- Production method of 2-methyl-3(5 or 6)-methylthio pyrazine
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The invention discloses a production method of 2-methyl-3(5 or 6)-methylthio pyrazine. The method comprises the following steps: adding solvents dichloroethane and triethylamine into a reaction kettle, sealing the reaction kettle, introducing chlorine to control the pressure in the kettle at 0.02-0.03 MPa, pumping a methylpyrazine solution into the reaction kettle by using a metering pump, controlling the temperature at 45-60 DEG C, reacting, and transferring reaction liquid(containing the chlorine)in the kettle into a dichloroethane turnover tank through filter pressing for recycling after the reaction is finished; dissolving the residual 2-methyl-3(5 or 6)-chloropyrazine hydrochloride solid in the reaction kettle with water, adjusting the neutrality, and layering to obtain a 2-methyl-3(5or 6)-chloropyrazine crude product; and dropwise adding thechloropyrazine crude product is into sodium methyl mercaptide, performing reflux reaction , and after reaction liquid is extracted, adding an aid into an organic phase to generate a hydrochloride for separating the non-pyrazine product from the product to greatly improve the aroma quality of the obtained product. The product grade is improved, and the whole production process is safe and environmentally friendly.
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Paragraph 0027-0028; 0031-0032
(2020/04/17)
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- A halogenated nitrogen-containing unsaturated cyclic hydrocarbon preparation method
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The invention discloses a halogenated nitrogen-containing unsaturated cyclic hydrocarbon of the preparation method, the steps of: (1) the nitrogen-containing unsaturated cyclic hydrocarbon dissolved in hydrochloric acid or hydrobromic acid, addition of an oxidizing agent, the reaction system halogenated reaction, in the reaction process timing sampling detection, when detecting the target product quality of a halide accounted for is a reaction system in the total of the organic matter of 70% - 95% when, added to the reaction system in the terminator to terminate reaction, to obtain containing nitrogen-containing unsaturated cyclic hydrocarbon feed; (2) to the liquid mixed into the organic solvent extraction, extraction to obtain the organic phase, the organic phase temperature is reduced to make the solid precipitation or distilling the organic solvent to obtain a liquid product to be deducted, the resulting solid or liquid product is halogenated nitrogen-containing unsaturated cyclic hydrocarbon. The method solves the problem of the nitrogen-containing unsaturated cyclic hydrocarbon over [...] reaction problems.
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Paragraph 0021
(2018/05/16)
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- N-heterocyclyl sulphonamide derivatives and their use as endothelin antagonists
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The invention concerns pharmaceutically useful N-heterocyclyl sulphonamide derivatives, their pharmaceutically acceptable salts, processes for their manufacture, their use for antagonising one or more actions of endothelin in a human or other warm-blooded animal, their use in methods of treatment of diseases or medical conditions in which elevated or abnormal levels of endothelin play a significant causative role.
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- Aromatic amino ethers as pain relieving agents
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The present invention relates to compounds of formula (I), STR1 wherein A is an optionally substituted phenyl naphthyl, pyridyl, pyrazinyl, pyridazinyl, pyrimidyl, thienyl, thiazolyl, oxazolyl, thiadiazolyl having at least two adjacent ring carbon atoms or a bicyclic ring system, provided that the --CH(R3)N(R2)B--R1 and --OCH(R4 --)--D linking groups arm positioned in a 1,2 relationship to one another on ring carbon atoms and the ring atom positioned ortho to the --OCHR4 -- linking group (and therefore in the 3-position relative to the --CHR3 NR2 -- linking group) is not substituted; B is an optionally substituted ring system; D is an optionally substituted ring system; R1 is a variety of group as defined in the description; R2 is hydrogen, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, phenylC1-3 alkyl or 5- or 6-membered heteroarylC1-3 alkyl; R3 is hydrogen or C1-4 alkyl; R4 is hydrogen or C1-4 alkyl; and N-oxides of NR2 where chemically possible; and S-oxides of sulphur containing rings were chemically possible; and pharmaceutically acceptable salts and in vivo hydrolysable esters and amides thereof. Process for their preparation, intermediates in theirpreparation, their use as therapeutic agents and pharmaceutical compositions containing them.
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- Reactions of Halogenomethanes in the Vapour Phase. Part 5. The Reactions of Imidazolines, Anils, and 1-Methylimidazole with Chloroform at 550 deg C, and a Comparison with their Liquid-Phase Reactions with Trichloroacetate Ion or Hexachloroacetone and Base
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The vapor-phase reactions of imidazolines and anils with chloroform at 550 deg C are compared with their liquid-phase reactions in the presence of hexachloroacetone and base or upon thermolysis with trichloroacetate ion.In the vapour-phase reactions imidazolines, unlike imidazoles, gave non-chlorinated pyrimidines, and 1-methyl-imidazole gave 2-cyanopyrrole and the four 3-chlorocyanopyridines.
- Busby, Reginald E.,Khan, Mohammad A.,Khan, Mohammad R.,Parrick, John,Shaw, C. J. Granville
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p. 1431 - 1435
(2007/10/02)
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- Reactions of Halogenomethanes in the Vapor Phase. Part 4. The Reactions of Imidazoles with Chloroform at 550 deg C, and a Comparison with their Liquid-phase Reactions with Trichloroacetate Ion or Hexachloroacetone and Base
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1-Unsubstituted imidazoles and chloroform at 550 deg C in a flow system give mainly 5-chloropyrimidines, together with 4-chloropyrimidines and chloropyrazines.The effects of methyl substituents on the ratio of products is considered.The liquid-phase reactions of 2-methyl- and 2,4,5-trimethyl-imidazole under conditions in which dichlorocarbene is said to be formed in basic or neutral conditions were studied, and compared with the gas-phase reactions with chloroform.
- Busby, Reginald E.,Khan, Mohammad A.,Khan, Mohammad R.,Parrick, John,Shaw, C. J. Granville,Iqbal, Mohammad
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p. 1427 - 1430
(2007/10/02)
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