- A PROCESS FOR THE PREPARATION OF SUBSTITUTED PYRIDINE COMPOUNDS AND INTERMEDIATES THEREOF
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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.
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Page/Page column 28-29
(2022/04/03)
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- Method for preparing 2, 3 -dichloropyridine from chlorination
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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.
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Paragraph 0032; 0055-0057
(2021/11/03)
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- Industrial synthesis method of 2, 3-dichloropyridine
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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.
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Paragraph 0103; 0112-0118; 0127-0133; 0142-0148; ...
(2021/10/27)
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- Preparation method of chlorantraniliprole
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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.
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Paragraph 0078-0081
(2021/03/30)
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- Preparation method of 2,3-dichloropyridine
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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.
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Paragraph 0019; 0022; 0027-0028; 0031-0032
(2021/01/20)
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- Preparation method of 2, 3-dichloropyridine
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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.
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Paragraph 0015-0026
(2021/04/03)
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- Synthesis method of high-efficiency 2, 3-dichloropyridine
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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.
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Paragraph 0036; 0046
(2021/03/13)
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- One-pot method 2 and 3 -dichloropyridine synthesis method
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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.
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Paragraph 0036-0073
(2021/08/25)
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- Synthetic method 2-3 -dichloropyridine (by machine translation)
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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)
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- Method for preparing 2, 3-dichloropyridine by selective dechlorination of tetrachloropyridine
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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.
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Paragraph 0026-0220
(2020/02/17)
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- Simple preparation method of 2,3-dichloropyridine
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The invention provides a simple preparation method of 2,3-dichloropyridine. According to the method, 2-piperidone(II) is used as a raw material, 1,3,3-trichloro-2-piperidone (III) is prepared througha chlorination reaction, then hydrogen chloride is eliminated to obtain 3-chloro-2-hydroxypyridine (IV), and then the 2,3-dichloropyridine (I) is prepared through a substitution reaction with a chlorination reagent. Through the method, the raw material is low in price and easy to obtain, the cost is low, the reaction intermediate and the raw material are stable, operation is safe, easy and convenient to perform, a small amount of wastewater is generated, the environment is protected, the reaction selectivity is high, the quantity of side reactions is small, the product yield and purity are high, and the method is suitable for industrial production.
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Paragraph 0052-0060
(2020/03/03)
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- Preparation method of 2,3-dichloropyridine
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The invention provides a preparation method of 2,3-dichloropyridine. The method comprises the following steps: preparing 2,3-dichloropyridine through an intermediate product 2-hydroxy-3-chloropyridine; preparing 3,3-dichloro-2-piperidone through a chlorination reaction by using 2-piperidone as a raw material; then preparing 2-hydroxy-3-chloropyridine through an elimination and oxidation reaction;and finally preparing the 2,3-dichloropyridine through a substitution reaction under action of the obtained 2-hydroxy-3-chloropyridine and a chlorination reagent. The method has the advantages of cheap and easily obtained raw materials, low cost, stable reaction intermediate and raw materials, safe and simple operation, less waste water generation, environmental protection, high reaction selectivity, few side reactions, and high product yield and purity, and is suitability for industrial production.
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Paragraph 0041; 0059-0065
(2020/03/03)
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- Transition-metal-free decarboxylative halogenation of 2-picolinic acids with dihalomethane under oxygen conditions
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A convenient and efficient method for the synthesis of 2-halogen-substituted pyridines is described. The decarboxylative halogenation of 2-picolinic acids with dihalomethane proceeded smoothly via N-chlorocarbene intermediates to afford 2-halogen-substituted pyridines in satisfactory to excellent yields under transition-metal-free conditions. This new type of decarboxylative halogenation is operationally simple and exhibits high functional-group tolerance.
- Zhang, Xitao,Feng, Xiujuan,Zhang, Haixia,Yamamoto, Yoshinori,Bao, Ming
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supporting information
p. 5565 - 5570
(2019/10/22)
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- Preparation method for 2,3-dichloropyridine
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The invention discloses a preparation method for 2,3-dichloropyridine. The method provided by the invention is carried out through the following steps: with 2,3,6-trichloropyridine as a raw material,a basic compound as an acid-binding agent, palladium on carbon as a catalyst and hydrogen as a hydrogen source, carrying out a hydrodechlorination reaction in a pure organic solvent system at a temperature of 20 to 100 DEG C and a pressure of 1.0 to 8.0 Mpa under stirring with a rotating speed controlled to be 100 to 1000 rmp/min, and after the reaction is performed for 2 to 10 h, subjecting a reaction liquid to post-treatment so as to obtain a 2,3-dichloropyridine product. The preparation method provided by the invention has the following advantages: the conversion rate of the raw material is95% or above; the selectivity of the product can reach 88%; meanwhile, the usage amount of the catalyst is small; operation is simple; the requirements for equipment are low; a solvent is easy to recycle; the product is easy to separate; the quality of the product is high; few three wastes are produced; and the preparation method is a green process applicable to industrial production.
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Paragraph 0022-0029
(2019/02/13)
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- A chloro pyridine and its derivatives synthetic method
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The invention discloses a method for synthesizing chloropyridines and derivatives thereof and belongs to the field of fine chemical industry. According to the method, aminopyridine and derivatives thereof undergo a reaction to generate chloropyridines and derivatives thereof. The method is characterized in that phosphorus trichloride, phosphorus oxychloride or thionyl chloride and nitric acid are added into a solution of aminopyridine and the derivatives of aminopyridine, and chloropyridines and derivatives of chloropyridines can be obtained by stirring and reaction. The method has the advantages of being simple to operate, high in yield and less in three wastes.
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Paragraph 0022; 0023
(2018/03/26)
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- Method for preparing 2,3-dichloropyridine through Sandmeyer reaction catalyst
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The invention relates to a method for preparing 2,3-dichloropyridine through a Sandmeyer reaction catalyst. The method comprises the following steps: i, obtaining graphite oxide from natural graphiteand performing ultrasonic stripping, and performing molecular assembly on the graphite oxide and copper oxide so as to obtain a graphene-copper oxide composite catalyst; ii, adding 2-chloro-3-pyridinamine and concentrated hydrochloric acid into a first reactor, cooling to 5 DEG C below zero, slowly dropping an aqueous solution of sodium nitrite, and controlling the temperature to 5 DEG C below zero for later use; iii, adding hydrochloric acid and the composite catalyst into a second reactor, dropping the mixed solution in the first reactor under nitrogen protection, gradually raising the temperature to 40 DEG C after dropping, reacting for an hour, extracting with dichloromethane, and performing organic phase rotary evaporation, thereby obtaining the crude 2,3-dichloropyridine. According to the 2,3-dichloropyridine prepared by the method disclosed by the invention, the production cost can be reduced, the used graphene-copper oxide composite catalyst can be repeatedly utilized, and heavy metal pollution brought by copper in liquid waste can be reduced.
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Paragraph 0029-0032
(2018/10/19)
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- Preparation method of 2,3-dichloropyridine
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The invention provides a preparation method of 2,3-dichloropyridine. The 2,3-dichloropyridine is prepared by a one-pot method, pyridine alkyl ester serves as a raw material, and synthesis is conductedby a mode of performing chlorination, performing hydrolysis and performing chlorination again; the chlorination is substitution reaction, substitution on a benzene ring is relatively easy, the alkylester group can protect the site of the first-time chlorination reaction to be at 2 position, the hydrolysis reaction is mild in condition and rapid in reaction compared with the prior art, the second-time chlorination is to substitute the hydroxyl, the reaction is easy and the reaction condition is relatively mild. The preparation method provided by the invention is simple in operation, few threewastes are generated in the production process, requirements on equipment are low and the yield is high.
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Paragraph 0071
(2018/06/15)
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- Preparation method of non-transition metal-catalyzed 2-halogenated pyridine compound
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The invention provides a preparation method of a non-transition metal-catalyzed 2-halogenated pyridine compound. The 2-halogenated pyridine compound is an important component of many medicines and bioactive molecules and has important application in the fields of organic synthesis, medicinal chemistry and the like and wide market prospects. The invention relates to the preparation method of the non-transition metal-catalyzed 2-halogenated pyridine compound. According to the method, pyridine-2-carboxylic acid, derivatives of the pyridine-2-carboxylic acid, NaF, KF, CsF, TBAF, NaCl, KCl, CsCl, TBAC, NCS, NaBr, KBr, CsBr, Br2, TBAB, NBS, NaI, KI, CsI, I2 and NIS are used as raw materials, and under the presence of base and an accelerant and mild conditions, the 2-halogenated pyridine compoundis synthesized. The method has the advantages that the steps are simple, the raw materials are easy to obtain, the reaction conditions are mild and the like; the method has great use value and socialand economic benefits.
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Paragraph 0052-0054
(2018/10/11)
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- Method for synthesizing 2, 3-dichloropyridine
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The invention discloses a method for synthesizing 2, 3-dichloropyridine (III). The method comprises that 1) pyridine (I) as a main starting raw material and chlorine undergo a full reaction in water or vapor as a reaction medium in the presence of a chlorination inducer to produce a pyridine chloride (II) as the next reaction raw material, and 2) the pyridine chloride (II) as a reaction raw material contacts with hydrogen and undergoes a catalytic hydrogenation reduction reaction in water or vapor as a reaction medium in the presence of an acid-binding agent and a catalyst to produce 2, 3-dichloropyridine (III) having purity of 99% or more, wherein the catalyst is a nanometer IrO2-ZnO-MnO2 composite catalyst. The reaction equation is shown in the description and n is 2-5. The method has the advantages of high reaction conversion rate, high selectivity, stable product quality, simple processes and low cost and solves the problem that the existing synthesis method produces 2, 3-dichloropyridine (III) having unstable quality and satisfying the quality standards after multiple rectification processes.
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Paragraph 0020 0022; 0024; 0026; 0028; 0029; 0030; 0031
(2018/04/02)
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- Method for synthesizing 2,3-dichloropyridine
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The invention discloses a method for synthesizing 2,3-dichloropyridine. The method comprises the steps that under the existence of solvent and an acid-binding agent, 2,3,6-trichloropyridine is taken as a raw material, oxygen is taken as a hydrogen source, rhodium(I) tris(triphenylphosphine) chloride or bromotris(triphenylphosphine)rhodium(I) is taken as a catalyzer, an organic phosphine-containingauxiliary is added, and catalytic hydrogenation is conducted under the conditions that the pressure is 0.8-8 MPa and the temperature is 20-200 DEC G to obtain the 2,3-dichloropyridine. According to the method, by adding the low-cost organic phosphine-containing auxiliary, under the conditions that using amount of the catalyzer rhodium(I) tris(triphenylphosphine) chloride or the bromotris(triphenylphosphine)rhodium(I) is greatly reduced, better percent conversion of the raw material 2,3,6-trichloropyridine and better selectivity of the product 2,3-dichloropyridine are still obtained, the percent conversion of the 2,3,6-trichloropyridine reaches 97% and the selectivity of the 2,3-dichloropyridine is close to 90%, so that production cost of the 2,3-dichloropyridine is greatly reduced, and the method has higher industrialization value.
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Paragraph 0018-0041
(2018/06/21)
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- Preparation method of 2,3-dichloropyridine
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The invention discloses a preparation method of 2,3-dichloropyridine, and aims to solve the problems that a large amount of triethylamine hydrochloride is generated in a reaction process to wrap a palladium-carbon catalyst when a toluene solvent and triethylamine are used as acid binding agents during the preparation of 2,3-dichloropyridine by an existing 2,3,6-trichloropyridine catalytic dechlorination method, so that the activity of the catalyst is not high, the dosage of the catalyst is large, and the reaction selectivity is still not high. In the preparation method provided by the invention, methanol is used as a solvent, the palladium-carbon catalyst with a high water content has good dispersibility in methanol, and the dosage of the palladium-carbon catalyst can be effectively reduced; magnesium hydroxide is used as an acid binding agent, the generated magnesium chloride can be dissolved in methanol, a homogeneous system appears at the later stage of the reaction, and the problemof wrapping the catalyst is avoided; and formic acid is selected as a buffer agent to ensure that formic acid preferentially reacts with magnesium hydroxide to generate magnesium formate dissolved inmethanol, magnesium formate reacts with hydrogen chloride generated in the reaction to generate formic acid and magnesium chloride, and the formic acid realizes a catalytic cycle. The reaction selectivity in the preparation method provided by the invention reaches 85-90% and the yield reaches 87%.
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Paragraph 0026; 0028; 0029
(2018/04/03)
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- Preparation technology of 2,3-dichloropyridine
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The invention discloses a preparation technology of 2,3-dichloropyridine. The preparation technology comprises the following process: with 2,3,6-trichloropyridine as a starting material, in a mixed solvent system of an organic solvent and water, with organic alkali or inorganic alkali as an acid-binding agent, under the catalysis of palladium carbon, 2,3-dichloropyridine is obtained through hydrogenation. By the preparation technology, the conversion rate is high, the reaction selectivity is good and a product is easy to separate; the preparation technology is suitable for industrial mass production.
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Paragraph 0019-0021; 0025-0027; 0028-0030
(2018/03/24)
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- A two-chloro pyridine production process (by machine translation)
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Dichloro pyridine is an important raw material in the chemical industry. Dichloro pyridine production process flow is: (1) chlorinated reaction; the 3 - aminopyridine is added to the chlorination kettle in, add a certain amount of hydrogen peroxide, its jacket into the freezing brine cooling to 10 °C, then slowly dropping hydrochloric acid chloride the reaction, the reaction temperature is controlled 25 °C, the reaction pressure is normal pressure, after the end of the chlorination reaction, to obtain 2 - chloro -3 - aminopyridine. (2) the diazotization reaction; the 2 - chloro -3 - aminopyridine into diazonium cauldron in to, its jacket into the freezing brine cooling to -5 °C, then slowly dropping sodium nitrite solution diazo-reaction, the reaction temperature is controlled 5 °C, the reaction pressure is normal. The diazotization reaction is obtained after the end of the 2 - chloro -3 amino pyridine diazonium salt. (3) after treatment; in the crude product into to the kettle, add a certain amount of liquid alkali neutralized, adding chloroform extraction separation, the aqueous phase is filtered after the cuprous chloride recovery into a waste water processing. (by machine translation)
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Paragraph 0003-0005
(2017/07/21)
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- A 2, 3 - dichloro pyridine synthesis method (by machine translation)
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The invention discloses a 2, 3 - chlorinate (III) synthetic method, the steps of: 1) to pyridine (I) as the main starting material, water or steam is used as the reaction medium, in the presence of chlorinated derivative, pyridine react with chlorine to the full, (II) to obtain the pyridine chloride as a next step the reaction raw material; 2) to obtain the 1st step (II) of the pyridine chloride as the reaction raw material, water or steam is used as the reaction medium, in the acid, the presence of a catalyst, pyridine chloride (II) contact with hydrogen gas, by catalytic hydrogenation reduction reaction, to obtain the purity of 99% or more of the 2, 3 - chlorinate (III), the catalyst is nano IrO2 - ZnO - MnO2 Composite catalyst. The reaction equation is for:???: ???: C:Program Files gwssi CPC????? cases inventions 097cc1fe - cb01 - 4116 - 9 cd3 - cbef3e3f4998 new 100002 dest_path_image002.jpgWherein n=2 - 5. The reaction of the invention conversion and high selectivity, stability of the product quality, production operation is simple, low cost and the like, overcomes the obtained synthetic method for 2, 3 - chlorinate (III) of the instability and must be approved by the numerous rectification can make the 2, 3 - chlorinate (III) the quality of the deficiency of the standard. (by machine translation)
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Paragraph 0019; 0021; 0023; 0025; 0026; 0027; 0028-0030
(2017/11/08)
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- Method for preparing 2,3-dichloropyridine
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The invention discloses a method for preparing 2,3-dichloropyridine. The method comprises the following steps that 3-pyridone is dissolved in a caustic alkali water solution, a sodium hypochlorite water solution is dropwise added, and the materials fully react; after the reaction is completed, acid is added to regulate the pH of the system to be neutral or acidic, cooling and filtering are carried out, and crude 2-chloro-3-pyridone is obtained; crude 2-chloro-3-pyridone is dissolved in dimethylformamide, a chloride agent is added, the materials fully react, cooling is carried out after the reaction is completed, water is added to decompose the chloride agent which does not react, the pH of the system is regulated to be neutral or acidic with caustic alkali, filtering is carried out, and 2,3-dichloropyridine is obtained. The method is short in reaction period, simple in production process, stable in reaction, low in production cost and high in product yield.
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Paragraph 0022; 0023; 0024; 0025; 0026; 0027; 0029
(2017/08/28)
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- A wicked grass ether and intermediate 2, 3, 5 - trichloro-pyridine synthesis method (by machine translation)
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The invention discloses a wicked grass ether and intermediate 2, 3, 5 - trichloro-pyridine synthesis method, in particular comprising the following steps: 1st step, pyridine (I) with chlorine in the chlorination reaction under the presence of a base catalyst, through a chlorination reaction, synthesis of chloro-pyridine (II); 2nd step, multi-chloro-pyridine (II) is mixed with hydrogen, by dechlorination reaction catalyst to catalyze the hydrogenation, by hydrogenation dechlorination reaction, by 2, 3, 5 - trichloropyridine (III), the hydrogenation dechlorination reaction catalyst is platinum, palladium, a ruthenium carbon; 3rd step, 2, 3, 5 - trichloropyridine (III) with the N - [( ±) - 2 - (4 - hydroxy benzene ammonia oxygen) propionyl] Isoxazolidine (IV), acid, organic solvent are mixed to obtain a wicked grass ether (V). The advantage of this invention is characterized in that: the main raw material sources are extensive, the product quality is high, high yield, waste water is less, large-scale production of 2, 3, 5 - dichloro pyridine, 2, 3 - chlorinate and downstream various pesticide production and model chloro pyridine pesticide development provides a convenient method of cleaning low energy consumption. (by machine translation)
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Paragraph 0032; 0033; 0034; 0037; 0038 0039; 0040; 0041; 004
(2017/07/19)
-
- HOMOGENEOUS PROCESS FOR HYDRODEHALOGENATING HALOGENATED HETEROARYL COMPOUNDS
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The present invention provides a homogeneous process for hydrodehalogenating a halo-substituted C3-C20 heteroaryl starting material to form a non-halogenated C3-C20 heteroaryl product and/or a halo- substituted C3-C20 heteroaryl product, wherein the halo-substituted C3-C20 heteroaryl product has at least one less halogen substituents than the halo-substituted C3-C20 heteroaryl starting material, the process comprising the step of hydrogenating the halo-substituted C3-C20 heteroaryl starting material in the presence of a rhodium or ruthenium complex, molecular hydrogen, a base and a solvent, wherein the process is carried out in a monophasic solvent system and the molar ratio of base to each halogen substituent to be removed is at least 1 :1.
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Page/Page column 12-13
(2017/07/11)
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- Method for synthesising 2,3-dichloropyridine
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The invention discloses a method for synthesising 2,3-dichloropyridine. The synthesis method disclosed by the invention specifically comprises the following steps: adding 2,3,6-trichloropyridine, hydridocarbonyltris(tri-phenylphosphine)rhodium, triethylamine and a solvent into an autoclave, carrying out airtight ventilation, charging hydrogen until the pressure is 50-100MPa, reacting at 50-80 DEG C until a hydrogen absorption phenomenon disappears, removing the solvent in a manner of reduced pressure distillation, adding water and then distilling out the mixture of 2,3-dichloropyridine and water in a manner of constant-pressure water vapour distillation, and obtaining 2,3-dichloropyridine through cooling and suction filtration. A dechloridation reaction can be selectively carried out on 6-site chlorine atom because a catalyst with a large volume is adopted, and then 2,3-dichloropyridine with both ideal purity and yield is obtained; and the used raw materials are relatively easily-available, the operation process is simple, convenient and practicable, and a great industrialized application prospect is achieved.
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Paragraph 0022; 0023; 0024; 0025; 0026; 0027; 0028-0031
(2017/05/27)
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- Method for preparing 2,3-dichloropyridine
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The invention discloses a method for preparing 2,3-dichloropyridine. The preparation method disclosed by the invention specifically comprises the following steps: adding 2,3,6-trichloropyridine, a palladium/carbon catalyst and 1-isopropyl-4-methylcyclohexene in a solvent, heating to 50-80 DEG C and reacting for 2-5 hours; and after the reaction is concluded, carrying out suction filtration and removing the solvent in a manner of reduced pressure distillation, adding water in residues, distilling out the mixture of 2,3-dichloropyridine and water in a manner of constant-pressure water vapour distillation, and obtaining 2,3-dichloropyridine through cooling and suction filtration. A dechloridation reaction can be selectively carried out on 6-site chlorine atom because a hydrogen donor with a large volume is adopted, and then 2,3-dichloropyridine with both ideal purity and yield is obtained; and the used raw materials are relatively easily-available, the operation process is simple, convenient and practicable, and a great industrialized application prospect is achieved.
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Paragraph 0022-0031
(2017/05/19)
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- Synthetic process for 2-hydrazinylpyridine derivative
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The invention discloses a synthetic process for a 2-hydrazinylpyridine derivative. The process includes the steps that a pyridine halide A, hydrazine hydrate and a solvent I are mixed for a reaction; and after the reaction and aftertreatment, a reaction product, namely the 2-hydrazinylpyridine derivative P is obtained. According to the process, the pyridine halide A can be obtained through a hydrogen substitution reaction of a precursor compound B under the conditions of bases and catalysts. N,N-dimethylpropanolamine in the solvent I plays the role of an acid-binding agent to a certain extent, and the reaction is promoted to the product generating direction; and in the hydrogen substitution reaction, the mixed catalysts are combined with compounding use of the strong base and the weak base, so that the selectivity of the hydrogen substitution reaction is improved, and the reaction speed of the hydrogen substitution reaction is increased.
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Paragraph 0088; 0089; 0095; 0096; 0102; 0103; 0109; 0110
(2017/08/28)
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- 2, 3-dichloropyridine preparation method
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The present invention discloses a 2, 3-dichloropyridine preparation method comprising the following steps: (1) 2,3-dimethylamide pyridine is dissolved in water, then a caustic soda aqueous solution and a sodium hypochlorite aqueous solution are successively added, after the addition is completed, the mixture is heated for full reaction, after the reaction is completed, the system is adjusted to be neutral or acidic by use of hydrochloric acid, and water is removed by distillation to obtain a 2,3-diaminopyridine crude product; (2) the 2,3-diaminopyridine crude product is dissolved in hydrochloric acid, a catalyst is added, then a sodium nitrite aqueous solution is added dropwise, after the addition is complete, the2,3-diaminopyridine crude product is completely reacted, and after the reaction is completed, a 2, 3-dichloropyridine crude product is obtained by distillation; and (3) the 2, 3-dichloropyridine crude product is added into an organic solvent for complete dissolving, then cooled for recrystallization, crystals are filtered off and dried to obtain a 2, 3-dichloropyridine finished product. The method avoids the problem of very low tendency for side effects of 2-site chlorination, the production process is simple, the reaction is smooth and steady, production cost is low, product yield is high, and product purity is high.
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Paragraph 0024-0026
(2017/02/09)
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- Preparation method of 2,3-dichloropyridine
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The invention discloses a preparation method of 2,3-dichloropyridine. The method comprises the steps that 2,3,6-trichloropyridine serves as the raw material, Pd/GO serves as a catalyst, tetrahydrofuran serves as solvent, hydrogen is fed, and a catalytic reaction is conducted on the condition that the hydrogen pressure ranges from 1 MPa to 6 MPa, and the temperature ranges from 20 DEG C to 100 DEG C, wherein the reaction is conducted for 3-18 h optimally; after the reaction is completed, after-treatment is conducted on reaction liquid, and the 2,3-dichloropyridine is obtained. According to the preparation method of the 2,3-dichloropyridine, the method of preparing the 2,3-dichloropyridine from the 2,3,6-trichloropyridine through selective catalytic hydrogenation of the Pd/GO is adopted; compared with a traditional technology for preparing the 2,3-dichloropyridine, use of a large amount of organic matter and inorganic salt is avoided, the operation process is simple and easy to carry out, the conversion rate and the selectivity are high, the conversion rate reaches 96.3 percent, the selectivity is 88.3 percent, and higher innovativeness and industrial application value are achieved.
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Paragraph 0032; 0033; 0034
(2016/10/17)
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- Synthesis method of 3-cloro-5-bromo-2-picolinic acid
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The invention discloses a synthesis method of 3-cloro-5-bromo-2-picolinic acid, and belongs to the field of chemosynthesis. According to the method, 3-aminopyridine is used as raw materials; concentrated hydrochloric acid and hydrogen peroxide are added for preparing a diazonium salt solution; CuCl, dichloromethane and concentrated hydrochloric acid are added into a three-mouth flask; the diazonium salt solution is dropwise added into the three-mouth flask; the pH value is regulated; extraction, separation and rotary evaporation are carried out to obtain 2, 3-dichloropyridine; absolute ethyl alcohol is used for dissolution; a hydrazine hydrate solution is dropwise added into the flask; under the nitrogen gas protection, backflow is carried out; 3-cloro-2-cyanopyridine can be obtained; then, through specific conditions, the 3-cloro-2-cyanopyridine is used for producing 3-chloropyridine-2-picolinic acid; then, N-bromo-succinimide is added for performing a bromination reaction to finally obtain the 3-cloro-5-bromo-2-picolinic acid.
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Paragraph 0007
(2017/01/23)
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- 2, 3-dichloro polypyridine manufacturing method
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PROBLEM TO BE SOLVED: To provide a new method for easily producing 2,3-dichloropyridine in high selectivity. SOLUTION: The method for producing 2,3-dichloropyridine comprises a step of reacting a compound expressed by formula (1) (wherein R1is hydroxyl or a chlorine atom; and R2is hydroxyl or nitro) with phosphorus pentachloride or thionyl chloride. The step may be a step of reacting the compound of formula (1) with phosphorus pentachloride or thionyl chloride further in the presence of phosphoryl chloride or in the presence of a solvent. COPYRIGHT: (C)2013,JPOandINPIT
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Paragraph 0033; 0034; 0036; 0037
(2018/10/31)
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- 2, 3-dichloro polypyridine manufacturing method
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PROBLEM TO BE SOLVED: To provide a new method for producing 2,3-dichloropyridine in high selectivity. SOLUTION: The method for producing 2,3-dichloropyridine comprises a step (1) to react 3-chloropyridine-N-oxide with an acylation agent expressed by RCOCl (acid chloride) or R(CO)O(CO)R (carbonate) (wherein R is 1C-12C alkyl or 6C-20C aryl) and a step (2) to react a compound of formula (2) (wherein R is same as defined above) obtained by the step (1) with a chlorinating agent. COPYRIGHT: (C)2013,JPOandINPIT
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Paragraph 0036
(2016/12/07)
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- METHOD FOR PREPARING 2,3-DICHLOROPYRIDINE
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Disclosed is a method for preparing 2,3-dichloropyridine, which comprises the following steps: (1). chlorination: reacting 2,6-dichloropyridine with chlorine gas in the presence of a catalyst to obtain 2,3,6-trichloropyridine; (2). hydrogenation: hydrogenating 2,3,6-trichloropyridine in an organic solvent in the presence of an acid-binding agent and a catalyst; (3). post-processing: cooling the aforementioned reaction mixture, adding water to dissolve the acid-binding agent hydrochloride, standing to separate the water layer after filtering, extracting the organic solvent layer with a hydrous acid at least three times, combining the hydrous acid layer, adding water to dilute to separate the solid, filtering and drying it to obtain 2,3-dichloropyridine.
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Paragraph 0012; 0013
(2014/02/15)
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- PROCESS FOR PREPARING DIHALOPYRIDINES
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Processes for manufacturing dihalopyridines without the use of copper salts are described. Additional processes for manufacturing dihalopyridines from niacinamide are described.
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Page/Page column 8; 9
(2014/01/07)
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- METHOD FOR THE PREPARATION OF CHLORINATED PYRIDINES
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The invention discloses a method for the preparation of halogenated pyridines by decarbonylation of pyridine acyl halides.
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Page/Page column 17;18;19
(2013/03/26)
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- PROCESS FOR PRODUCING DIHALOPYRIDINES
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Disclosed herein an improved process for producing 2,3-dihalopyridine with high purity at industrial scale with minimum effluent.
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Page/Page column 4
(2010/07/04)
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- IMPROVED PROCESS FOR THE MANUFACTURE OF 2,3-DICHLOROPYRIDINE
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A method for preparing 2,3-dichloropyridine is disclosed in which 3-amino-2- chloropyridine is contacted with a nitrite salt in the presence of aqueous hydrochloric acid to form a diazonium salt; and the diazonium salt is subsequently decomposed in the presence of sulfamic acid and a copper catalyst wherein at least about 50% of the copper is the copper (II) oxidation state.
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Page/Page column 13-14
(2009/10/22)
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- Aqueous process chemistry: The preparation of aryl sulfonyl chlorides
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The use of aqueous acidic conditions for the preparation of arylsulfonyl chlorides from diazonium salts in the presence of copper salts, preferably CuCl, together with thionyl chloride as the sulfur dioxide source, has considerable advantages over recommended literature procedures, whereby reactions are carried out in acetic acid with minimisation of water content of the solvent. The method has been shown to be successful for a wide range of electron-deficient and electron-neutral aryl substrates. The sulfonyl chlorides are protected from hydrolysis by their low solubility in water, which results in their direct precipitation from the reaction mixture in good yields (>70%) and high strength (>98% w/w). The aqueous process, which is additionally safer and more robust, can be readily scaled up and has significant environmental benefits.
- Hogan, Philip J.,Cox, Brian G.
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scheme or table
p. 875 - 879
(2010/04/22)
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- PROCESS FOR THE MANUFACTURE OF 2,3-DICHLOROPYRIDINE
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A method for preparing 2,3-dichloropyridine is disclosed in which 3-amino-2-chloropyridine is contacted with an alkali metal nitrite in the presence of aqueous hydrochloric acid to form a diazonium salt; and the diazonium salt is subsequently decomposed in the presence of copper catalyst wherein at least about 50% of the copper is the copper(II) oxidation state.
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Page/Page column 15
(2008/06/13)
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- First regioselective c-2 lithiation of 3- and 4-chloropyridines
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We have shown that the BuLi/LiDMAE reagent promotes the clean and regioselective C2 lithiation of 3- and 4-chloropyridines, while other reagents such as LDA or BuLi/TMEDA lead to classical ortho lithiation products or mixtures of regioisomers. The method was successfully applied to the preparation of various reactive 2,3- and 2,4-disubstituted pyridines.
- Choppin, Sabine,Gros, Philippe,Fort, Yves
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p. 603 - 606
(2007/10/03)
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- Substituent Effect on the Chlorination of 2-Alkoxypyridines to give 2-Chloropyridines under Vilsmeier-Haack Conditions
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Various substituted 2-alkoxypyridines were converted into the corresponding 2-chloropyridines in 28-91% yields by use of POCl3 and DMF, in which the methyl, halogen, ester and nitro groups displayed an activating effect; in contrast, an amino group exhibited a deactivating effect.
- Lai, Long-Li,Lin, Pen-Yuan,Wang, Jy-Shih,Hwu, Jih Ru,Shiao, Min-Jen,Tsay, Shwu-Chen
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p. 194 - 195
(2007/10/03)
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- Preparation of substituted 2-chloropyridines
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A process for the preparation of a substituted 2-chloropyridine derivatives of the formula STR1 in which R1, R2, R3 and R4 represent hydrogen or various other radicals, which comprises reacting a pyridine-1-oxide of the formula STR2 with an aromatic carbonyl chloride in the presence of an inert organic solvent and in the presence of an acid acceptor at a temperature between about -20° C. and 200° C.
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- Process for the preparation of substituted 2-chloropyridines
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A new process has been found for the preparation of substituted 2-chloropyridine derivatives of the formula (I) STR1 wherein R1 to R4 have the meanings as defined in the description. The new process is characterized in that pyridine 1-oxides of the formula II STR2 are reacted with a chlorine-containing phosphoric acid derivative from the series of the chlorophosphoric esters and chlorophosphoramides in the presence of an inert organic solvent and in the presence of an acid acceptor at temperatures between -20° C. and 200° C., and the resulting product is separated further, if appropriate. Compound (I) is known as an intermediate product for medicaments (cf.DE-A 2,812,585) or for insecticidel nitromethylene derivatives (cf. EP-A 163,855).
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- Utilizing Acetyl Hypofluorite for Chlorination, Bromination, and Etherification of the Pyridine System
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Acetyl hypofluorite, which is easily made from F2, possesses a strong electrophilic fluorine.This electrophile is able to attach itself to the nitrogen atom of pyridine and activate the ring toward nucleophilic attacks.The ultimate elimination of HF results in an overall easy nucleophilic displacement of the hydrogen of the important 2-position .The nucleophiles used: Clδ-, Brδ-, ROδ-, originate from solvents such as CH2Cl2, CH2Br2, and various primary alcohols.Thus, 2-halo- or 2-alkoxypyridines were formed.The reaction conditions (room temperature, very short reaction times, and good yields) transform the task of direct substitution of the pyridine ring from an extremely difficult to a very easy procedure.
- Hebel, David,Rozen, Shlomo
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p. 6298 - 6301
(2007/10/02)
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- A Convenient Synthesis of Halogenated 2-Chloropyridines by Transformation of Halogenated 2-Methoxypyridines under Vilsmeier-Haack Conditions
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Several halogenated 2-chloropyridines 2a-2h were conveniently synthesized by transformation of halogenated 2-methoxypyridines 1a-1h under Vilsmeier-Haack conditions in a yield of 50-71percent.
- Shiao, Min-Jen,Shyu, Li-Ming,Tarng, Kai-Yih,Ma, Ying-Tsun
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p. 2971 - 2977
(2007/10/02)
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- Site-Selectivity in the Reaction of 3-Substituted Pyridine 1-Oxides with Phosphoryl Chloride
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Site-selectivity in the reaction of 3-substituted pyridine 1-oxide with phosphoryl chloride was investigated.When a strongly electron-withdrawing group (e.g.CN, CONRR', COOR, or NO2) was substituted at the 3-position, the reaction of 3-substituted pyridine 1-oxides with phosphoryl chloride yielded 3-substituted 2-chloropyridines as the main products.Keywords- site-selectivity; 3-substituted pyridine 1-oxide; phosphoryl chloride; 3-substituted 2-chloropyridine; chlorination
- Yamanaka, Hiroshi,Araki, Tomio,Sakamoto, Takao
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p. 2244 - 2247
(2007/10/02)
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