A .beta.-lactam series compound represented by the formula (I): ##STR1## wherein R.sup.1 represents a hydrogen atom or a lower alkyl group; R.sup.2 represents a hydrogen atom; R.sup.3 represents a halogen atom, a nitro group, an amino group, a hydroxy group, a lower alkyl group, a lower alkoxy group, a lower alkanoylamino group, a lower alkanesulfonyloxy group or a group represented by the formula ##STR2## where R.sup.5 represents a hydrogen atom, a lower alkanoyl group, or a lower alkanesulfonyl group; R.sup.4 represents a hydrogen atom or a hydroxy group; n is 0 or 1; l is 0, 1 or 2; and A represents --C(CH.sub.3).sub.2 --CH(COOH)-- or --CH.sub.2 C(CH.sub.2 R.sup.6).dbd.C(COOH)-- where R.sup.6 represents a lower alkanoyloxy group, a group represented by the formula ##STR3## where R.sup.7 and R.sup.8 each represents a lower alkyl group and when n is 0, R.sup.1 and R.sup.2 can combine to form a cyclohexane ring together with the carbon atoms to which they are attached, and pharmaceutically acceptable salts thereof as well as a method for preparing same are disclosed. These compounds have antimicrobial activity.
公式(I)所表示的β-内酰胺系列化合物:##STR1##其中,R.sup.1代表氢原子或低碳基;R.sup.2代表氢原子;R.sup.3代表卤素原子、硝基、
氨基、羟基、低碳基、低烷氧基、低烷酰胺基、低烷基磺酰氧基或由公式##STR2##所表示的基团,其中,R.sup.5代表氢原子、低烷酰基或低烷基磺酰基;R.sup.4代表氢原子或羟基;n为0或1;l为0、1或2;A代表--C(CH.sub.3).sub.2 --CH(COOH)--或--CH.sub.2 C(CH.sub.2 R.sup.6).dbd.C(COOH)--,其中,R.sup.6代表低烷酰氧基、由公式##STR3##所表示的基团,其中,R.sup.7和R.sup.8各代表低碳基,当n为0时,R.sup.1和R.sup.2可以与它们附着的碳原子一起形成
环己烷环,并且公开了制备它们的方法及其药学上可接受的盐。这些化合物具有抗微
生物活性。