Triethylamine → (2R,5R)-5-(6-bromo-3-fluoro-pyridin-2-yl)-2,5-dimethyl-2-trifluoromethyl-5,6-dihydro-2H-[1,4]oxazin-3-ylamine

Participants

Reaction Conditions

Reaction Steps

A suspension of (R)-2-[(R)-2-(6-bromo-3-fluoro-pyridin-2-yl)-2-(4-nitro-benzenesulfonylamino)-propoxy]-3,3,3-trifluoro-2-methyl-propionamide (8.43 g, 14.70 mmol) and triethylamine (5.12 ml, 36.8 mmol) in 85 ml DCM was cooled to 0-5° C. Trifluoroacetic anhydride (2.49 ml, 17.64 mmol) was added dropwise over 30 min. Additional triethylamine (1.54 ml, 11.07 mmol) and trifluoroacetic anhydride (0.75 ml, 5.29 mmol) were added to complete the reaction. The reaction mixture was quenched by addition of 14 ml aqueous ammonia (25%) and 14 ml water. The emulsion was stirred for 15 min, more water and DCM were added and the layers were separated. The organic layer was dried with MgSO4 H2O, filtered and evaporated. Purification by column chromatography on a silica gel (hexanes/10-25% EtOAc) gave 8.09 g of the title compound as a yellow resin.

Provenance & Evidence