Acetic Acid → 4-amino-3-(2-(benzyloxy)ethyl)-8-(cyclopentyloxy)-7-methoxy-2H-chromen-2-one

Participants

Reaction Steps

Ammonium acetate (27.7 g, 360 mmol) was added to a solution of 3-(2-(benzyloxy)ethyl)-8-(cyclopentyloxy)-4-hydroxy-7-methoxy-2H-chromen-2-one (5 g, 12 mmol), acetic acid (25 mL), and toluene (100 mL). The reaction was refluxed with the water being removed using a Dean-Stark apparatus. After 2 h, the toluene was removed by distillation. After an additional 5 h at reflux, the reaction was allowed to cool to rt, poured into cold water (100 mL), and then extracted with ethyl acetate (100 mL×3). The combined extracts were washed with sat'd NaHCO3 (100 mL×4) and then brine (50 mL×3), filtered, concentrated, and purified by silica gel chromatography (ethyl acetate:petroleum ether) to give 4-amino-3-(2-(benzyloxy)ethyl)-8-(cyclopentyloxy)-7-methoxy-2H-chromen-2-one: MS (ESI): 410.

Provenance & Evidence