141109-13-9Relevant 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.
Synthesis process of anti-cancer drug (glycinate methyl ester)
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Paragraph 0010-0011, (2019/10/10)
The invention provides a synthesis process of an anti-cancer drug (glycinate methyl ester). The process includes the steps of firstly, adding methyl alcohol into a flask with a stirrer, a thermometer and a constant-pressure dropping funnel, controlling the temperature at 0-5 DEG C, and slowly dropwise adding acetyl chloride into the flask for thermal insulation reaction for 1.5 hours; secondly, adding o-chlorophenylglycine to be heated to 45 DEG C for reaction for 15 hours; thirdly, conducting depressurized rotary evaporating to remove most of solvent, and conducting separation and suction-filtration to obtain a product (hydrochloride solid); fourthly, dissolving the obtained solid in water, adding dichloromethane, adjusting the pH value to be 7.5 through ammonium hydroxide, extracting a water layer through dichloromethane, combining an organic layer, conducting washing through saturated table salt until the neutral state is reached, conducting drying and suction filtration on anhydrous magnesium sulfate, and conducting depressurized rotary evaporating to remove a solvent to obtain a colorless transparent oily substance. Through the improvement, the synthesis method has the advantages that the process is green and free of pollution, the reaction conditions are mild, the operation is simple, the product can be easily extracted, and the yield is high; thus, the problems and defects in the background are effectively solved and overcome.
Pasteur's Tweezers revisited: On the mechanism of attrition-enhanced deracemization and resolution of chiral conglomerate solids
Hein, Jason E.,Huynh Cao, Blessing,Viedma, Cristobal,Kellogg, Richard M.,Blackmond, Donna G.
supporting information; scheme or table, p. 12629 - 12636 (2012/09/05)
Insights into the mechanism of attrition-enhanced deracemization and resolution of solid enantiomorphic chiral compounds are obtained by crystal size and solubility measurements and by isotopic labeling experiments. Together these results help to deconvolute the various chemical and physical rate processes contributing to the phenomenon. Crystal size measurements highlight a distinct correlation between the stochastic, transient growth of crystals and the emergence of a single solid enantiomorph under attrition conditions. The rapid mass transfer of molecules between the solution and solid phases under attrition is demonstrated, and the concept of a crystal-size-induced solubility driving force is exploited to overcome the stochastic nature of the crystal growth and dissolution processes. Extension to non-racemizing conditions provides a novel methodology for chiral resolution. Implications both for practical chiral separations and for the origin of biological homochirality are discussed.
