0.21 ml of diisopropylethylamine and 0.22 ml of diphenylphosphoryl chloride were added dropwise to an ice-cooled solution of 363 mg of p-nitrobenzyl (5R,6S)-6-[(1R)-1-hydroxyethyl]-2-oxo-1-carbapenam-3-carboxylate in 5 ml of anhydrous acetonitrile, and the solution was stirred for one hour with ice-cooling. A solution of 0.18 ml of diisopropylethylamine and 282 mg of 2-(3-hydroxyiminopyrrolidin-1-yl)-2-iminoethylmercaptan hydrochloride in 3 ml of dimethylsulfoxide was added, and the mixture was then stirred for a further 20 minutes with ice-cooling. The reaction mixture was poured into 100 ml of anhydrous ether, and the solvent was decanted off from the gummy material which formed. This material was dissolved in a mixture of 20 ml of tetrahydrofuran, 7 ml of water and 23 ml of 0.1M phosphate buffer (pH 7.0), and the solution was catalytically hydrogenated at room temperature for 2 hours in the presence of 0.3 g of 10 % palladium-carbon. The product was worked up and purified in the same manner as in Example 2, giving 15 mg of the title compound.
