Hydrochloric Acid → 1-Benzofuran-2-Sulfonamide

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of benzo[b]furane (2.5 mmol) in dry THF (1.5 mL) and cooled to 0° C. is slowly added 1.6 M n-BuLi in hexane (1.7 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 (410 μL, 5.1 mmol) in hexane (2.0 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 and the product extracted into ethyl acetate. The organic phase is washed with water and brine, dried over Na2SO4 and concentrated in vacuo. The crude product is purified by silica gel chromatography (eluent: hexane 4/ethyl acetate 1) to afford the title compound (211 mg, 43%).

Provenance & Evidence