Preparation method for 2-cyano-5-bromopyridine

Abstract

The invention belongs to the field of organic synthesis, and specifically relates to a preparation method for 2-cyano-5-bromopyridine. To solve the above technical problems, the preparation method for2-cyano-5-bromopyridine taking sulfolane as a solvent can be provided. The method has advantages of simple operation and less steps; the purity of the prepared 2-cyano-5-bromopyridine which is not further purified can reach 94%; and the purity of products can reach 99% after purifying.

Description

technical field [0001] The invention belongs to the field of organic synthesis, and in particular relates to a preparation method of 2-cyano-5-bromopyridine. Background technique [0002] 2-cyano-5-bromopyridine is an important intermediate widely used in the fields of medicinal chemistry, organic synthesis and material chemistry. There are many reports on the synthesis route of 2-cyano-5-bromopyridine, such as using 2,5-dibromopyridine as raw material to carry out Li-Br reaction with n-butyllithium at ultra-low temperature, and then adding DMF or tert-butyl isocyanate to react The corresponding aldehyde or amide is obtained, and 2-cyano-5-bromopyridine is obtained through condensation reaction, but this method needs to be carried out under ultra-low temperature conditions and at a very dilute reaction concentration, which is not conducive to industrial production. Such as CN104496979A, EP2692727A2, "European Journal of Medicinal Chemistry" (2011,46 (4): 1027) with DMF as a...

AI Technical Summary

Problems solved by technology

There are many reports on the synthesis route of 2-cyano-5-bromopyridine, such as using 2,5-dibromopyridine as raw material to carry out Li-Br reaction with n-butyllithium at ultra-low temperature, and then adding DMF or tert-butyl isocyanate to react The corresponding aldehyde or amide is obtained, and 2-cyano-5 bromopyridine is obtained through condensation reaction, but this method needs to be carried out under ultra-low temperature conditions, and is carried out at a very dilute reaction concentration, which is not conducive to industrial production

Such as CN104496979A, EP2692727A2, "European Journal of Medicinal Chemistry" (2011,46 (4): 1027) with DMF as a solvent, after the reaction, water needs to be added thereto, and extracted with ethyl acetate, then the organic layer is washed with brine and dehydrated, Filtration and vacuum concentration are cumbersome steps

[0003] Therefore, the existing method for preparing 2-cyano-5-bromopyridine has shortcomings such as many reaction steps, low purity, low yield, and the need to use a catalyst.

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