Sodium Bicarbonate → ethyl 4-[(2-chloro-4,4-difluoro-spiro[5H-thieno[2,3-c]pyran-7,4'-piperidine]-1'-yl)methyl]-1-(3-fluoro-2-pyridyl)pyrazole-3-carboxylate

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Reaction Steps

To a solution of ethyl 1-(3-fluoro-2-pyridyl)-4-formyl-pyrazole-3-carboxylate (342.5 mg) in 1,2-dichloroethane (6.7 mL), 2-chloro-4,4-difluoro-spiro[5H-thieno[2,3-c]pyran-7,4′-piperidine] (280 mg, 1 mmol) is added. The mixture is stirred for 10 min. Then, sodium triacetoxyborohydride (442 mg) is added and the mixture is stirred overnight at room temperature. Sodium bicarbonate (saturated aqueous solution) is added and the organic phase extracted with dichloromethane, dried over magnesium sulfate and solvent evaporated in vacuo. Crude is purified by normal phase Isco chromatography using as eluent ethyl acetate and hexane to give 450 mg of ethyl 4-[(2-chloro-4,4-difluoro-spiro[5H-thieno[2,3-c]pyran-7,4′-piperidine]-1′-yl)methyl]-1-(3-fluoro-2-pyridyl)pyrazole-3-carboxylate. MS (m/z): 527 (M+1).

Provenance & Evidence