Hydrochloric Acid → N-(5-bromo-2-chloropyridin-3-yl)-4-fluorobenzenesulfonamide

Temperature

25 °C

To a 50-mL, round-bottomed flask was added 3-amino-5-bromo-2-chloropyridine (0.50 g, 2.4 mmol, Asymchem, Morrisville, N.C.), pyridine (10 mL, 120 mmol) and 4-fluorobenzenesulfonyl chloride (2.0 g, 10 mmol, Fluka, Buchs, Switzerland). The mixture was stirred at 25° C. After 18 hours, the mixture was concentrated in vacuo. To the residue was added methanol (10 mL), 1,4-dioxane (10 mL) and potassium carbonate (3.4 g, 25 mmol). The mixture was stirred at 60° C. After 16 hours, the mixture was poured into water (100 mL) and the pH was adjusted to ˜7 with 1 N HCl. The solution was extracted with EtOAc (3×75 mL) and the combined extracts were washed with water (100 mL), brine (100 mL) and then dried (Na2SO4) and concentrated onto silica. Purification by silica gel chromatography (2.0 to 30% EtOAc/hexane) afforded the title compound as a white solid (0.53 g, 58% yield). MS (ESI pos. ion) m/z: 367 (M+1). 1H NMR (400 MHz, DMSO-d6) δ ppm 10.63 (br. s, 1H), 8.42 (d, J=2.3 Hz, 1H), 7.94 (d, J=2.3 Hz, 1H), 7.77-7.84 (m, 2H), 7.40-7.47 (m, 2H).

1. concentrationthe mixture was concentrated in vacuo
2. stirringThe mixture was stirred at 60° C
3. waitAfter 16 hours
4. extractionThe solution was extracted with EtOAc (3×75 mL)
5. washthe combined extracts were washed with water (100 mL), brine (100 mL)
6. dry with materialdried (Na2SO4)
7. concentrationconcentrated onto silica
8. customPurification by silica gel chromatography (2.0 to 30% EtOAc/hexane)

ORD record

ord-ae39fcef37e34a83b01f71b8ef40027b

Source dataset

uspto-grants-2010_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07820665B2