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

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Phenol (188.22 grams, 2.0 moles) and chloroacetone (102.81 grams, 1.0 mole as chloroacetone) are added to a reactor and cooled to -10° C. with stirring. The chloroacetone used is a technical grade containing 90% chloroacetone, 2.5% acetone, 6.5% 1,1-dichloroacetone and 1.0% 1.3-dichloroacetone. Concentrated sulfuric acid (98.08 grams, 1.0 mole) is added dropwise to the stirred solution over a one hour period in order to maintain the reaction temperature between -10° C. and -11° C. After two hours of post reaction at the -10° C. temperature, the viscous orange oil product is mixed with 500 milliliters of iced deionized water. The oil product is separated then washed with a second 500 milliliter portion of chilled deionized water. After separation, the recovered oil product is added to a 2-liter beaker along with 250 milliliters of ethanol and stirred to provide a solution. Deionized water (250 milliliters) is added to the stirred solution and heating commenced. As the temperature of the mixture increases, the stirred mixture begins to clear. Each time clearing is observed, sufficient deionized water is added to induce cloudiness, followed by continuation of the mixing and heating. Once the temperature reaches 90° C., a massive precipitation of white crystalline plates occurs. At this time, heating and stirring ceases and the mixture is chilled to 5° C. and held therein for 12 hours. The crystalline product is recovered by filtration, washed with two 150 milliliter portions of deionized water, then dried at 90° C. and 5 mm Hg to a constant weight of 103 grams. Nuclear magnetic resonance spectroscopy and infrared spectrophotometric analysis confirms the product structure for 4,4'-dihydroxy-α-methylstilbene.

Herkunft & Nachweise