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

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Reaction Steps

To a stirred solution of ethyl 4-amino-2-bromo-6-methylthieno[2,3-b]pyridine-5-carboxylate (Description 66) (390 mg, 1.24 mmol) in THF (12 mL) was added sodium tert-butoxide (297 mg, 3.09 mmol) and 3-chlorobenzenesulfonyl chloride (0.35 mL, 2.47 mmol). The reaction mixture was stirred at RT under nitrogen for ca. 3 h. The reaction mixture was diluted with ethyl acetate (ca. 30 mL) and water (ca. 50 mL). The organic layer was separated and the aqueous layer re-extracted with ethyl acetate (ca. 30 mL×2). The combined organic phase was dried over Na2SO4 and then concentrated in vacuo. Purification by chromatography on silica, eluting with a gradient of 0-20% ethyl acetate in DCM, afforded the title compound (252 mg). LCMS (A) m/z: 490/492 [M+1]+, Rt 1.48 min (acidic).

Provenance & Evidence