound of formula I:

• ##STR23## wherein:
• R.sup.1 and R.sup.2 are either (i), (ii) or (iii) as follows:
• (i) R.sup.1 and R.sup.2 are independently selected from H, NH.sub.2, NO.sub.2, halide, pseudohalide, alkyl, alkenyl, alkynyl, aryl, arylalkyl, heterolaryl, alkoxy, alkylamino, hydroxyalkyl, alkoxyalkyl, alkylthio, haloalkoxy, haloalkyl, alkylsufinyl, alkylsulfonyl, aryloxy, arylamino, arylthio, arylsufinyl, arylsulfonyl, haloalkyl, haloaryl, alkoxycarbonyl, alkylcarbonyl, aminocarbonyl, arylcarbonyl, formyl, substituted or unsubstituted amido, substituted or unsubstituted ureido, in which the alkyl, alkenyl and alkynyl portions contain from 1 up to about 14 carbon atoms and are either straight or branched chains or cyclic, and the aryl portions contain from about 4 to about 16 carbons, with the proviso that R.sup.2 is not halide or pseudohalide;
• or,
• (ii) R.sup.1 and R.sup.2 together form --(CH.sub.2).sub.n, where n is 3 to 6;
• or,
• (iii) R.sup.1 and R.sup.2 together form 1,3-butadienyl;
• and
• Ar.sup.2 is a heterocycle containing up to about 16 carbons in the ring, except that Ar.sup.2 is not naphthyl unless the compound is an N-isoxazolylsulfonamide substituted at the 4-position on the isoxazolyl group with halide or higher alkyl that contains from 8 to 15 carbon atoms and is a straight or branched chain.