Trifluoroacetic acid → HCID 57896671, compound

Participants

Reaction Conditions

Reaction Steps

To a suspension of tert-butyl 7-(tert-butylcarbamoyl)-2,3-dihydro-1H-pyrido[2,3-b][1,4]oxazine-1-carboxylate (1.425 g, 4.25 mmol) in DCM (5 mL) and DMF (5 mL) was added TFA (3 mL, 38.9 mmol). The reaction was stirred at 40° C. for 24 h. Additional TFA (2.2 mL, 28.5 mmol) was added to consume unreacted starting material. The reaction was allowed to stir at room temperature for 2 h. A further addition of TFA (4.4 mL, 57.0 mmol) was performed and the reaction was allowed to stir for 2 h. Upon consumption of the starting material the reaction mixture was concentrated in vacuo and purified by flash column chromatography using a gradient elution of DCM and 2-8% MeOH spiked with 1% TEA. The eluant was evaporated to yield an orange oil. The oil was treated with saturated aqueous NaHCO3 (100 mL) and extracted with EtOAc (2×50 mL). The combined organics were dried over Na2SO4 and concentrated in vacuo to provide N-tert-butyl-2,3-dihydro-1H-pyrido[2,3-b][1,4]oxazine-7-carboxamide (203 mg, 0.864 mmol, 20% yield 3 steps) as a white solid. LCMS (+ESI) m/z=236.1 [M+H]+;

Provenance & Evidence