- An improved synthesis of memantine hydrochloride: Anti-Alzhelmer's drug
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An economical new process route has been developed for the large-scale synthesis of memantine hydrochloride (1) an anti-Alzheimer's drug. The procedure involves the conversion of 1,3-dimethyl adamantane (2) to formamide intermediate 8 as a key step, followed by hydrolysis to (1-amino-3,5-dimethyl adamantane) hydrochloride (1) in good yield.
- Reddy, Jambula Mukunda,Prasad, Ganji,Raju, Veeramalla,Ravikumar, Mylavarapu,Himabindu, Vurumidi,Reddy, Ghanta Mahesh
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- PROCESS FOR PREPARATION OF MEMANTINE
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The present invention provides an improved process of manufacturing 1-Bromo-3,5-dimethyladamantane compound of formula-IV starting from 1,3-dimethyladamantane that avoids use of liquid bromine and minimizes the use of hazardous chemicals. The present invention also provides use of 1-Bromo-3,5-dimethyladamantane prepared by the process of present invention in the process of producing Memantine hydrochloride and pharmaceutical compositions thereof.
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Page/Page column 8-9
(2020/05/19)
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- Preparation method of memantine hydrochloride (by machine translation)
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The preparation method of the memantine hydrochloride, comprises the following steps,1 - bromo - 333355-dimethyladamantane, used as a hydrolysis reagent, to hydrolyze the formamide group to obtain a finished product of memantine hydrochloride . The method disclosed by the invention is relatively mild in preparation conditions and low in cost, obtained by hydrolysis of the amino substituent, by using formamide as a hydrolysis reagent . The method, further comprises the following steps: preparing a finished product of, memantine hydrochloride by using, a sodium hydroxide solution as a, hydrolysis reagent. (by machine translation)
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Paragraph 0025-0026; 0030-0031; 0035-0036; 0040-0041
(2020/05/08)
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- Method for synthesizing N-alkanoyl memantine
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The invention discloses a method for synthesizing N-alkanoyl memantine. The method comprises the steps that (a) memantine hydrochloride reacts with a formylation reagent or an acetylation reagent in areactive solvent; (b) after the reaction is completed, separation is carried out to obtain a target product. The method for synthesizing the N-alkanoyl memantine has the advantages that the operationis simple, the raw materials are easy to obtain, the preparation yield and product purity are higher, and the method is suitable for rapid preparation in analytical laboratories.
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Paragraph 0076; 0077
(2019/07/04)
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- Improvement method for synthesis process of memantine hydrochloride
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The invention discloses an improvement method for a synthesis process of memantine hydrochloride; with 1,3-dimethyl adamantane as a raw material, 3,5-dimethyl-1-adamantanol is obtained through a bromination reaction and a hydrolysis reaction; 3,5-dimethyl-1-adamantanol is subjected to a chlorination reaction to obtain 1-chloro-3,5-dimethyl adamantane; and 1-chloro-3,5-dimethyl adamantane is subjected to an ammoniation reaction, acid hydrolysis and salt formation, and the target product of methamine hydrochloride is produced, wherein in the bromination reaction, the reaction molar ratio of 1,3-dimethyl adamantane and bromine is 1:1.1, the reaction is performed in dichloroethane, and after the hydrolysis reaction, an organic phase is separated and washed to remove bromine and washed and dried, and an obtained solution is directly used for a next reaction. The improvement method provided by the invention can improve the yield, increase reaction safety and reduce waste and waste water.
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Paragraph 0017; 0020
(2018/07/30)
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- PROCESS FOR MANUFACTURING ADAMANTANE DERIVATIVES WITH HIGH YIELD
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The present invention pertains to process for the amidation of a substituted 1-bromo-adamantane comprising a step (0) of reacting a substituted adamantane with an excess of bromine to obtain a 1-bromo-adamantane and a step (i) of reacting said substituted 1-bromo-adamantane with an amide, wherein the substituted 1-bromo-adamantane is used in the form of a mixture comprising bromine as obtained in step (0), wherein in step (0) a bromine: substituted adamantane molar ratio of from [2.5:1] to less than [5:1] is employed.
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Page/Page column 16-17
(2010/04/03)
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- A PROCESS FOR PREPARING MEMANTINE
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The present invention relates to a process for preparing memantine, or a pharmaceutically acceptable salt thereof (e.g., memantine hydrochloride), which is substantially free of impurities.
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Page/Page column 20-21
(2010/08/08)
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- Process for the manufacture of memantine and intermediate product
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The present invention relates to a process for manufacturing N-Formyl-1-amino-3,5-dimethyladamantane, an intermediate product in the overall process of producing 1-Amino-3,5-dimethyladamantane hydrochloride (Memantine). Therein, the process comprises the following steps: (a) reacting 1,3-dimethyladamantane with an acid mixture comprising concentrated sulfuric acid and concentrated nitric acid, wherein 1 to 6 volume parts of sulfuric acid are used per weight part of 1,3-dimethyladamantane; (b) reacting the solution from step (a) with an amount of formamide varying from 1 to 5 molar equivalents per mole of deprotonated 1,3-dimethyladamantane from step (a) to obtain N-Formyl-1-amino-3,5-dimethyladamantane. In step (b), the molar ratio of total acid, i.e. the molar amount of sulfuric acid and the molar amount of nitric acid taken together versus the molar amount of formamide is at least 1.5 and that the temperature is at least 50°C. The present invention also relates to the overall process of manufacturing Memantine from 1,3-dimethyladamantane by means of hydrolyzing the intermediate NFORM.
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Page/Page column 6
(2009/10/01)
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- Method for Producing 1-Formamido-3,5-Dimethyladamantane
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The invention relates to a method for producing 1-formamido-3,5-dimethyladamantane in only two reaction steps by direct formamide formation of 1,3-dimethyladamantane, the 1,3-dimethyladamantane being reacted with formamide in concentrated acids.
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Page/Page column 2
(2009/12/23)
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- γ-aminoadamantanecarboxylic acids through direct C-H bond amidations
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Utilizing bromine-free, direct C-H bond amidations we have synthesized a large variety of adamantane amides. Depending on the precursors used these amides directly yield pharmaceutically active aminoadamantanes or γ-aminoadamantanecarboxylic acids after hydrolytic cleavage. These rigid analogues of γ-aminobutyric acid (GABA) were protected at the C- and N-termini and we synthesized a number of peptides incorporating γ-aminoadamantanecarboxylic acids in solution as well as via solid phase peptide synthesis. These peptides are promising scaffolds for applications in medicinal chemistry as well as in organocatalysis. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
- Wanka, Lukas,Cabrelle, Chiara,Vanejews, Maksims,Schreiner, Peter R.
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p. 1474 - 1490
(2008/09/19)
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- PROCESS FOR PREPARING MEMANTINE
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A process for preparing memantine or an acid addition salt of memantine comprises reacting 1-bromo-3,5-dimethyl adamantane with formamide to form 1-N-formyl-3,5-dimethyl adamantane.
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Page/Page column 13
(2008/06/13)
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