反应详情

Freshly polished lithium flakes (2.0 g, 0.28 mol) were added to a solution of 1-benzyl-1H-benzo[c][1,2]thiazine 2,2-dioxide (6.5 g, 24 mmol) in THF (120 mL)/EtOH (12 mL) and liquid NH3 (150 mL) at −40° C. with stirring over 0.5 h. The reaction was quenched with NH4Cl powder (10 g). Water (200 mL) and EtOAc (200 mL) were added. 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=1:4) to afford 3,4-dihydro-1H-benzo[c][1,2]thiazine 2,2-dioxide (1.5 g, 34% yield).

1. customThe reaction was quenched with NH4Cl powder (10 g)
2. additionWater (200 mL) and EtOAc (200 mL) were added
3. customThe two layers were separated
4. extractionthe aqueous phase was extracted with EtOAc (100 mL×3)
5. washThe combined organic phases were washed with brine (200 mL×3)
6. dry with materialdried over anhydrous sodium sulfate
7. concentrationconcentrated
8. customThe residue was purified by flash column chromatography on silica gel (EtOAc/hexane=1:4)