| 摘要 |
A compound of the formula: …<CHEM>… wherein… R<1> is carboxy(lower)alkyl or protected carboxy(lower)alkyl,… R<2> is carboxy or protected carboxy,… R<3> is hydrogen or lower alkyl, and… R<4> is lower alkyl, lower alkoxy, acyloxymethyl, lower alkylthiomethyl, lower alkoxymethyl, halogen, lower alkenyl or hydrogen,… and pharmaceutically acceptable salts thereof, and processes for the preparation thereof and also an antibacterial composition comprising the above compound in association with pharmaceutically acceptable carriers. The invention further relates to intermediate compounds of the formula …<CHEM>… and the preparation thereof. |
