Dicyclohexylcarbodiimide → 7-Methylsulfonylacetamido-3-cephem-4-carboxylic acid

Participants

Reaction Steps

A solution of benzhydryl 7-amino-3-cephem-4-carboxylate (0.78 g, 2 mmol), methylsulfonylacetic acid (0.27 g, 2 mmol), and dicyclohexylcarbodiimide (0.4 g, 2 mmol) in dry tetrahydrofuran (15 ml) is stirred at room temperature overnight. The precipitate is collected and washed with tetrahydrofuran and the combined filtrate and washings are evaporated in vacuo. The residue is treated with a cold solution of trifluoroacetic acid (10 ml) and anisole (0.5 g) for 15 minutes and then concentrated in vacuo. The residue is dissolved in ethyl acetate and treated with 5% NaHCO3. The aqueous phase is adjusted to pH 2 and the precipitated product is collected and dried.

Provenance & Evidence