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.
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.
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.