O-Cresol → 6-Cyclopentyl-o-cresol

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Reaction Steps

170 ml of boron trifluoride/phosphoric acid adduct are added to 1.08 kg (10 moles) of o-cresol in 400 ml of pentane. 680 g (10 moles) of cyclopentene, dissolved in 1 l of pentane, are added dropwise at the reflux temperature in the course of 3 hours. The mixture is stirred for a further hour at the reflux temperature and then poured into ice water. The organic phase is separated off and is extracted with 4 times 600 ml of 10% strength sodium hydroxide solution. The organic phase is dried and evaporated down and the residue is distilled (84°-88° C./0.2 mbar). 515 g of 2-cyclopentyl-6-methylphenol (corresponding to 37% of theory, based on converted cresol) are obtained. 217 g of o-cresol and 282 g of 4-cyclopentyl-2-methylphenol are obtained from the alkaline wash solution after acidification, extraction and distillation.

Provenance & Evidence