31925-29-8Relevant articles and documents
Method for preparing D-p-methylsulfonylphenylserine ethyl ester with high stereoselectivity
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Paragraph 0013; 0015; 0034-0060, (2021/03/13)
The invention discloses a method for preparing D-p-methylsulfonylphenyl serine ethyl ester with high stereoselectivity, which has the advantages of mild reaction conditions, high stereoselectivity andlow corrosivity to production equipment, and belongs to the field of organic reaction catalyzed by small molecules. According to the preparation method provided by the invention, p-methylsulfonylbenzaldehyde and N-Boc glycine ethyl ester are used as basic raw materials, and trifluoromethanesulfonic acid di-n-butyl boron ester is used as an additive, so that optically pure D-type p-methylsulfonylphenylserine ethyl ester is obtained with high stereoselectivity under the condition that Lproline is used as a catalyst. Compared with the existing chemical synthesis method, the method disclosed by the invention has the advantages that the highest total yield of the D-methylsulfonylphenyl serine ethyl ester can reach 75%, and the ee value of the obtained product reaches 73%. The method is low incost and has better yield and optical purity.
Preparation method of (2S, 3R)-p-methylsulfonylphenyl serine ethyl ester
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Paragraph 0016; 0017; 0019; 0027, (2021/02/06)
The invention provides a preparation method of (2S, 3R)-p-methylsulfonylphenyl serine ethyl ester. The preparation method comprises the following steps: dissolving p-methylsulfonyl benzaldehyde and 2-halogenated ethyl acetate serving as raw materials in a solvent A to prepare (2R, 3R)-2-halogen-3-hydroxy-3-(4-methylsulfonyl) phenyl ethyl propionate under the action of a catalyst A, substituting halogen atoms with azide, and performing catalytic hydrogenation reduction to prepare (2S, 3R)-p-methylsulfonyl phenyl serine ethyl ester; or using p-methylsulfonyl benzaldehyde and 2-halogenated ethylacetate as raw materials and dissolving in a solvent B, and preparing (2S, 3S)-2-halogen-3-hydroxy-3-(4-methylsulfonyl) phenyl ethyl propionate under the action of a catalyst B, substituting halogen atoms with benzamide, and preparing (2S, 3R)-p-methylsulfonyl phenyl serine ethyl ester through cyclization, configuration transformation and hydrolysis. The preparation method is high in product purity and high in yield.
Synthesis method of D-p-methylsulfonylphenyl serine ethyl ester
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Paragraph 0008-0009, (2020/01/25)
The invention discloses a synthesis method of D-p-methylsulfonyl phenyl serine ethyl ester. The method comprises the following steps: preparing p-methylsulfonylphenylserine copper by taking p-methylsulfonylbenzaldehyde, copper sulfate and glycine as main raw materials; then adding anhydrous ethanol and concentrated sulfuric acid into an esterification reaction kettle, carrying out heating for a reaction, filtering out copper sulfate while the solution is hot, carrying out cooling for crystallizing, and carrying out filtering to obtain DL p-methylsulfonylphenyl serine ethyl ester sulfate, dissolving the DL p-methylsulfonylphenyl serine ethyl ester sulfate into water, removing copper ions by using a saturated sodium sulfide solution, adding an alkali into the mother solution for dissociationto obtain DL p-methylsulfonylphenyl serine ethyl ester, and adding a resolving agent for resolving to obtain a product. The method is simple in process, high in yield, low in cost and small in environmental pollution and is suitable for enterprise production.
