40412-06-4Relevant articles and documents
Preparation method of clopidogrel hydrogen sulfate intermediate
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Paragraph 0032, (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.
Structure-Odor Correlations in Homologous Series of Mercapto Furans and Mercapto Thiophenes Synthesized by Changing the Structural Motifs of the Key Coffee Odorant Furan-2-ylmethanethiol
Schoenauer, Sebastian,Schieberle, Peter
, p. 4189 - 4199 (2018/05/01)
Furan-2-ylmethanethiol (2-furfurylthiol; 2-FFT, 1) is long-known as a key odorant in roast and ground coffee and was also previously identified in a wide range of thermally treated foods such as meat, bread, and roasted sesame seeds. Its unique coffee-like odor quality elicited at very low concentrations, and the fact that only a very few compounds showing a similar structure have previously been described in foods make 1 a suitable candidate for structure-odor activity studies. To gain insight into the structural features needed to evoke a coffee-like odor at low concentrations, 46 heterocyclic mercaptans and thio ethers were synthesized, 32 of them for the first time, and their odor qualities and odor thresholds were determined. A movement of the mercapto group to the 3-position kept the coffee-like aroma but led to an increase in odor threshold. A separation of the thiol group from the furan ring by an elongation of the carbon side chain caused a loss of the coffee-like odor and also led to an increase in odor thresholds, especially for ω-(furan-2-yl)alkane-1-thiols with six or seven carbon atoms in the side chain. A displacement of the furan ring by a thiophene ring had no significant influence on the odor properties of most of the compounds studied, but the newly synthesized longer-chain 1-(furan-2-yl)- and 1-(thiophene-2-yl)alkane-1-thiols elicited interesting passion fruit-like scents. In total, only 4 out of the 46 compounds also showed a coffee-like odor quality like 1, but none showed a lower odor threshold. Besides the odor attributes, also retention indices, mass spectra, and NMR data of the synthesized compounds were elaborated, which are helpful in possible future identification of these compounds in trace levels in foods or other materials.
Method for preparing D-(+)-alpha-(2-thiopheneethylamino)-alpha-(2-chlorophenyl)methyl acetate hydrochloride
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Paragraph 0009; 0058; 0064; 0067; 0076; 0083; 0094; 0103, (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.