6515-09-9Relevant articles and documents
Preparation method of chlorantraniliprole
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Paragraph 0078-0081, (2021/03/30)
The invention relates to the field of insecticide synthesis, and discloses a preparation method of chlorantraniliprole. The preparation method comprises the following steps: synthesis of an intermediate I, synthesis of an intermediate II and synthesis of chlorantraniliprole. The method comprises the following steps: reacting 2, 3, 6-trichloropyridine serving as a raw material with hydrazine hydrate under the action of a catalyst A to obtain 3, 6-dichloro-2-hydrazinopyridine, carrying out hydrogenation reduction reaction under the action of a catalyst B to obtain an intermediate I, reacting theintermediate I with diethyl maleate, and preparing the 2-(3-chloropyridine-2-yl)-5-hydroxypyrazole-3-ethyl formate under the action of a catalyst C, and hydrolyzing after bromination to obtain an intermediate II, and preparing chlorantraniliprole from the intermediate II. According to the invention, 2, 3, 6-trichloropyridine is adopted to replace 2, 3-dichloropyridine as a raw material to preparethe intermediate I, so that the defects of difficulty in obtaining the 2, 3-dichloropyridine raw material, harsh synthesis conditions, low yield and the like are avoided, the total reaction yield ofthe intermediate I is improved, the intermediate II is prepared by a one-pot method, the post-treatment operation is reduced, and the synthesis cost of chlorantraniliprole is reduced.
Method for preparing 2, 3, 6-trichloropyridine
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Paragraph 0054; 0055, (2019/05/22)
The invention discloses a preparation method of 2, 3, 6-trichloropyridine. The preparation method comprises the following steps: taking 3-methylpyridine and chlorine as raw materials and preparing 2,3, 6-trichloropyridine through catalytic one-step gas-phase chlorination and trichloromethyl removal by a molecular sieve catalyst in the presence of water vapor. The molecular sieve catalyst is prepared by taking raw molecular sieve powder as an active component. The raw material 3-methylpyridine adopted in the invention is a byproduct in the synthesis of pyridine by an aldehyde ammonia method, and the source is cheap and easy to obtain. The molecular sieve catalyst has strong treatment capacity, the 3-methylpyridine and the chlorine are used as the raw materials, a proper amount of water isadded, gas-phase chlorination and trichloromethyl removal reactions are carried out under the action of a molecular sieve acid center and water vapor molecules, and the 2, 3, 6-trichloropyridine is synthesized by one step. The process is simple, the product purity and conversion rate are high, the yield can be maintained at 85% or above generally, the maximum yield can reach up to 95%, and the preparation method of the 2, 3, 6-trichloropyridine has good industrial application prospect.
The Specificity of Reductive Dechlorination in the Polychloropyridine Series. Synthesis of 2,3,5-Trichloro- and 2,3,5,6-Tetrachloropyridine
Sutter, P.,Weis, C. D.
, p. 493 - 496 (2007/10/02)
The high specificity of the reduction system zinc and ammonium salts in dimethyl methylphosphonate as solvent is demonstrated in several reductive dechlorination reactions of polychloropyridines.The reduction of pentachloropyridine with zinc/ammonium chloride system in dimethyl methylphosphonate yielded solely 2,3,5,6-tetrachloropyridine.Similarly, the reduction of 2,3,4,5-tetrachloropyridine with zinc and tetramethylammonium salt of methyl methylphosphonate furnished exclusively 2,3,5-trichloropyridine.A synthetic procedure for the preparation of the new ammonium salts of methyl methylphosphonate is given.
