141109-14-0Relevant articles and documents
Asymmetric Hydrocyanation of N-Phosphinoyl Aldimines with Acetone Cyanohydrin by Cooperative Lewis Acid/Onium Salt/Br?nsted Base Catalysis
Junge, Thorsten,Titze, Marvin,Frey, Wolfgang,Peters, René
, p. 1509 - 1512 (2021/02/09)
α-Amino acids are of fundamental importance for life. Both natural and artificial α-amino acids also play a crucial role for pharmaceutical purposes. The catalytic asymmetric Strecker reaction still provides one of the most attractive strategies to prepare scalemic α-amino acids. Here we disclose a new concept for Strecker reactions, in which an achiral Br?nsted base cooperates with a Lewis acid and an aprotic ammonium salt, which are both arranged in the same chiral catalyst entity. The described method could successfully address various long-standing practical issues of this reaction type. The major practical advantages are that (1) the N-protecting group is readily removable, (2) acetone cyanohydrin is attractive as cyanation reagent in terms of atom economy and cost efficiency, (3) an excess of the cyanation reagent is not necessary, (4) the new method does not require additives and (5) is performed at ambient temperature.
Preparation method of clopidogrel hydrogen sulfate crystal form II
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Paragraph 0034; 0054; 0070, (2020/02/29)
The invention discloses a preparation method of a clopidogrel hydrogen sulfate crystal form II. The method includes: preparation of (+)o-chlorophenylglycine methyl ester; preparation of (+)alpha-(2-thiophene ethylamino)-alpha-(2-chlorphenyl)methyl acetate hydrochloride; preparation of (+)clopidogrel free alkali; preparation of (+)clopidogrel camphorsulfonic acid double salt; hydrolysis of (+)clopidogrel camphorsulfonic acid double salt; and preparation of clopidogrel hydrogen sulfate. The preparation method of the clopidogrel hydrogen sulfate crystal form II provided by the invention optimizesthe synthesis process of clopidogrel hydrogen sulfate, selects cheap and easily available materials, adopts mild reaction conditions, and can achieve safe and environment-friendly production of a high-purity product.
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.
