6-bromo-3,4-dihydro-1H-2lambda6,1-benzothiazine 2,2-dioxide

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: NBS (1.5 g, 8.2 mmol) was added to a solution of 3,4-dihydro-1H-benzo[c][1,2]thiazine 2,2-dioxide (1.5 g, 8.2 mmol) in DMF (15 mL). The reaction mixture was stirred overnight at ambient temperature followed by addition of water (200 mL) and EtOAc (100 mL). The two layers were separated and the aqueous phase was extracted with EtOAc (100 mL×3). The combined organic phases were washed with brine (200 mL×3), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by flash column chromatography on silica gel (EtOAc/hexane=1:3) to afford 6-bromo-3,4-dihydro-1H-benzo[c][1,2]thiazine 2,2-dioxide (1.7 g, 79% yield). The two layers were separated the aqueous phase was extracted with EtOAc (100 mL×3) The combined organic phases were washed with brine (200 mL×3) dried over anhydrous sodium sulfate concentrated The residue was purified by flash column chromatography on silica gel (EtOAc/hexane=1:3)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: NBS (1.5 g, 8.2 mmol) was added to a solution of 3,4-dihydro-1H-benzo[c][1,2]thiazine 2,2-dioxide (1.5 g, 8.2 mmol) in DMF (15 mL). The reaction mixture was stirred overnight at ambient temperature followed by addition of water (200 mL) and EtOAc (100 mL). The two layers were separated and the aqueous phase was extracted with EtOAc (100 mL×3). The combined organic phases were washed with brine (200 mL×3), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by flash column chromatography on silica gel (EtOAc/hexane=1:3) to afford 6-bromo-3,4-dihydro-1H-benzo[c][1,2]thiazine 2,2-dioxide (1.7 g, 79% yield). The two layers were separated the aqueous phase was extracted with EtOAc (100 mL×3) The combined organic phases were washed with brine (200 mL×3) dried over anhydrous sodium sulfate concentrated The residue was purified by flash column chromatography on silica gel (EtOAc/hexane=1:3)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: NBS (1.5 g, 8.2 mmol) was added to a solution of 3,4-dihydro-1H-benzo[c][1,2]thiazine 2,2-dioxide (1.5 g, 8.2 mmol) in DMF (15 mL). The reaction mixture was stirred overnight at ambient temperature followed by addition of water (200 mL) and EtOAc (100 mL). The two layers were separated and the aqueous phase was extracted with EtOAc (100 mL×3). The combined organic phases were washed with brine (200 mL×3), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by flash column chromatography on silica gel (EtOAc/hexane=1:3) to afford 6-bromo-3,4-dihydro-1H-benzo[c][1,2]thiazine 2,2-dioxide (1.7 g, 79% yield). The two layers were separated the aqueous phase was extracted with EtOAc (100 mL×3) The combined organic phases were washed with brine (200 mL×3) dried over anhydrous sodium sulfate concentrated The residue was purified by flash column chromatography on silica gel (EtOAc/hexane=1:3)