Intermediate compounds for preparing endothelin-receptor antagonist triterpene derivatives.

摘要

Intermediate compounds for the preparation of endothelin-receptor antagonist triterpene compounds have the formula <CHEM> wherein R<2> is hydrogen or -R<3><->R<4> wherein R<3> is -SO3-, -CH2COO-, -COCOO-, or -COR<5>COO- wherein R<5> is C1 - C6 alkylene or up to C6 alkenylene, R<4> is hydrogen, straight or branched C1 - C6 alkyl and R<6> is t-butoxycarbonyl or hydrogen, or a pharmaceutically acceptable salt thereof.