Toluene → HCID 70855385, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-(3,4-dihydro-2H-1-benzopyran-6-yl)-imidazo[1,2-a]pyridine (19b) (50 mg, 0.2 mmol), ethyl glyoxylate 50% in toluene (0.20 mL, 1.0 mmol) and p-toluenesulfonic acid (6 mg, 0.03 mmol) in ethanol (1 mL) was heated at 80° C. for 1 hour. Ethyl glyoxylate 50% in toluene (0.10 mL, 0.5 mmol) was added and the heating was maintained for one supplementary hour. The mixture was concentrated in vacuo. The residue was dissolved in ethyl acetate (10 mL), washed with a saturated solution of sodium hydrogencarbonate (5 mL), dried over sodium sulfate and concentrated in vacuo. The residue was purified by flash chromatography on silica gel (cyclohexane/ethyl acetate 40/60) to provide the desired hydroxyl-ester (19c) (56 mg, 0.159 mmol, 80%) as a white solid.

Provenance & Evidence