Process for production of optically active organic carboxylic acid

An organic carboxylic acid and optically active technology, which is applied in the direction of organic chemical methods, the preparation of organic compounds, and the preparation of carboxylate, can solve the problems of low enantiomeric excess rate, time-consuming and laborious, etc., and achieve the improvement of enantiomeric The effect of conformational excess ratio

Inactive Publication Date: 2011-09-28
MITSUBISHI GAS CHEM CO INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, generally speaking, most of the other optically active substances have a low enantiomeric excess rate, and it will take time and effort to effectively recover them in this case.

Method used

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  • Process for production of optically active organic carboxylic acid
  • Process for production of optically active organic carboxylic acid
  • Process for production of optically active organic carboxylic acid

Examples

Experimental program
Comparison scheme
Effect test

manufacture example 1

[0065] Asymmetric Esterification of 6-Hydroxy-2,5,7,8-Tetramethylchroman-2-Carboxylic Acid

[0066] 100 g (399.5 mmol) of raw materials 6-hydroxyl-2,5,7,8-tetramethylchroman-2-carboxylic acid, 60 g of methanol, and 1,500 g of isopropyl ether were added to a 5 L stainless steel pressure vessel. 40 g of immobilized enzyme Novozym 435 (manufactured by Novozymes) as a symmetric esterification catalyst was replaced with argon, and reacted at 80° C. for 24 hours. After 24 hours, the catalyst was removed by filtration, and the reaction solution was recovered. Analyzing the reaction solution, the transformation rate of raw material 6-hydroxyl-2,5,7,8-tetramethylchroman-2-carboxylic acid is 45.0mol%, S-(-)-6-hydroxyl-2,5,7 , The optical purity of methyl 8-tetramethylchroman-2-carboxylate was 99% ee. On the other hand, the optical purity of R-(+)-6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid was 81%ee. In addition, the analysis of optical purity was performed by high perform...

Embodiment 1

[0068](1) recovery of unreacted 6-hydroxyl-2,5,7,8-tetramethylchroman-2-carboxylic acid

[0069] Add 219.7ml (399.5mmol÷10×(1-0.45)=21.97mmol) of 0.1N sodium hydroxide to 10 aliquots of the above-mentioned reaction solution to make unreacted 6-hydroxyl-2,5,7,8-tetra Methylchroman-2-carboxylic acid was removed as a sodium salt and recovered as an aqueous layer.

[0070] (2) Recovery of R-(+)-6-hydroxyl-2,5,7,8-tetramethylchroman-2-carboxylic acid

[0071] The water layer recovered in the above (1) was added to a 500mL glass container, and while heating and stirring at 50°C, 4.17ml (21.97mmol×(100- 81) / 100=4.17mmol), and the free primary crystal was filtered out. Next, the remaining 17.80 ml of 1N hydrochloric acid was added to the obtained filtrate, and free secondary crystals were filtered off.

[0072] The yield of one crystallization was 0.95 g, and the optical purity of R-(+)-6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid in the crystal was 7.4%ee.

[0073] The ...

Embodiment 2

[0075] The water layer recovered in (1) of Example 1 was added to a 500mL glass container, and while heating and stirring at 50°C, 4.05ml (21.97ml× (100-81) / 100×0.97 times), the free primary crystals were filtered out. Next, the remaining 17.92 ml of 1N hydrochloric acid was added to the obtained filtrate, and free secondary crystals were filtered out.

[0076] The yield of one crystallization was 0.80 g, and the optical purity of R-(+)-6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid in the crystal was 2.7%ee.

[0077] The yield of the second crystallization was 4.63 g, and the optical purity of R-(+)-6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid in the crystal was 95.4%ee. The results are shown in Table 1.

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Abstract

Provided is a simple and easy process for the production of an optically active organic carboxylic acid. The simple and easy process comprises: either adding a specific amount of an alkali to an optically active enantiomer mixture which consists of enantiomers of an organic carboxylic acid and which has a difference between the molar proportions of the enantiomers, or neutralizing such a mixture with an alkali and adding a specific amount of an acid to the neutralized mixture; and then separating an organic carboxylic acid salt which is present in the mother liquor from an organic carboxylic acid which has been precipitated as a crystalline substance. The simple and easy process enables the production of an optically active organic carboxylic acid having an enhanced enantiomeric excess. Thus, the invention provides a simple and easy process for producing an optically active organic carboxylic acid having an enhanced enantiomeric excess from an optically active enantiomer mixture which consists of enantiomers of an organic carboxylic acid and which has a difference between the molar proportions of the enantiomers.

Description

technical field [0001] The present invention relates to techniques for increasing the enantiomeric excess of optically active organic carboxylic acids. Optically active organic carboxylic acids are very useful as raw materials for the synthesis of chemical substances requiring chirality, such as medicines and agricultural chemicals. Background technique [0002] Since optically active organic carboxylic acids are important synthetic intermediates such as pharmaceutical intermediates and functional chemicals, various methods for obtaining optically active compounds from racemates have been proposed. As such a method for obtaining an optically active substance from a racemate, there are a preferential crystallization method, a diastereoisomer method, an enzymatic method, a chromatography method, and the like. [0003] The preferential crystallization method is a method in which desired crystals are seeded into a supersaturated solution of a racemate, and only the crystals are...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C53/134C07D311/66C07C51/487C07B57/00C07C51/43
CPCC07B2200/07C07C51/487C07B57/00C07D311/66C07C53/134
Inventor 久古阳一
Owner MITSUBISHI GAS CHEM CO INC
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