Hydrochloric Acid → 6-(4-Hydroxy-3-methoxyphenyl)hex-5-ene-2,4-dione

Participants

Reaction Steps

Boric anhydride (16.32 g, 237.2 mmoles) and acetylacetone are stirred at room temperature under nitrogen for 12 hours. 4-Hydroxy-3-methoxybenzaldehyde (18.06 g, 118.8 mmoles) and tributyl borate (364 g, 3.16 moles) are combined with the acetyl acetone/boric anhydride complex in 100 ml of ethyl acetate. The reaction is stirred at room temperature for one hour, at which time n-butylamine (4.34 g, 59.4 mmoles) is added in 4 equal portions over 8 hours. The reaction is allowed to stir for 12 hours. 300 ml of water containing 20 ml of concentrated hydrochloric acid is added to the reaction and stirred for 2 hours. The solid which forms is removed by filtration through celite, and the layers of filtrate are separated. The ethyl acetate layer is washed with 2×100 ml of saturated sodium bicarbonate, followed by 100 ml of brine. Drying over magnesium sulfate followed by evaporation of the solvent gives a red solid. Chromatography in 5% ethyl acetate/chloroform gives 11.06 g (40%) of a yellow solid. mp=146°-147° C. Analysis for C13H14O4 requires C-66.65, H-6.04. Found C-66.88, H-6.18.

Provenance & Evidence