CN105622397A - Purification method of dehydroabietic acid - Google Patents

Abstract

The invention relates to a method for purifying dehydroabietic acid, which belongs to the field of chemical industry. The method of the present invention mixes disproportionated rosin and absolute ethanol to open a special field, slowly adds 2-ethanolamine in the amount of disproportionated rosin to react, and adds water isothermal and equal to the solvent after the reaction is completed. After crystallization for a certain period of time, the ether layer was extracted with preheated petroleum ether while it was hot, the ether layer was colorless, cooled and crystallized, and filtered with suction to obtain the rough body of dehydroabietic acid ethanolamine salt; recrystallized with ethanol to obtain dehydroabietic acid ethanolamine salt crystals; the amine salt Soluble in ethanol, acidify with hydrochloric acid to pH<4, add appropriate amount of distilled water to crystallize, cool and filter with suction to obtain crude dehydroabietic acid, recrystallize with ethanol for 1 to 4 times, filter and dry to obtain dehydroabietic acid crystals. The method of the invention has lower reaction temperature, shorter reaction time, energy saving, less recrystallization time and recrystallization times, shortens the entire reaction cycle, and the product purity is as high as 98%.

Description

A kind of purification method of dehydroabietic acid

technical field

The invention relates to a method for purifying dehydroabietic acid, in particular to a method for purifying dehydroabietic acid assisted by a special field, and belongs to the field of chemical industry.

Background technique

For nearly half a century, the utilization of rosin has been continuously developed from primary products to deep-processed products. Disproportionated rosin is a modified product with a large output and a wide range of uses among rosin deep-processing products. It has the characteristics of high thermal stability, good oxidation resistance, light color, and low brittleness. It has a wide range of applications in industries such as surfactants and fine chemicals, and has achieved considerable results.

Dehydroabietic acid is one of the main components of disproportionated rosin. It is stable in nature and has a large specific rotation. It is a stable structure containing a tricyclic phenanthrene skeleton structure and a carboxyl group. The benzene ring contains isopropyl group in its structure. The special structure makes dehydroabietic acid widely used in medicine, surfactant and fine chemicals. Although dehydroabietic acid is widely used, it is present in disproportionated rosin in the form of a mixture, and dihydroabietic acid and tetrahydroabietic acid in disproportionated rosin also have similar chemical structures with dehydroabietic acid, so It is difficult to separate dehydroabietic acid monomer by conventional physical methods.

Molecular formula of dehydroabietic acid

At present, there are roughly four techniques for separating dehydroabietic acid:

(1) Saponification: saponification method isolating dehydroabietic acid is mainly to separate neutral matter from disproportionated rosin, and then according to the difference in acidity of resin acid, acidify in stages, and separate by controlling pH value.

(2) Conventional amination method: the amination method uses disproportionated rosin as raw material to heat up to 70°C, add an appropriate amount of 2-ethanolamine, and then add an appropriate amount of water at 70-80°C, extract with isooctane, and pump the solution after cooling. Filter the crystals, dissolve and recrystallize with 50% ethanol several times, add hydrochloric acid for reduction to obtain dehydroabietic acid, and recrystallize with 75% ethanol solution to obtain high-purity dehydroabietic acid.

(3) Ultrasonic-enhanced amination reaction crystallization coupling: Ultrasonic-enhanced amination reaction is mainly to strengthen the reaction between disproportionated rosin and 2-ethanolamine. Adding the special field of ultrasonic wave makes the pressure and temperature increase, the solution viscosity and surface tension decrease, and the intermolecular Collisions are more frequent, promoting the rapid completion of the entire crystallization process.

(4) Microwave-enhanced amination reaction crystallization coupling: Microwave-enhanced amination reaction is consistent with the auxiliary effect of ultrasonic waves. Microwave heating speeds up the reaction speed, reduces the activation energy of the reaction, and reduces the reaction temperature, which can shorten the entire recrystallization process. Purification cycle, and improve product purity and yield.

Contents of the invention

In order to solve the shortcomings of high reaction temperature, long time, low yield, low purification, and inability to be used in large quantities for industrialization in the purification of dehydroabietic acid, the present invention provides a method for purifying dehydroabietic acid, which specifically includes The following steps:

(1) Add disproportionated rosin to absolute ethanol at a ratio of 0.1-1g/mL, mix and dissolve in a special field at 50-70°C, cool to room temperature, and obtain a mixed solution;

(2) Turn on the special field, slowly add 2-ethanolamine to the mixed solution for reaction, wherein the molar ratio of 2-ethanolamine to disproportionated rosin is 1:1~3:1, the reaction temperature is 50~75°C, and the reaction time is 5~20min After the reaction, add water isothermal and equivalent to absolute ethanol, after rapid crystallization, extract while hot with preheated petroleum ether until the ether layer is colorless, cool and crystallize the lower layer extract, and obtain dehydroabietic acid ethanolamine by suction filtration salt bold;

(3) Recrystallize the crude ethanolamine salt of dehydroabietic acid with 10-80% ethanol under the assistance of a special field for 1 to 4 times to obtain ethanolamine salt of dehydroabietic acid; Hydroabietic acid ethanolamine salt is added in 10 ~ 80% ethanol solution, wherein, the amount of the ethanol is the same as the amount of absolute ethanol added in step (1);

(4) The solution obtained in step (3) is acidified with hydrochloric acid with a mass percentage of 1-15% to pH<4, crystallized by adding distilled water, cooled and suction filtered to obtain the crude product of dehydroabietic acid, and the crude product of dehydroabietic acid is washed with hot distilled water Wash 1~3 times;

(5) With the help of a special field, the crude dehydroabietic acid is recrystallized 1 to 4 times with 50-95% ethanol, and the crystallization time is 12-70 hours each time;

(6) Suction filtration and drying to obtain dehydroabietic acid crystals.

The special field is an auxiliary field for microwave and ultraviolet integration, the microwave power is 1-1000W, the microwave power is adjusted according to the required temperature, and the ultraviolet power is 300W.

Preferably, the drying process conditions in step (8) of the present invention are: vacuum drying at 50-100° C. for 0.5-3 hours.

Compared with prior art, the beneficial effect of the present invention:

(1) The present invention uses special field assistance throughout the experimental process including the reaction and dissolution heating process. Compared with the prior art, the amination reaction temperature in the present invention is lower.

(2) The present invention uses special field assistance in the process of amination reaction. Compared with the prior art, the present invention has shorter amination reaction time and faster crystallization, which significantly shortens the entire purification cycle.

(3) Compared with the existing method, the present invention has relatively higher yield and purity, reduces the reaction temperature, shortens the reaction cycle, and obtains a product with higher purity.

detailed description

The present invention will be described in further detail below in conjunction with the examples, but the protection scope of the present invention is not limited to the content.

Example 1

(1) Add disproportionated rosin to absolute ethanol at a ratio of 0.5g/ml, mix and dissolve under the auxiliary field of microwave and ultraviolet integration at 60°C, and cool to room temperature to obtain a mixed solution;

(2) Turn on the auxiliary field for microwave-ultraviolet integration, slowly add 2-ethanolamine to the mixed solution with a dropping funnel for reaction, wherein the molar ratio of 2-ethanolamine to disproportionated rosin is 1:1, the reaction temperature is 60°C, and the reaction time is 10min, add isothermal and equal amount of water with absolute ethanol after the reaction finishes;

(3) After rapid crystallization, extract twice while hot with preheated (60°C) petroleum ether until the ether layer is colorless, cool and crystallize the extract in the lower layer, and filter with suction to obtain the crude dehydroabietic acid ethanolamine salt;

(4) Recrystallize the crude dehydroabietic acid ethanolamine salt with 10% ethanol under the assistance of the auxiliary field of microwave and ultraviolet integration to obtain dehydroabietic acid ethanolamine salt;

(5) Under the assistance of the auxiliary field of microwave and ultraviolet integration, add the dehydroabietic acid ethanolamine salt obtained in step (4) into 10% ethanol solution, wherein, the amount of the ethanol and the step (1) added without The same amount of water and ethanol;

(6) Acidify with 10% hydrochloric acid to pH<4, add appropriate amount of distilled water to crystallize, cool and suction filter to obtain crude dehydroabietic acid, and wash the crude dehydroabietic acid once with hot distilled water;

(7) Recrystallize twice with 75% ethanol under the auxiliary field of microwave and ultraviolet integration, and the crystallization time is 24 hours each time;

(8) Suction filtration and vacuum drying at 80°C for 2 hours to obtain dehydroabietic acid crystals.

The results are as follows: the yield of dehydroabietic acid is 28.9%, and the purity reaches 100%.

In this example, if other conditions are the same, only microwave assistance is added, the yield of dehydroabietic acid is 27.4%, and the purity reaches 96.03%.

Example 2

(1) Add disproportionated rosin to absolute ethanol at a ratio of 0.1g/ml, mix and dissolve under the auxiliary field of microwave and ultraviolet integration at 50°C, and cool to room temperature to obtain a mixed solution;

(2) Turn on the auxiliary field for microwave-ultraviolet integration, slowly add 2-ethanolamine to the mixed solution with a dropping funnel for reaction, wherein the molar ratio of 2-ethanolamine to disproportionated rosin is 2:1, the reaction temperature is 50°C, and the reaction time is 20min, add isothermal and equal amount of water with absolute ethanol after the reaction finishes;

(3) After rapid crystallization, extract twice while hot with preheated (50°C) petroleum ether until the ether layer is colorless, cool and crystallize the extract in the lower layer, and filter with suction to obtain the crude dehydroabietic acid ethanolamine salt;

(4) Recrystallize the crude dehydroabietic acid ethanolamine salt with 80% ethanol under the assistance of the auxiliary field of microwave and ultraviolet integration to obtain dehydroabietic acid ethanolamine salt;

(5) Under the assisted action of the auxiliary field of microwave-ultraviolet integration, the dehydroabietic acid ethanolamine salt obtained in step (4) is added in 40% ethanol solution, wherein, the amount of the ethanol and the step (1) added without The same amount of water and ethanol;

(6) Acidify with 1% hydrochloric acid to pH<4, add appropriate amount of distilled water to crystallize, cool and suction filter to obtain the crude product of dehydroabietic acid, and wash the crude product of dehydroabietic acid twice with hot distilled water;

(7) Recrystallize once with 90% ethanol under the assistance of the auxiliary field of microwave and ultraviolet integration, and the time for each crystallization is 12h;

(8) Suction filtration and vacuum drying at 50°C for 3 hours to obtain dehydroabietic acid crystals.

The results are as follows: the yield of dehydroabietic acid is 36.51%, and the purity reaches 98.04%.

In this example, if other conditions are the same, only microwave assistance is added, the yield of dehydroabietic acid is 33.79%, and the purity reaches 96.87%.

Example 3

(1) Add disproportionated rosin to absolute ethanol at a ratio of 1g/ml, mix and dissolve under the auxiliary field of microwave and ultraviolet integration at 75°C, and cool to room temperature to obtain a mixed solution;

(2) Turn on the auxiliary field for microwave-ultraviolet integration, slowly add 2-ethanolamine into the mixed solution with a dropping funnel for reaction, wherein the molar ratio of 2-ethanolamine to disproportionated rosin is 3:1, the reaction temperature is 75°C, and the reaction time is 5min, add isothermal and equal amount of water with absolute ethanol after the reaction finishes;

(3) After rapid crystallization, extract twice while hot with preheated (75°C) petroleum ether until the ether layer is colorless, cool and crystallize the extract in the lower layer, and filter with suction to obtain the crude dehydroabietic acid ethanolamine salt;

(4) Recrystallize the crude dehydroabietic acid ethanolamine salt with 40% ethanol under the assistance of the auxiliary field of microwave and ultraviolet integration to obtain dehydroabietic acid ethanolamine salt;

(5) Under the assisted action of the auxiliary field of microwave-ultraviolet integration, the dehydroabietic acid ethanolamine salt obtained in step (4) is added in 80% ethanol solution, wherein, the amount of the ethanol and the step (1) added without The same amount of water and ethanol;

(6) Acidify with 15% hydrochloric acid to pH<4, add an appropriate amount of distilled water to crystallize, cool and suction filter to obtain crude dehydroabietic acid, and wash the crude dehydroabietic acid three times with hot distilled water;

(7) Recrystallize 4 times with 50% ethanol under the auxiliary field of microwave and ultraviolet integration, and the crystallization time is 70h each time;

(8) Suction filtration and vacuum drying at 100° C. for 0.5 h to obtain dehydroabietic acid crystals.

The results are as follows: the yield of dehydroabietic acid is 24.67%, and the purity reaches 99.64%.

In this example, if other conditions are the same, only microwave assistance is added, the yield of dehydroabietic acid is 23.69%, and the purity reaches 97.48%.

Claims (3)

1. the method for purification of a dehydroabietic acid, it is characterised in that specifically include following steps:

(1) in the ratio of 0.1 ~ 1g mL, disproportionated rosin is joined in dehydrated alcohol, mixed dissolution under the particular field of 50 ~ 70 DEG C, it is cooled to room temperature, obtains mixed solution;

(2) particular field is opened, mixed solution is slowly added to 2-ethanolamine react, wherein 2-ethanolamine is 1:1 ~ 3:1 with the mol ratio of disproportionated rosin, reaction temperature 50 ~ 75 DEG C, response time 5 ~ 20min, reaction adds the water with dehydrated alcohol isothermal and equivalent after terminating, after rapid crystallization, being extracted to ether layer while hot with the petroleum ether of preheating colourless, by lower floor's extract crystallisation by cooling, sucking filtration obtains dehydroabietic acid ethanolamine salt runic;

(3) under the assosting effect of particular field, with 10 ~ 80% ethanol, dehydroabietic acid ethanolamine salt runic is carried out recrystallization and obtain dehydroabietic acid ethanolamine salt 1 ~ 4 time; Under the assosting effect of particular field, being added by dehydroabietic acid ethanolamine salt in 10 ~ 80% alcoholic solution, wherein, the amount of this ethanol is identical with the amount of the dehydrated alcohol added in step (1);

(4) hcl acidifying that solution mass percent is 1 ~ 15% that step (3) obtains is to pH < 4, adds distilled water crystallization, cools down sucking filtration, obtains dehydroabietic acid crude product, the distilled water wash of dehydroabietic acid crude product heat 1 ~ 3 time;

(5) under the assosting effect of particular field, dehydroabietic acid crude product with 50 ~ 95% ethyl alcohol recrystallization 1 ~ 4 time, each crystallization time is 12 ~ 70h;

(6) sucking filtration dries and obtains dehydroabietic acid crystal;

Described particular field is the auxiliary field of microwave ultraviolet integration.

2. the method for purification of dehydroabietic acid according to claim 1, it is characterised in that: the microwave power 1-1000W of described particular field, UV power 300W.

3. the method for purification of dehydroabietic acid according to claim 1, it is characterised in that: the dry run condition described in step (8) is: vacuum drying 0.5 ~ 3h at 50 ~ 100 DEG C.