Hydrochloric Acid → 1-Benzothiophene-2-Sulfonamide

Temperature

0 °C

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)−.

1. waitAfter 1 hr
2. customThe white precipitated sulfonamide
3. filtrationis filtrated
4. dissolutiondissolved in NaOH (0.5 N)
5. extractionextracted with ethyl ether
6. extractionthe product is extracted into ethyl acetate
7. washThe organic phase is washed with water and brine
8. dry with materialdried over Na2SO4
9. concentrationconcentrated in vacuo

ORD record

ord-0bc982123e03494eaa2ba68507c47e46

Source dataset

uspto-grants-2007_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07282595B2