108-99-6Relevant articles and documents
The first SiHi22+ Complex, Difaydridotetrakis(3-picoline)silicon Dichloride-tetrakis (chloroform)5 [H2Si(3pic)44]Cl2 · CHCl3: Formation chemical equilibria, and structural by NMR spectroscopy and single-crystal X-ray diffraction
Fleischer, Holger,Hensen, Karl,Stumpf, Thorsten
, p. 765 - 771 (1996)
Bis(dichlorosilyl)amine reacts in chloroform solution with 2-picoline to give H3SiCl, H2SiCl2, and HSiCl3 whereas with 3-picoline the two hypervalent silicon compounds H2SiCl2-(3pic)2 and [H2Si(3pic)4]Cl2 ·4 CHCl3 containing hexacoordinated Si atoms are formed. These complexes are in a chemical equilibrium with each other in chloroform solution, from which crystals of [H2Si(3pic)4]Cl2 ·4 CHCl3 could be isolated. The crystal structure of the latter was determined by single-crystal X-ray diffraction. The complex can be regarded as an "contact ion trio" of [H2Si(3pic)4]2+ and two Cl- ions. The N→Si bond lengths, r(Si-N) = 196.9(3} and 197.5(3) pm, are similar to those found in neutral hexacoordinated Si complexes. The data obtained from a 1H1H ROESY experiment suggest that dissolution has no significant impact on the molecular structure of [H2Si(3pic)4]Cl2 ·4 CHCl3. VCH Verlagsgcsellschaft mbH, 1996.
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McCall,Tenbrink
, p. 335 (1975)
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In situ formation and reaction of 2-pyridylboronic esters
Fuller, Amelia A.,Hester, Heidi R.,Salo, Eric V.,Stevens, Erland P.
, p. 2935 - 2938 (2003)
2-Pyridylboronic esters were generated by cross-coupling 2-bromopyridines with bis(pinacolato)diboron in the presence of a base and palladium catalyst. The boronic esters reacted in situ with unreacted 2-bromopyridines to afford high yields of 2,2′-bipyridines as homocoupled products. Depending upon the reaction conditions, varying amounts of protodeboronated products were also observed. An attempted cross-coupling between two different 2-bromopyridines produced a nearly statistical mixture of homo- and cross-coupled products.
Thermal decomposition and ring expansion in 2,4-dimethylpyrrole. Single pulse shock tube and modeling studies
Lifshitz, Assa,Suslensky, Aya,Tamburu, Carmen
, p. 4851 - 4861 (2003)
The thermal decomposition of 2,4-dimethylpyrrole was studied behind reflected shock waves in a pressurized driver single-pulse shock tube over the temperature range 1050-1250 K at overall densities of ～3 × 10-5 mol/cm3. A plethora of decomposition products, both with and without nitrogen, were found in the post-shock mixtures. They were, among the nitrogen containing products: pyridine, two isomers of methylpyrrole, 2-picoline, 5-picoline, HCN, CH3CN, C2H3CN, C2H5CN, and CH≡C-CN. Very small quantities of cis- and trans-CH3CH=CHCN and CH2=CHCH2CN were also found in the post-shock mixtures. Among the products without nitrogen were CH4, C2H4, C2H6, C2H2, CH3H≡CH, CH2=C=CH2, C4H4 and C4H2, and very small quantities of other C4 hydrocarbons and C5 hydrocarbons. The initiation of a chain mechanism in the decomposition of 2,4-dimethylpyrrole takes place via ejection of hydrogen atoms from sp3 carbons and dissociation of the two methyl groups attached to the ring. The H atoms and the methyl radicals initiate a chain mechanism by abstraction of a hydrogen atom from the methyl group and by dissociative recombination of an H atom and removal of a methyl group from the ring. In addition to the dissociation reactions, there are several unimolecular channels that involve ring cleavage. Ring expansion processes that lead to the production of high yields of pyridine and picoline take place from radical species: CH3[C4H2NH]CH2 in the production of picoline and [C4H3NH]CH2 in the production of pyridine. In addition to the chain mechanism, there are unimolecular breakdown processes of the pyrrole ring to yield stable products such as HCN, CH3CN, and others. The total decomposition of 2,4-dimethylpyrrole in terms of a first-order rate constant is given by ktotal = 1016.31 exp(-75.7 × 103/RT) s-1. A reaction scheme containing 36 species and 69 elementary reactions was composed and a computer simulation was performed over the temperature range 1050-1250 K at 25 K intervals. The agreement between the experimental results and the model prediction for most of the species is satisfactory.
Thermal analysis of complexes of cadmium chloride picoline
Liptay, G.,Borbely-Kuszmann, A.,Wadsten, T.,Losonczi, J.
, p. 915 - 922 (1988)
The thermal decomposition of the α, β and γ-picoline complexes of cadmium were studied by means of TG-DTG-DTA. In connection with the preparation of the complex compounds, it was established that the ligand number was influenced by the reaction medium. The thermal decomposition took place stepwise, and intermediates were formed which could be isolated with a derivatograph by the 'freezing-in' method. The structures and properties of these previously unknown compounds were investigated by far-IR spectroscopy and X-ray powder diffraction.
Mild and efficient deoxygenation of amine-N-oxides with BiCl3/Indium system
Yoo, Byung Woo,Choi, Jin Woo
, p. 3550 - 3554 (2009)
The BiCl3/indium system was found to be a new reagent for deoxygenation of various amine-N-oxides to the corresponding amines in good to excellent yields under mild conditions.
Preparation of pyridine and 3-picoline from acrolein and ammonia with HF/MgZSM-5 catalyst
Zhang, Xian,Wu, Zhen,Liu, Wei,Chao, Zi-Sheng
, p. 10 - 14 (2016)
Pyridine and 3-picoline were prepared from acrolein and ammonia using HF/MgZSM-5 as catalyst. The HF/MgZSM-5 catalyst was produced from modification of HZSM-5 by HF and Mg(NO3)2. It was found that the micropore structure of the HZSM-5 carrier would be destroyed when Mg and HF were loaded. This corrosion process could be promoted by employing HF onto MgZSM-5 carrier comparing with HZSM-5 one, because of the damage of MgO to ZSM-5 stability. A micro-mesoporous HZSM-5 zeolite with fewer and weaker acid sites was prepared after HF modification. Under the optimized conditions, a total yield of 68% can be reached, with 36% being 3-picoline and 30% being pyridine.
Mechanism of pyridine bases prepared from acrolein and ammonia by in situ infrared spectroscopy
Zhang, Xian,Wu, Zhen,Chao, Zi-Sheng
, p. 19 - 26 (2016)
The in situ infrared spectroscopy of acrolein and ammonia over HF/MgZSM-5 was investigated to check the adsorption reaction of acrolein and ammonia. It was proved that propylene imine intermediate came up during the condensation process of adsorbed acrolein with ammonia. The strong adsorption of C=O helps the formation of propylene imine. The reaction order and active energy were calculated according to the intensity of acrolein infrared spectroscopy. The synthesis of 3-picoline is likely to go through a flat adsorption of propylene imine and a deamination of amino dihydropyridine.
Mild and Efficient Deoxygenation of Amine-N-oxides with Titanium Tetrachloride-Indium System
Yoo, Byung Woo,Choi, Kwang Hyun,Choi, Kyung Il,Kim, Joong Hyup
, p. 4185 - 4189 (2003)
TiCl4/In system was found to be a new reagent for deoxygenation of various amine-N-oxides to the corresponding amines in good to excellent yields under mild conditions.
Thermal conversion of glycerol to value-added chemicals: Pyridine derivatives by one-pot microwave-assisted synthesis
Bayramoglu, Duygu,Guerel, Goekay,Sinag, Ali,Guellue, Mustafa
, p. 661 - 670 (2014)
One-pot syntheses of the value-added heterocyclic compounds 3-methylpyridine and pyridine using a renewablechemical, glycerol, were achieved in acidic medium by thermal conversion reactions. Condensation/cyclization reactions of the thermal degradation products of glycerol were investigated in situ using different ammonia and acidic moiety producing inorganic ammonium salts under pyrolysis or microwave heating conditions. The reaction parameters were studied in detail and satisfying product yields up to 72% were obtained under optimized conditions. Structural identification of all compounds was accomplished by spectroscopic methods. TUeBITAK.
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Egger,Vitins
, p. 17,18,20,21 (1974)
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Interconversion of nicotine enantiomers during heating and implications for smoke from combustible cigarettes, heated tobacco products, and electronic cigarettes
Moldoveanu, Serban C.
, p. 667 - 677 (2022/02/02)
Physiological properties of (R)-nicotine have differences compared with (S)-nicotine, and the subject of (S)- and (R)-nicotine ratio in smoking or vaping related items is of considerable interest. A Liquid Chromatography-Mass Spectrometry/Mass Spectrometry (LC-MS/MS) method for the analysis of (S)- and (R)-nicotine has been developed and applied to samples of nicotine from different sources, nicotine pyrolyzates, several types of tobacco, smoke from combustible cigarettes, smoke from heated tobacco products, e-liquids, and particulate matter obtained from e-cigarettes aerosol. The separation was achieved on a Chiracel OJ-3 column, 250 × 4.6 mm with 3-μm particles using a nonaqueous mobile phase. The detection was performed using atmospheric pressure chemical ionization (APCI) in positive mode. The only transition measured for the analysis of nicotine was 163.1 → 84.0. The method has been summarily validated. For the analysis, the samples of tobacco and smoke from combustible cigarettes were subject to a cleanup procedure using solid phase extraction (SPE). It was demonstrated that nicotine upon heating above 450°C for several minutes starts decomposing, and some formation of (R)-enantiomer from a sample of 99% (S)-nicotine is observed. An analogous process takes place when a 99% (R)-nicotine is heated and forms low levels of (S)-nicotine. This interconversion has the effect of slightly increasing the content of (R)-nicotine in smoke compared with the level in tobacco for combustible cigarettes and for heated tobacco products. The (S)/(R) ratio of nicotine enantiomers in e-liquids was identical with the ratio for the particulate phase of aerosols generated by e-cigarette vaping.
Synthetic method of 3-methylpyridine
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Paragraph 0022-0043, (2021/04/21)
The invention relates to a synthetic method of 3-methylpyridine, and belongs to the technical field of chemical synthesis. The invention relates to a synthetic method of 3-methylpyridine, which comprises the following steps: by using acetaldehyde or polymer thereof and formaldehyde or polymer thereof as raw materials, reacting in a pipeline reactor or fixed bed reactor at 180-300 DEG C and 4-10MPa under the action of a catalyst, cooling the reacted materials to obtain a 3-methylpyridine reaction solution, extracting, concentrating, and rectifying, and obtaining a 3-methylpyridine product and a catalyst capable of being recycled. According to the synthesis method disclosed by the invention, acid catalyst and continuous production are adopted, so that low-cost, high-yield and high-selectivity 3-methylpyridine synthesis is realized. By changing the catalyst, the application of the catalyst and the change of the reactor are realized, the stable improvement of the product yield is ensured, and the cost is reduced.
Catalytic Deoxygenation of Amine and Pyridine N-Oxides Using Rhodium PCcarbeneP Pincer Complexes
Tinnermann, Hendrik,Sung, Simon,Cala, Beatrice A.,Gill, Hashir J.,Young, Rowan D.
, p. 797 - 803 (2020/03/13)
Rhodium PCcarbeneP pincer complexes 1-L (L = PPh3, PPh2(C6F5), PCy3) readily facilitate deoxygenation of amine and pyridine N-oxides. The resulting complexes exhibit δ2-C= O coordination of the resulting keto POP pincer ligand. These δ2-Ca? O linkages in the metalloepoxide complexes are readily reduced by isopropyl alcohol and various benzylic alcohols. Thus, efficient catalytic deoxygenation of amine and pyridine N-oxides is possible using complexes 1-L and isopropyl alcohol. This represents a pioneering example of PCcarbeneP pincer complexes being used as catalysts for catalytic deoxygenation.
