Trifluoroacetic acid → 5-Cyano-pyridine-2-carboxylic acid [3-((R)-5-amino-3-difluoromethyl-3,6-dihydro-2H-[1,4]oxazin-3-yl)-4-fluoro-phenyl]-amide

Participants

Reaction Steps

((R)-5-{5-[(5-Cyano-pyridine-2-carbonyl)-amino]-2-fluoro-phenyl}-5-difluoromethyl-5,6-dihydro-2H-[1,4]oxazin-3-yl)-carbamic acid tert-butyl ester (44.47 g, 91.0 mmol) was dissolved in 450 ml DCM and mildly chilled with a rt water bath. TFA (150 ml) was added. The reaction was slightly exothermic. The mixture was stirred for 1.5 h at rt. The volatiles were removed with vacuum at rt. The residue was taken up in DCM and the procedure repeated twice. The residue was taken up in 3 L EtOAc and washed with 10% aqueous Na2CO3 and brine. The organic phase was dried with sodium sulfate and partially evaporated. iPrOH was added and the mixture chilled. The title compound was collected as snow-white crystals. Yield 30.56 g.

Provenance & Evidence