3-Chlorobenzenesulphonyl chloride → Ethyl 2-bromo-4-{[(3-chlorophenyl)sulfonyl]amino}-6-methylthieno[2,3-b]pyridine-5-carboxylate

Participants

Reaction Steps

Alternatively, to a stirred solution of ethyl 4-amino-2-bromo-6-methylthieno[2,3-b]pyridine-5-carboxylate (Description 66) (3.76 g, 11.93 mmol) in THF (60 mL) and DMF (30 mL) was added sodium tert-butoxide (2.87 g, 29.8 mmol) and 3-chlorobenzenesulfonyl chloride (3.36 mL, 23.86 mmol). The reaction mixture was stirred at RT under nitrogen for ca. 30 min and was then diluted with water (ca. 30 mL) and concentrated in vacuo. The residue was purified by chromatography on silica, eluting with a gradient of 0-50% ethyl acetate/DCM, to afford the title compound (4.06 g). Alternatively, to a stirred solution of ethyl 4-amino-2-bromo-6-methylthieno[2,3-b]pyridine-5-carboxylate (Description 66) (7 g, 22.21 mmol) in THF (100 mL) and DMF (50 mL) was added sodium tert-butoxide (5.34 g, 55.5 mmol) and 3-chlorobenzenesulfonyl chloride (6.25 mL, 44.4 mmol). The reaction mixture was then stirred at RT under nitrogen for ca. 30 min. The reaction mixture was quenched with saturated NH4Cl solution (ca. 200 mL) and extracted with DCM (ca. 80 mL×5). The combined organics were dried and concentrated in vacuo. The residue was purified by chromatography on silica, eluting with a gradient of 0-50% ethyl acetate in DCM, to afford material (8.24 g). 200 mg of the material was re-purified with a gradient of 0-30% ethyl acetate in DCM, to afford the title compound (115 mg).

Provenance & Evidence