CN113443982A

CN113443982A - Method for purifying milk lactone crude product

Info

Publication number: CN113443982A
Application number: CN202011423160.9A
Authority: CN
Inventors: 夏青青
Original assignee: Suzhou Ryan Pharmachem Technology Co ltd
Current assignee: Suzhou Ryan Pharmachem Technology Co ltd
Priority date: 2020-12-08
Filing date: 2020-12-08
Publication date: 2021-09-28

Abstract

The invention discloses a purification method of a milk lactone crude product, which comprises the following steps: s1, sequentially adding the milk lactone crude product and dicyclohexylamine into an organic solvent, carrying out a salt forming reaction under a stirring condition, separating out crystals from a mixed solution after the reaction is finished, and filtering to obtain a filter cake; and S2, adjusting the pH value of the filter cake obtained in the step S1 to 2-3 by adopting a neutralizing agent, extracting by ethyl acetate, combining organic phases, washing and concentrating to obtain the pure milk lactone. The purification method of the milk lactone crude product has the advantages of simple process, safety and environmental protection, and the purity of the obtained milk lactone pure product can reach more than 98 percent, so the purification method is suitable for industrial production.

Description

Method for purifying milk lactone crude product

Technical Field

The invention relates to the technical field of milk lactone purification methods, in particular to a purification method of a milk lactone crude product.

Background

Lactol is a mixture of 5(6) -decenoic acids, english name: milk, 5(6) -decenoic acids mix, is a Milk-flavored flavor product. The unsaturated fatty acid is actually an unsaturated fatty acid, and the extremely small amount of unsaturated fatty acid can generate milk fragrance, has strong fragrance and lasting fragrance, and can be widely applied to foods such as milk, cream, cheese essence, chocolate and the like as spices. In addition, the milk lactone has high boiling point, can be used in baked food, is not easy to be damaged like compound milk essence, and has very wide application prospect.

Chinese patent publication No. CN1266841 discloses a method for synthesizing milk lactone, using cyclohexanone and butyraldehyde as starting materials, performing alkaline condensation, selective hydrogenation, peroxide ring expansion to obtain lactone, and finally dehydrating under acidic condition to obtain 5- (6) -decenoic acid mixture, as shown in fig. 1 specifically; the purity of the milk lactone obtained in the patent is 70-75%, and the purity can only reach 90-94% after once rectification, wherein the purity contains 5-10% of decalactone impurities.

Many domestic and foreign documents also describe that the purity of the milk lactone crude product can be improved to more than 98% by rectification, but the applicant repeatedly adopts the rectification method to purify the milk lactone crude product for many times, and finds that the purity of the milk lactone by the rectification purification method can hardly reach more than 98%, and generally can only reach 90% -94%.

Disclosure of Invention

The invention aims to overcome the defects, provides a method for purifying the crude milk lactone product, has simple, safe and environment-friendly process, ensures that the purity of the obtained pure milk lactone product can reach more than 98 percent, and is suitable for industrial production.

In order to realize the purpose, the invention provides the following technical scheme that the method for purifying the milk lactone crude product comprises the following steps:

s1, sequentially adding the milk lactone crude product and dicyclohexylamine into an organic solvent, carrying out a salt forming reaction under a stirring condition, separating out crystals from a mixed solution after the reaction is finished, and filtering to obtain a filter cake;

and S2, adjusting the pH value of the filter cake obtained in the step S1 to 2-3 by adopting a neutralizing agent, extracting by ethyl acetate, combining organic phases, washing and concentrating to obtain the pure milk lactone.

Preferably, the purity of the crude milk lactone product in the step S1 is 90-94%, and the purity of the pure milk lactone product obtained in the step S2 is more than or equal to 98%.

Preferably, the mass ratio of the crude milk lactone product to the dicyclohexylamine in the step S1 is 1: 0.95 to 1.15.

Preferably, the organic solvent in step S1 is ethyl acetate or acetonitrile.

Preferably, in the step S1, the crude milk lactone is dissolved in an organic solvent, cooled to 0-5 ℃, and then dicyclohexylamine is added.

Preferably, in the step S2, the pH of the filter cake is adjusted to 2-3 by using a neutralizing agent after the filter cake is washed.

Preferably, in the step S2, the filter cake is washed with ethyl acetate, and then the pH of the filter cake is adjusted to 2-3 with a neutralizing agent.

Preferably, in the step S2, the neutralizing agent is 1mol/L hydrochloric acid.

Preferably, in the step S2, extraction is performed 3 times by ethyl acetate.

Preferably, the combined organic phases are washed 1 time with brine.

Compared with the prior art, the invention has the beneficial effects that: the purification method of the milk lactone crude product has the advantages of simple process, safety and environmental protection, and the purity of the obtained milk lactone pure product can reach more than 98 percent, so the purification method is suitable for industrial production.

Drawings

FIG. 1 is a schematic diagram of a method for synthesizing lactonic acid in the Chinese patent publication No. CN 1266841;

FIG. 2 is a schematic diagram of the method for purifying the crude milk lactone product of the present invention.

Detailed Description

In order to make the technical means of the implementation of the present invention, and the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments.

In the following examples, the purity of the product was qualitatively and quantitatively analyzed by gas chromatography. The gas chromatography comprises a chromatographic column (30m × 0.25mm) and a hydrogen ion flame detector, and the detection sample volume is 0.2 μ L, wherein the sample is the obtained pure milk lactone. The injector temperature was 280 ℃, the column box temperature was 60 ℃ and the detector temperature was 280 ℃. The pressure before the column was 150kpa, the split flow was 20ml/min, and the tail blow was 20 ml/min. The temperature programming for the gas chromatograph was: holding at 60 deg.C for 3min, heating to 280 deg.C at 15 deg.C/min, and holding at 280 deg.C for 3 min. The components are calculated according to an area normalization method.

Example 1

Referring to fig. 2, this embodiment discloses a method for purifying a crude milk lactone product, which includes the following steps:

s1, dissolving 200.0g of a milk lactone crude product (with the purity of 92%) in 800ml of ethyl acetate, cooling to 0-5 ℃, adding 218.5g of dicyclohexylamine, stirring at room temperature, carrying out salt forming reaction for 1 hour, and filtering to obtain a filter cake;

s2, washing the filter cake obtained in the step S1 with 50ml of ethyl acetate, then placing the filter cake into a 1L three-necked bottle, adding 1mol/L hydrochloric acid to neutralize until the pH value is 2-3, adding ethyl acetate to extract for 3 times (100ml multiplied by 3), combining organic layers, washing with saturated salt water for 1 time (400ml), drying with anhydrous sodium sulfate, filtering, and concentrating to obtain pure 163.0g of pure milk lactone, wherein the purity of the pure milk lactone is 98.8%.

Example 2

s1, dissolving 1100.0g of a milk lactone crude product (with the purity of 90%) in 4.8L of ethyl acetate, cooling to 0-5 ℃, adding 1200g of dicyclohexylamine, stirring at room temperature, carrying out a salt forming reaction for 2 hours, and filtering to obtain a filter cake;

s2, washing the filter cake obtained in the step S1 with 200ml of ethyl acetate, then placing the filter cake into a 5L three-necked bottle, adding 1mol/L hydrochloric acid to neutralize until the pH value is 2-3, adding ethyl acetate to extract for 3 times (1.0L multiplied by 3), combining organic layers, washing with saturated salt for 1 time (1L), drying with anhydrous sodium sulfate, filtering, and concentrating to obtain 872g of a pure milk lactone; wherein the purity of the obtained pure milk lactone product is 98.6%.

Example 3

s1, dissolving 1100.0g of a milk lactone crude product (with the purity of 90%) in 4.8L of acetonitrile, cooling to 0-5 ℃, adding 1200g of dicyclohexylamine, stirring at room temperature, carrying out a salt forming reaction for 2 hours, and filtering to obtain a filter cake;

Example 4

s1, dissolving 1100.0g of a milk lactone crude product (with the purity of 90%) in 4.8L of ethyl acetate, cooling to 0-5 ℃, adding 1045g of dicyclohexylamine, carrying out salt forming reaction for 2 hours under stirring at room temperature, and filtering to obtain a filter cake;

s2, washing the filter cake obtained in the step S1 with 200ml of ethyl acetate, then placing the filter cake into a 5L three-necked bottle, adding 1mol/L hydrochloric acid to neutralize until the pH value is 2-3, adding ethyl acetate to extract for 3 times (1.0L multiplied by 3), combining organic layers, washing with saturated salt for 1 time (1L), drying with anhydrous sodium sulfate, filtering, and concentrating to obtain 757g of a pure milk lactone product; wherein the purity of the obtained pure milk lactone product is 98.8%.

Example 5

s1, dissolving 1100.0g of a milk lactone crude product (with the purity of 90%) in 4.8L of ethyl acetate, cooling to 0-5 ℃, adding 1265g of dicyclohexylamine, stirring at room temperature, carrying out a salt forming reaction for 2 hours, and filtering to obtain a filter cake;

s2, washing the filter cake obtained in the step S1 with 200ml of ethyl acetate, then placing the filter cake into a 5L three-necked bottle, adding 1mol/L hydrochloric acid to neutralize until the pH value is 2-3, adding ethyl acetate to extract for 3 times (1.0L multiplied by 3), combining organic layers, washing with saturated salt for 1 time (1L), drying with anhydrous sodium sulfate, filtering, and concentrating to obtain 936g of a pure milk lactone; wherein the purity of the obtained pure milk lactone product is 98.8%.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The method for purifying the milk lactone crude product is characterized by comprising the following steps:

2. The method for purifying the crude milk lactone product of claim 1, wherein the purity of the crude milk lactone product in the step S1 is 90-94%, and the purity of the pure milk lactone product obtained in the step S2 is not less than 98%.

3. The method for purifying a crude milk lactone product of claim 1, wherein the mass ratio of the crude milk lactone product to the dicyclohexylamine in the step S1 is 1: 0.95 to 1.15.

4. The method of claim 1, wherein the organic solvent in step S1 is ethyl acetate or acetonitrile.

5. The method for purifying a milk lactone crude product as claimed in claim 1, wherein in the step S1, the milk lactone crude product is dissolved in an organic solvent, cooled to 0-5 ℃, and then dicyclohexylamine is added.

6. The method for purifying a milk lactone crude product as claimed in claim 1, wherein the pH of the filter cake is adjusted to 2-3 by using a neutralizing agent after the filter cake is washed in the step S2.

7. The method for purifying the crude milk lactone according to claim 4, wherein in the step S2, the filter cake is washed by ethyl acetate, and then the pH of the filter cake is adjusted to 2-3 by a neutralizing agent.

8. The method of claim 1, wherein in step S2, the neutralizing agent is 1mol/L hydrochloric acid.

9. The method of claim 1, wherein in step S2, the crude milk lactone is extracted 3 times with ethyl acetate.

10. The method of claim 1, wherein the combined organic phases are washed with brine 1 time.