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.
Method for preparing 2, 3 -dichloropyridine from chlorination
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Paragraph 0032; 0055-0057, (2021/11/03)
The invention relates to a method for preparing 2 and 3 - dichloropyridine from chlorination. The method introduces the graphene oxide catalyst in the traditional 3 - aminopyridine chlorination step, reduces the concentration and the dosage of hydrochloric acid and hydrogen peroxide, improves the selectivity of 2 -position chlorination, and reduces the generation of 2, 6 - dichloro -3 - aminopyridine. , The process enables high yield to obtain 2 - chloro -3 - aminopyridines of higher quality. , The method has good environmental friendliness and economical efficiency, and is suitable for being popularized and used in industry.
Industrial synthesis method of 2, 3-dichloropyridine
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Paragraph 0103; 0112-0118; 0127-0133; 0142-0148; ..., (2021/10/27)
The invention discloses an industrial synthesis method of 2, 3-dichloropyridine, which comprises the following steps of S1, taking anhydrous acetaldehyde as a raw material, and carrying out dehydration reaction with benzylamine to synthesize N-substituted enamine, S2, reacting the N-substituted enamine with an acylating agent in the presence of an acid-binding agent and a solvent to synthesize N-substituted-N-(1-vinyl)-chloroacetamide, S3, carrying out cyclization reaction on the N-substituted-N-(1-vinyl)-chloroacetamide and a vilsmeier reagent in the presence of a solvent, so as to generate N-substituted-2, 3-dichloropyridine pyridinium chloride salt, S4, enabling the N-substituted-2, 3-dichloropyridine pyridinium chloride salt to be heated and then subjected to a pyrolytic reaction, and producing a 2, 3-dichloropyridine crude product, and S5, purifying the 2, 3-dichloropyridine crude product to obtain a 2, 3-dichloropyridine finished product. The method has the advantages of mild reaction conditions, wide and easy-to-purchase reaction raw materials, no focused dangerous process in the reaction process, high reaction yield, safe and easy-to-control process, less three wastes generated by the process, and suitableness for expanded production.
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 0019; 0022; 0027-0028; 0031-0032, (2021/01/20)
The invention provides a preparation method of 2,3-dichloropyridine. The preparation method comprises the steps: uniformly mixing 3-chloropyridine and a solvent, adding a catalyst, adding chlorosulfonic acid, carrying out sulfonation reaction, carrying out post-reaction treatment to obtain an intermediate, and chlorinating the intermediate under the actions of hydrochloric acid and sodium chlorateto obtain 2,3-dichloropyridine. The preparation method has the advantages of short reaction steps, simple operation, few side reactions, few three wastes in the production process, low equipment requirements, no need of high equipment investment, and high product yield.
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.
Synthesis method of high-efficiency 2, 3-dichloropyridine
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Paragraph 0036; 0046, (2021/03/13)
The invention relates to the technical field of synthesis of compound intermediates, in particular to an efficient synthesis method of 2, 3-dichloropyridine; 2, 3, 6 trichloropyridine is subjected toa synthesis reaction to form 2, 3-dichloropyridine, a catalyst of the synthesis reaction is a metal catalyst, and a cocatalyst of the reaction is X(YH4)n; wherein X represents one of Li, Na, K, Mg andCa; Y represents B or Al; n is 1 or 2. According to the scheme, the technical problem that the conversion rate of raw materials for synthesizing 2, 3-dichloropyridine is low can be solved. On the basis of the traditional synthetic route, the cocatalyst X(YH4)n of the scheme is added, so that the reaction can be promoted to obtain higher reaction efficiency, shorter reaction time and ideal selectivity and conversion rate. The scheme can be applied to practical operation of synthesis of 2, 3-dichloropyridine, so that the utilization rate of raw materials is increased, the production efficiencyis improved, and the production cost is reduced.
One-pot method 2 and 3 -dichloropyridine synthesis method
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Paragraph 0036-0073, (2021/08/25)
The invention discloses a one-pot method 2 and 3 -dichloropyridine synthesis method, and belongs to the technical field of chloropyridine synthesis. The method comprises the following steps: (1) heating dehydration of dichloromethane and 3 - aminopyridine, dropping the excess chloride sulfoxide, refluxing the temperature, and preserving 5 - 8 hours. (2) Chromatography Tracking 3 - aminopyridine content is less 0.3%, cooling to -10 - 5 °C, dropping into sodium hydroxide, pH9 - 10, maintaining -10 - 5 °C, dropwise adding sodium nitrite solution and cuprous chloride, and completing heat preservation 4 - 6 hours after completion. (3) Warm up to 40 - 50 °C, keep warm 2 - 4 hours, concentrate, freeze, centrifuging and dry, obtain the finished product. In the step (1), 3 - aminopyridine is chlorinated by using thionyl chloride as a chlorinating agent to generate a product. In the step (2), cuprous chloride is used as a chlorination reaction catalyst to carry out diazotization reaction under the action of sodium nitrite as oxidant Sandmeyer.
Method for preparing 2, 3-dichloropyridine by selective dechlorination of tetrachloropyridine
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Paragraph 0026-0220, (2020/02/17)
The invention discloses a method for preparing 2, 3-dichloropyridine by selective dechlorination of tetrachloropyridine, and the method comprises the following steps: 1, putting the tetrachloropyridine, a catalyst, an acid-binding agent, an assistant and an organic solvent into a high-pressure reaction kettle, and vacuumizing the high-pressure reaction kettle; 2, using nitrogen for replacement three times, and then using hydrogen for replacement three times; 3, controlling the hydrogen pressure in the kettle to be 0.1-2MPa and the temperature to be 20-60 DEG C, reacting for 4-10 hours under the stirring condition, and cooling to room temperature; 4, completely discharging the hydrogen in the kettle, replacing with nitrogen for three times, and filtering to obtain a filtrate; and 5, carrying out reduced pressure rectification to obtain the 2, 3-dichloropyridine. According to the method, the tetrachloropyridine is used as a raw material, hydrogen is used as a hydrogen source, and the 2,3-dichloropyridine is obtained through selective dechlorination in the presence of the acid-binding agent, the catalyst and the auxiliary agent. The raw material conversion rate is high, the yield exceeds 93%, and the purity is high.
Synthetic method 2-3 -dichloropyridine (by machine translation)
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, (2020/09/16)
The invention provides 2-3 -dichloropyridine synthesis method which comprises the following steps: reacting cyclopentanone with hydroxylamine hydrochloride to obtain compound A; compound A under the action of ammonium chloride to obtain compound C; compound C under the action of ammonium chloride to obtain compound D; compound E reacts with chlorine to obtain compound E; compound E and tert-butylphosphinic acid ester are reacted to obtain 2, 3 - dichloropyridines. The method has the advantages of simple operation steps, cheap and easily available reaction raw materials, 68.88%% of total molar yield, 2 or more purity 3 - 98.0% -dichloropyridine, and good product quality, and is suitable for industrial production. (by machine translation)
