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Asymmetric hydrogenation synthesis method of d pantolactone under a kind of ionic liquid condition

An ionic liquid, asymmetric technology, applied in the field of asymmetric hydrogenation to synthesize D-pantolactone, can solve the problems of low catalytic activity and unsatisfactory enantioselectivity

Active Publication Date: 2017-05-24
广州骊加生物科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Studies have shown that for the asymmetric hydrogenation of ketopantolactone, chiral catalysts often show high catalytic activity and enantioselectivity in weakly polar solvents, such as benzene or toluene, and are currently widely used The imidazole-type ionic liquid used in the asymmetric hydrogenation reaction is generally insoluble in weak polar solvents such as benzene and toluene, and the catalytic reaction is generally carried out in a two-phase system, but due to the limitation of the mass transfer resistance of the two-phase system, it is often asymmetric The catalytic activity of the hydrogenation reaction is low, and the enantioselectivity is not ideal

Method used

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  • Asymmetric hydrogenation synthesis method of d pantolactone under a kind of ionic liquid condition
  • Asymmetric hydrogenation synthesis method of d pantolactone under a kind of ionic liquid condition
  • Asymmetric hydrogenation synthesis method of d pantolactone under a kind of ionic liquid condition

Examples

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Effect test

Embodiment 1

[0020] [Rh]-3([Rh]=[Rh(COD)Cl] 2 ; 1 =Boc) / [CH 3 (EO) 16 TMG] SO 3 CH 3 Asymmetric hydrogenation of ketopantolactone in / benzene system

[0021] Add rhodium catalyst precursor [Rh(COD)Cl] in a stainless steel autoclave under argon or nitrogen atmosphere 2 , chiral bisphosphine ligand 3(R 1 =Boc), polyether alkylguanidine salt ionic liquid [CH 3 (EO) 16 TMG] SO 3 CH 3 , ketopantolactone and benzene, the mol ratio of 3 and Rh is 1.1:1, the mass ratio of ionic liquid and rhodium catalyst precursor is 500:1, and the mol ratio of ketopantolactone and Rh is 100:1, The volume ratio of benzene to ionic liquid is 4:1, replace the air with nitrogen or argon 4-6 times, then pressurize with hydrogen to 5.0MPa, react at 50°C for 4 hours, then quickly cool to room temperature, and release the hydrogen, Remove benzene under reduced pressure, add methyl tert-butyl ether to extract twice, the volume ratio of methyl tert-butyl ether and benzene is 1:1, the system is divided into two ...

Embodiment 2

[0023] [Rh]-5([Rh]=[Rh(COD)Cl] 2 ; 3 =Cp) / [CH 3 (EO) 16 TMG] SO 3 CH 3 Asymmetric hydrogenation of ketopantolactone in / toluene system

[0024] The reaction conditions and steps are the same as in Example 1, except that the solvent is replaced by toluene, the molar ratio of ketopantolactone to Rh is 200:1, the hydrogen pressure is 0.1 MPa, the reaction temperature is 25°C, and the reaction time is 2h. Analysis by gas chromatography showed that the conversion rate of ketopantolactone was 97.5%, and the ee value of D-pantolactone was 92.2%.

Embodiment 3

[0026] [Rh]-3([Rh]=[Rh(COD)Cl] 2 ; 1 is the amino acid side chain, X=CF 3 COO - , m=0, n=1, its stereo configuration is S type) / [CH 3 (EO) 16 TMG] SO 3 CH 3Asymmetric hydrogenation of ketopantolactone in / benzene system

[0027] Reaction condition and step are with embodiment 1. Analysis by gas chromatography showed that the conversion rate of ketopantolactone was 76.4%, and the ee value of D-pantolactone was 57.5%.

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Abstract

The invention relates to a method for synthesizing D-pantolactone through asymmetric hydrogenation under an ionic liquid condition. The method adopts a homogeneous-phase asymmetric hydrogenation system which is composed of a chiral catalyst formed by chiral diphosphine ligand and a rhodium catalyst, a polyether alkyl guanidine salt ionic liquid, ketopantolactone and benzene or toluene; and asymmetric hydrogenation is carried out a certain reaction temperature and hydrogen pressure. According to the method provided by the invention, the immobilization effect of the ionic liquid on the chiral catalyst is utilized, separation and circulation of the chiral catalyst are realized through simple liquid-liquid separation, and the chiral catalyst can be cyclically used for a plurality of times; and the conversion rate of pantolactone or stereoselectivity of D-pantolactone is not obviously decreased.

Description

technical field [0001] The invention relates to the technical field of chemistry and chemical engineering, in particular to a method for synthesizing D-pantolactone by asymmetric hydrogenation under ionic liquid conditions. Background technique [0002] Calcium D-pantothenate is an important food, feed additive and pharmaceutical raw material. At present, the demand for calcium D-pantothenate in the world is increasing year by year, and the supply of products is in short supply. The key to preparing D-calcium pantothenate and pantothenic acid series products is the synthesis and chiral resolution technology of its precursor D-pantolactone (abbreviated as D-pantolactone). [0003] At present, most enterprises in the domestic food and feed additive industry are still using the isobutyraldehyde-formaldehyde-hydrocyanic acid process developed in the 1960s to produce DL-pantolactone, and then prepare D-pantolactone by chiral resolution , the technology is backward, the pollution...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D307/33C07B53/00B01J31/24
CPCY02P20/584
Inventor 金欣李淑梅崔菲菲
Owner 广州骊加生物科技有限公司