反应详情

To a solution of benzo[b]thiophene-2-sulfonyl chloride (1.165 g, 5 mmol) in 25 mL of dichloromethane was added 3.6 mL of concentrated nitric acid (>22.05 mol/L) dropwise, the resulting mixture was refluxed overnight and cooled to room temperature before it was poured into 20 gram of crushed ice. The organic layer was separated and the aqueous layer was extracted by 220 mL 2 dichloromethane. The organic layers were combined and dried over MgSO4. Solvent was then removed by rotary evaporator. The crude product was purified by flash column chromatography with an eluent of hexane, followed by a gradient eluent of hexane/ethyl acetate (6/1-3/1) to afford 0.58 g of product (mixture of 65% of 4-nitro-benzo[b]thiophene-2-sulfonyl chloride and 35% of 7-nitro-benzo[b]thiophene-2-sulfonyl chloride).

1. temperaturethe resulting mixture was refluxed overnight
2. customThe organic layer was separated
3. extractionthe aqueous layer was extracted by 220 mL 2 dichloromethane
4. dry with materialdried over MgSO4
5. customSolvent was then removed by rotary evaporator
6. customThe crude product was purified by flash column chromatography with an eluent of hexane