- Preparation method of N-methyl triazine
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The invention discloses a preparation method of N-methyl triazine. The preparation method comprises eight operation processes including BTCT preparation, low-temperature reaction, reflux reaction, salt filtering, distillation, amination, filtering and drying. Compared with the conventional preparation method, the preparation method provided by the invention has the obvious advantages in the aspects of lowering the safety risk, improving the product quality, reducing the work intensity, reducing the environment harm and the like.
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Paragraph 0012
(2017/01/26)
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- Regio- and stereoselective methods for the conversion of (2S,3R)-β-phenylglycidic acid esters to taxoids and other enantiopure (2R,3S)-phenylisoserine esters
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A novel efficient method was proposed for the synthesis of enantiopure precursors of taxane-containing cytostatics, i.e., methyl esters of (2R,3S)- and (2S,3R)-N-benzoylphenylisoserine and similar taxoid esters. The method is based on the regio- and stereoselective hydrobromolysis of the corresponding trans-β-phenyl glycidate enatiomers, consecutive reactions of O-acylcarbamoylation of the obtained 3-bromohydrins, intramolecular cyclization to 4-phenyloxazolidin-2-one-5-carboxylic acid derivatives, and oxazolidinone ring opening.
- Afon'Kin,Kostrikin,Shumeiko,Popov,Matveev,Matvienko,Zabudkin
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p. 2149 - 2162
(2013/10/01)
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- POLYMORPHS OF A HYDROISOINDOLINE TACHYKININ RECEPTOR ANTAGONIST
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This application is directed to a novel polymorph of a hydroisoindoline tachykinin receptor antagonist having the following structural formula A.
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Page/Page column 24-25
(2008/12/05)
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- Preparation of nitriles from primary amides under Swern oxidation conditions
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In order to establish a mild conversion method of primary amides to nitriles, various types of carboxamides were heated under Swern oxidation conditions, (COCl)2-DMSO and Et3N, as a dehydrating agent to obtain desired nitriles in 75-96% yields.
- Nakajima, Noriyuki,Ubukata, Makoto
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p. 2099 - 2102
(2007/10/03)
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- Kinetics of the reactions of acetonitrile with chlorine and fluorine atoms
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The rate coefficients for the reactions of chlorine and fluorine atoms with acetonitrile have been measured using relative and direct methods. In the case of chlorine atoms the rate coefficient k1 was measured between 274 and 345 K using competitive chlorination and at 296 K using laser flash photolysis with atomic resonance fluorescence. The rate coefficient measured at ambient temperature (296 ± 2 K) is (1.15 ± 0.20) × 10-14 cm3 molecule-1 s-1, independent of pressure between 5 and 700 Torr (uncertainties are 2 standard deviations throughout). This result is a factor of 6 higher than the currently accepted value. The results from the three independent determinations reported here yield the Arrhenius expression k1 = (1.6 ± 0.2) × 10-11 exp[-(2140 ± 200)/T] cm3 molecule-1 s-1. Product studies show that the reaction of Cl atoms with CH3CN proceeds predominantly, if not exclusively, by hydrogen abstraction at 296 K. The rate coefficient for the reaction of fluorine atoms with acetonitrile was measured using both the relative rate technique and pulse radiolysis with time-resolved ultraviolet absorption spectroscopy. The rate coefficient for the reaction of F atoms with CH3-CN was found to be dependent on total pressure. The observed rate data could be fitted using the Troe expression with Fc = 0.6, k0 = (2.9 ± 2.1) × 10-28 cm6 molecule-2 s-1, and k∞ = (5.8 ± 0.8) × 10-11 cm3 molecule-1 s-1, with a zero pressure intercept of (0.9 ± 0.4) × 10-11 cm3 molecule-1 s-1. The kinetic data suggest that the reaction of F atoms with CH3CN proceeds via two channels: a pressure-independent H atom abstraction mechanism and a pressure-dependent addition mechanism. Consistent with this hypothesis, two products were observed using pulsed radiolysis with detection by UV absorption spectroscopy. As part of the product studies, relative rate techniques were used to measure k(Cl+CH2ClCN) = (2.8 ± 0.4) × 10-14 and k(F+CH2FCN) = (3.6 ± 0.2) × 10-11 cm3 molecule-1 s-1.
- Tyndall, Geoffrey S.,Orlando, John J.,Wallington, Timothy J.,Sehested, Jens,Nielsen, Ole J.
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p. 660 - 668
(2007/10/03)
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- Absence of Isotopic Exchange Between Solid Anhydrous Iron(III) Chloride and Molecular Chlorine-36. Chlorination of Acetonitrile in the Presence of Iron(III) Chloride or the Hexakis(acetonitrile)-iron(III) Cation.
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Chlorine-36 exchange between molecular chlorine-36 and anhydrous iron(III) chloride is not observed under heterogenous conditions at room temperature, although adsorption of 36Cl2 by FeCl3 occurs.Chlorine reacts with a solution of FeCl3 in acetonitrile at room temperature to give mono- and trichloroacetonitrile and the tetrachloroferrate(III) anion as identified products.Similar behaviour is observed between Cl2 and hexakis(acetonitrile)iron(II) hexafluorophosphate in MeCN.A reaction scheme involving an iron(III)-iron(II) redox cycle is proposed to account for the (36)Cl tracer, spectroscopic, and analytical data obtained.
- Draper, Therese,Winfield, John M.,Prescott, Ann,Winterton, Neil
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p. 1584 - 1597
(2007/10/02)
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