Pyridine → Benzhydryl (6R,7R)-8-oxo-7-(2-phenylacetamido)-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate

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Reaction Steps

To a solution of 7-amino-3-acetoxycepham-4-carboxylic acid diphenylmethyl ester (4) in dichloromethane (7 parts) cooling at -30° to -10° C. are added pyridine (1.7 equivalents) and phenylacetyl chloride (1.1 equivalents). After stirring for 30 minutes, the mixture is neutralized with triethylamine (1 to 9 equivalents), stirred at 0° to 5° C. for 24 hours, and diluted with ice water. The formed organic layer is taken, washed with hydrochloric acid and water, dried, and concentrated. The residue is crystallized from a mixture of ethyl acetate and ether to give 7beta-phenylacetylamino-3-cephem-4-carboxylic acid diphenylmethyl ester (6). Yield: 70.0%. mp. 170°-171° C. (decomposition).

Provenance & Evidence