Sodium Hydroxide → (4S,6S)-4-(2-fluoro-3-methyl-5-nitrophenyl)-4-(fluoromethyl)-6-(trifluoromethyl)-5,6-dihydro-4H-1,3-oxazin-2-amine

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Reaction Steps

(4S,6S)-4-(2-fluoro-3-methylphenyl)-4-(fluoromethyl)-6-(trifluoromethyl)-5,6-dihydro-4H-1,3-oxazin-2-amine (1.13 g, 3.67 mmol) was dissolved in conc. H2SO4 (20 mL) and cooled in an ice-bath. Then potassium nitrate (0.264 ml, 5.50 mmol) was added in one portion and the reaction was stirred for 5 min, removed from the ice-bath and after 5 min at room temperature LCMS showed the reaction went to completion and ice was added. The reaction mixture was poured into a mixture of DCM, water, ice and potassium phosphate tribasic (61.5 g, 290 mmol) and stirred for 5 min followed by the slowly addition of saturated NaHCO3. The mixture was neutralized with 5 N NaOH and extracted with DCM. The combined organics were dried over Na2SO4, filtered and concentrated to afford a pale yellow foam as (4S,6S)-4-(2-fluoro-3-methyl-5-nitrophenyl)-4-(fluoromethyl)-6-(trifluoromethyl)-5,6-dihydro-4H-1,3-oxazin-2-amine (1.26 g, 3.57 mmol, 97% yield). MS m/z=353.9 [M+H]+. Calculated for C13H12F5N3O3: 353.08.

Provenance & Evidence