Unlock instant, AI-driven research and patent intelligence for your innovation.

Preparation method for low-residue lipoic acid

A lipoic acid and low-residue technology, applied in the direction of organic chemistry, can solve the problems of reducing the total yield and increasing costs, and achieve the effects of increasing product yield, improving product quality, and reducing costs

Active Publication Date: 2012-11-28
上海津力药业股份有限公司
View PDF10 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For this reason, it has been reported that the lipoic acid product after the recrystallization is further ansolvated (US6462202), but this will inevitably reduce the total yield and increase the cost

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Preparation method for low-residue lipoic acid
  • Preparation method for low-residue lipoic acid
  • Preparation method for low-residue lipoic acid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0049] A preparation method of low-residue lipoic acid, the method comprising the following steps:

[0050] Add 20ml of water and 4.0 grams of NaOH (0.1mol) in the three-necked flask, stir to dissolve, add 10ml of 95% ethanol and 24.1 grams (0.1mol) of ethyl 6,8-dichlorooctanoate, when the pH of the reaction system drops from> 12 When pH ≈ 8, the saponification reaction is over; add 70ml of water, add 4.8g (0.15mol) of sulfur, heat up to 80±2°C, add dropwise a solution of 26.4g of sodium sulfide nonahydrate (0.11mol) in 110ml of water, about 1.5 After hours drop, the reaction solution was dark brown, and 18.9 grams of composite reducing agent (Na 2 SO 3 ·NaHSO 3 ·Na 2 S 2 o 3 ) solution in 75ml of water, the temperature of the system was reduced to 60-65°C, stirred for about 3 hours, added 1.5 grams of activated carbon, filtered after cooling slightly, and the filtrate was acidified to pH ≈ 2 with 10wt% dilute hydrochloric acid at 0-10°C At this time, a large number of w...

Embodiment 2

[0053] A preparation method of low-residue lipoic acid, the method comprising the following steps:

[0054] Add 20ml of water and 4.0g of NaOH (0.1mol) into the three-necked flask, stir to dissolve, add 20ml of 95% ethanol and 24.1g (0.1mol) of ethyl 6,8-dichlorooctanoate and stir at 50±2°C for saponification React until the pH of the system drops from 12 to about 8, add 70ml of water, add 3.52 grams (0.11mol) of sulfur, heat up to 80±5°C, add dropwise a solution of 31.2 grams of sodium sulfide nonahydrate (0.13mol) in 110ml of water, After dripping in about 2 hours, heat for another 2 hours, add 16.87 grams of composite reducing agent (2Na 2 SO 3 ·Na 2 S 2 o 3 ) solution in 75ml of water, stirred and reacted at 50-55°C for 3 hours, added 1.5 grams of activated carbon, filtered while hot, and the filtrate was acidified to pH ≈ 2 with 5wt% dilute hydrochloric acid at 0-10°C, filtered, and the filter cake was watered Rinse, drain, and dry at <35°C to obtain crude lipoic aci...

Embodiment 3

[0057] A preparation method of low-residue lipoic acid, the method comprising the following steps:

[0058] Add 20ml of water and 4.8 grams of NaOH (0.12mol) in the there-necked flask, stir to dissolve, add 10ml of 95% ethanol and 24.1 grams (0.1mol) of ethyl 6,8-dichlorooctanoate, when the pH of the reaction system drops from> 12 To pH ≈ 8, the saponification reaction is over; add 70ml of water, add 6.4 grams (0.2mol) of sulfur, heat up to 70±5°C, add dropwise a solution of 48 grams of sodium sulfide nonahydrate (0.2mol) in 110ml of water, about 3 Hour drop is finished, and this moment reaction solution is dark brown, adds 25 gram composite reductive agents (Na 2 SO 3 2NaHSO 3 ) solution in 75ml of water, stirred and reacted at 100°C for about 2 hours, added 1.5 grams of activated carbon, filtered after cooling slightly, and the filtrate was acidified to pH ≈ 2 with 10wt% dilute hydrochloric acid at 0-10°C, and a large amount of white When light yellow crystals are precipi...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention relates to a preparation method for low-residue lipoic acid, which comprises the following steps: taking 6,8-dichloro-ethyl octylate as a raw material and water as a solvent; subjecting the mixture to saponification, vulcanization reactions, conversion reaction of S-3 acid and acidizing reaction to obtain lipoic acid cruse products; and refining the lipoic acid cruse products to obtain the low-residue lipoic acid. Compared with the prior art, the preparation method has reasonable process, and takes the 6,8-dichloro-ethyl octylate as the raw material and the water as the solvent without using other solvents except extremely-less ethanol, thereby greatly reducing the environment pollution, embodying green synthezation and reducing the cost of products; by adopting a composite reducer, the byproduct S-3 acid is converted into the lipoic acid, thereby greatly improving the yield of the products and the quality of the products; and the mole yield of the products reaches more than or equal to 70 percent, the content of the products reaches 99 percent, and the residual content of the solvents (methylbenzene, cyclohexanone, ethyl acetate and the like) is nearly equal to 0 ppm.

Description

technical field [0001] The invention relates to bioengineering and medical technology, in particular to a preparation method of low-residue lipoic acid. Background technique [0002] Lipoic acid, also known as α-lipoic acid, its English name is α-Lipoic acid (or 1,2-Dithiolane-3-pentanoic acid), and its chemical name is 1,2-dithiolane-3-pentanoic acid. CAS is: [1077-28-7], molecular formula is C 8 h 14 o 2 S 2 , the structural formula is as follows: [0003] [0004] There is a chiral center in the structure of lipoic acid, so its racemate is also called DL-lipoic acid (abbreviated as lipoic acid). After splitting, optically active R(+)-α-lipoic acid and S( -)-alpha-lipoic acid. [0005] α-lipoic acid is a light yellow crystal that is insoluble in water, and widely exists in biological tissues such as animals and plants. It was first isolated from pig liver by Reed et al. in the United States in 1950. Lipoic acid contains a disulfide five-membered ring structure, w...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C07D339/04
Inventor 潘朝阳李三运戴龙华徐峰杨忠愚胡惟孝
Owner 上海津力药业股份有限公司