Phenol → 4,4'-Dihydroxy-alpha-methylstilbene

Participants

Reaction Conditions

Reaction Steps

Phenol (376.44 grams, 4.0 moles), chloroacetone (205.62 grams, 2.0 moles as chloroacetone) and methylene chloride (300 grams) were added to a reactor and cooled to -10° C. with stirring. The chloroacetone used was a technical grade containing 90% chloroacetone, 2.5% acetone, 6.5% 1,1-dichloroacetone and 1.0% 1,3-dichloroacetone, Concentrated sulfuric acid (196.16 grams, 2.0 mole) was added to dropwise to the stirred solution over a thirty minute period so as to maintain the reaction temperature between -9° and -11° C. After two hours of post reaction between the -9° to -11° C. temperature, the viscous orange oil solution was mixed with 500 milliliters of iced deionized water. The oil solution was separated then washed with a second 500 milliliter portion of iced deionized water. After separation, the recovered oil solution was added to a 2 liter beaker along with 250 milliliters of ethanol and stirred to provide a solution. Deionized water (250 milliliters) was added to the stirred solution and heating commenced. As the temperature of the mixture increased, the stirred mixture began to clear. Each time clearing was observed, sufficient deionized water was added to induce cloudiness, followed by continuation of the mixing and heating. Once the temperature reached 70° C., a massive precipitation of white crystalline plates occurred and was followed by immediate coalesence of the precipitated product to an oil. The oil layer was recovered by decantation of the water layer and 250 milliliters of ethanol was added. Deionized water was again added to the stirred solution as heating commenced, in an amount sufficient to induce cloudiness each time clearing was observed. Once the temperature reached 90° C., a massive precipitation of white crystalline plates again occurred. At this time, stirring was stopped and the crystalline slurry, as well as the decanted water layer were both chilled to 5° C. and held therein for 12 hours. The crystalline product was recovered by filtration, combined with 250 milliliters of deionized water then stirred with heating to 90° C. After cooling to 5° C., the crystalline product was recovered by filtration then dried in a vacuum oven at 100° C. and 5 mm Hg to a constant weight of 226.7 grams. Proton magnetic resonance spectroscopy and infrared spectrophotometric analysis confirmed the product structure.

Provenance & Evidence