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Method for separating mixed methyl cyclohexane diacid

A technology of methylcycloadipic acid and cycloadipic acid, which is applied in the separation/purification of carboxylic acid compounds, organic chemistry and other directions, can solve the problems of difficult separation, high cost, difficult separation, etc., and achieves good repeatability and recovery. High rate, good for industrial amplification

Active Publication Date: 2010-06-09
ZHEJIANG UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] 3-Methyl-1,2-cyclohexanedioic acid and 4-methyl-1,2-cyclohexanedioic acid are important intermediates in the pharmaceutical industry. Generally, 3-methyl-1,2-cyclohexanedi Acid or 4-methyl-1,2-cyclohexanedioic acid are synthesized from isoprene or pentadiene and the cost is relatively expensive
[0006] However, the physical properties of 3-methyl-1,2-cyclohexanedioic acid and 4-methyl-1,2-cyclohexanedioic acid are very similar, with a melting point of 168°C, and it is very difficult to separate them, even for their anhydrides. Since the boiling point is close to 120°C, it is also not easy to separate
Therefore, there is no report on the separation of 3-methyl-1,2-cyclohexanedioic acid and 4-methyl-1,2-cyclohexanedioic acid

Method used

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  • Method for separating mixed methyl cyclohexane diacid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036] The mixture comes from a chemical plant in Shangyu, and the contents of the two acids are 50wt% (3-methyl-1,2-cyclohexanedioic acid) and 48wt% (4-methyl-1,2-cyclohexanedioic acid) respectively. adipic acid).

[0037] In a 250ml round bottom flask equipped with a condensing reflux tube, add 9.6g (0.1mol) of 3-aminopyridine, 38g of the mixture and 200ml of methanol, heat to reflux for 0.5h while stirring, and cool to room temperature. After standing for 2 days, the white crystal crude product was obtained, filtered, and the filtrate A was retained, the filter cake A was recrystallized with enough methanol to dissolve the filter cake A, filtered, washed 3 times with methanol (3×50ml), and naturally dried in the air to obtain a white compound crystals.

[0038] Dissolve the above white complex crystals in 50ml of 1N hydrochloric acid, adjust the pH value to 7.0, let it stand for precipitation, and filter to obtain filter cake B and filtrate B. Filter cake B was washed wit...

Embodiment 2

[0042] The mixture comes from a chemical plant in Shangyu, and the contents of the two acids were tested to be 65wt% (3-methyl-1,2-cyclohexanedioic acid), 32wt% (4-methyl-1,2-cyclohexanedioic acid) adipic acid)

[0043]In a 500ml round bottom flask equipped with a condensing reflux tube, add 18.8g of 3-picoline, 60g of the mixture and 400ml of methanol respectively, heat to reflux for 0.3h while stirring, and cool to room temperature. After standing for 2 days, the white crystal crude product was obtained, filtered, the filtrate A was retained, the filter cake A was recrystallized with enough ethanol to dissolve the filter cake A, filtered, washed with ethanol 3 times (3×50ml), and naturally dried in the air to obtain a white complex crystals.

[0044] Dissolve the above white complex crystals in 90ml of 1N hydrochloric acid, adjust the pH value to 7.0, let it stand for precipitation, and filter to obtain filter cake B and filtrate B. Filter cake B was washed with 20 ml of s...

Embodiment 3

[0048] The mixture comes from a chemical plant in Shangyu, and the contents of the two acids are 55wt% (3-methyl-1,2-cyclohexanedioic acid) and 43wt% (4-methyl-1,2-cyclohexanedioic acid) respectively. adipic acid)

[0049] In a 2000ml round bottom flask equipped with a condensing reflux tube, add 80g of pyridine, 180g of the mixture and 1500ml of water, heat to reflux for 0.3h under stirring, and cool to room temperature. After standing for 2 days, the white crystal crude product was obtained, filtered, the filtrate A was retained, the filter cake A was recrystallized with enough water to dissolve the filter cake A, filtered, washed with water 3 times (3×50ml), and naturally dried in the air to obtain a white complex crystal .

[0050] Dissolve the above-mentioned white complex crystal in 130ml of 1N hydrochloric acid, adjust the pH value to 7.0, let it stand for precipitation, and filter to obtain filter cake B and filtrate B. Filter cake B was washed with 40 ml of saturate...

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Abstract

The invention discloses a method for separating a mixed methyl cyclohexane diacid, comprising the following steps of: (1) dissolving the mixed methyl cyclohexane diacid into a resolving solvent; adding an organic amines compound; heating and refluxing to completely react under stirring; cooling reaction liquid to 0-30 DEG C after reaction; standing for separating out crystals; filtering to obtain a filter cake A and filter liquor A, wherein a 4-methyl-1, 2-cyclohexane diacid is retained in the filter liquor A, the filter cake A is a rough crystal of a 3-methyl-1, 2-cyclohexane diacid, the organic amines compound is 2-aminopyridine, 3-aminopyridine, pyridine and 2-methylpyridine or 3-methylpyridine, and the resolving solvent is methanol and ethanol or water. Compared with the prior art, the invention has higher resolution efficiency, needs only once crystallization, can achieve the yield coefficient of each acid between 80 percent and 95 percent and the purity between 93 percent and 99 percent, has simple separation method, low implement cost and good repeatability and is beneficial to industrial scale-up.

Description

(1) Technical field [0001] The invention relates to a method for separating 3-methyl-1,2-cyclohexanedioic acid and 4-methyl-1,2-cyclohexanedioic acid mixture by inclusion method. (2) Background technology [0002] 3-Methyl-1,2-cyclohexanedioic acid and 4-methyl-1,2-cyclohexanedioic acid are important intermediates in the pharmaceutical industry. Generally, 3-methyl-1,2-cyclohexanedi Acid or 4-methyl-1,2-cyclohexanedioic acid are synthesized from isoprene or pentadiene, and the cost is relatively expensive. [0003] Mixed pentadiene and butenedioic anhydride are catalyzed to synthesize methyltetrahydrophthalic anhydride, then hydrogenated and then hydrolyzed to obtain mixed methylcyclohexanedioic acid, which contains 3-methyl-1,2-cyclohexanedioic acid and 4 -Methyl-1,2-cyclohexanedioic acid, as shown in the following reaction formula: [0004] [0005] If a single 3-methyl-1,2-cyclohexanedioic acid or 4-methyl-1,2-cyclohexanedioic acid can be separated from mixed methylc...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C61/08C07C51/43
Inventor 金志敏徐威王平平王聪
Owner ZHEJIANG UNIV OF TECH
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