Acetic Acid → methyl 5-bromo-3-(ethyl(tetrahydro-2H-pyran-4-yl)amino)-2-methylbenzoate

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Reaction Steps

To a stirred solution of methyl 5-bromo-2-methyl-3-((tetrahydro-2H-pyran-4-yl)amino)benzoate (14 g, 43 mmol) and acetaldehyde (3.75 g, 85.4 mmol) in dichloroethane (150 mL), was added acetic acid (15.36 g, 256 mmol). After stirring at room temperature for 20 minutes, sodium triacetoxyborohydride (27.0 g, 128 mmol) was added at 0° C. The mixture was stirred at room temperature for 2 h. and quenched with aqueous sodium bicarbonate. The organic phase was separated and the aqueous phase was extracted with dichloromethane. The combined organic layers were dried over sodium sulphate and concentrated under reduced pressure to give crude material which was purified by column chromatography over silica gel to afford methyl 5-bromo-3-(ethyl(tetrahydro-2H-pyran-4-yl)amino)-2-methylbenzoate (14 g, 93%).

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