A compound of the formula:
in which R' is aryl which may have one or more suitable substituent(s) or a heterocyclic group,
R' is an esterfied carboxy group,
R3 is lower alkyl, acyl, protected acyl or cyano,
R4 is lower alkyl and
A is lower alkylene,
and pharmaceutically acceptable salt thereof, processes for its preparation and pharmaceutical compositions, containing them in association with pharmaceutical carrier or diluent. The invention also relates to intermediates for preparing the above compounds.
以下式子的化合物
其中 R' 为芳基,可带有一个或多个合适的取代基,或杂环基、
R' 是酯化羧基、
R3 是低级烷基、酰基、受保护酰基或
氰基、
R4 是低级烷基
A 是低级亚烷基、
及其药学上可接受的盐、制备方法和药物组合物,其中含有与药物载体或稀释剂结合的这些物质。本发明还涉及制备上述化合物的中间体。