4-Hydroxybenzaldehyde → 1,2-Ethanediol, 1,2-bis(4-hydroxyphenyl)-

Participants

Reaction Conditions

Reaction Steps

A solution containing 20.0 grams (0.16 mole) of 4-hydroxybenzaldehyde and 200 milliliters of 1.0 molar aqueous sodium hydroxide was charged to the reservoir. Also charged to the reservoir was a small amount of Union Carbide SAG 470 silicone antifoam agent. The solution was circulated through the cell at a flow rate of about 1500 milliliters per minute. The electrolysis was conducted at a constant current of 5.0 amperes and a temperature of 30° C over a 1.36-hour (4900-second) period. After the electrolysis had been completed, the solution was removed from the apparatus, which was then washed with water. The combined solution and washings were reduced in volume to 100 milliliters by evaporation in vacuo. The remaining solution was acidified to about pH 6.3 by the dropwise addition of dilute (approximately 6 molar) hydrochloric acid and cooled to 15° C in an ice-water bath. The precipitate was collected by suction filtration, washed with cold water, and dried to yield 15.2 grams of 1,2-bis(4-hydroxyphenyl)ethane-1,2-diol.

Provenance & Evidence