Water → 2-Benzhydryloxycarbonyl-7-t-butoxycarbonylamino-3-(2-dimethylamino-vinyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene

Participants

Reaction Conditions

Reaction Steps

2-Benzhydryloxycarbonyl-7-tert.-butoxycarbonylamino-3-methyl-8-oxo-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene (90.5 g) is dissolved in anhydrous N,N-dimethylformamide (400 cc). The solution obtained is heated at 80° C. under an atmosphere of nitrogen. A solution, preheated to 80° C., of bis-dimethylamino-tert.-butoxymethane (36.1 g) in anhydrous N,N-dimethylformamide (60 cc) is then added rapidly. The reaction mixture is kept at 80° C. for 5 minutes and then poured into ethyl acetate (3 liters). After addition of distilled water (1 liter), the organic phase is decanted, washed with distilled water (4×1 liter), dried over sodium sulphate and filtered in the presence of decolorising charcoal. The filtrate is concentrated to dryness under reduced pressure (20 mm Hg) at 30° C., and 2-benzhydryloxycarbonyl-7-tert.-butoxycarbonylamino-3-(2-dimethylaminovinyl)-8-oxo-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene (E-form) (101 g) is obtained in the form of an orange-coloured froth.

Provenance & Evidence