A compound of the formula: ##STR1## wherein R.sup.1 -A- is a group of the formula: ##STR2## in which R.sup.1 is aryl or a heterocyclic group, each of which may be substituted with substituent(s) selected from the group consisting of lower alkyl, lower alkoxy, lower alkylthio, halo(lower)alkyl, acyl, acylamino and halogen, or lower alkyl which may be substituted with a heterocyclic group optionally substituted with acyl, and X is O or S, and R.sup.2 is hydrogen or lower alkyl, provided that when R.sup.1 is lower alkyl, then R.sup.1 -A- is a group of the formula: ##STR3## in which R.sup.1 and X are each as defined above, processes for the preparation thereof and pharmaceutical composition comprising the same.
化合物的公式为:##STR1## 其中 R.sup.1 -A- 是公式的一个基团:##STR2## 其中 R.sup.1 是芳基或杂环基团,每个基团可以被选自下列取代基组成的群体取代,所述取代基包括低烷基、低烷氧基、低烷
硫基、卤素(低)烷基、酰基、酰基
氨基和卤素,或者可以被选自可选地取代酰基的杂环基团取代的低烷基,X 是 O 或 S,R.sup.2 是氢或低烷基,但当 R.sup.1 是低烷基时,R.sup.1 -A- 是公式的一个基团:##STR3## 其中 R.sup.1 和 X 的定义如上所述,其制备方法和包含其的制药组合物。