Method for preparing amantadine
AssigneeShandong Holly Pharmaceutical Co., Ltd.
InventorsLanhua Li, Yuenan Qiu, Donghong Xu, Zhiyuan Liu, Huaqiang Wu, Zhufeng Zhou, Lihong Chen, Zhen Lin
Life of this patent
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Abstract
A method for preparing amantadine includes chlorinating adamantane with chlorine gas in a solvent in the presence of a Lewis acid catalyst to obtain a reaction liquid, and then removing the solvent and residues containing the catalyst in the reaction liquid, to obtain a chlorinated product. The chlorinated product is mixed with urea to a mixture, and the mixture is subjected to an amination reaction, to obtain amantadine. The results of examples show that the purity of the prepared amantadine could reach 99.5% or more.
Claims19
A method for preparing amantadine, the method comprising:
- chlorinating adamantane with chlorine gas in a solvent in a presence of a Lewis acid catalyst to obtain a reaction liquid, and then removing the solvent and residues containing the catalyst in the reaction liquid, to obtain a chlorinated product;
- carrying out the chlorinating of the adamantane with chlorine gas at a temperature of −10° C. to 10° C.;
- selecting the Lewis acid from at least one of the group consisting of ferric chloride, aluminum chloride and tungsten hexachloride;
- providing a mixture of monochloroadamantane and adamantane as the chlorinated product;
- providing a weight ratio of adamantane to the Lewis acid in a range of 1:0.01-0.1;
- providing a weight ratio of adamantane to the chlorine gas in a range of 1:0.37-0.55;
- and
- mixing the chlorinated product with urea to obtain a mixture, and subjecting the mixture to an amination reaction, to obtain amantadine;
- after the amination reaction, subjecting the aminated product to a post-treatment;
- carrying out the post-treatment by dissolving the aminated product in an acid, filtering, and adjusting a pH value of a resulting filtrate to 6-7, to precipitate out amantadine;
- providing adamantane as the residue after filtering, and returning the adamantane to the chlorinating step.
A method for preparing amantadine, the method comprising:
- chlorinating adamantane with chlorine gas in a solvent in a presence of a Lewis acid catalyst to obtain a reaction liquid, and then removing the solvent and residues containing the catalyst in the reaction liquid, to obtain a chlorinated product;
- and
- mixing the chlorinated product with urea to obtain a mixture, and subjecting the mixture to an amination reaction, to obtain amantadine;
- after the amination reaction, subjecting the aminated product to a posttreatment;
- and
- carrying out the post-treatment by dissolving the aminated product in an acid, filtering, and adjusting a pH value of a resulting filtrate to 6-7, to precipitate out amantadine.
Dependencies are inferred from the claim text.