The main application background and overview of 2-amino-4-chloro-5-bromopyridine
2-Amino-4-chloro-5-bromopyridine is an organic intermediate, which can be prepared by bromination of 2-amino-4-chloropyridine.
Main application preparation of 2-amino-4-chloro-5-bromopyridine
Dissolve 2-amino-4-chloropyridine (50g) in dichloromethane (500mL), cool to 0°C, slowly add N-bromosuccinimide (76.5g) in batches, complete the addition Stir evenly and react for 30 minutes. TLC detects that the reaction is complete. First spin the solvent of the reaction solution to dryness, dissolve the crude product in ethyl acetate, wash it with 1 mol/L hydrochloric acid, adjust the alkali and extract with ethyl acetate, combine the organic phases, wash with brine, dry over sodium sulfate, and concentrate to obtain Product 2-amino-4-chloro-5-bromopyridine (70g), yield 87%.
Main applications of 2-amino-4-chloro-5-bromopyridine
Can be used to synthesize 2,4-dichloro-5-bromopyridine. 2,4-Dichloro-5-bromopyridine is an important biopharmaceutical intermediate and can be widely used in the synthesis of various drugs. Its molecular weight is small and its structure is unique. It can be derived from a variety of downstream products and has a wide range of uses.
React at -30°C for 1 hour, add cuprous chloride, raise to room temperature, and detect complete reaction by TLC; adjust the reaction solution to alkaline with di-tert-butyl dicarbonate sodium hydroxide, and extract with ethyl acetate. The organic phases were combined, washed with brine, dried over sodium sulfate, concentrated and then subjected to column chromatography to obtain 2,4-dichloro-5-bromopyridine.
This method can be directly scaled up and used in industrial production. The conventional reaction operation process is adopted, and the relatively cheap raw material of 2-amino-4-chloropyridine is used as the starting reactant. After bromination and diazotization reactions, the synthesis route is short and avoids the need for butyllithium, phosphorus oxychloride, etc. The use of hazardous raw materials avoids low-temperature operation and has a higher reaction yield, making the scale-up of the compound easy to achieve. It can also reduce reaction costs and increase reaction yields. It is simple to operate and easy to purify. It can be directly scaled up for production, which solves the disadvantage of expensive scaled up production costs. The prepared product can be produced on a large scale and is low in price, making it easy to promote nitrobenzene boric acid.
