141109-18-4Relevant academic research and scientific papers
Preparation method of clopidogrel hydrogen sulfate intermediate
-
Paragraph 0032; 0035-0073; 0083, (2021/05/15)
The present invention relates to a preparation method of a clopidogrel hydrogen sulfate intermediate. (+)-2-chlorophenylglycine methyl ester and alpha-thiopheneethanol p-toluenesulfonate are adopted as raw materials, a reaction solvent and an acid-binding agent are added for a condensation reaction, the condensation reaction process is divided into a first stage and a second stage, and when 60-95% of the condensation reaction is completed, first-stage reaction is completed; after the first-stage reaction is completed, firstly part of the reaction solvent is removed, and then second-stage reaction is carried out; and after the second-stage reaction is completed, a target product is obtained, namely the clopidogrel hydrogen sulfate intermediate. After the first-stage reaction is completed, part of the reaction solvent is removed firstly, and then the second-stage reaction is continued, so that the concentration of the reaction material can be increased in the later stage of the condensation reaction, the use amount of the reaction solvent is reduced, and racemization and side reaction in the reaction process are effectively inhibited, thereby improving the chiral purity of the product, increasing the yield, reducing the use of auxiliary materials greatly, and reducing the production cost.
Preparation method of clopidogrel hydrogen sulfate
-
Paragraph 0075; 0078-0079; 0082; 0085-0086; 0089; 0092-0093, (2021/02/10)
The invention relates to a preparation method of clopidogrel hydrogen sulfate. The preparation method comprises the following steps: reacting (S)-o-chlorophenylglycine methyl ester with 1, 1, 1, 3, 3,3-hexamethyldisilazane to obtain trimethylsilyl protected (S)-o-chlorophenylglycine methyl ester; in the presence of acetonitrile, superfine powder potassium carbonate and the trimethylsilyl protected (S)-o-chlorophenylglycine methyl ester, adding 2- (2-bromoethyl) thiophene, evaporating acetonitrile in batches, adding water and methyl acetate, extracting to obtain a methyl acetate solution of (S)-2-thiophene ethylamino-2-chlorophenylmethyl acetate, dropwise adding concentrated hydrochloric acid, carrying out pulping and cooling to obtain (S)-2-thiophene ethylamino methyl-2-chlorophenyl acetate hydrochloride, mixing the (S)-2-thiophene ethylamino methyl-2-chlorophenyl acetate hydrochloride with a formaldehyde aqueous solution for reaction, and carrying out reaction with concentrated sulfuric acid to obtain the clopidogrel hydrogen sulfate. According to the method, the high-purity (S)- 2-thiophene ethylamino-2-chlorophenyl methyl acetate hydrochloride and clopidogrel hydrogen sulfate can be obtained with high efficiency and high yield, and the method is suitable for industrial production.
Preparation method of sulfonic clopidogrel impurity
-
Paragraph 0012; 0034-0035, (2020/08/02)
The invention discloses a preparation method of a sulfonic clopidogrel impurity. The preparation method comprises the following steps: reacting thiophene-2-ethanol with toluenesulfonyl chloride to generate p-toluenesulfonic acid-2-thienylethyl ester; carrying out esterification on o-chlorophenylglycine and methanol to generate o-chlorophenylglycine methyl ester; resolving the o-chlorophenylglycinemethyl ester by using L(+) tartaric acid; converting into free S-(+)-o-chlorophenylglycine methyl ester in dichloromethane; carrying out a condensation reaction on the p-toluenesulfonic acid-2-thienylethyl ester and the S-(+)-o-chlorophenylglycine methyl ester under an alkaline condition; acidifying the obtained product to generate (S)-2-(2-thienylethylamino)(2-chlorphenyl)methyl acetate, carrying out a condensation reaction on the (S)-2-(2-thienylethylamino)(2-chlorphenyl)methyl acetate and formaldehyde to obtain clopidogrel, and carrying out a reaction on the clopidogrel and chlorosulfonicacid to generate sulfonic clopidogrel impurity. The preparation method of the sulfonic clopidogrel impurity has the advantages of mild reaction conditions, accessible raw materials, low cost and highyield and purity.
Synthesis of clopidogrel intermediate (S)-2-(2- thiophene ethylamine-)-(2-chlorophenyl)- methyl acetate
-
Paragraph 0050-0133, (2020/03/17)
The invention belongs to the technical field of medicines, and relates to a novel process (S)- 2 - (2 - for synthesizing the intermediate) - (2 - thiophene ethyl amino) - chlorophenyl, methyl acetate and the salt thereof, for the first time, and the inven
Method for preparing D-(+)-alpha-(2-thiopheneethylamino)-alpha-(2-chlorophenyl)methyl acetate hydrochloride
-
Paragraph 0011; 0061-0064; 0070-0072; 0079; 0084-0108, (2018/12/14)
The invention provides a novel method for preparing D-(+)-alpha-(2-thiopheneethylamino)-alpha-(2-chlorophenyl)methyl acetate hydrochloride, aiming at solving the technical problems of a traditional synthesis technology of the D-(+)-alpha-(2-thiopheneethylamino)-alpha-(2-chlorophenyl)methyl acetate hydrochloride that the technology is complicated, the cost is high and the yield is low. The method comprises the following steps: 1) preparing 2-bromothiophene; 2) preparing 2-thiopheneethanol; 3) preparing 2-thiopheneethanol p-toluenesulfonate; 4) preparing L-(+)-o-chlorophenylglycine methyl esterL-tartrate; 5) preparing the D-(+)-alpha-(2-thiopheneethylamino)-alpha-(2-chlorophenyl)methyl acetate hydrochloride. The preparation method provided by the invention is low in cost, high in yield andhigh in safety and is suitable for industrial production.
The clopidogrel hydrogen sulfate synthesis method (by machine translation)
-
Paragraph 0006; 0008, (2018/11/22)
The invention discloses a clopidogrel hydrogen sulfate synthesis method, comprises the following steps: S1, 2 - (2 - thiophene) ethanol tosylates synthetic, S2, (+) - O-chlorobenzene glycine methyl brown oil of synthetic, S3, (S)- 2 - (2 - thiophene ethylamine) (2 - chlorophenyl) acetic acid methyl ester hydrochloride of synthetic, S4, the finished synthetic; the invention with conventional clopidogrel hydrogen sulfate existing synthesis method, the processing operation is more convenient, after treatment is simple, and is suitable for commercial production; high yield, few by-products, impurity removal easier; simple and easy to obtain, the cost is cheap. (by machine translation)
A compound clopidogrel hydrogensulfate method for the preparation of
-
Paragraph 0103-0105, (2017/01/26)
The invention relates to a preparation method of clopidogrel disulfate. The preparation method comprises the following steps of step one. carrying out esterification reaction, namely preparing (+/-) DL-2-Chlorophenylglycine methyl ester; step two. carrying out splitting reaction, namely preparing (+) DL-2-Chlorophenylglycine methyl ester; step three. carrying out activating reaction, namely preparing alpha-thiophene ethanol p-toluenesulfonates; step four. carrying out substitution reaction, namely preparing (+) alpha-(2-thiophene ethylamino)-2-(2-chlorobenzene) methyl acetate hydrochloride; step five. carrying out ring closing reaction, namely preparing clopidogrel; and step six. carrying out salt-forming reaction, namely preparing the clopidogrel disulfate. The preparation method has the advantages that the preparation technology is optimized and improved, reaction conditions are mild, the splitting and the racemization are truly and synchronously carried out, and an obtained crude product has high specific rotation; a catalyst is used in the substitution reaction, so that the reaction time is shortened; the ring closing reaction is carried out at 40 DEG C under the condition of avoiding light, so that the purity of the product is relatively high; and the period of the whole synthetic route is shortened, the aftertreatment operation is simple, and therefore, the preparation method is suitable for mass production.
AN IMPROVED PROCESS FOR THE PREPARATION OF CLOPIDOGREL BISULFATE FORM-I
-
Page/Page column 6; 7, (2014/08/19)
The present invention provides an improved process for the preparation of pure Clopidogrel bisulfate Form-I of formula (I), which comprises: reacting S(+)-methyl-2- [2-(thiophen-2-yl)ethylamino]-2-(2-chlorophenyl) acetate hydrochloride (Formula II) with Formaldehyde and R-(-) Camphor sulphonic acid to yield S (+)-Clopidogrel camphor sulfonate salt (Formula III), which is on further treatment with C1-5 carboxylic acid followed by sulphuric acid to get Clopidogrel Form-I.
AN IMPROVED PROCESS FOR THE PREPARATION OF CLOPIDOGREL BISULFATE
-
Page/Page column 7, (2011/02/24)
The present invention provides an improved process for the preparation of Clopidogrel of Formula (I) or its pharmaceutically acceptable salts, and its intermediate of Formula (II). Formula (I) Formula (II).
PROCESS FOR PREPARING CLOPIDOGREL
-
Page/Page column 7, (2008/06/13)
A process for preparing clopidogrel or a salt thereof.
