Phosphoric Acid → Ethyl 2-(2-(((2-(benzyloxy)-4,6-dimethylpyridin-3-yl)methyl)amino)ethoxy)-3-bromo-6-methyl-5-((methylsulfonyl)oxy)benzoate

Participants

Reaction Steps

To a solution of ethyl 2-(2-(((2-(benzyloxy)-4,6-dimethylpyridin-3-yl)methyl)(tert-butoxycarbonyl)amino)ethoxy)-3-bromo-6-methyl-5-((methylsulfonyl)oxy)benzoate (116e, 0.58 g, 0.80 mmol) in dichloromethane (8 mL) was added 85% phosphoric acid (0.20 mL, 2.8 mmol). The mixture was stirred at room temperature for 2 hours then additional 85% phosphoric acid (0.20 mL, 2.8 mmol) was added and stirring was continued for 2 hours. The reaction was carefully quenched with saturated aqueous sodium bicarbonate (10 mL) and extracted with dichloromethane (2×15 mL). The combined organic layers were washed with brine (15 mL), dried over magnesium sulfate, concentrated under vacuum, and purified by column chromatography (20% EtOAc/Heptane) to give ethyl 2-(2-(((2-(benzyloxy)-4,6-dimethylpyridin-3-yl)methyl)amino)ethoxy)-3-bromo-6-methyl-5-((methylsulfonyl)oxy)benzoate (116f, 0.25 g, 50% yield) as a clear sticky solid.

Provenance & Evidence