p-Toluenesulfonic acid monohydrate → 7-Amino-2-benzhydryloxycarbonyl-3-(2-mesyloxyprop-1-en-1-yl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene

Participants

Reaction Steps

A solution of the Z form of 2-benzhydryloxycarbonyl-7-t-butoxycarbonylamino-3- (2-mesyloxyprop-1-en-1-yl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene (1 g) in acetonitrile (12 cc) is heated to 38° C. A solution of p-toluenesulphonic acid monohydrate (0.63 g) in acetonitrile (10 cc) is added in the course of 20 minutes and the mixture is then kept at 38° C. for 1 hour. It is diluted with methylene chloride (30 cc) and the solution obtained is washed with a saturated solution of sodium bicarbonate (20 cc) and then with distilled water (50 cc), dried over sodium sulphate and concentrated to a volume of 15 cc under reduced pressure (20 mm Hg; 2.7 kPa) at 20° C. This yields a solution of the Z form of 7-amino-2-benzhydryloxycarbonyl-3-(2-mesyloxyprop-1-en-1-yl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene, to which triethylamine (0.7 cc) is added (Solution A).

Provenance & Evidence