3-Methylbenzenesulphonyl chloride → 6-bromo-4-(toluene-3-sulfonyl)-3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazine

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Reaction Conditions

Reaction Steps

6-Bromo-3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazine (1.0 g, 4.65 mmol) and m-tolylsulfonyl chloride were dissolved in pyridine (10 mL). The resulting mixture was stirred at 80° C. for one hour. An additional portion of m-tolylsulfonyl chloride (0.98 g, 5.12 mmol) was added and the reaction mixture was stirred at 80° C. for 16 hours. Next, excess solvent was removed under vacuum, and the resulting oil was triturated with water to obtain a tan solid, which was collected by vacuum filtration and washed with water and diethyl ether to give 6-bromo-4-(toluene-3-sulfonyl)-3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazine. Yield 1.3 g (76%). LCMS (ESI): calc. C14H13BrN2O3S=368, 370; obs. M+H=369, 371.

Provenance & Evidence