HCID 11143952, compound → HCID 10959751, compound

Participants

Reaction Steps

4,5-Dimethoxy-2-(3,4,5-trimethoxybenzoyl)benzaldehyde dimethyl acetal (1.0 g) is dissolved with heating in a mixture of acetone (15 ml) and water (0.5 ml), and thereto is added an acidic ion-exchange resin (IRA-20) (50 nig). The mixture is stirred at room temperature for two hours. After the reaction is complete, the acidic resin is removed by filtration, and the filtrate is concentrated under reduced pressure. The residue is dissolved in dioxane (12 ml), and thereto are added resorcinol (456 nig) and acetate buffer (pH 3.8, 12 ml). To the mixture is added dropwise and gradually aqueous solution of sodium chlorite (374 mg), and the mixture is stirred at room temperature overnight. After the reaction is complete, the pH value of the mixture is adjusted to pH 1 with conc. hydrochloric acid, and the mixture is extracted with chloroform. The chloroform layer is washed, dried, and concentrated under reduced pressure. The precipitated crystals are collected by filtration with diethyl ether to give 4,5-dimethoxy-2-(3,4,5-trimethoxybenzoyl)benzoic acid (8 10 mg) as listed in Table 51.

Provenance & Evidence