2402-77-9Relevant articles and documents
A PROCESS FOR THE PREPARATION OF SUBSTITUTED PYRIDINE COMPOUNDS AND INTERMEDIATES THEREOF
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Page/Page column 28-29, (2022/04/03)
The present invention discloses a process for the preparation of substituted pyridine compounds of formula (I), comprises a step in which vinylogous nitriles of formula (II), are obtained from substituted α,β-unsaturated nitrile compounds of formula (III), and a further step of converting the vinylogous nitrile compounds of formula (II) into substituted pyridines of formula (I); wherein R1, R2, R3, R4 and LG are as defined in the description.
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.
Preparation method of 2, 3-dichloropyridine
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Paragraph 0015-0026, (2021/04/03)
The invention relates to a preparation method of 2, 3-dichloropyridine, which comprises the following steps: by using 2, 3, 6-trichloropyridine and hydrogen as raw materials, carrying out catalytic hydrogenation reaction in the presence of a heterogeneous catalyst and an acid-binding agent to obtain 2, 3-dichloropyridine, wherein the active component of the heterogeneous catalyst is palladium, thecarrier of the heterogeneous catalyst is gamma-Al2O3, and the acid-binding agent is transition metal acetate.