Cyclohexylmethyl bromide

100-49-2

2550-36-9

The general procedure for the synthesis of bromomethylcyclohexane from cyclohexanemethanol is as follows: 1.4 kg of cyclohexanemethanol (colorless liquid), 8.4 L of toluene, and 969.8 g of pyridine were added to a 20 L four-neck flask. The reaction system was cooled to 0 to 10 °C, and then a mixture of 1.66 kg of phosphorus tribromide with 7 L of toluene was slowly added with controlled titration rate to keep the reaction temperature below 5 °C. The dropwise addition process was completed in about 1 hour. Subsequently, the reaction system was warmed to room temperature and the reaction was continued with stirring for 10 hours. Upon completion of the reaction, the system was cooled to below 20 °C and about 2.5 L of 5% sodium hydroxide solution was slowly added dropwise, followed by the addition of 1.85 kg of solid sodium hydroxide to form a mixture. Liquid-liquid separation was carried out and the aqueous phase was extracted twice with 4 L of toluene. The organic phases were combined and washed with saturated brine, and the washed organic phase was dried with anhydrous sodium sulfate. The dried organic phase was concentrated to give 1.73 kg of crude product. The crude product was purified by distillation under reduced pressure to give 722.8 g of bromomethylcyclohexane with 97.5% purity in 33.3% yield. The structure of the product was confirmed by 1H NMR (400 MHz, CDCl3): δ 3.82 (m, 1H), 1.79-1.53 (m, 6H), 1.13-0.90 (m, 6H).