Hydrochloric Acid → 1-Benzothiophene-2-Sulfonamide

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of benzo[b]thiophene (2.2 mmol) in dry THF (1.5 mL) is cooled to 0° C. and is slowly added 1.6 M n-BuLi in hexane (1.6 mL, 2.5 mmol). The temperature is maintained at 0° C. and the reaction mixture is stirred for 20 min. Then the heterogeneous mixture is diluted with 2 mL of THF and is transferred by canula to a well-stirred solution of sulfuryl chloride (368 μL, 4.6 mmol) in hexane (1.5 mL) at 0° C. After 1 hr, the suspension is diluted with acetone and the resulting solution of the corresponding sulfonyl chloride is added slowly to a solution of 2 mL of NH4OH in acetone (5 mL). The mixture is diluted with water and acidified with concentrated HCl. The white precipitated sulfonamide is filtrated and dissolved in NaOH (0.5 N) and extracted with ethyl ether. The aqueous phase is acidified and the product is extracted into ethyl acetate. The organic phase is washed with water and brine, dried over Na2SO4 and concentrated in vacuo to afford the title compound (200 mg, 42%). ES(−)MS m/z 212, (M−H)−.

Provenance & Evidence