Endothelin antagonists

Abstract

A compound of formula (I), in which: R1 is lower alkyl, cyclo(lower)alkyl, optionally substituted aryl, optionally substituted heterocyclic group, cyclo(lower)alkyl(lower)alkyl, or ar(lower)alkyl; R2 is hydrogen, hydroxy or protected hydroxy; R3 is lower alkyl, aryl, ar(lower)alkyl or optionally substituted heterocyclic(lower)alkyl; R4 is carboxy, protected carboxy or lower alkylsufonylcarbamoyl; R5 is hydrogen or lower alkyl; R6 is hydrogen or heterocyclic group; A is a single bond or lower alkylene, and Ar is optionally substituted aryl, or pharmaceutically acceptable salts thereof, having endothelin antagonistic activity.

Dependencies are inferred from the claim text.