反应详情

Pivaloyloxymethyl bromide (247 mg, 1.27 mmol) and sodium iodide (247 mg, 1.65 mmol) in acetone (5 ml) were stirred for 30 min., filtered, and the filtrate concentrated in vacuo. The resulting iodide in toluene (3 ml) was added to a solution of sodium (6R,7R)-7-[2-(2-aminothiazol-4-yl)-2-(Z)-methoxyiminoacetamido]-3-[(R)-tetrahydrofuran-2-yl]ceph-3-em-4-carboxylate (320 mg, 0.67 mmol) in N-methylpyrrolidinone (5 ml). After stirring for 30 min. at room temperature, the reaction mixture was diluted with ethyl acetate, washed successively with water (×3) and brine, dried over MgSO4 and concentrated in vacuo. The residue was chromatographed on silica gel eluting with 80% ethyl acetate in hexane to give the title compound as a yellow foam (297 mg, 78%); νmax (CH 2Cl2) 3387, 1786, 1752, 1735, 1686, 1605 cm-1 ; δH (CDCl3, 250 MHz) 1.22 (9H, s), 1.69 (1H, m), 1.98 (2H, m), 2.18 (1H, m), 3.43 and 3.62 (2H, ABq, J 18.0 Hz), 3.80-3.96 (2H, m), 4.10 (3H, s), 5.08 (1H, d, J 4.7 Hz), 5.19 (1H, m), 5.83-5.92 (3H, m), 6.32 (2H, br. s, exch), 7.02 (1H, s), 7.63 (1H, br. d, exch., J 8.6 Hz). [Mass spectrum: +ve ion (thioglycerol) MH+ (568)].

1. filtrationfiltered
2. concentrationthe filtrate concentrated in vacuo
3. washwashed successively with water (×3) and brine
4. dry with materialdried over MgSO4
5. concentrationconcentrated in vacuo
6. customThe residue was chromatographed on silica gel eluting with 80% ethyl acetate in hexane