Trifluoroacetic acid → NB-360

Participants

Reaction Conditions

Reaction Steps

To a solution of ((2R,5R)-5-{5-[(5-cyano-3-methyl-pyridine-2-carbonyl)-amino]-2-fluoro-phenyl}-2,5-dimethyl-2-trifluoromethyl-5,6-dihydro-2H-[1,4]oxazin-3-yl)-carbamic acid tert-butyl ester (2.27 g, 4.13 mmol) in CH2Cl2 (25 ml) was added TFA (41.3 mmol, 3.18 ml) and the reaction mixture was stirred at 25° C. for 2.5 h. The reaction mixture was added to 10% aqueous NaHCO3 solution (pH>8) and the free base was extracted with EtOAc. Combined organic layers were washed with water and brine, dried over MgSO4, filtered and concentrated. The crude product was re-crystallized twice by dissolving the material in EtOH (15 ml) at 50-60° C. and after saturation with H2O (6-8 ml) the clear solution was allowed to cool to ambient temperature overnight to provide after filtration and drying the title compound in >99% purity as white crystals: UPLC RtH5=0.905 min; ESIMS: 450 [(M+H)+]; 1H NMR (600 MHz, DMSO-d6): 10.72 (s, 1H), 8.97 (s, 1H), 8.39 (s, 1H), 7.78 (d, 1H), 7.71 (m, 1H), 7.15 (t, 1H), 6.08 (br s, 2H), 3.91 (d, 1H), 3.78 (d, 1H), 2.52 (s, 3H), 1.46 (s, 3H), 1.41 (s, 3H).

Provenance & Evidence