4-Hydroxybenzaldehyde → p-(Difluoromethoxy)benzaldehyde

Participants

Reaction Conditions

Reaction Steps

Sodium hydroxide (48 g; 1.2 mole) is added to a stirred suspension of p-hydroxybenzaldehyde (48.9 g; 0.4 mole) in dioxane (142 ml) and water (87 ml). The mixture is heated to 70° C. and chlorodifluoromethane (33 g) added slowly. When this addition is completed, 50% sodium hydroxide solution (32 ml) is added to the reaction mixture, followed by the slow addition of chlorodifluoromethane (33 g). This recharging is repeated three times, and a total of 96 g (2.4 mole) of sodium hydroxide and 133 g (1.54 mole) of (1.54 mole) of chlorodifluoromethane is used in the reaction. The reaction mixture is cooled down, diluted with water (1500 ml) and extracted with ether several times. The ether layers are combined, washed with 10% sodium hydroxide and then dried over magnesium sulfate. Concentration of the ethereal solution yields 39 g (57%) of a yellow oil. This oil is purified by chromatography on a silica gel column using a mixture of hexane:methylene chloride (1:3), to afford 27 g (39%) of title product.

Provenance & Evidence