Acetone → Ethyl 7-(Benzyloxy)chroman-2-carboxylate

Participants

Reaction Steps

To a 5 L acetone solution of ethyl 7-hydroxy-chromane-2-carboxylate (630.1 g, 2.84 mol) was added potassium carbonate powder (785 g, 5.68 mol) and benzyl bromide (405 ml, 3.41 mol). The resulting suspension was heated to reflux for 16 hr. The reaction mixture was filtered through a pad of celite. The filtrate was concentrated to give solid material, which was re-dissolved in AcOEt, washed with water to remove residual salt, dried over MgSO4, filtered, concentrated to a small volume. Addition of hexanes caused precipitation of the title compound, which was collected by suction-filtration. The filtrate was triturated from dichloromethane-hexanes to give more precipitates. Finally the filtrate was concentrated and chromatographed on silica gel eluting with 20 to 80% dichloromethane/hexanes. Combination of all crops yielded the title compound 760.2 g as off-white solid (86%).

Provenance & Evidence