| abstract |
A novel endothelin receptor antagonist is provided. A compound of formula I or a pharmaceutically acceptable salt thereof. [Wherein R 1 is (1-6C) alkyl, (2-6C) alkenyl, (2-6C) Selected from alkynyl, (1-6C) alkoxy or (1-6C) alkylthio, R 2 and R 3 are optionally present, and m and n are 0, 1 or 2 respectively. And Het is a substituted or unsubstituted pyrazine ring. ] [Selection figure] None |