176721-04-3Relevant articles and documents
METHOD FOR PREPARING DEXMEDETOMIDINE
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Page/Page column 19; 23, (2021/05/15)
The present invention relates to a method for preparing dexmedetomidine having the following formula (I): or a pharmaceutically acceptable salt and/or solvate thereof, comprising the following successive steps: a) asymmetric hydrogenation of a methylene derivative of the following formula (II): in order to obtain dexmedetomidine, and b) optionally salifying and/or solvating dexmedetomidine in order to obtain a pharmaceutically acceptable salt and/or solvate of dexmedetomidine, wherein the methylene derivative of formula (II) is prepared from a halide of the following formula (V), in which Hal2 represents a halogen atom such as Br, and a cyanoimidazole of the following formula (VI):. The present invention relates also to methods for preparing synthesis intermediates of dexmedetomidine from the halide of formula (V) and the cyanoimidazole of formula (VI), these synthesis intermediates being the methylene derivative of formula (II), an alcohol of the following formula (III), and a ketone of the following formula (IV):.
Preparation method of dexmedetomidine hydrochloride and its intermediate
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, (2018/07/15)
The invention discloses a preparation method of dexmedetomidine hydrochloride and its intermediate. A preparation method of dexmedetomidine L-tartrate comprises the steps of subjecting dexmedetomidineintermediate III and hydrogen to reduction reaction in an organic solvent in the presence of a chiral catalyst, and subjecting the reduced product and tartaric acid to neutralization reaction to obtain dexmedetomidine L-tartrate II, wherein the chiral catalyst is (+)-1,2-bis(2S-5S)-diethylphospholano-benzene(1,5-cyclooctadiene)rhodium trifluoromethanesulfonate. The preparation method herein has ashort step path, has no need for chiral splitting, and has high total molar yield; the product prepared herein has high purity, reaches the standard for bulk pharmaceutical chemicals and is suitablefor industrial production.
Preparation process of dexmedetomidine hydrochloride for ICU (intensive care unit) sedation and analgesia
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Paragraph 0065; 0066; 0067; 0068; 0069; 0070, (2017/08/28)
The invention discloses a preparation process of dexmedetomidine hydrochloride for ICU (intensive care unit) sedation and analgesia. The preparation process includes the steps: first, stirring and reacting 1-(1-halogenated ethyl)-2, 3-dimethyl benzene and imidazole in ionic liquid under catalysis of ferric trichloride to obtain 4-[1-(2, 3-dimethyl phenyl) ethyl]-1H-imidazole; second, refluxing the 4-[1-(2, 3-dimethyl phenyl) ethyl]-1H-imidazole obtained in the first step and L-(+)-tartaric acid in absolute ethyl alcohol, and performing standing, cooling and suction filtration to obtain dexmedetomidine tartrate; third, stirring the dexmedetomidine tartrate in sodium hydroxide aqueous solution, extracting methylene dichloride, concentrating the solution, stirring the solution in saturated hydrochloric acid methanol solution to obtain the dexmedetomidine hydrochloride. The method is short in reaction time, high in yield, milder in condition and suitable for industrial popularization.