- Synthesis of alkyl- and aryl-substituted pyridines from (α,β-unsaturated) imines or oximes and carbonyl compounds
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Reaction of a variety of (α,β-unsaturated) imines or oximes with aliphatic aldehydes or cyclic ketones in the presence of a secondary amine afforded alkyl-, and/or aryl-, and/or cycloalkyl-substituted pyridines. To explain their formation, a hetero Diels-Alder reaction has been postulated, in which an 1-aza-1,3-butadiene reacts with an in situ generated enamine.
- Vijn,Arts,Green,Castelijns
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Read Online
- ZEOLITE CATALYST
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The present disclosure relates to the preparation of pyridine derivatives, such as α-picoline or α-parvoline, and catalysts useful for the selective preparation of such pyridine derivatives. Particularly, the present disclosure relates to the selective preparation of certain pyridine derivative using dealuminated zeolite catalysts.
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Paragraph 0124
(2019/05/22)
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- Mesoporous Aluminosilicates in the Synthesis of N-Heterocyclic Compounds
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Abstract: The catalytic properties of samples of amorphous mesoporous aluminosilicate ASM with different Si/Al molar ratios (40, 80, 160) were studied in the synthesis of practically important pyridines (by the interaction of С2–С5 alcohols with formaldehyde and ammonia, cyclocondensation of acetaldehyde and propionic aldehyde with ammonia), dialkylquinolines and alkyltetrahydroquinolines (by reaction of aniline with C3, C4 aldehydes) and alkyldihydroquinolines (by interaction of aniline with ketones, acetone and acetophenone). It is found that mesoporous aluminosilicate ASM sample with a molar ratio of Si/Al = 40, which has the highest acidity among the studied samples, exhibits the highest activity and selectivity in these reactions.
- Agliullin, M. R.,Bikbaeva, V. R.,Bubennov, S. V.,Filippova, N. A.,Gataulin, A. R.,Grigor’eva, N. G.,Kostyleva, S. A.,Kutepov, B. I.,Narender, Nama
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p. 733 - 743
(2020/02/25)
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- Direct deamination of primary amines by water to produce alcohols
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Just add water! The title reaction is catalyzed by an acridine-based pincer complex (1, see scheme). This one-step transformation uses water as the only reagent in the absence of additional bases, oxidants, or reductants. Cyclization of 1,4-diaminobutane and 1,6-diaminohexane catalyzed by 1 leads to the formation of pyrrolidine and azepane, respectively. Copyright
- Khusnutdinova, Julia R.,Ben-David, Yehoshoa,Milstein, David
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supporting information
p. 6269 - 6272
(2013/07/19)
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- Synthesis and characterization of new polysubstituted pyridinium-based ionic liquids: Application as solvents on desulfurization of fuel oils
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The production of transportation fuels which have a very low content of sulfur has became one of the priority challenges for the oil industry worldwide, due to by strict new regulatory requirements. Ionic liquids (ILs) have been proposed as suitable and promising solvents for this purpose due to their excellent qualities as solvents. In this work a series of ten new ILs derived from pyridinium cation substituted with different alkyl chains have been synthesized from 2-alkyl-3,5-dimethylpyridines. The starting materials were prepared by selective metalation of 2,3,5-trimethylpyridine, which allowed the introduction of different alkyl groups in pyridine position 2 with high yields. To test the ILs sulfur-removal capacity, liquid-liquid equilibrium (LLE) data for ternary systems (heptane + thiophene + IL) were determined at T = 298.15 K and atmospheric pressure. Selectivity and solute distribution ratio, calculated from tie-lines, were used to evaluate whether these new ILs could be used as solvents for the extraction of thiophene from heptane. Finally, the experimental LLE data were correlated with the NRLT thermodynamic model.
- Verdia, Pedro,Gonzalez, Emilio J.,Rodriguez-Cabo, Borja,Tojo, Emilia
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experimental part
p. 2768 - 2776
(2011/12/05)
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- Synthesis of 2-ethyl-3,5-dimethylpyridine by heterocyclization of allylamine, cyclopropylamine, and diallylamine in the presence of palladium complexes
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2-Ethyl-3,5-dimethylpyridine was synthesized by disproportionation and heterocyclization of allylamine, cyclopropylamine, and diallylamine in the presence of palladium catalysts.
- Atnabaeva,Muslimov,Khusnutdinov,Dzhemilev
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body text
p. 1831 - 1835
(2009/09/06)
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- Inhibitors of cell proliferation, angiogenesis, fertility, and muscle contraction
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The invention concerns inhibitors of cell proliferation, angiogenesis, fertility, and muscle contraction, characterized by formula I wherein, X, Y and Z independently represent C or N; ------ is an optional double bond; n is 0 or 1; R1, R2, and R4 independently represent hydrogen, a chemical bond, C1-10 alkyl; C2-10 alkenyl; C2-10 alkinyl; aryl; aryl-C1-10 alkyl; C3-10 heterocyclyl; C5-10 heteroaryl; halo, CF3; NO2; NHC(O)R*, OR, said alkyl, alkenyl, alkinyl, aryl, arylalkyl, heterocyclyl, or heteroaryl being optionally substituted; R3, R5, and R6 independently represent hydrogen, C1-10alkyl; C2-10 alkenyl; C2-10 alkinyl; aryl; aryl-C1-10alkyl; C3-10 heterocyclyl; C5-10 heteroaryl; halo, CF3; NO2; NHC(O)R*, OR, said alkyl, alkenyl, alkinyl, aryl, heterocyclyl, or heteroaryl being optionally substituted; or R5 and R6 together form a 5- or 6-member aryl, heterocyclyl or heteroaryl group; R is hydrogen or C1-6 alkyl; R* is hydrogen, or C1-6 alkyl, or OH, wherein the optional substituents are preferably selected from the group of one to three OH, C1-6 alkyl, halo, NO2, C1-6 alkoxy, and CF3, or a pharmaceutically acceptable salt thereof.
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- SYNTHESIS OF ALKYL-SUBSTITUTED PYRIDINES FROM CO, C2H4, H2, and NH3 ON HETEROGENEOUS CATALYSTS
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The reaction of preparation of alkyl-substituted pyridines by hydroformylation of ethylene in the presence of ammonia on heterogeneous Rh-containing catalysts with the formation of 2-ethyl-3,5-dimethylpyridine (I) as the basic product with up to 70-80percent conversion of gases and up to an 80 wt. percent concentration of the basic product was investigated.The dependence of the activity and selectivity of the catalysts on the concentration of Rh and nature of the support was determined.A correlation between the activity of the catalysts and their acid properties was established by IR spectroscopy.
- Kosolapova, B. S.,Levin, D. Z.,Sominskii, S. D.,Rar, L. F.,Mortikov, E. S.,Lapidus, A. L.
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p. 2244 - 2248
(2007/10/02)
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- An Improved Liquid-Phase Synthesis of Simle Alkylpyridines
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The synthesis of pyridines from mixtures of aldehydes or ketones and NH3 in the liquid phase has been reinvestigated, using continuous dosage of the carbonyl components to the reaction mixture.The main product from the reaction of acetaldehyde and formaldehyde is 3-methylpyridine (6), which is also the main product from the reaction of acrolein or a mixture of crotonaldehyde and formaldehyde under the same conditions.The reaction of other aldehydes with formaldehyde give 3,5-dialkylpyridines, e.g. 10, 16.Acetone reacts with either formaldehyde or acetaldehyde to give polysubstituted alkylpyridines.A mechanistic pathway is proposed which accounts for the formation of the observed products.
- Grayson, J. Ian,Dinkel, Rolf
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p. 2100 - 2110
(2007/10/02)
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- Conversion of tetrahydropyrimidines to pyridines
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A process of converting 2,3,4,5-tetrahydropyrimidines containing at least 1 hydrogen in the 2-position and at least one methylene group in the 4-position to corresponding pyridines which comprises heating said tetrahydropyrimidines to a temperature sufficiently high to remove ammonia and hydrogen so as to form said pyridines.
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