Phosphorus pentachloride → benzhydryl (6R)-3-(chloromethyl)-8-oxo-7-[[(2Z)-2-prop-2-ynoxyimino-2-[2-(tritylamino)-1,3-thiazol-4-yl]acetyl]amino]-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate

Participants

Reaction Steps

Phosphorus pentachloride (910 mg) was added to a solution of (Z)-2-propargyloxyimino-2-(2-tritylaminothiazol-4-yl)acetic acid (IV-f) (1.7 g, 3.6 mmoles) in dichloromethane (30 ml). After stirring for 1 hour at room temperature, the mixture was added in one portion to an ice-cooled solution of (V) (1.98 g, 4.4 mmoles) and N,O-bis(trimethylsilyl)acetamide (1.5 ml) in dichloromethane (30 ml). After stirring for 1 hour, the reaction mixture was poured into 10% aqueous NaHCO3 (300 ml) and extracted with ethyl acetate (300 ml). The extract was washed with water, dried over MgSO4 and evaporated under reduced pressure. The residue was chromatographed on a silica gel column. Elution with CHCl3 gave the title compound [VI-f] as an amorphous powder weighing 2.1 g (66%).

Provenance & Evidence