Benzenesulfonyl chloride → methyl 1-(phenylsulfonyl)-2,3-dihydro-1H-pyrido[2,3-b][1,4]oxazine-7-carboxylate

Participants

Reaction Steps

To a solution of methyl 2,3-dihydro-1H-pyrido[2,3-b][1,4]oxazine-7-carboxylate (278.9 mg, 1.436 mmol) in DCM (20 mL) was added benzenesulfonyl chloride (278 μL, 2.156 mmol), DIPEA (753 μL, 4.31 mmol) and DMAP (88 mg, 0.719 mmol). The reaction was stirred at room temperature for 16 hours. LCMS analysis indicated a predominance of product in the reaction mixture. The solvent was removed under reduced pressure and the resulting oil was purified by flash column chromatography using a gradient elution of hexanes with 25-70% EtOAc to provide methyl 1-(phenylsulfonyl)-2,3-dihydro-1H-pyrido[2,3-b][1,4]oxazine-7-carboxylate (280 mg, 0.837 mmol, 58.3% yield) as a yellow glass. LCMS (+ESI) m/z=334.8 [M+H]+.

Provenance & Evidence