- Electroorganic synthesis of 6-aminonicotinic acid from 2-amino-5-chloropyridine
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A synthesis of 6-aminonicotinic acid by electrochemical hydrogenation of 5-chloro-2-nitropyridine and electrochemical carboxylation of 2-amino-5-chloropyridine at a cathode surface in the presence of sulphuric acid and carbon dioxide in a dimethylformamide (DMF) solution at an apparent current density of 10 mA/cm2 using an undivided cell with good yields is reported.
- Ramesh Raju,Krishna Mohan,Jayarama Reddy
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- Convenient chlorination of some special aromatic compounds using N-chlorosuccinimide
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Some chlorinated aromatic compounds, including indole, benzofuran, carbazole, pyridine and aniline derivatives, are difficult to obtain through convenient chlorination. We herein report their efficient synthesis through chlorination with N-chlorosuccinimide (NCS). Optimization of the reaction conditions, including the temperature and the choice of solvent, was also investigated. This approach, which is characterized by a facile procedure, comparatively high yields and environmentally friendly features, provides a straightforward and inexpensive route to several chlorinated aromatic compounds. Georg Thieme Verlag Stuttgart · New York.
- Gan, Zongjie,Hu, Bin,Song, Qiao,Xu, Yungen
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- Activator free, expeditious and eco-friendly chlorination of activated arenes by N-chloro-N-(phenylsulfonyl)benzene sulfonamide (NCBSI)
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N-Chloro-N-(phenylsulfonyl)benzene sulfonamide (NCBSI) has been explored for the first time as a chlorinating reagent for direct chlorination of various activated arenes and heterocycles without any activator. A comparative in-silico study was performed to determine the electrophilic character for NCBSI and commercially available N-chloro reagents to reveal the reactivity on a theoretical viewpoint. The reagent was prepared by an improved method avoiding the use of hazardous t-butyl hypochlorite. This reagent was proved to be very reactive compared to other N-chloro reagents. The precursor of the reagent N-(phenylsulfonyl)benzene sulfonamide was recovered from aqueous spent, which can be recycled to synthesize NCBSI. The eco-friendly protocol was equally applicable for the synthesis of industrially important chloroxylenol as an antibacterial agent.
- Misal, Balu,Palav, Amey,Ganwir, Prerna,Chaturbhuj, Ganesh
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- N-azinylpyridinium N-aminides: An approach to pyrazolopyridines via an intramolecular radical pathway
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Intramolecular radical arylation, under thermal conditions, to a π-deficient pyridinium, linked to a π-excessive 2-azinyliminopyridine moiety is described. The method allows a new entry to pyrazolo[1,5-a]pyridine nucleus.
- Nu?ez, Araceli,García de Viedma, Aránzazu,Martínez-Barrasa, Valentín,Burgos, Carolina,Alvarez-Builla, Julio
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- Method for catalytic synthesis of 2-amino-5-chloropyridine by microwave synergistic lewis acidic ionic liquid
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The invention relates to a method for catalytic synthesis of 2-amino-5-chloropyridine by microwave synergistic lewis acidic ionic liquid, which comprises the following steps: adding 2-aminopyridine asa raw material into an organic solvent, introducing chlorine under the action of a catalyst lewis acidic ionic liquid and microwave radiation, and carrying out chlorination reaction; and carrying outreduced pressure distillation on the obtained reaction solution to remove the solvent, and further recrystallizing the solution to obtain the high-purity 2-amino-5-chloropyridine. Compared with the prior art, the method has the advantages that the production process is simplified, the reaction conditions are mild, the product purity is higher, the lewis acidic ionic liquid can be recycled, and the production cost is low.
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Paragraph 0018-0020
(2020/10/14)
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- Preparation method of 2-amino substituted six-membered nitrogen-containing heterocycle complex
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The invention discloses a preparation method of a 2-amino substituted six-membered nitrogen-containing heterocycle complex. The preparation method comprises the following steps: mix 2-fluorine substituted six-membered nitrogen-containing heterocycle complex and amidine hydrochloride salt compound, and then react under the action of a alkaline substance to obtain a 2-amino substituted six-memberednitrogen-containing heterocycle complex. Preferably, the 2-amino substituted six-membered nitrogen-containing heterocycle complex is a 2-amino pyridine compound, a 2-aminopyrimidine compound or a 2-aminopyrazine compound. Compared with the prior art, the method has the advantages of simple synthesis conditions, less reaction steps, mild reaction conditions, low cost of the catalyst used, less waste discharge and good functional group tolerance.
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Paragraph 0025; 0026; 0081
(2019/02/08)
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- One-step high-efficient high-selective synthesis of 2 - amino -5 - chloro pyridine method (by machine translation)
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The invention belongs to the technical field of the synthesis of intermediates, in particular relates to a one-step high-efficient high-selective synthesis of 2 - amino - 5 - chloro pyridine method. In order to 2 - aminopyridine as raw material, in the added to the organic solvent, in the blue LED lamp irradiation, instillment bromide as a catalyst, to be solution after the fading, access chlorine, to carry out a chlorination reaction; the resulting reaction solution is distilled under reduced pressure to obtain crude, further recrystallization to obtain high-purity 2 - amino - 5 - chloro pyridine. This invention adopts the bromine as catalyst, under irradiation of the blue LED lamp, produces the bromine radical with 2 - aminopyridine ring 5 phase combination, then chlorinated, avoid direct chlorinated products caused by 2 - amino - 5 - chloro pyridine series reaction generating multi-chloro, good selectivity of chloride content at the same time higher 2 - amino - 5 - chloro pyridine. The invention compared with the existing technology, the production process is simplified, mild reaction conditions, high product purity, the production cost is low, small amount of waste water. (by machine translation)
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Paragraph 0023; 0024; 0025; 0026; 0027; 0028
(2019/01/23)
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- Simple 2-amino-5-halogenated pyridine preparation method
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The invention provides a 2-amino-5-halogenated pyridine preparation method, which comprises: carrying out an addition reaction on 4-cyano-1-butyne and a halogen element X2 in a solvent under the catalysis of an acidic catalyst to obtain 4,4,5,5-tetrahalogenated n-valeronitrile, and carrying out cyclization on the 4,4,5,5-tetrahalogenated n-valeronitrile and ammonia through pyridine to obtain 2-amino-5-halogenated pyridine. According to the present invention, the preparation method has advantages of mild preparation condition, safety, environmental protection, low cost, high selectivity, less by-products and high product yield, and is suitable for industrial production.
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Paragraph 0029-0032
(2019/10/01)
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- BF3·SMe2 for Thiomethylation, Nitro Reduction and Tandem Reduction/SMe Insertion of Nitrogen Heterocycles
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Herein, a general, solvent-free and straightforward thiomethylation of electron deficient heterocycles using BF3·SMe2 as a dual thiomethyl source and Lewis acidic activator is presented. A range of heterocycles including pyrimidine, pyrazine, pyridazine, thiazole and purine derivatives were successfully substituted using this method. An unexpected reductive property of BF3·SMe2 towards nitropyridines was also discovered including an intriguing tandem reduction/SMe insertion process in certain substrates. Notable features of the present work include its convenience and use of a non-malodorous reagent while the discovery of novel chemical transformations using BF3·SMe2 provides fundamental new insights into the reactivity of this commonly employed reagent.
- S?derstr?m, Marcus,Zamaratski, Edouard,Odell, Luke R.
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p. 5402 - 5408
(2019/06/27)
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- A 2 - amino -5 chloro pyridine preparation method (by machine translation)
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The invention discloses a 2 - amino - 5 chloro pyridine of the preparation method, which belongs to the technical field of pharmaceutical intermediate synthesis. The invention relates to 2 - aminopyridine as raw materials, using saturated and sodium chlorate aqueous solution is used as the reaction solvent, to TEBA as catalyst, control the reaction process Cl atoms in the slow release of the reaction to obtain 2 - amino - 5 chloro pyridine, basic without side reaction, then the methanol and activated carbon to decolorize the refined, the obtained product by chromatography, purity can be as high as 99.8% of the left and right, the invention provides a preparation method, the reaction step is simple, easy to control, does not need to ethanol and other organic reagent as a reaction reagent, has reduced the three waste discharge, and also improves the purity and quality of the product. (by machine translation)
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Paragraph 0033-0036; 0048-0054; 0066-0069; 0081-0084
(2018/11/03)
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- Transition-metal-free access to 2-aminopyridine derivatives from 2-fluoropyridine and acetamidine hydrochloride
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Under catalyst-free conditions, an efficient method for the synthesis of 2-aminopyridine derivatives through the nucleophilic substitution and hydrolysis of 2-fluoropyridine and acetamidine hydrochloride has been developed. This amination uses inexpensive acetamidine hydrochloride as the ammonia source and has the advantages of a high yield, high chemoselectivity and wide substrate adaptability. The results suggest that other N-heterocycles containing fluorine substituents can also complete the reaction via these reaction conditions and yield the target products.
- Li, Yibiao,Huang, Shuo,Liao, Chunshu,Shao, Yan,Chen, Lu
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supporting information
p. 7564 - 7567
(2018/11/02)
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- Preparation of 2-amino-5-chloropyridine
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The invention discloses a preparation method of 2-amino-5-chloropyridine, and belongs to the field of organic chemical synthesis. The method comprises the following steps of using 2-amino-pyridine as a raw material and N-fluoro-N-chlorobenzene sulfonamide as a chlorinating agent, in an organic solvent, using imidazole ionic liquid as a catalyst, and carrying out a reaction, wherein a reaction temperature is 0 to 40 DEG C, and a reaction time is 0.2h to 24h. The method provided by the invention is simple and convenient in preparation process, mild in reaction condition, low in cost and high in product yield.
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Paragraph 0037; 0038; 0039; 0040; 0041; 0042; 0043-0050
(2017/08/28)
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- A method for preparation of 2-amino-5-chloro-pyridine
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The invention provides a method for preparation of 2-amino-5-chloro-pyridine and belongs to the technical field of fine organic synthesis. 2-amino-5-chloro-pyridine is prepared by adopting 2-aminopyridine as a raw material and using hydrochloric acid and sodium hypochlorite for an oxidative chlorination reaction. The method mainly includes the following steps: at 10 DEG C, slowly and dropwise adding a certain amount of concentrated hydrochloric acid in a mixed solution of 2-aminopyridine and NaClO, conducting a reaction at constant temperature for 2 hours, increasing the temperature to 25 DEG C for continuing the reaction for 4 hours, regulating the pH of a reaction product, extracting the reaction product with dichloroethane, and conducting separation to obtain 2-amino-5-chloro-pyridine. The yield of 2-amino-5-chloro-pyridine is up to 72%. The method has the advantages that the cheap NaClO solution generated by chlorination of tail gas by chlorine gas and hydrochloric acid are used as chlorinating agents, the cost is thus reduced, and the comprehensive utilization of resources is achieved; the reaction conditions are mild, direct use of chlorine gas is avoided, safety is high, and pollution is little.
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Paragraph 0023; 0024; 0025; 0026; 0027; 0028; 0029-0031
(2017/03/24)
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- Synthesis of 5-chloro-7-azaindoles by Fischer reaction
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[Figure not available: see fulltext.] A simple and effective method on the basis of Fischer reaction in polyphosphoric acid is proposed for the synthesis of previously unknown heterocyclic structures that contain the 5-chloro-1H-pyrrolo[2,3-b]pyridine system. This method can be used for the synthesis of 3-substituted and 2,3-disubstituted 5-chloro-7-azaindoles with alkyl and aryl substituents.
- Alekseyev, Roman S.,Amirova, Sabina R.,Terenin, Vladimir I.
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p. 196 - 206
(2017/05/19)
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- PROCESS FOR THE CATALYTIC DIRECTED CLEAVAGE OF AMIDE-CONTAINING COMPOUNDS
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The present invention relates to a catalytic method for the conversion of amide-containing compouds by means of a build-in directing group and upon the action of a heteronucleophilic compound (in se an amine (RNH2 or RNHR') or an alcohol (ROH) or a thiol (RSH)) in the presence of a metal catalyst to respectively esters, thioesters, carbonates, thiocarbonates and to what is defined as amide-containing compounds (such as carboxamides, urea, carbamates, thiocarbamates). The present invention also relates to these amide-containing compounds having a build-in directing group (DG), as well as the use of such directing groups in the catalytic directed cleavage of N-DG amides with the use of heteronucleophiles (in se an amine (RNH2 or RNHR') or an alcohol (ROH) or thiol (RSH)).
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Page/Page column 51; 53
(2017/04/11)
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- Tertiary formylated amines by microwave irradiation of N,N-dimethyl- N′-(2-pyridyl) formamidines with methyl vinyl ketone
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Treatment of N,N-dimethyl-N′-(2-pyridyl)formamidine with methyl vinyl ketone under microwave irradiation yields N-formyl-N-(3-oxobutyl)-2- pyridylamine without decomposition or polymerization of methyl vinyl ketone. The result is an alternative non-oxidat
- Gomez-Garcia, Omar,Salgado-Zamora, Hector,Campos-Aldrete, Elena
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- A new class of pyrazolopyridine nucleus with fluorescent properties, obtained through either a radical or a Pd arylation pathway from N-azinylpyridinium N-aminides
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(Chemical Equation Presented) The synthesis of dipyridopyrazole and pyridopyrazolopyrazine derivatives - both of which incorporate a 3-aryl moiety - can be achieved in moderate yields by intramolecular radical arylation of pyridinium N-aminides using tris(trimethylsilyl)silane and azobisisobutyronitrile. Improved results were obtained on using Pd direct arylation in conjunction with microwave irradiation. A preliminary study into the fluorescent properties of the target compounds is also reported.
- Abet, Valentina,Nunez, Araceli,Mendicuti, Francisco,Burgos, Carolina,Alvarez-Builla, Julio
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scheme or table
p. 8800 - 8807
(2009/04/11)
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- SUBSTITUTED QUINAZOLINE DERIVATIVES AND THEIR USE AS INHIBITORS
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The use of a compound of formula (I) 1 or a salt, ester or amide thereof; where X is O, or S, S(O) or S(O)2, or NR6 where R6 is hydrogen or C1-6 alkyl,; R5 is an optionally substituted 5-membered heteroaromatic ring, R1, R2 ,R3, R4 are independently selected from various specified moieties, in the preparation of a medicament for use in the inhibition of aurora 2 kinase. Certain compounds are novel and these, together with pharmaceutical compositions containing them are also described and claimed
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- SUBSTITUTED BENZENE DERIVATIVES OR SALTS THEREOF
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There are provided compounds having an anticoagulant action on the basis of inhibition of activated blood coagulation factor X and being useful as anticoagulants or preventive/therapeutic agents for diseases induced by thrombosis or embolism. Effective ingredients are the compounds such as 4'-bromo-2'-[(5-chloro-2-pyridyl)carbamoyl)-6-β-D-galactopyranosyloxy-1-isopropylpiperidine-4-carboxanilide, 2'-(2-acetamido-2-deoxy-β-D-glucopyranosyloxy)-4'-bromo-6'-[(5-chloro-2-pyridyl)carbamoyl]-1-isopropylpiperidine-4-carboxanilide, etc. or salts thereof.
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- Halogenation of pyridinium-N-(2'-pyridyl)aminide: An easy synthesis of halo-2-aminopyridines
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The regioselective halogenation of pyridinium-N-(2'-pyridyl)aminide 1 with N-chloro, bromo or iodosuccinimide under mild conditions is described. The method, combined with a reduction of the N-N bond, allows an easy preparation of 5-halo and 3,5-dihalo-2-aminopyridines 4.
- Burgos,Delgado,Garcia-Navio,Izquierdo,Alvarez-Builla
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p. 8649 - 8654
(2007/10/02)
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- Process for the preparation of (3-fluoropyridin-2-yloxy)phenoxypropionic acids
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(3-Fluoropyridin-2-yloxy)phenoxypropionic acids of formula I STR1 wherein X is hydrogen, fluoro, chloro, bromo or trifluoromethyl and Y is hydrogen, sodium or potassium, are prepared by reacting a compound of formula II STR2 wherein X and Y are as defined for formula I, in an anhydrous mixture of hydrogen fluoride, dimethylsulfoxide and a diazotising agent under normal pressure, and converting the diazonium fluoride so produced by thermal decomposition into the (3-fluoropyridin-2-yloxy)phenoxypropionic acid of formula I.
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- Studies on 1,3-Benzoxazines. I. Synthesis of Primary 2-Amino-pyridines via the Reaction of Imidoyl Chlorides of 1,3-Benzoxazines with Pyridine N-Oxides
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A new synthetic method for primary 2-aminopyridine derivatives is described.Treatment of the imidoyl chlorides of 1,3-benzoxazines (1a-i) with pyridine N-oxides resulted in the introduction of an oxazine moiety into the α-position of the pyridine ring through rearrangement of the initially formed reaction adduct.Acid hydrolysis of the rearrangement products afforded 2-aminopyridine derivatives in excellent yields.When methoxypyridine N-oxides were used, products of a different type (10 and 14) were obtained.
- Wachi, Kazuyuki,Terada, Atsusuke
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p. 465 - 472
(2007/10/02)
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- Process for preparing 2-amino-5-chloropyridine
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2-Amino-5-chloropyridine is prepared by chlorinating 2-aminopyridine in a strongly acidic medium. 2-Amino-5-chloropyridine is a useful intermediate in the preparation of chloro-substituted-imidazo-pyridine herbicides.
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