Sodium Bicarbonate → HCID 70616087, compound

Participants

Reaction Steps

A suspension of t-butyl 7β-amino-3-vinylceph-3-em-4-carboxylate hydrogen p-toluenesulphonate (1.14 g, 2.5 mmole) in methylene chloride (25 ml) was shaken with 4%-aqueous sodium hydrogen carbonate solution (10 ml) until the organic phase cleared. The aqueous phase was reextracted with methylene chloride (10 ml), and the combined organic phases were washed with water (10 ml) and dried (MgSO4). The solution of t-butyl 7β-amino-3-vinylceph-3-em-4-carboxylate so obtained was stirred and treated with a solution of dicyclohexylcarbodiimide (515 mg, 1 equiv.) in dry methylene chloride (10 ml). A solution of p-nitrophenylacetic acid (453 mg, 1 equiv.) in methylene chloride (15 ml) was added over a period of 5 minutes and the mixture was stirred at 30° for 2 hours. The precipitated N,N'-dicyclohexylurea was filtered off, and the filtrate was washed with 3%-sodium hydrogen carbonate solution (50 ml), water (50 ml), 2N-hydrochloric acid (25 ml) and water (25 ml), dried (MgSO4) and evaporated to an orange gelatinous solid. This solid was triturated with ethyl acetate (150 ml), the insoluble dicyclohexylurea was removed by filtration, and the filtrate was evaporated to give t-butyl 7β-(p-nitrophenylacetamido)-3-vinylceph-3-em-4-carboxylate (1.02 g, 92%) (see Table 1).

Provenance & Evidence