Hydrogen Bromide → (2-Bromoethyl)cyclohexane

Participants

Reaction Steps

To a solution of 10 g of (2-hydroxyethyl)cyclohexane in 50 ml of dry diethyl ether was added dropwise a solution of 9.85 g of phosphorous tribromide in 20 ml of dry diethyl ether at -40° C., and the mixture was stirred at -40° to -10° C. for 30 minutes and at 2° to 4° C. for 2.5 hours. The reaction mixture was then poured into ice-water and extracted with diethyl ether. The extract was washed with water, an aqueous solution of sodium bicarbonate and water, dried over magnesium sulphate and concentrated under reduced pressure. To the residue thus obtained were added 50 ml of 47% w/v hydrobromic acid at -30° C. 20 ml of sulphuric acid were then added dropwise at the same temperature. The reaction mixture was refluxed at 100° to 110° C. for 3 hours and extracted with diethyl ether. The extract was washed with water, an aqueous solution of sodium bicarbonate and water, dried over magnesium sulphate and concentrated under reduced prssure. The residue was purified by distillation under reduced pressure to give 8.04 g of the title compound having the following physical characteristics:

Provenance & Evidence