2-Chloro-5-methylpyridine

clear light yellow to straw-yellow liquid

There are many synthetic methods for 2-chloro-5-methylpyridine. According to the different raw materials used, there are mainly the following three routes. Using N-benzyl-N-propenylacetamide as raw material, N-benzyl-N-propenylacetamide and phosphorus oxychloride are stirred and reacted at 100℃ for 16h in the solvent dimethylformamide to obtain 2 -Chloro-5-methylpyridine, the yield is 67.5%. Take aminopyridine as raw material. The methanol solution of 2-amino-5-methylpyridine is first saturated with hydrogen chloride, and then the mixture of methyl nitrite and hydrogen chloride is passed through to obtain 2-chloro-5-methylpyridine. Methyl nitrite can also be replaced by nitroso chloride, or chlorobenzene can be used as a solvent. Take 3-methylpyridine-N-oxide as raw material. Depending on the chlorinating agent used, there are four different ways to choose from. Phosphorus oxychloride is used as a chlorinating agent. The 3-methylpyridine-N-oxide reacts with phosphorus oxychloride in the presence of an organic base to form 2-chloro-5-methylpyridine, and 2-chloro-3-methylpyridine as a by-product. Add a certain amount of 3-methylpyridine-N-oxide and solvent into the reaction kettle, add phosphorus oxychloride and organophosphorus at -10°C, after the dropwise addition, react at -2°C for 5 hours, and then hydrolyze, The crude product is obtained by desolventization and distillation, and then frozen and crystallized to obtain the fine monochloride. COCl2 can also be used instead of POCl3 as the chlorinating agent. N, N-diethylaminophosphorus oxychloride is used as a chlorinating agent. At room temperature, the dichloromethane solution of 3-methylpyridine-N-oxide was treated with N, N-diethylaminophosphorus oxychloride and diisopropylamine dissolved in dichloromethane to obtain 2- A mixture of 82% chloro-5-methylpyridine and 12% 2-chloro-3-methylpyridine, yielding 83%. Phthaloyl chloride is used as a chlorinating agent. Phthaloyl chloride was added dropwise to a mixture containing 3-methylpyridine-N-oxide, triethylamine, and dichloromethane for reaction to obtain 84% 2-chloro-5-methylpyridine, 2- A mixture of chloro-3-methylpyridine 16%, yield 85%. Use organic salts as intermediates. 2-Chloro-5-methylpyridine can also be prepared by using n-propionaldehyde, methyl acrylate and morpholine as raw materials. At present, some domestic enterprises adopt this method.

2-chloro-5-methylpyridine is an intermediate of imidacloprid and acetamiprid, abbreviated as monochloride, which is used to synthesize the next intermediate 2-chloro-5-chloromethylpyridine.

Molecular Weight:127.57
XLogP3:2.3
Hydrogen Bond Acceptor Count:1
Exact Mass:127.0188769
Monoisotopic Mass:127.0188769
Topological Polar Surface Area:12.9
Heavy Atom Count:8
Complexity:74.9
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes