| abstract |
Antibiotic cephalosporin compounds, method of making and pharmaceutical composition thereof represented by the general formula wherein R1 is amino, lower alkylamino, a protected amino, a protected lower alkylamino, hydroxy or lower alkoxy, R2 is hydrogen, acyloxy, pyridium or a heterocyclicthio group which may have suitable substituent(s), R3 is carboxy or its derivative, A is carbonyl, hydroxy(lower)alkylene or a protected hydroxy(lower)alkylene and R4 is hydrogen or halogen, or R2 and R3 are linked together to represent a group of the formula -COO-, this divisional application being directed to intermediate compounds of the formula: |