Water → 2,2-dimethylpropanoyloxymethyl (6R)-3-(carbamoyloxymethyl)-7-[[(2Z)-2-methoxyimino-2-(1,3-thiazol-4-yl)acetyl]amino]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate

Participants

Reaction Steps

To a solution of sodium 7-[(Z)-2-methoxyimino-2-(thiazol-4-yl)acetamido]-3-carbamoyloxymethyl-3-cephem-4-carboxylate (0.86 g) in dimethylsulfoxide (8 ml) was added pivaloyloxymethyl iodide (0.67 g). This reaction mixture was stirred for 100 min. at room temperature, and then added to a mixture of water (86 ml) and ethyl acetate (86 ml) with stirring. The ethyl acetate layer was separated, washed twice with water, and dried over anhydrous magnesium sulfate. The ethyl acetate was evaporated under reduced pressure. Petroleum ether was added to the residue. Filtration of resulting crystals and drying thereof under reduced pressure gave the title compound (0.67 g) in crude form. This crude product was purified by chromatography on a reverse phase column (LiChroprep® RP-8) with a mobile phase consisting of water-acetonitrile-acetic acid (650:350:5), and the fractions containing the product were freeze-dried. The product thus obtained was contaminated with 2-cephem isomer.

Provenance & Evidence