Coupling of thioacetylproline derivative (I) with p-nitrobenzyl ester of ciprofloxacin (II) in the presence of dicyclohexylcarbodiimide (DCC) and 4-dimethylaminopyridine (DMAP) provided amide (III). Treatment with pyrrolidine in acetonitrile gave thiol (IV), which was subsequently alkylated with the carbapenem phosphate (V) in the presence of diisopropylethylamine to give thioether (VI). Then, hydrogenolytical removal of p-nitrobenzyl protecting groups in the presence of Pd-C, followed by treatment with sodium 2-ethylhexanoate in acetone provided the target disodium salt.