- Method for preparing florfenicol intermediate and compound obtained by method
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The invention belongs to the technical field of chemical synthesis and provides a method for preparing a florfenicol intermediate. The method comprises the steps: carrying out a reaction of p-methylthiobenzaldehyde with isocyanoacetate under the catalysis of a chiral catalyst, oxidizing a chiral catalytic product to obtain a methylsulfonyl substituted product, and removing formyl from the methylsulfonyl substituted product to obtain the florfenicol intermediate. According to the preparation method, the chiral center of the intermediate is directly generated through the first-step reaction, theyield of the product in the first step reaches 75-80% and is remarkably higher than the yield obtained through a conventional chiral resolution method (the yield is about 40%), and the chiral purityof the product is high. According to the method, anhydrous cupric sulfate which pollutes the environment is not used, so that the environmental pressure is reduced. In addition, two compounds comprising p-methylthiobenzaldehyde and isocyanoacetate are adopted to react to synthesize the chiral intermediate, so that the material utilization rate and the synthesis efficiency are higher than those ofa linear synthesis means.
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Paragraph 0084; 0093-0096
(2020/07/08)
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- Stereoselective synthesis of (-)-chloramphenicol, (+)-thiamphenicol and (+)-sphinganine via chiral tricyclic iminolactone
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The stereoselective syntheses of (-)-chloramphenicol, (+)-thiamphenicol and (+)-sphinganine are described. The two continuous chiral centers within three target molecules were constructed through aldol reaction of chiral tricyclic iminolactone and aldehyde. Concise and efficient syntheses of (-)-chloramphenicol, (+)-thiamphenicol and (+)-sphinganine have been accomplished in practical four or three steps. The synthetic route featured in an aldol reaction between iminolactone 1a and 1b with aldehyde, which introduced the two continuous chiral centers within three target molecules. Copyright
- Li, Qiong,Zhang, Hongbo,Li, Chenguang,Xu, Pengfei
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p. 149 - 153
(2013/08/24)
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