Chloroacetyl chloride → (+/-)-(5S,7aR)-7-(2,5-Difluorophenyl)-2-cyclopropyl-5-phenyl-1,2,5,7a-tetrahydro-3H-pyrrolo[1,2-c]imidazol-3-one

Participants

Reaction Conditions

Reaction Steps

A solution of the azidocarbamate 2-1a (0.39 g, 0.95 mmol) in THF (10.0 mL) was treated with polystyrene bound triphenylphosphine and heated at 60° C. for 2 h. The reaction was quenched with water and heated at 60° C. for an additional hour. The reaction was diluted with EtOAc and filtered. The filtrate was washed with brine, dried over MgSO4, filtered and concentrated. A solution of this product (0.025 g, 0.07 mmol) in CH2Cl2 (3 mL) was treated with chloroacetyl chloride (0.007 g, 0.07 mmol) and triethylamine (0.007 g, 0.07 mmol) and stirred at rt for 2 h. The reaction was partitioned between dichloromethane and water. The organic solution was washed with brine, dried over MgSO4, filtered, and concentrated. The residue was dissolved in 4M HCl/dioxane and stirred for 1 hr. The reaction was then made basic with 3N aq NaOH and stirred vigorously. After 2 h, the reaction mixture was extracted with EtOAc. The organic solution was washed with brine, dried over MgSO4, filtered and concentrated. The remaining oil was dissolved in CH3CN (0.5 mL) and purified on a Gilson automated system affixed with a YMC J'sphere H80 20×50 mm column (eluting with 5-95% CH3CN +0.1% TFA in water +0.11% TF A over 10 min) to afford pure 5-1.

Provenance & Evidence