18635-38-6Relevant articles and documents
Synthesis method of methyl 2-acetylamino-3-chloropropionate
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Paragraph 0042; 0047-0049; 0053-0055; 0059-0061; 0065-0066, (2020/01/12)
The invention discloses a synthesis method of methyl 2-acetylamino-3-chloropropionate. The method comprises the following steps: adding L-serine methyl ester hydrochloride into dichloromethane, dropwise adding thionyl chloride A, carrying out a sectional controlled-temperature reaction, then performing cooling to 20 DEG C, adding water for layering, and removing impurities by activated carbon so as to obtain an aqueous 3-chloro-L-alanine methyl ester hydrochloride solution; controlling the temperature of the aqueous 3-chloro-L-alanine methyl ester hydrochloride solution to be 15-25 DEG C, dropwise adding an aqueous sodium bicarbonate solution and acetic anhydride at the same time, and keeping the temperature for 1-4 h after drop-by-drop addition is completed; and carrying out extracting, concentrating, recrystallizing, centrifuging and drying to obtain the methyl 2-acetylamino-3-chloropropionate. The system is heated in a sectional controlled-temperature mode, so the method has the advantages of mild reaction conditions, high reaction yield, and few byproducts; and the aqueous 3-chloro-L-alanine methyl ester hydrochloride solution is directly used as a reaction raw material, so that the yield and the purity of the final product are improved.
N-acetyl-β-chloro-L-alanine methyl ester preparation method
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Paragraph 0047, (2016/10/17)
The invention provides a method for preparing N-acetyl-beta-chlorine-L-alanine methyl ester. The method includes the steps that (a) serine serves as a starting material and is esterified through methanol or ethyl alcohol, (b) the esterified matter is chlorinated through sulfoxide chloride, (c) the chlorinated matter undergoes acylation, (d) the acylated matter is recrystallized, and accordingly the N-acetyl-beta-chlorine-L-alanine methyl ester is obtained. The method is high in reaction yield, by-products are few, reaction mother liquor is recycled and reused, distilled liquid obtained after acylation is acetic acid and acetic anhydride, and the liquid is recycled and reused after being purified. Accordingly, cost is low, tail gas generated in reactions is absorbed through strong-base solutions to form salt and then is separated and used, and accordingly environment protection is achieved.
Derivatives of bicyclic aminoacids agents containing these compounds and their use
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, (2008/06/13)
Disclosed are cis, exo- and trans-compounds of the formula I STR1 in which n denotes 0, 1 or 2, R1 denotes hydrogen, (C1 -C6)-alkyl which can optionally be substituted by amino, (C1 -C4)-acyl- or bezoylamino, (C2 -C6)-alkenyl, (C5 -C9)-cycloalkyl, (C5 -C9)-cycloalkenyl, (C5 -C7)-cycloalkyl-(C1 -C4)-alkyl, aryl or partially hydrogenated aryl, which can, in each case, be substituted by (C1 -C2)-alkyl, (C1 -C2)-alkoxy or halogen, aryl-(C1 -C4)-alkyl, /which can be substituted as defined previously in the aryl radical/, a monocyclic or bicyclic sulfur or nitrogen and/or nitrogen heterocyclic radical, or a side chain of naturally occurring aminoacid, R2 denotes hydrogen, (C1 -C6)-alkyl, (C2 -C6)-alkenyl or aryl-(C1 -C4)-alkyl, Y denotes hydrogen or hydroxyl, Z denotes hydrogen or Y and Z together denote oxygen, X denotes (C1 -C6)-alkyl, (C2 -C6)-alkenyl, (C6 -C9)-cycloalkyl or aryl which can be mono-, di- or tri- substituted by (C1 -C4)-alkyl, (C1 -C4)-alkoxy, hydroxyl, halogen, nitro, amino, (C1 -C4)-alkylamino, di-(C1 -C4 -alkylamino or methylenedioxy, or indol-3-yl, or physiologically acceptable salts thereof, a process of the preparation thereof, agents containing them, their use as a medicine and intermediates for the preparation thereof.
