- A heavy metal- and oxidant-free, one-pot synthesis of pyridines and fused pyridines based on a Lewis acid-catalyzed multicomponent reaction
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The InCl3-catalyzed sequential multicomponent reaction between 2-furfurylamine, β-dicarbonyl compounds and α,β-unsaturated aldehydes in ethanol, followed by microwave irradiation in solvent-free conditions, afforded good to excellent yields of highly substituted pyridines, with loss of a 2-furylmethyl side chain. The method was also adapted to the synthesis of quinolones, isoquinolines, phenanthridines and more complex fused pyridine systems.
- Raja, V. P. Alex,Tenti, Giammarco,Perumal, Subbu,Menndez, J. Carlos
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- Method for preparing 2 -methylnicotinate and derivatives thereof
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The invention belongs to the technical field of preparation of fine chemicals, and discloses 2 -methylnicotinate and a preparation method thereof, and the method comprises the following steps: (1) alkyl vinyl ether. The raw materials including 1,3 -carbonyl compound and formaldehyde raw materials react 60 °C - 100 °C at 6 hours - 9 hours, and the reaction products are separated to obtain 2 - alkoxy -3 and 4 -dihydropyran derivatives. (2) 2 - Alkoxy -3, 4 -dihydropyran derivatives are reacted 7 to 10 hours with an ammonium salt at a certain temperature under the action of an oxidant methylene blue and a Lewis acid to give 2 -methylnicotinate or a derivative thereof. The overall reaction process of the preparation method is designed. Compared with the traditional 2 -methylnicotinate and derivatives thereof, the method has the advantages of cheap and easily available raw materials, easy separation of the products, simple steps, high industrial application value and the like.
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Paragraph 0036; 0039-0041
(2021/12/07)
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- Sonochemical synthesis of 2-substituted nicotinic acid ethyl ester derivatives: Their in vitro and in silico evaluation against SIRT1
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Based on the initial docking studies of a representative compound in silico the evaluation of SIRT1 inhibitory potential of 2-substituted nicotinic acid ethyl ester derivatives was undertaken in vitro. A sonochemical method was developed and employed for the faster synthesis of this class of compounds. The methodology involved the iodine-mediated reaction of β-enamino esters with allylic alcohols in aqueous DMSO in the presence of air under mild conditions. A number of 2-substituted nicotinic acid ethyl ester derivatives were synthesized by employing this ultrasound assisted method in good to acceptable yield. The use of less expensive iodine and aqueous media, milder reaction condition and shorter reaction time are the key advantages of the current approach. All the synthesized compounds were tested for their SIRT1 inhibitory potential in vitro when some of them showed good activities and the compound 3g being the best among them. The docking studies suggested that the fused lactone ring of 3g played a key role in interacting with the SIRT1 in silico via formation of H-bonds. The overall outcome of the in vitro and in silico studies suggested the compound 3g as an initial hit molecule for further pharmacological studies.
- Challa, Chandra Sekhar,Kapavarapu, Ravikumar,Katari, Naresh Kumar,Nallanchakravarthula, Varadacharyulu,Nayakanti, Devanna,Pal, Manojit
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- 2-methyl nicotinate as well as preparation method and application thereof
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The invention relates to 2-methyl nicotinate as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) reacting 1, 1, 3, 3-tetramethoxypropane or 1, 1, 3, 3-tetraethoxypropane under the action of acid to obtain a compound B; (2) reacting the compound B and beta-aminocrotonate in a first organic solvent to obtain 2-methyl nicotinate, wherein no foul acrolein is used in the process, the safety coefficient of production is effectively improved, the reaction raw materials are easy to obtain, the conditions are mild, the operation is simple, the yield is greater than 65%, the product purity reaches 98% or above, and the method is suitable for industrial production and has a wide application prospect. The obtained product can be used as an intermediate for synthesizing 2-methyl nicotinic acid, and can be used for synthesizing medicines.
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Paragraph 0114-0146
(2021/05/22)
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- Transition-Metal-Free Synthesis of Pyridine Derivatives by Thermal Cyclization of N -Propargyl Enamines
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A transition-metal-free synthesis of pyridine derivatives by 6- endo - dig cyclization of N -propargyl enamines was developed. This method is environmentally friendly and is a high atom economy reaction that is easily accessed to provide pyridine derivatives in moderate to good yield by heating N -propargyl enamines in solvent without additives. The total synthesis of onychine was achieved in 51% yield in only two steps by using this method.
- Chikayuki, Yuya,Higashiyama, Kimio,Kirita, Akiko,Matsuo, Natsuko,Miyashige, Takakane,Sasaki, Shigeru,Teramoto, Hiroyoshi,Yamauchi, Takayasu,Yonekawa, Shiori
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p. 1113 - 1121
(2020/04/01)
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- Synthesis of 3-Keto Pyridines from the Conjugated Allenone – Alkynylamine Oxidative Cyclization Catalyzed by Supported Au Nanoparticles
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Recyclable supported Au nanoparticles on TiO2 catalyze the cyclization of N-propargyl or N-homopropargyl β-enaminones followed by dehydrogenation (aromatization) leading to substituted 3-keto pyridines or 4-picolines in very good yields. This pathway is in contrast to their known cyclization in the presence of Au(I) or Au(III) catalysts which provides 1,4-oxazepines, instead. The enaminones are formed in situ upon mixing a conjugated allenone or allenyl ester with the alkynylamine, thus the pyridine-forming transformation is typically a one pot process. (Figure presented.).
- Fragkiadakis, Michael,Kidonakis, Marios,Stratakis, Manolis,Zorba, Leandros
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supporting information
p. 964 - 968
(2020/01/28)
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- One-Pot Reactions for Modular Synthesis of Polysubstituted and Fused Pyridines
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A 2-fluoro-1,3-dicarbonyl-initiated one-pot Michael addition/[5 + 1] annulation/dehydrofluorinative aromatization reaction sequence is introduced for regioselective synthesis of di-, tri-, tetra-, and pentasubstituted pyridines as well as fused pyridines. This simple and modular synthesis is performed using readily available starting materials and under transition-metal catalyst-free conditions.
- Song, Zhidong,Huang, Xin,Yi, Wenbin,Zhang, Wei
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supporting information
p. 5640 - 5643
(2016/11/17)
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- Synthesis of regioisomeric pyrido[c]azocanones from azaindanone derivatives
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A ring enlargement reaction with methylamine gave new pyrido[2,3-c]-, pyrido[3,4-c]- and pyrido[3,2-c]azocanone derivatives from cyclic β-oxo esters with a cyclopentapyridine skeleton and a 1,4-diketone moiety. The starting materials for this ring transformation were either prepared from halogenopyridine carboxylates by Heck reaction and subsequent hydrogenation, or (halogenomethyl)pyridine carboxylates were submitted to SN reaction with diethyl malonate. Both routes were completed by Dieckmann condensation to build the cyclic β-oxo ester structure and alkylation with phenacylbromide to install the 1,4-diketone motif. Copyright
- Penning, Miriam,Christoffers, Jens
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p. 2140 - 2149
(2014/04/17)
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- IBX mediated reaction of β-enamino esters with allylic alcohols: A one pot metal free domino approach to functionalized pyridines
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IBX facilitated the reaction of β-enamino esters with allylic alcohols affording a direct, one-pot and metal free synthesis of functionalized pyridines including 2-substituted nicotinic acids, densely substituted pyridines and precursors of azafluorenones. The methodology also afforded the racemic pyridine core of cyclothiazomycin.
- Gade, Narendar Reddy,Devendram,Pal, Manojit,Iqbal, Javed
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supporting information
p. 7926 - 7928
(2013/09/02)
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- Synthesis of 2,5-dihydropyridine derivatives by gold-catalyzed reactions of β-ketoesters and propargylamines
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The reaction of simple β-ketoesters and propargylamines under gold(III) catalysis leads to the formation of the elusive 2,5-dihydropyridine system. This new reaction provides the synthesis of potentially bioactive compounds in moderate to high yields.
- Fananas, Francisco J.,Arto, Tamara,Mendoza, Abraham,Rodriguez, Felix
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scheme or table
p. 4184 - 4187
(2011/10/04)
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- NEW TRICYCLIC DERIVATIVES AS LTD4 ANTAGONISTS
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Compounds of formula (I) and their pharmaceutically acceptable salts are provided as well as processes for the manufacture of such compounds. The compounds are useful in the treatment or prevention of inflammatory and allergic diseases.
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- Formation of pyridines from N-methylpyrimidinium iodide and enaminoesters
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The reaction of N-methylpyrimidinium iodide with enaminoesters yiels a mixture of 3-ethoxycarbonyl-2-methylpyridine and 3,5-diethoxycarbonyl-2,6-dimethylpyridine.Mechanisms of the transformations of the pyrimidine ring found are suggested. - Keywords: N-methylpyridinium iodide; enaminoesters; ring transformation; pyridines; β-substituted.
- Gromov, S. P.,Razinkin, M. A.
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p. 1272 - 1275
(2007/10/02)
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- Nonpeptide angiotensin II receptor antagonists. I. Synthesis and biological activity of pyridine derivatives
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Substituted pyridines were synthesized as potential angiotensin II (AII) receptor antagonists. Substitution at the position 2 in the pyridine resulted in potent activity, and the optimal alkyl length was four carbons. The potency further increased with the introduction of a hydroxymethyl group at the position 4. One of the compounds, 2-butyl-6-chloro-4-hydroxymethyl-5-methyl-3-[[2'-(1H-tetrazol-5-yl)bip henyl-4-yl]methyl]pyridine 9 h (KT3-579)is a competitive AII antagonist with a pA2 value of 9.31, and is about 10 times more potent than Du Pont 753. It was found to be an AT1 specific antagonist with an IC50 of 3.09 nM.
- Ueyama,Yanagisawa,Kawai,Sonegawa,Baba,Mochizuki,Kosakai,Tomiyama
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p. 1841 - 1849
(2007/10/02)
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- 3-Substituted 2-Pyridinecarbaldoximes
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A series of 2-pyridinecarbaldoximes and salts derived from them by methylation of the pyridine nitrogen, all of which are substituted at the 3-position with carbon (i.e., derivatives of nicotinic acid and its homologues) or oxygen, have been prepared.
- Kao, Bo-Chan,Doshi, Haresh,Reyes-Rivera, Hector,Titus, Donald D.,Yin, MaLi,Dalton, David R.
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p. 1315 - 1324
(2007/10/02)
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- Preparation of some Thiopyranopyridine Derivatives
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In the first systematic study of thiopyranopyridines in which the sulphur atom is separated from the pyridine ring by one carbon atom, the four isomeric enol esters, ethyl 5-hydroxy-8H-thiopyranopyridine-6-carboxylate (4b), ethyl 8-hydroxy-5H-thiopyranopyridine-7-carboxylate (5b), and ethyl 4-hydroxy-1H-thiopyrano- and pyridine-3-carboxylate (6b) and (7b), have been synthesised.Improved methods for the preparation of their pyridine precursors are described.With phenylhydrazine, the enol esters (4b) - (7b) give condensed pyrazole derivatives (15) - (18), which have dipolar structures; with hot mineral acid they undergo decarboxylative hydrolysis, to give the corresponding oxothiopyranopyridines (4a) - (7a).
- Clarke, Kenneth,Goulding, John,Scrowston, Richard M.
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p. 1501 - 1505
(2007/10/02)
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- 6-C1-4 Alkyl-7-phenyl or substituted phenyl-1,6-naphthyridine-5(6H)-ones
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Compounds of the formula STR1 and pharmaceutically acceptable acid addition salts thereof, wherein R1 is C1-4 alkyl, R2 is hydrogen, C1-4 alkyl, C1-4 alkoxy, halo, trifluoromethyl, C1-4 alkylthio or --NR5 R6, wherein each of R5 and R6 is independently hydrogen or C1-3 alkyl, R3 is hydrogen, C1-3 alkyl, C1-3 alkoxy, halo or trifluoromethyl, and R4 is hydrogen, C1-3 alkyl, C1-3 alkoxy or halo, their use as muscle relaxants and as anti-inflammatory agents, pharmaceutical compositions comprising them, processes for their synthesis and compounds of the formulae STR2 wherein R1, R2, R3 and R4 are as defined above, useful as intermediates in their synthesis.
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- Imino-bridged Heterocycles. II (1). Regiospecific Synthesis of the 11H-Benzocycloheptapyridin-6,11-imine and 5H-Benzocycloheptapyridin-5,10-imine Systems
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Regiospecific synthetic pathways for two of the eight isomeric benzocycloheptapyridinimines have been developed based upon intramolecular acid catalyzed additions between an amine function and an internal olefin.The requisite amines were generated from known tricyclic ketones by ketimine formation followed by sodium borohydride reduction.
- Brenner, Daniel G.,Halczenko, Wasyl,Shepard, Kenneth L.
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p. 897 - 900
(2007/10/02)
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