反应详情

温度

25 °C

A solution of thiourea (0.054 g) in distilled water (1 cc) is added to a solution of 2-benzhydryloxycarbonyl-3-(1-bromo-2-oxoethyl)-7-(3,4-dichlorophenylthio)acetamido-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene (mixture of the diastereoisomers at the substituent in the 3-position) (0.5 g) in tetrahydrofuran (10 cc), and the reaction mixture is then stirred for 17 hours at 25° C. before being poured into a mixture of distilled water (250 cc), a saturated solution of sodium bicarbonate (60 cc) and ethyl acetate (60 cc). The organic phase is washed with distilled water (3×30 cc) and then with a saturated solution of sodium chloride (30 cc) and dried over magnesium sulphate. The residue obtained after concentration of the solvent to dryness under reduced pressure (30 mm Hg; 4 kPa) at 30° C. is chromatographed on a column (height: 28 cm, diameter: 2 cm) of silica gel (0.04-0.063 mm), elution being carried out under a pressure of 0.5 bar (50 kPa) with a 30/70 by volume mixture of cyclohexane and ethyl acetate, and 15 cc fractions being collected. Fractions 7 to 10, containing the pure product, are combined and concentrated under reduced pressure (30 mm Hg; 4 kPa) at 30° C. to give 3-(2-aminothiazol-5-yl)-2-benzhydryloxycarbonyl-7-(3,4-dichlorophenylthio)acetamido-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene (0.29 g) in the form of a hard, pale yellow foam.

1. washThe organic phase is washed with distilled water (3×30 cc)
2. dry with materialwith a saturated solution of sodium chloride (30 cc) and dried over magnesium sulphate
3. customThe residue obtained after concentration of the solvent to dryness under reduced pressure (30 mm Hg; 4 kPa) at 30° C.
4. customis chromatographed on a column (height: 28 cm, diameter: 2 cm) of silica gel (0.04-0.063 mm), elution
5. additionbeing carried out under a pressure of 0.5 bar (50 kPa) with a 30/70 by volume mixture of cyclohexane and ethyl acetate, and 15 cc fractions
6. custombeing collected
7. additionFractions 7 to 10, containing the pure product
8. concentrationconcentrated under reduced pressure (30 mm Hg; 4 kPa) at 30° C.