Process for production of optically active organic carboxylic acid

An organic carboxylic acid, optically active technology, applied in organic chemical methods, preparation of organic compounds, preparation of carboxylates, etc., can solve the problems of low enantiomeric excess rate, time-consuming and labor-intensive, etc. Effect of Conform Excess Rate

Inactive Publication Date: 2013-12-11
MITSUBISHI GAS CHEM CO INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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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 off.

[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

The present invention is a simple method, in which a specific amount of alkali is added to an enantiomeric mixture of an optically active organic carboxylic acid where enantiomers are present in a non-equimolar ratio, or in which the enantiomeric mixture of an optically active organic carboxylic acid is neutralized with an alkali, and then a specific amount of acid is added thereto, thereby separating an organic carboxylic acid salt in the mother liquor and a crystallized organic carboxylic acid from each other. The method makes it possible to obtain an optically active organic carboxylic acid with improved enantiomeric excess. The present invention provides a simple production method for obtaining an optically active organic carboxylic acid with improved enantiomeric excess from an enantiomeric mixture of an optically active organic carboxylic acid where enantiomers are present in a non-equimolar ratio.

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