ChemicalBook CAS DataBase List 2-Bromopyridine

2-Bromopyridine synthesis

12synthesis methods

Product Name:2-Bromopyridine
CAS Number:109-04-6
Molecular formula:C5H4BrN
Molecular Weight:158

2-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%.

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109-04-6
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Yield:109-04-6 91%

Reaction Conditions:

with 2-methylphenyl bromide;copper(I) bromide in cyclohexane at 5 - 45; for 3.41667 h;Concentration;Temperature;

Steps:

3 Example 3

(3) 1.9mol, reducing the solution temperature to 5 , control the stirring speed 170rpm, adding 1.5mol of cuprous bromide, the mass fraction is 55%, the reaction temperature is 5min, Cyclohexane 600ml, reaction 120min, the temperature increased to 45 , continue reaction 80min, adding the mass fraction of 35% sodium sulfite solution 300ml, reduce the solution temperature to 35 , 50min reaction, the solution with 65% acetonitrile extraction 5 times , The combined acetonitrile extract, potassium nitrate solution washing, anhydrous potassium carbonate dehydration, recovery of acetonitrile, 1.9kPa vacuum distillation, 90-95 ° C fractions collected 90% ethylenediamine in the mass fraction recrystallization, was 186.91 g of 2-bromopyridine was obtained in 91% yield.

References:

CN105439944,2016,A Location in patent:Paragraph 0015; 0016

14305-17-0 Synthesis