cas 86347-14-0, Medetomidine | Articles data

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Preparation method of high-purity dexmedetomidine hydrochloride
The invention discloses a preparation method of high-purity dexmedetomidine hydrochloride, which comprises the following steps: by taking 1-(1-chloroethyl)-2, 3-dimethyl benzene and N-trimethylsilylimidazole as reaction raw materials, carrying out Friedel-Crafts alkylation reaction under the catalysis of an aprotic organic solvent and lewis acid, recrystallizing the obtained post-treated oil by using a specific solvent to obtain medetomidine solid, splitting by chiral acid, free of alkali and salt forming, and preparing the high-purity dexmedetomidine hydrochloride. According to the dexmedetomidine hydrochloride prepared by the preparation method disclosed by the invention, the splitting and refining times can be effectively reduced, the chemical purity and optical purity of the obtained dexmedetomidine hydrochloride can reach 100%, and the total yield is relatively high; and moreover, main starting materials are conventional industrial commodities, so that the preparation method is suitable for industrial production and has relatively high industrial application value.
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Paragraph 0054-0056; 0061-0062

(2021/06/22)

Novel method for the preparation of Medetomidine
The present invention relates to a method for manufacturing medetomidine from 1H-imidazole-4-carbaldehyde and 1-bromo-2,3-dimethylbenzene. The present invention provides a novel method for manufacturing medetomidine represented by chemical formula I. The method for manufacturing medetomidine according to the present invention has an effect of having stability of a manufacturing process and being able to manufacture a final material with high purity.
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Paragraph 0075; 0076; 0082-0088

(2021/02/09)

Preparation method of dexmedetomidine hydrochloride
The invention discloses a preparation method of dexmedetomidine hydrochloride. The preparation method comprises the following steps: in a reaction solvent dichloromethane, carrying out a Friedel-Crafts reaction on 1-(1-chloroethyl)-2,3-dimethylbenzene and N-TMS imidazole under the action of lewis acid titanium tetrachloride to generate medetomidine; in a reaction solvent ethanol, resolving medetomidine by using L-(+)-tartaric acid to obtain medetomidine with a dextrorotation configuration; in a reaction solvent ethyl acetate, salifying dexmedetomidine in a hydrochloric acid solution to obtaina crude dexmedetomidine hydrochloride product; and finally, carrying out refining in a recrystallization mode to obtain a finished dexmedetomidine hydrochloride product. The preparation method has fewsteps, is simple and convenient to operate and is suitable for industrial production.
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Paragraph 0036; 0038-0046

(2020/07/02)

Synthetic process of dexmedetomidine hydrochloride
The present invention provides a dexmedetomidine hydrochloride synthesis process, and relates to the technical field of drug synthesis, the dexmedetomidine hydrochloride synthesis process uses 1-(1-chloroethyl)-2,3-xylene and trimethylsilylimidazole as starting materials, and alkylation, resolution, dissociation and salification reactions are performed to synthesize the dexmedetomidine hydrochloride. According to the method, L-tartaric acid is used as a resolving agent, and the resolving efficiency is improved by controlling the proportion of the resolving agent and the number of resolving times; a one-step method is adopted for free salification, intermediate quality control and purification steps are not needed, the purity of the prepared finished product is larger than 99.8%, the isomeris not larger than 0.2%, through process optimization, the efficiency of the synthesis process is remarkably improved, and the obtained finished product directly meets the commercial production requirements of raw material medicines.
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Paragraph 0004; 0016-0019

(2020/08/27)

Method for synthesizing dexmedetomidine hydrochloride
The invention belongs to the technical field of drug preparation, and particularly relates to a method for synthesizing dexmedetomidine hydrochloride. The method for synthesizing dexmedetomidine hydrochloride comprises the steps that reaction of 2,3-dimethylbenzoyl chloride and 1-N,N-dimethyl sulfonyl-2-(tert-butyldimethylsily)-5-(2,3-dimethyl benzoyl) imidazole is adopted, reflux is carried out to remove a protecting group under the action of hydrochloric acid, intermediate 4(5)-(2,3-dimethyl benzoyl) imidazole is obtained, lastly, reduction is carried out to obtain medetomidine under the action of monomethylamine, dexmedetomidine is obtained through the resolution of medetomidine under the action of tartaric acid, and lastly, dexmedetomidine is salified with hydrochloric acid to obtain dexmedetomidine hydrochloride. Compared with the prior art, the method for synthesizing dexmedetomidine hydrochloride has the advantages that a synthetic route is shorter, the operation is easy, and astarting material is easy to obtain.
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(2019/04/26)

Preparation method of dexmedetomidine hydrochloride and its intermediate
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.
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(2018/07/15)

Process method for preparation of dexmedetomidine hydrochloride
The invention provides a synthetic method for dexmedetomidine hydrochloride. The synthetic method is characterized in that the dexmedetomidine hydrochloride is synthesized by using 2,3-dimethyl benzaldehyde and (1-(trimethylsilyl)-1H-imidazole-4-yl)magnesium bromide as starting materials through a reaction. The method adopts Dess-Martin to synthesize a compound III, and uses a Wittig reagent to synthesize a compound IV, so reaction conditions are greatly reduced, and synthetic reaction steps are shortened. The synthetic method provided by the invention has the advantages of simple operation, mild control points, high product purity, and applicability to industrial production.
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Paragraph 0025

(2018/04/21)

Industrial preparation method of dexmedetomidine hydrochloride
The invention discloses an industrial preparation method of dexmedetomidine hydrochloride, and belongs to the field of medicines. The method comprises the following steps: directly carrying out a Friedel-Crafts alkylation reaction on initial raw materials comprising 1-(2,3-dimethylphenyl)ethanol not subjected to a chlorination (thionyl chloride) reaction and protected imidazole under the catalysis of a Lewis acid to obtain racemic dexmedetomidine, carrying out pre-resolution purification on the racemic dexmedetomidine through a chiral acid, carrying out chiral acid resolution and alkali dissociation, and adding a hydrochloric acid organic solvent to form a salt in order to obtain the dexmedetomidine hydrochloride. The method avoids use of the toxic and corrosive regent thionyl chloride, allows the above product with high chiral and chemical purity to be obtained and the yield to be high, and is suitable for industrial production.
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Paragraph 0019

(2017/08/28)

A novel and facile route for the synthesis of medetomidine as the α2-adrenoceptor agonist
Abstract: We report here a novel and facile method for the synthesis of (±)-4(5)-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole (medetomidine) in a good yield in five steps. The method involves Wittig olefination of the phenylimidazolylketones, followed by a hydrogenation. We demonstrate that the Wittig alkenylation reaction provides a convenient step for the synthesis of medetomidine without requiring methylation and dehydration steps, which are problematic processes in the previous methods. Graphical Abstract: Novel route for the synthesis of medetomidine.[Figure not available: see fulltext.].
Kaboudin, Babak,Haghighat, Hamideh,Aieni, Samira,Behrouzi, Leila,Kazemi, Foad,Kato, Jun-ya,Aoyama, Hiroshi,Yokomatsu, Tsutomu
p. 1735 - 1739
(2017/06/27)

Synthesis process of dexmedetomidine hydrochloride midbody
The invention provides a synthesis process of a dexmedetomidine hydrochloride midbody. The process comprises the following steps: in the presence of titanium tetrachloride, carrying out reaction on 1-(1-chloroethyl)-2,3-dimethylbenzene and N-(trimethylsilyl)imidazole in a non-protonic solvent, so as to prepare medetomidine, wherein the mole ratio of 1-(1-chloroethyl)-2,3-dimethylbenzene to N-(trimethylsilyl)imidazole to titanium tetrachloride is (0.8-1.0): 2: (1.005-1.05). According to the process provided by the invention, the charge rates of the raw materials are initiatively adjusted, and the use amount of titanium tetrachloride is decreased while the use amount of N-(trimethylsilyl)imidazole is increased, so that the yield of the target product can be remarkably improved, the yield is 72.4% when an optimum raw material ratio is achieved, and the yield is much higher than the yield of 39.3% in the prior art.
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Paragraph 0041; 0042; 0043; 0044; 0045; 0046; 0047-0074

(2017/08/29)

Selective Oxidation of Secondary Amines to N,N-Disubstituted Hydroxylamines by Choline Peroxydisulfate
N,N-Disubstituted hydroxylamines were prepared directly from secondary amines by a reliable method using an oxidizing task-specific ionic liquid, choline peroxydisulfate. The operational simplicity, high selectivity, and green reaction conditions, make this method efficient and practical.
Banan, Alireza,Valizadeh, Hassan,Heydari, Akbar,Moghimi, Abolghasem
p. 2315 - 2319
(2017/10/06)

Method for preparing dexmedetomidine hydrochloride for anesthesia and sedation during operation
The invention discloses a method for preparing dexmedetomidine hydrochloride for anesthesia and sedation during an operation. The method comprises the following steps: (a) stirring and reacting 2,3-dimethyl styrene and imidazole in ionic liquid to obtain 4-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole in the presence of an iron salt; (b) reacting the 4-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole with L-(+)-tartaric acid, and performing suction filtering to obtain dexmedetomidine tartrate; (c) stirring the dexmedetomidine tartrate in an aqueous solution of sodium hydroxide, performing dichloromethane extraction and concentration, and stirring in a saturated hydrochloric acid methanol solution to obtain the dexmedetomidine hydrochloride. According to the method, the ionic liquid is used for alkylation reaction of the imidazole under catalysis of the iron salt, so that the reaction time is effectively shortened, and high yield is achieved; fewer steps are required, and the cost is lower; conditions in each step are mild, use of a large amount of lewis acid is avoided, and easiness for industrial production is achieved.
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Paragraph 0035-0037

(2017/07/05)

Preparation method of medetomidine and intermediate thereof
The invention relates to a preparation method of 2-(2, 3-xylyl)-2-methyloxirane. The method is characterized in that the preparation process includes the following reaction shown as the specification, wherein Y is selected from Cl, Br, I, CH3SO4 or HSO4; alkali is selected from KOH, NaOH, LiOH, CsOH, K2CO3, Li2CO3, Cs2CO3, Na2CO3, EtONa, EtOK, (CH3)2CHONa, (CH3)2CHOK, (CH3)3CONa, (CH3)3COK, NH2Na or NH2K. The invention adopts the synthesis method using the 2-(2, 3-xylyl)-2-methyloxirane critical intermediate to prepare medetomidine.
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Paragraph 0095; 0096; 0097; 0098

(2017/08/28)

PROCESSES FOR THE PREPARATION OF COMPOUNDS, SUCH AS 3-ARYLBUTANALS, USEFUL IN THE SYNTHESIS OF MEDETOMIDINE
There is provided a process for the preparation of a compound of formula (I) as defined herein, wherein said process comprises reacting a compound of formula (II) as defined s herein with one or more suitable Vilsmeier reagent.
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(2016/08/23)

Method for preparing dexmedetomidine hydrochloride key intermediate
The invention discloses a method for preparing a dexmedetomidine hydrochloride key intermediate. The method comprises the following steps: by taking 1-(1-chloroethyl)-2,3-dimethyl benzene and N-Boc-imidazole as raw materials, carrying out a low-temperature reaction in an aprotic organic solvent in the presence of Lewis acid, thereby obtaining a compound of a formula (III). According to the method disclosed by the invention, the starting materials refer to industrialized popular commodities and are stable in properties and easy to preserve, the defect that the raw materials are unstable in the process of preparing the conventional dexmedetomidine hydrochloride intermediate is overcome, and the method is high in reaction yield, suitable for industrial production and has high application value. The structural formula is as shown in the specification.
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Paragraph 0031; 0032

(2016/11/24)

Method for preparing dexmedetomidine and intermediate thereof
The invention provides a method for preparing dexmedetomidine and an intermediate thereof. Specifically speaking, the method comprises the steps that a compound shown as a formula II (please see the formula in the description) reacts with metal magnesium to prepare a metal magnesium Grignard reagent, and then the metal magnesium Grignard reagent reacts with a compound shown as a formula III (please see the formula in the description). The process has the advantages of being few in step, high in yield, easy to operate, high in product purity and the like and is quite suitable for large-scale industrialized production.
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(2017/04/03)

Synthesis and enantiomeric resolution of medetomidine
Medetomidine {4-[l-(2,3-dimethylphenyl)ethyl]-3H-imidazole], 5} is a selective α2-adrenoceptor agonist used in veterinary medicine for its analgesic and sedative properties. It is also an alternative and environmentally acceptable anti-fouling biocide which impedes the settlement of barnacles at nanomolar concentrations and replaces toxic antifouling coatings based on heavy metals. Several syntheses of medetomidine have been reported. The first method for the preparation of 5 and of other related 4-benzylimidazoles was described in a patent starting from 2,3-dimethylbromobenzene as shown in Scheme 1; unfortunately the yields were not reported.
Fakhraian,Toulabi,Choobdari,Peyrovi,Ghanbary, H. Hadj
p. 141 - 148
(2015/05/20)

NEW PROCESSES FOR PREPARING 4-SUBSTITUTED IMIDAZOLES
There is provided a novel process for the preparation of a compound of formula (I), (Formula (I)). There is also provided novel processes to intermediates of the compound of formula (I), as well as novel intermediates themselves.
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(2013/03/26)

METHOD FOR THE PREPARATION OF MEDETOMIDINE
The invention discloses a method for the preparation of medetomidine starting from 1-bromo 2,3-dimethylbenzene and aceton.
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(2013/02/28)

METHOD FOR THE PREPARATION OF MEDETOMIDINE WITH CHLOROACETONE
The invention discloses a method for the preparation of medetomidine starting from 1-bromo 2,3-dimethylbenzene and chloroacetone.
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Page/Page column 26

(2013/02/28)

2-(2,3-DIMETHYLPHENYL)-1-PROPANAL AND ITS USE AS PERFUME
The invention discloses 2-(2,3-dimethylphenyl)-1-propanal, a method for its preparation from -bromo 2,3-dimethylbenzene and aceton, its use in perfumes and its use for the preparation of medetomidine.
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(2013/02/28)

METHOD FOR THE PREPARATION OF 2-(2,3-DIMETHYLPHENYL)-1-PROPANAL
The invention discloses a method for the preparation of 2-(2,3-dimethylphenyl)-1-propanal starting from 1-bromo 2,3-dimethylbenzene and chloroacetone, its use in perfumes and its use for the preparation of medetomidine.
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Page/Page column 26

(2013/02/28)

PROCESS FOR PREPARATION OF MEDETOMIDINE
The present disclosure relates to a process for the preparation of medetomidine, 4-[1-(2,3-Dimethylphenyl)ethyl]- 1H-imidazoIe in an environmentally favourable and commercially feasible manner. Previous methods for the preparation of medetomidine use expensive 4-substituted imidazole derivatives as starting material. A practical way of synthesis is provided in which the imidazole ring is built up during a multi-step process starting from commercially affordable, 2,3-dimethylbenzoic. Mild reaction conditions are used throughout the process.
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(2011/06/26)

PROCESS FOR THE PREPARATION OF MEDETOMIDINE
A process of preparing Medetomidine of Formula (I) or an acid addition salt thereof, which process comprises: (i) reacting 2,3-dimethyl-methylbenzylalcohol with N-trimethylsilylimidazole, and, if desired, converting the Medetomidine to an acid addition salt thereof.
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Page/Page column 15-16

(2009/05/28)

Efficient synthesis of (S)-4(5)-[1-(2,3-dimethylphenyl) ethyl]imidazole tartrate, the potent α2 adrenoceptor agonist dexmedetomidine
(S,R)-4(5)-[1-(2,3-dimethylphenyl)ethyl]imidazole 5 is prepared in 41% yield, by a new reliable method from readily available starting materials. The separation of the enantiomers proceeds through the selective crystallisation of the (+)-tartrate of the (S) enantiomer 6 in the presence of the (R) enantiomer free base.
Cordi, Alex A.,Persigand, Thierry,Lecouve, Jean-Pierre
p. 1585 - 1593
(2007/10/03)

Expedient synthesis of 4(5)-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole, the α2-adrenergic agonist medetomidine
(+)-4(5)-[1-(2,3-Dimethylphenyl)ethyl]-1H-imidazole hydrochloride (5) is prepared in three steps in 79% overall yield from 1-(N,N-dimethylsulfamoyl)imidazole by bis-protection, regioselective lithiation followed by an efficient tandem addition-reduction of the resulting 2,3-dimethylbenzoyl chloride adduct with lithium/ammonia/ammonium chloride.
Kudzma,Turnbull Jr.
p. 1021 - 1022
(2007/10/02)

Antihypertensive substituted imidazole derivatives
The invention provides novel compounds of the formula: STR1 wherein the various substituents are defined herein below. Processes for the preparation of these compounds are described, as are novel pharmaceutical compositions comprising at least one of the compounds of their salts. The compounds and their non-toxic salts exhibit valuable pharmacological activity and are useful in the treatment of mammals, especially as antihypertensive agents. Furthermore, some of the compounds have proved to possess antithrombotic and diuretic activity. Antimycotic and antifungal properties have also been found.
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(2008/06/13)