Salicylaldehyde → 3-formyl-2H-chromene-2-carboxylic acid ethyl ester

Participants

Reaction Steps

To a stirred mixture of commercially available (S)-(−)-α{tilde over (α)}Diphenyl-2-pyrrolidinemethanol (0.83 g, 3.28 mmol) in toluene (40 mL) was added 2-nitrobenzoic acid (0.55 g, 3.28 mmol), commercially available 2-Hydroxybenzaldehyde (2.00 g, 16.38 mmol) and (E)-4-oxo-but-2-enoic acid ethyl ester (2.51 g, 19.65 mmol). After addition was complete the mixture was stirred at room temperature for 3 days. Upon completion of the reaction the toluene was removed by vacuum distillation. The residue was diluted with ethyl acetate and washed with water, a saturated sodium bicarbonate solution and a saturated sodium chloride solution. The organic fraction was then dried over magnesium sulfate. The crude product obtained was purified by ISCO flash chromatography (Teledyne Isco RediSep Flash Column 40 g; (0% to 100% ethyl acetate/hexane) to afford 3-formyl-2H-chromene-2-carboxylic acid ethyl ester as a yellow oil, 1.09 g (29% yield). (Ref: Chem. Eur. Journal; 2007, 13, pg 574).

Provenance & Evidence