- Microporous and Micro-meso-macroporous Y Zeolites in the Synthesis of 2-Methyl-5-ethylpyridine
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Abstract: The study investigates the catalytic properties of microporous (H–Y) andmicro-meso-macroporous (H–Y-mmm) FAU-type zeolites in the synthesis of2-methyl-5-ethylpyridine (MEP) by the reaction of acetaldehyde with ammonia. At150°C, an acetaldehyde to ammonia molar ratio of 1 : 3, and a catalyst contentof 10 wt %, a MEP yield of 58% (0.95H–Y) and 63% (0.95H–Y-mmm) was achieved witha MEP selectivity of 91 and 93%, respectively. The examination of the catalyststability revealed that hierarchical H–Y-mmm zeolites ensure a 100% MEPselectivity during 4–5 cycles with a slight decline in the catalytic activity,while H–Y zeolites are active during the first cycle only.
- Grigor’eva,Filippova,Bubennov,Khazipova,Kutepov,Dyakonov
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p. 364 - 369
(2021/03/19)
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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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- Deoxygenation of amine N-oxides using gold nanoparticles supported on carbon nanotubes
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Deoxygenation of a variety of aromatic and aliphatic amine N-oxides has been carried out in excellent yield using dimethylphenylsilane as the reducing agent under the catalytic influence of a carbon nanotube-gold nanohybrid at room temperature. Low catalyst loading, good TON and TOF values, and recyclability of the catalyst are some of the salient features of our methodology.
- Donck, Simon,Gravel, Edmond,Shah, Nimesh,Jawale, Dhanaji V.,Doris, Eric,Namboothiri, Irishi N. N.
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p. 50865 - 50868
(2015/06/25)
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- Process for the production of 6-methylnicotinic acid ester
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A process for the production of 6-methylnicotinic acid ester by oxidation of 2-methyl-5-ethylpyridine at an elevated temperature. Specifically, 2-methyl-5-ethylpyridine is mixed while cooling with at least a molar quantity of sulfuric acid. The mixture is heated to a temperature of 140° to 225° C. At least 3 moles of nitric acid per mole of educt is added to the heated mixture in such a way that water and/or diluted nitric acid are continuously distilled off. The distillation after addition of the nitric acid which is needed for the oxidation is continued until all of the water and all of the nitric acid are removed. Subsequently the reaction mixture is mixed with an alcohol and the alcoholic reaction mixture is heated until the acids contained in the reaction mixture are esterified. The 6-methylnicotinic acid ester is isolated from the ester mixture.
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- Hydroboration. 75. Directive Effects in the Hydroboration of Vinyl and Propenyl Heterocycles with Representative Hydroborating Agents
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The hydroboration of representative heterocyclic compounds bearing a vinyl or propenyl substituent with borane-methyl sulfide (BMS), 9-borabicyclononane (9-BBN), dicyclohexylborane (Chx2BH), and disiamylborane (Sia2BH) was investigated systematically to establish directive effects in the hydroboration.The directive effects observed for 2-vinylfuran and 2-vinylthiophene are similar to those realized in styrene.The hydroboration of vinylpyridine required an excess of borane hydroborating agent.Alternatively, the nitrogen atom could be protected by complexing with boron trifluoride.When the vinyl group is ortho or para to the pyridine nitrogen, α-organoboranes are the major products in the hydroboration.However, when the vinyl group is meta to the pyridine nitrogen, β-organoboranes are formed predominantly.Hydroboration of the vinyl-pyridine-BF3 complexes results in an increase in the formation of α-organoboranes, as compared to β.The distribution of boron in the hydroboration of 2-propenyl heterocyclic compounds compared to that of trans-1-propenylbenzene showed that the effect of the heterocycle is pronounced in directing the boron atom strongly to the α-carbon atom.
- Brown, Herbert C.,Prasad, J. V. N. Vara,Zee, Sheng-Hsu
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p. 439 - 445
(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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