4-Bromobutanol

Description4-Bromo-1-butanol can be prepared by azeotropic distillation of butane-1,4-diol with 47% HBr with a yield of about 65%.1 4-Bromo-1-butanol can be used to prepare 2-(4-bromo-butoxy)-tetrahydro-pyran by reacting with 3,4-dihydro-2H-pyran in the presence of amberlyst 15 and the menstruum hexane.1 It reacts with dihydropyran to prepare tetrahydropyranyl ethers.2

Uses4-Bromo-1-butanol is used to prepare 2-(4-bromo-butoxy)-tetrahydro-pyran by reacting with 3,4-dihydro-2H-pyran in the presence of amberlyst 15 as a catalyst. It reacts with dihydropyran to prepare tetrahydropyranyl ethers.

Preparation200 kg of tetrahydrofuran and 19 kg (0.07 eq) of concentrated sulfuric acid were added sequentially to a 1000 L reactor. The system temperature was controlled at 2 ± 2 °C. 420 kg (0.9 eq) of 48% hydrobromic acid aqueous solution was slowly added dropwise. After the addition was complete, the temperature was raised to 80 ± 2 °C and maintained for 3 h. After the reaction was completed, the temperature was lowered to 0 ± 2 °C. The pH of the system was adjusted to 7-8 with 23 kg (0.1 eq) of sodium bicarbonate. Extraction was performed, the organic phase was washed, and the mixture was concentrated to obtain 286 kg of the oily product 4-bromo-1-butanol, with a yield of 67.5% and a gas chromatographic purity (GC) of 97.0%.