Preparing method of (R)-(-)-4-chloromandelic acid

A technology of chloromandelic acid and R-4-, which is applied in the field of chemical separation and preparation of chiral compounds, can solve the problems such as unreported preparation methods of R-4-chloromandelic acid, and achieves high separation efficiency and simple operation. , mild conditions

Inactive Publication Date: 2015-11-25
彭静
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

There is no report about the preparation method of R-4-chloromandelic acid at present

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0008] (1) Resolution of 4-chloromandelic acid

[0009] In a 500ml round bottom flask, add 400ml of methanol and 18.7g of racemic 4-chloromandelic acid, start stirring and heat up. Add 18.0 g of R-1-naphthylethylamine dropwise to the system at 50°C. After the dropwise addition was completed, the reaction was refluxed for 1.5 hours, cooled to room temperature, and a white solid was precipitated, which was filtered to obtain 16.3 g of R-1-naphthylethylamine salt of crude R-4-chloromandelic acid. Add 16.3 g of the obtained R-1-naphthylethylamine salt of R-4-chloromandelic acid into 160 ml of methanol solution, heat up to dissolve, and wait for the solid to completely dissolve, then lower the temperature to 0°C, and dissolve the crystalline solid Filtration was performed to obtain 14.4 g of R-1-naphthylethylamine salt of R-4-chloromandelic acid after purification.

[0010] (2) Acid hydrolysis of salt to obtain R-4-chloromandelic acid

[0011] Dissolve 14.4 g of R-1-naphthylethy...

Embodiment 2

[0015] (1) Resolution of 4-chloromandelic acid

[0016] Add 300ml of ethanol and 18.7g of racemic 4-chloromandelic acid into a 500ml round bottom flask, start stirring, raise the temperature, and add 20.0g of R-1-naphthylethylamine dropwise to the system at 55°C. After the dropwise addition was completed, react under reflux conditions for 1.0 hour, then cool down to room temperature, and a white solid precipitated out. After filtration, 15.6 g of crude product R-1-naphthylethylamine salt of R-4-chloromandelic acid was obtained. Add 15.6 g of the obtained R-1-naphthylethylamine salt of R-4-chloromandelic acid into 150 ml of ethanol solution, raise the temperature to dissolve, wait for the solid to completely dissolve, then lower the temperature to 0°C, and crystallize The solid was filtered to obtain 14.2 g of refined R-1-naphthylethylamine salt of R-4-chloromandelic acid.

[0017] (2) Acid hydrolysis of salt to obtain R-4-chloromandelic acid

[0018] Dissolve 14.2 g of R-1-n...

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Abstract

The invention discloses a preparing method of (R)-(-)-4-chloromandelic acid through resolution by taking (R)-(+)-1-(1-naphthyl)ethylamine as a chiral resolution agent. 4-chloromandelic acid and the chiral resolution agent (R)-(+)-1-(1-naphthyl)ethylamine react in a suitable alcohol solvent to generate (R)-(+)-1-(1-naphthyl)ethylamine salt of the 4-chloromandelic acid, by using different solubilities of an enantiomer salt, crystallizing and suction filtration are performed to obtain the (R)-(+)-1-(1-naphthyl)ethylamine salt of the (R)-(-)-4-chloromandelic acid, and after salt recrystallization, the (R)-(-)-4-chloromandelic acid can be obtained by acidizing; after the solution containing the (R)-(+)-1-(1-naphthyl)ethylamine is combined, alkalization treatment is performed, the resolution agent (R)-(+)-1-(1-naphthyl)ethylamine can be recycled. The preparing method has the characteristics of mild conditions, simple operation, good product yield and high optical purity. The resolution agent can be recycled for use, and is extremely suitable for industrial production of (R)-(-)-4-chloromandelic acid.

Description

technical field [0001] The invention relates to a method for preparing chiral compounds by chemical resolution, in particular to a method for preparing R-4-chloromandelic acid by using R-1-naphthylethylamine as a resolving agent. Background technique [0002] 4-Chloromandelic acid has two enantiomeric configurations of R-type and S-type, and is widely used in many fields such as pharmaceutical production, asymmetric synthesis, and optical resolution. There is no report about the preparation method of R-4-chloromandelic acid at present. Therefore, the preparation of R-4-chloromandelic acid is a problem to be solved in the present invention. Contents of the invention [0003] The present invention adopts R-1-naphthylethylamine as a resolving agent, and can successfully realize the resolution and preparation of R-4-chloromandelic acid. The operation of the invention is as follows: the present invention is in a suitable alcohol solvent, R-1-naphthylethylamine is a chiral res...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C51/487C07C51/42C07C59/56
CPCC07C51/487C07B57/00C07B2200/07C07C51/42C07C59/56
Inventor 彭静
Owner 彭静
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