2402-79-1Relevant articles and documents
Safety Aspects of the Under-Pressure Reaction of Trichloroacetyl Chloride and Acrylonitrile in the Preparation of 3,5,6-Trichloro-2-pyridinol
Fakhraian,Bazaz,Hadj-Ghanbary
, p. 1040 - 1042 (2003)
The under-pressure reaction of trichloroacetyl chloride (1) with acrylonitrile (2) in the preparation of 3,5,6-trichloro-2-pyridinol becomes explosive in certain circumstances. The studies of the reaction's enthalpy, the instability of the 2-chloropropionitrile (8), and the observation of the unexpected increase of pressure have helped us to point out that the above feature is due to the exothermic nature of the reactions and the HCl released by the 2-chloropropionitrile decomposition at elevated temperature. So, controlling the temperature and well-done stirring of the reaction mixture is very important in large-scale production to avoid the explosion nature of the reaction.
Facile preparation of Mn3O4 hollow microspheres via reduction of pentachloropyridine and their performance in lithium-ion batteries
Jiang, Zhan,Huang, Kaihua,Yang, Dian,Wang, Shuai,Zhong, Hong,Jiang, Chongwen
, p. 8264 - 8271 (2017)
Mn3O4 hollow microspheres have been facilely prepared via a green synthesis of 2,3,5,6-tetrachloropyridine reduced from pentachloropyridine by manganese. The specific hollow microspheres were made by a H2 gas bubble-templating method presenting a high specific surface area (87.1 m2 g-1) and a big total pore volume (0.2030 cm3 g-1). The Mn3O4 hollow microspheres as an anode material demonstrate a good electrochemical performance, with a high reversible capacity of 646.9 mA h g-1 after 240 cycles at a current density of 200 mA g-1. The good cycling performance is attributed to numerous mesopores, high specific surface area and big total pore volume, which can offer good electrical contact and conductivity as well as accommodate the mechanism strains. In addition, the yield and selectivity of 2,3,5,6-tetrachloropyridine achieved up to 99.2% and 99.5%, respectively.
A Convenient Synthesis of 2,3,5,6-Tetrahalogenopyridines and of 3,5-Bis(alkylthio)pyridines from 2,6-Diaminopyridine
Chen, Ted K.,Flowers, William T.
, p. 1139 - 1140 (1980)
Controlled chlorination of 2,6-diaminopyridine (1) affords 2,6-diamino-3,5-dichloropyridine (2a) which is then bis(diazotised) to give 2,3,5,6-tetrachloropyridine (3a); similarly prepared are other 2,3,5,6-tetra(chloro/bromo) pyridines and 2,6-dichloro-3,5-bis(thiocyanato)pyridine (3h), from which 3,5-bis(alkylthio)pyridines are easily obtained.
Preparation method of 3,5-difluoro-2,6-diaminopyridine
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Paragraph 0009-0012, (2019/02/04)
The invention discloses a preparation method of 3,5-difluoro-2,6-diaminopyridine, and belongs to the technical field of preparation methods of chemical drug intermediates. 2,3,4,5,6-pentachloropyridine is utilized as a raw material; and the 3,5-difluoro-2,6-diaminopyridine is prepared through reduction by a metallic reducing agent, fluorination and aminolysis. The method provided by the inventionis simple to operate, short in reaction time, environmentally friendly in process route and higher in yield, and has higher industrialization value; and an economical and high-efficiency catalyst is adopted.
Preparation method of 2,3,5,6-tetrachloropyridine
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Paragraph 0021-0023; 0026; 0029; 0031; 0033, (2018/03/25)
The invention discloses a preparation method of 2,3,5,6-tetrachloropyridine and belongs to the field of chemical industry. The preparation method comprises: introducing 2-chloropyridine and chlorine gas as raw materials into a fixed-bed reactor loaded with an activated carbon catalyst, and generating 2,3,5,6-tetrachloropyridine under the action of the activated carbon catalyst. The catalyst uses one or more of AlCl3, NiCl2, CuCl2, ZnCl2, FeCl3, CaCl2, BaCl2, MgCl2, CoCl2 and LaCl2 as active components and activated carbon as a support; the active components in the catalyst account for 4-27% bymass, and the activated carbon accounts for 73-96% by mass; the catalyst uses 2-chloropyridine and chlorine gas as raw materials, and the 2-chloropyridine and chlorine gas is generated under the action of the catalyst that is nontoxic and harmless; the preparation method has high conversion rate, good selectivity and zero pollution.
Synthesis method of 2,3,5,6-tetrachloropyridine
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Paragraph 0035-0045; 0047-0054; 0056-0063; 0065-0070; 0072-0, (2018/09/12)
The invention provides a synthesis method of 2,3,5,6-tetrachloropyridine, and relates to the field of organic synthesis. The synthesis method comprises the following steps that pentachloropyridine, acatalyst and an acid binding agent are added into a high pressure reactor, and the high pressure reactor is sealed; the air in the high pressure reactor is replaced with hydrogen gas firstly, then hydrogen gas is pumped into the high pressure reactor till the pressure in the high pressure reactor reaches 2-6 MPa, the temperature is increased to be 200-500 DEG C, and a thermal insulation reaction is conducted for 0.5-6 hours; after the reaction is ended, sampling is conducted to detect the content of tetrachloropyridine, the temperature is decreased to be the room temperature, and the acid gasin the high pressure reactor is exhausted through decompression; the previous steps are repeated till the content of tetrachloropyridine is detected to be higher than or equal to 90%; and a solvent isadded into the high pressure reactor and stirred for 20-40 minutes, suction filtration is conducted, the filter liquid is subjected to vacuum concentration, water is added and stirred at the room temperature, suction filtration is conducted again, and a filter cake is dried. In the synthesis method, hydrogen gas serves as a cleaning reduction agent, the synthesis conversion rate is high, the synthesis cost is low, the synthesis method is simple and suitable for large-scale industrialized popularization, the three wastes are less, the majority of the solvent used in the synthesis method can berecycled and reused, and thus the environmental protection and cost pressure is relieved further.
Preparation method of 2,3,5,6-tetrachloropyridine
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Paragraph 0021-0028, (2017/08/30)
The invention provides a preparation method of 2,3,5,6-tetrachloropyridine, comprising: mixing pyridine, a chlorinating agent and a solvent, and chlorinating for 6-8 hours to obtain the finished 2,3,5,6-tetrachloropyridine; to be specific, adding pyridine into a solvent, maintaining the reaction solution at 20 DEG C, dropwise adding sulfur dichloride, and heating for reflux reaction for 6-8 h after dropwise adding; cooling the reaction solution to room temperature, and filtering to remove solid; maintaining inner temperature not less than 10 DEG C, and dropwise adding 20% sodium hydroxide solution until the reaction solution is neutral; separating the solution, collecting organic phase, drying with anhydrous magnesium sulfate overnight, removing the solvent under reduced pressure, and purifying by column chromatography to obtain the 2,3,5,6-tetrachloropyridine. The preparation method has the advantages of good condition mildness, high reaction speed, and high selectivity; the 2,3,5,6-tetrachloropyridine prepared by using the preparation method has purity of >97%.
Method for synthesizing 2,3,5,6-tetrachloropyridine and co-producing manganous-manganic oxide
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Paragraph 0078-0083; 0084-0089; 0100-0105; 0109-0125, (2017/10/31)
The invention discloses a method for synthesizing 2,3,5,6-tetrachloropyridine and co-producing manganous-manganic oxide. With one or more of ester, lower alcohol and methylbenzene as the solvent, inorganic ammonium salt as the catalyst and manganese powder as the reducing agent, pentachloropyridine is reduced into tetrachloropyridine, and manganese powder is converted into manganous chloride or hydroxyl manganese chloride; manganous chloride or hydroxyl manganese chloride is oxidized by air to obtain manganous-manganic oxide. The method has the advantages of being high in reaction efficiency, mild in reaction condition and the like, the two products including 2,3,5,6-tetrachloropyridine and manganous-manganic oxide with high specific surface area can be obtained at the same time, the tetrachloropyridine purity reaches 98% or above, and the specific surface area of manganous-manganic oxide is 30-53 m/g.
Synthesis and crystal structure of 3,5-dichloro-6-morpholinopyridin-2-ol
Zheng, Hui,Liu, Yun-Kui,Shen, Chao,Xu, Zhen-Yuan
scheme or table, p. 919 - 922 (2010/06/19)
A new compound having potential bioactivities 3,5-dichloro-6- morpholinopyridin-2-ol (1) was synthesized and characterized by single crystal X-diffraction. The crystal is monoclinic, space group P21/c with a = 10.3609 (6), b = 10.5711 (7), c = 10.3190 (5) A, β = 108.9433 (15)°, V = 1068.99 (11) A3, Z = 4, C9H 10Cl2N2O2, D c = 1.548 g/cm3, μ (MoKα) = 0.71075 A, S = 1.01, F (000) = 512.00, R = 0.0397 and wR = 0.1364. In the unit cell, there are two independent molecules linked by intermolecular O-H???O (2.693(2) A) hydrogen bonds forming onedimensional expanded structure. Graphical Abstract: As part of our ongoing research work on pyridine derivatives, the title compound crystal structure is important to study the relationship between the structure and its biological activities, thus it is urgent to publish in time.[Figure not available: see fulltext.]
Reactions of 4-(dimethylamino)pyridinium activated pentachloropyridine with nitrogen nucleophiles and hydride
Schmidt, Andreas,Namyslo, Jan Christoph,Mordhorst, Thorsten
, p. 6893 - 6898 (2007/10/03)
Substitution reactions on 2′,3′,5′,6′-tetrachloro-4-dimethylamino-[1,4]bipyridinyl-1-ylium chloride with nitrogen nucleophiles such as n-propylamine, isopropylamine, glycine, morpholine, and piperidine were examined. Highly functionalized Cl2,Cl3,N4,Cl5,Cl6- and N2,Cl3,N4,Cl5,Cl6-substituted pyridines were obtained, in part possessing unsubstituted 4-amino groups due to dealkylation. Detailed NMR studies were performed in order to elucidate the regiochemistry of these dealkylations.
