反应详情

温度

0 °C

A solution of 85% pure m-chloroperbenzoic acid (1.6 g) in methylene chloride (50 cc) is added, in the course of 20 minutes, to a solution, cooled to 0° C., of a mixture of the 3-acetonyl-2-benzhydryloxycarbonyl-7-[2-methoxyimino-2-(2-tritylaminothiazol-4-yl)-acetamido]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene and -oct-3-ene isomers (6.7 g) in methylene chloride (100 cc). The mixture is stirred for 11/2 hours at 0° C. and a saturated solution of sodium bicarbonate (50 cc) is then added. The organic phase is decanted, dried over sodium sulphate and concentrated to dryness under reduced pressure (20 mm Hg; 2.7 kPa) at 20° C. The residue is chromatographed on a column of Merck silica gel (0.06-0.20) (75 g) (diameter of the column: 3 cm; height: 21 cm). Elution is carried out with a 70/30 (by volumne) ethyl acetate/cyclohexane mixture (1.5 liters), 100 cc fractions being collected. Fractions 7 to 10 are concentrated to dryness under reduced pressure (20 mm Hg; 2.7 kPa) at 20° C. This yields the syn isomer of 3-acetonyl-2-benzhydryloxycarbonyl-7-[2-methoxyimino-2-(2-tritylaminothiazol-4-yl)-acetamido]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-5-oxide (5 g) in the form of a hard yellow foam.

1. customThe organic phase is decanted
2. dry with materialdried over sodium sulphate
3. concentrationconcentrated to dryness under reduced pressure (20 mm Hg; 2.7 kPa) at 20° C
4. customThe residue is chromatographed on a column of Merck silica gel (0.06-0.20) (75 g) (diameter of the column
5. washElution
6. custombeing collected
7. concentrationFractions 7 to 10 are concentrated to dryness under reduced pressure (20 mm Hg; 2.7 kPa) at 20° C