Thionyl Chloride → 1-(phenylsulfonyl)-2,3-dihydro-1H-pyrido[2,3-b][1,4]oxazine-7-carbonyl chloride

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-(phenylsulfonyl)-2,3-dihydro-1H-pyrido[2,3-b][1,4]oxazine-7-carboxylic acid (230 mg, 0.718 mmol) in DCE (20 mL) was added thionyl chloride (0.5 mL, 6.85 mmol). The solution turned cloudy white. The reaction was heated to 70° C. and stirred at that temperature for 2 hours, after which time the solution was clear. LCMS analysis of the reaction mixture indicated consumption of starting material. The reaction mixture was concentrated in vacuo. 1-(phenylsulfonyl)-2,3-dihydro-1H-pyrido[2,3-b][1,4]oxazine-7-carbonyl chloride (243 mg, 0.718 mmol, 100% yield) was used without purification. LCMS (methanol adduct, i.e. the methyl ester; +ESI) m/z=335.0 [M+H]+.

Provenance & Evidence