Chrysanthemic acid chloride

In the preparation of pyrethroids, chrysanthemum chloride is generally used to react with corresponding alcohols, so chrysanthemum chloride is also an important intermediate in the production of pyrethroids. It has many preparation methods, the common ones are thionyl chloride method, phosphorous trichloride method and phosgene method. These three methods have their own characteristics. In the thionyl chloride method, in the presence of the catalyst DMF, chrysanthemum acid and thionyl chloride are heated to reflux for 4 hours in a certain inert solvent (such as benzene, toluene, dichloroethane, etc.). After the reaction, the 2 solvents are removed by distillation And excess thionyl chloride, and then rectify under reduced pressure to obtain chrysanthemumyl chloride. The purity of chrysanthemum chloride obtained by this method is relatively high, but the quality of thionyl chloride is the key. At present, most domestic production of chrysanthemum chloride is produced by this method. The phosphorous trichloride method dissolves chrysanthemum acid in toluene or benzene, puts it in a reactor, adds a metered amount of phosphorous trichloride, heats and stirs for 4-6 hours, stands still for stratification, separates the lower phosphorous acid, and removes the upper reaction liquid Transfer to a distillation pot, first evaporate the solvent, and then rectify under reduced pressure to obtain chrysanthemumyl chloride. With the phosphorus trichloride method, the separation of phosphorous acid is the key, which will affect the quality of chrysanthemum chloride. In addition, the phosphorous acid must be recycled. The phosgene method is to dissolve chrysanthemum acid in toluene, add the catalyst and heat up to about 90℃, and pass in phosgene under stirring. After passing in a certain amount to reach the end point, use nitrogen to drive off the remaining phosgene to absorb and utilize. The liquid is transferred into the distillation pot to reduce the pressure to dissolve, and then chrysanthemumyl chloride is obtained. The chrysanthemum oxychloride prepared by the phosgene method is generally no longer rectified, because its purity is already high, but the use of phosgene must be safe, and the tail gas must be destroyed with alkali and catalyst.

Chrysanthemum chloride is an important intermediate for pyrethroids. It can synthesize pyrethroids such as allethrin, promethrin, permethrin, methrin, and pyrethrin.

Molecular Weight:186.68
XLogP3:4.4
Hydrogen Bond Acceptor Count:1
Rotatable Bond Count:2
Exact Mass:186.0811428
Monoisotopic Mass:186.0811428
Topological Polar Surface Area:17.1
Heavy Atom Count:12
Complexity:236
Undefined Atom Stereocenter Count:2
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes