Compounds of formula (I):
in which:
one of X and Y is N and the other is CH;
Z represents oxygen or sulfur;
and R1 to R7 represent various substituent groups;
and pharmaceutically acceptable salts thereof.
化合物的公式(I):其中:X和Y中的一个是N,另一个是CH;Z代表氧或
硫;R1到R7代表各种取代基;以及其药学上可接受的盐。