反应详情

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 soluton 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.

1. customThe precipitate is collected
2. washwashed with tetrahydrofuran
3. customthe combined filtrate and washings are evaporated in vacuo
4. additionThe residue is treated with a cold soluton of trifluoroacetic acid (10 ml) and anisole (0.5 g) for 15 minutes
5. concentrationconcentrated in vacuo
6. dissolutionThe residue is dissolved in ethyl acetate
7. additiontreated with 5% NaHCO3
8. customthe precipitated product is collected
9. customdried