In a 500-ml three-necked flask equipped with a stirrer, thermometer, dropping funnel, and calcium chloride tube, place 96 g of redistilled PBr₃ and 50 ml of dry benzene. Add 15 g of dry pyridine dropwise with stirring over 15 minutes.
Cool the flask in an ice-salt bath to -5°C. Then, slowly add a mixture of 102 g of tetrahydrofurfuryl alcohol and 5 g of dry pyridine over 4 hours, maintaining the internal temperature between -5° and -3°C. Stir for an additional hour and allow the mixture to warm to room temperature.
Let the mixture stand for 24-48 hours. Transfer it to a Claisen flask, rinse with a little benzene, and remove the benzene by distillation under reduced pressure (bath temperature ≤90°C). Finally, distill the product under high vacuum (5-10 mm Hg) with the bath temperature up to 150-155°C.
The crude product is redistilled to give pure tetrahydrofurfuryl bromide, boiling at 69-70°C/22 mm Hg. The yield is 90-102 g (53-61%)
[1].
