Methanol → 2-Styryloxazole-4-carbaldehyde

Participants

Reaction Steps

Diisobutylaluminum hydride (1.0N hexane solution, 66 ml) was added dropwise to a solution of 4-ethoxycarbonyl-2-(trans-styryl)oxazole (8.57 g) in dichloromethane (80 ml) at −78° C. After 15 minutes, methanol (11 ml) was added dropwise, and the mixture was warmed to room temperature over 1 hour. The reaction mixture was filtered through Celite, and the resultant pasty substance was dissolved in ethyl acetate (200 ml) and a saturated aqueous solution (200 ml) of ammonium chloride was added, and an organic layer was separated. The water layer was then extracted with dichloromethane (2×100 ml). The resultant organic layers were collected and washed with a saturated aqueous solution (100 ml) of sodium hydrogencarbonate and saturated saline (100 ml), combined with the filtrate obtained by the filtration through Celite and then dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by column chromatography on silica gel (dichloromethane:ethyl acetate=5:1→dichloromethane:methanol=10:1) to obtain the title compound (5.86 g) as colorless needle crystals.

Provenance & Evidence