Boric Acid → 1-(3,5-dimethoxyphenyl)-2-(4-methoxyphenyl)ethanone

Participants

Reaction Conditions

Reaction Steps

26.7 g of boric acid (0.43 mol) and 74.4 g of crude methyl 3-(3,5-dimethoxyphenyl)-2-(4-methoxyphenyl)-3-oxopropionate (0.216 mol) prepared according to Example 1 are introduced into a round-bottomed flask equipped with a distillation head. Heating is carried out, the temperature being brought gradually to 100° C. for 1 h, 120° C. for 1 h, 140° C. for 1 h and then 160° C. for 4 h while distilling off light products. The mixture is cooled to 80° C., 250 ml of water and then 200 ml of toluene are added, the mixture is kept stirred at 60° C. for 1 h, separation by settling is then carried out and the toluene phase is recovered, washed with 100 ml of a saturated aqueous sodium bicarbonate solution and concentrated on a rotary evaporator. The crude oily product obtained is taken up in 200 ml of MTBE to precipitate the product, which is filtered off and dried. Thus, after drying, 33.6 g of 1-(3,5-dimethoxyphenyl)-2-(4-methoxyphenyl)ethanone are obtained in the form of a cream-white solid, i.e. a yield of 54.4% with respect to the crude starting β-ketoester. M.p.: 93-4° C.

Provenance & Evidence