A compound of the formula ##STR1## wherein (1) R.sub.1 is a lower alkyl group of 2 to 6 carbon atoms or a cycloalkyl group of 5 to 7 carbon atoms and R.sub.2 is a cycloalkyl group of 5 to 7 carbon atoms or a lower alkyl group of 1 to 3 carbon atoms which is substituted by a cycloalkyl group of 5 to 7 carbon atoms or by a phenyl group, or (2) R.sub.1 is a cycloalkyl group of 5 to 7 carbon atoms and R.sub.2 is a lower alkyl group of 1 to 5 carbon atoms, or a pharmaceutically acceptable salt thereof, processes for preparing the same and a pharmaceutical composition thereof are provided. The compound can orally be applied as antibiotics having improved bioavailability.
提供一种化合物的公式 ##STR1## 其中(1) R.sub.1是2到6个碳原子的低级烷基或5到7个碳原子的环烷基,R.sub.2是5到7个碳原子的环烷基或1到3个碳原子的低级烷基,该低级烷基被5到7个碳原子的环烷基或苯基取代,或者(2) R.sub.1是5到7个碳原子的环烷基,R.sub.2是1到5个碳原子的低级烷基,或其药学上可接受的盐,提供制备该化合物的方法以及其制剂。该化合物可口服应用作为具有改善
生物利用度的抗生素。