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

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Phenol (752.8 grams, 8.0 moles), chloroacetone (384.7 grams, 4.0 moles as chloroacetone) and methylene chloride (600 grams) are added to a reactor and cooled to -10° C. with stirring under a nitrogen atmosphere. The chloroacetone used is a commercial grade containing 96.25% chloroacetone, 0.05% acetone, 3.05% 1,1-dichloroacetone and 0.60% mesityl oxide. Concentrated sulfuric acid (392.32 grams, 4.0 mole) is added dropwise to the stirred solution over a forty five minute period and so as to maintain the reaction temperature between -11° and -9° C. After 150 minutes of post reaction at -11° to -9° C., the viscous, orange colored oil product is mixed with iced deionized water (1000 milliliters). The oil product is separated then washed with a second portion (1000 milliliters) and then a third portion (1000 milliliters) of deionized water. After separation, the recovered oil product is added to a pair of 2 liter beakers along with ethanol (250 milliliters) and stirred to provide solutions. Deionized water (250 milliliters) is added to the stirred solutions and heating commences. As the temperature of the mixture increases, the stirred mixtures began 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 and is followed by immediate coalesence of the precipitated product to an oil. The oil layer is recovered by decantation of the water layer and ethanol (250 milliliters) is added. Deionized water is again added to the stirred solutions as heating commences, in an amount sufficient to induce cloudiness each time clearing is observed. Once the temperature reaches 70° C., a massive precipitation of white crystalline plates again occurs. At this time, stirring is stopped, sufficient deionized water is added to fill both of the beakers and the crystalline slurries are chilled to 4° C. and held therein for 16 hours. The crystalline product is recovered by filtration of the chilled crystalline slurries, added to a beaker along with deionized water (1000 milliliters), then stirred with heating to 100° C. After maintaining the stirred slurry at 100° C. for thirty minutes, the crystalline product is recovered by filtration then again combined with deionized water (1000 milliliters) and stirred with heating to 100° C. The crystalline product is recovered by filtration then dried in a vacuum oven at 100° C. and 5 mm Hg to a constant weight of 478.8 grams. Proton magnetic resonance spectroscopy and Fourier transform infrared spectrophotometric analysis confirms the product structure.

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