Pyridine → 3-(p-Tert.butyl-phenyl)-2-methyl-allyl bromide

Reaction equation

[C:1]([C:5]1[CH:10]=[CH:9][C:8]([CH:11]=[C:12]([CH3:15])[CH2:13]O)=[CH:7][CH:6]=1)([CH3:4])([CH3:3])[CH3:2].N1C=CC=CC=1.P(Br)(Br)[Br:23]>CCCCC>[C:1]([C:5]1[CH:10]=[CH:9][C:8]([CH:11]=[C:12]([CH3:15])[CH2:13][Br:23])=[CH:7][CH:6]=1)([CH3:4])([CH3:3])[CH3:2]

Participants

Procedure

73.2 g of 3-(p-tert.butyl-phenyl)-2-methyl-allyl alcohol nd 8.6 ml of pyridine in 700 ml of n-pentane are cooled down to -5° C. At this temperature there are added dropwise while stirring over a period of 2 hours 15.2 ml of phosphorus tribromide in 700 ml of n-pentane and the mixture is stirred at room temperature for 3 hours. The mixture is poured on to 500 g of ice and stirred up for 30 minutes. The pentane phase is separated and the aqueous phase is back-extracted with n-pentane. The combined n-pentane phases are washed neutral with saturated sodium bicarbonate solution and water, dried over sodium sulphate and evaporated. The 3-(p-tert.butyl-phenyl)-2-methyl-allyl bromide, distilled in a high vacuum, boils at 123° C./0.01 Torr.