- Method for synthesizing mepiquat chloride original medicine
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The invention discloses a method for synthesizing a mepiquat chloride original medicine. The method comprises the following steps: adding ethanol into a container, adding pyridine for mixing, adding chloromethane after dissolution, and performing heating reaction to obtain N-methylpyridine chloride; adding the N-methylpyridine chloride and a catalyst into a reaction container, introducing hydrogen, performing heating reaction to obtain an N-methylpiperidine hydrochloride system, adding an acid binding agent into the N-methylpiperidine hydrochloride system for neutralization reaction, and performing filtering to obtain N-methylpiperidine; dissolving the N-methylpiperidine in ethanol, and adding chloromethane for heating reaction; evaporating a reaction system to remove the ethanol and the chloromethane to obtain a high-purity mepiquat chloride product. According to the method, the using amount of the acid binding agent is reduced in a production process, and the water cost for production is reduced; in addition, the sustainability is high, the energy consumption is effectively reduced, and the method is a novel production process. Therefore, the method has remarkable economic benefits and social benefits.
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Paragraph 0037-0039; 0048; 0057; 0066
(2017/07/19)
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- Does alkyl chain length really matter? Structure-property relationships in thermochemistry of ionic liquids
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DSC was used for determination of reaction enthalpies of synthesis of ionic liquids [Cnmim][Cl]. A combination of DSC with quantum chemical calculations presents an indirect way to study thermodynamics of ionic liquids. The indirect procedure for vaporization enthalpy was validated with the direct experimental measurements by using thermogravimetry. First-principles calculations of the enthalpy of formation in the gaseous phase have been performed for the ionic species using the CBS-QB3 and G3 (MP2) theory. Experimental DSC data for homologous series of alkyl substituted imidazolium, pyridinium, and pyrrolidinium based ionic liquids with anions [Cl] and [Br] were collected from the literature. We have shown that enthalpies of formation, enthalpies of vaporization, and lattice potential energies are linearly dependant on the alkyl chain length. The thermochemical properties of ILs generally obey the group additivity rules and the values of the additivity parameters for enthalpies of formation and vaporization seem to be very close to those for molecular compounds.
- Verevkin, Sergey P.,Zaitsau, Dzmitry H.,Emel'Yanenko, Vladimir N.,Ralys, Ricardas V.,Yermalayeu, Andrei V.,Schick, Christoph
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- Monotopic and heteroditopic calix[4]arene receptors as hosts for pyridinium and viologen ion pairs: A solution and solid-state study
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The binding efficiency of a series of monotopic (1-2) and heteroditopic (3-4) calix[4]arene-based receptors has been evaluated in chloroform solution toward N-methylpyridinium ion pairs using NMR and UV/vis spectroscopic techniques. These experiments provided evidence that, due to a positive cooperative effect, the presence of a phenylurea H-bond donor group on the upper rim of the calix[4]arene macrocycle increases the recognition abilities of the heteroditopic receptors by up to two orders of magnitude with respect to the monotopic receptors. The heteroditopic receptors are also able to form 2:1 host-guest inclusion complexes with dimethylviologen salts both in low polarity solvents and in the solid state. These complexes are stabilized through the cooperation of weak (CH-π and cation-π) and strong (hydrogen bonding) intramolecular interactions between the binding domains of the calix[4]arene host and the two ions of the guest ion pair.
- Pescatori, Luca,Arduini, Arturo,Pochini, Andrea,Secchi, Andrea,Massera, Chiara,Ugozzoli, Franco
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experimental part
p. 3698 - 3708
(2009/10/23)
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- Alkylpyridiniums. 1. Formation in model systems via thermal degradation of trigonelline.
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Trigonelline is a well-known precursor of flavor/aroma compounds in coffee and undergoes significant degradation during roasting. This study investigates the major nonvolatile products that are procured after trigonelline has been subjected to mild pyrolysis conditions (220-250 degrees C) under atmospheric pressure. Various salt forms of trigonelline were also prepared and the thermally produced nonvolatiles analyzed by thin layer chromatography, liquid chromatography-electrospray ionization tandem mass spectrometry, and (1)H and (13)C nuclear magnetic resonance. Results revealed the decarboxylated derivative 1-methylpyridinium as a major product of certain salts, the formation of which is positively correlated to temperature from 220 to 245 degrees C. Moreover, trigonelline hydrochloride afforded far greater amounts of 1-methylpyridinium compared to the monohydrate over the temperature range studied. Investigations into other potential quaternary amine products of trigonelline also indicate nucleophilic substitution reactions that lead to dialkylpyridiniums, albeit at concentration levels approximately 100-fold lower than those recorded for 1-methylpyridinium.
- Stadler, Richard H,Varga, Natalia,Hau, Joerg,Vera, Francia Arce,Welti, Dieter H
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p. 1192 - 1199
(2007/10/03)
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- The chemistry of the N-methyl-3-dehydropyridinium ylid
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The reaction of atomic carbon with N-methylpyrrole, 5b, at 77 K generates the N-methyl-3-dehydropyridinium ylid, 6b, which can be trapped with added hydrogen halides or CO2. The addition of CO2 is strong evidence for the ylid 6b rather than cumulene 7. Deuterium and 13C labeling studies demonstrate that 6b rapidly rearranges to the N-methyl-2-dehydropyridinium ylid, 13, by an intermolecular mechanism. Ylid 13 can be trapped with added acids or with O2 to form 1-methyl-2-pyridone.
- Pan, Weitao,Shevlin, Philip B.
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p. 5091 - 5094
(2007/10/03)
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- ASYMMETRIC NITROGEN - 70. GEMINAL SYSTEMS - 44. TRIALKOXYAMINES(ORTHONITRITES). SYNTHESIS AND PROPERTIES
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The chlorination of acyclic N,N-dialkoxyamines under the action of tert-BuOCl results in the formation of unstable N-chloro-N,N-dialkoxyamines wich in situ react with sodium methoxide to give previously unknown trialkoxyamines (orthonitrites).The properties of the N-chloro-N,N-dialkoxy- and trialkoxyamines have been demonstrated to be similar to those of their carbon analogues: dialkoxyalkylchlorides and orthoesters, respectively.
- Rudchenko, Vladimir F.,Ignatov, Sergei M.,Chervin, Ivan I.,Kostyanovsky, Remir G.
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p. 2233 - 2240
(2007/10/02)
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- Stereoelectronic Effects in Hydrogen Atom Abstraction from Substituted 1,3-Dioxanes
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An EPR technique and a method involving the gas chromatographic determination of the relative rates of consumption of substrates have been employed to measure the relative rates of hydrogen atom abstraction by tert-butoxy radicals from various substituted 1,3-dioxanes.The high relative reactivities of dioxanes equitorially substituted at C-2 as compared with their axially substituted epimers are attributed to the favorable stereoelectronic interactions in the former between the axial C-H bonds and adjacent oxygen lone pairs.The effects of methoxy substituents on the relative reactivities of cyclic ethers have been similarly rationalized.The photoinduced reaction between benzophenone and the methoxydioxane (8) has been shown to be reversible.
- Beckwith, A. L. J.,Easton, C. J.
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p. 615 - 619
(2007/10/02)
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- Method for the preparation of 1-alkyl pyridinium chlorides
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A method for preparing alkyl pyridinium chlorides by effecting a direct reaction between the corresponding alkyl chloride and pyridine.
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