Acetaldehyde → 6-Ethyl-2-(ethylamino)-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3-carboxamide

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Reaction Steps

To a stirred mixture of compound F4 (200 mg, 0.888 mmol), acetaldehyde (5 M in tetrahydrofuran, 0.360 mL, 1.80 mmol), acetic acid (two drops), anhydrous magnesium sulfate (200 mg) in anhydrous methanol (6 mL) and anhydrous tetrahydrofuran (3 mL) was added sodium cyanoborohydride (167 mg, 2.66 mmol) at room temperature under nitrogen. The reaction mixture was stirred for 23 h and then filtered. The filtrate was concentrated. The resulting residue was purified by flash column chromatography on silica gel eluting with 10% to 20% methanol/methylene chloride to afford compound R1 as a colourless syrup (181 mg, 80%): MS (M+H) 254.

Provenance & Evidence