2-Bromopyridine

Preparation2-Bromopyridine is synthesized from 2-aminopyridine by bromination. In industrial production, hydrobromic acid (over 48%) is first cooled to below 0°C, 2-aminopyridine is slowly added, and then liquid bromine is added dropwise in a salt bath under freezing, and the rate of addition is to control the reaction temperature below -5°C appropriate. After adding, add sodium nitrite aqueous solution dropwise, control the reaction temperature to be below 0°C, stir for 20-30min, dropwise add 50% sodium hydroxide solution, extract the reaction solution with ether, wash with water, dry with anhydrous sodium sulfate, filter, and recover Diethyl ether, the residue was distilled under reduced pressure, and the 88°C-94°C/3333Pa fraction was collected to obtain the finished product of 2-bromopyridine with a yield of 83.8%.