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.
化合物的公式(I),其中:R1是较低的烷基,环状(较低)烷基,可选的取代芳基,可选的取代杂环基,环状(较低)烷基(较低)烷基,或芳基(较低)烷基;R2是氢,羟基或保护羟基;R3是较低的烷基,芳基,芳基(较低)烷基或可选的取代杂环(较低)烷基;R4是羧基,保护羧基或较低的磺酰
氨基甲酰基;R5是氢或较低的烷基;R6是氢或杂环基;A是单键或较低的烷基,Ar是可选的取代芳基,或其药学上可接受的盐,具有内皮素拮抗活性。