preparation and application of 3-bromopyridine_industrial additives

background and overview of preparation and application of 3-bromopyridine

in the fields of medicine and pesticides, 3-bromopyridine is widely used. it is an important intermediate for the antidepressant zimeridine hydrochloride and an important intermediate for the neurological drug acylamol; in addition, 3-bromopyridine is used in it also has applications in the field of optoelectronic materials.

preparation and application of 3-bromopyridine

a synthesis method of chromium-3-picolinate-bromopyridine, which includes the following steps:

add 60g pyridine and 100ml water into a 500ml three-necked flask, add 40% hbr (160g, temperature control 20-30°c during the dropping process) dropwise with stirring, stir until dissolved, and obtain the bromination reaction solution;

heat the bromination reaction solution to 70°c and slowly add 80 ml of 30% h2o2 dropwise. during the dropping process, control the temperature to 70-80°c (slowly exothermic during the dropping process). after the addition is completed, control the temperature to 80°c and stir for 24 hours. , get the crude product;

cool the crude product to below 10°c, adjust the ph to ph=8 with 3n naoh aqueous solution, add ethyl acetate (350ml×3) for extraction, and backwash the organic phase with sodium sulfite aqueous solution to obtain the extract (organic phase) ;

the extract (organic phase) was concentrated and distilled under reduced pressure to obtain 31g of 3-bromopyridine with a gc purity of 85.1%.

preparation and application of 3-bromopyridine

2-carboxy-3-bromopyridine hydrochloride nitrobenzene borate is a white solid and an important intermediate raw material for many pharmaceutical intermediates. cn201210223281.8 discloses a synthesis method of 2-carboxy-3-bromopyridine hydrochloride. using readily available 3-bromopyridine as raw material, 3-bromopyridine is first oxidized with hydrogen peroxide in acetic acid, and then react with trimethylcyanosilane in the presence of triethylamine to obtain a mixture of 2-cyano-3-bromopyridine and 6-cyano-3-bromopyridine, which is then hydrolyzed in concentrated hydrochloric acid to precipitate a white solid, which is 2- carboxy-3-bromopyridine hydrochloride is directly separated from 6-carboxylic acid-3-bromopyridine hydrochloride.

references

[1] [chinese invention] cn201410356568.7 a synthesis method of 3-bromopyridine

[2] [chinese invention] cn201210223281.8 a synthesis method of 2-carboxy-3-bromopyridine hydrochloride