Boron Trichloride → HCID 66782856, compound

Participants

Reaction Steps

Boron trichloride solution (1 M in CH2Cl2, 1.33 mL, 1.33 mmol) was added at 0° C. to a solution of 4-(tert-butyl-diphenyl-silanyloxy)-2-[3-methyl-2-oxo-4-(3-trifluoromethoxy-phenyl)-piperazin-1-yl]-butyric acid methyl ester (430 mg, 0.68 mmol) in CH2Cl2 (6 mL), then the ice bath was removed and the solution stirred for 18 h. Another portion of boron trichloride solution (1 M in CH2Cl2, 0.70 mL, 0.70 mmol) was then added, then after 6 h the reaction mixture was partitioned between CH2Cl2 and sat. aq. NaHCO3 solution. The organic layer was washed with brine, dried (MgSO4), filtered, and evaporated. Chromatography (SiO2; heptane/EtOAc 4:1) afforded the title compound (131 mg, 42%), which contained 15% of the lactonized side product, 3-methyl-1-(2-oxo-tetrahydro-furan-3-yl)-4-(3-trifluoromethoxy-phenyl)-piperazin-2-one. Light yellow oil, MS: 391.1 (M+H)+.

Provenance & Evidence