CN112125799A

CN112125799A - Production method of vanillin isobutyrate

Info

Publication number: CN112125799A
Application number: CN202011096426.3A
Authority: CN
Inventors: 汪洋; 甘建强; 罗洋; 张玉梅; 唐凌
Original assignee: Chongqing Thrive Chemical Co ltd
Current assignee: Chongqing Thrive Chemical Co ltd
Priority date: 2020-10-14
Filing date: 2020-10-14
Publication date: 2020-12-25

Abstract

The invention discloses a method for producing vanillin isobutyrate, which is characterized by comprising the following steps: mixing vanillin and isobutyric anhydride under the protection of nitrogen in the vacuum environment and the whole process, carrying out synthesis reaction under the condition of constant temperature, carrying out reduced pressure distillation to recover the unreacted isobutyric anhydride and isobutyric acid mixture after sampling is qualified, and continuously carrying out reduced pressure distillation on the rest product to obtain vanillin isobutyrate with the gas analysis content of more than 98.5% and the yield of more than 90%. The method has the advantages of stable process, high yield, no need of catalyst, simple and easily controlled reaction process and good purification effect.

Description

Production method of vanillin isobutyrate

Technical Field

The invention relates to a production method of vanillin isobutyrate, belonging to the technical field of production of safe and environment-friendly food additives in fine chemical engineering.

Background

Vanillin isobutyrate is a flavor which has been widely used in the food flavor industry in recent ten years, and is widely used in foods such as dairy products, candies, and beverages. The application of the method in the daily chemical industry field is more and more extensive, and the application research of the method is more. Vanillin isobutyrate is a flavor with sour taste of fermented milk, and is colorless to pale yellow or yellow viscous liquid, which is easily discolored in alkaline solution. Vanillin isobutyrate has a boiling point of 312.9 ℃, a refractive index of 1.522-1.528, and poor stability at high temperature. Vanillin isobutyrate can be used for edible essence and food additives, but the dosage of the vanillin isobutyrate used for preparing the essence cannot exceed the maximum allowable dosage and the maximum allowable residual quantity in GB 2760.

The traditional preparation process adopts vanillin and isobutyric anhydride to react in an alkaline catalyst or vanillin and isobutyric acid chloride to react in the alkaline catalyst, and the catalyst or toxic solvent is used in the reaction process. As food additives, the existence of environmental pollution and solvent residues brings serious challenges to the safety performance of food.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides the production method of vanillin isobutyrate, which has the advantages of stable process, high yield, no need of a catalyst, simple and easily controlled reaction process and good purification effect.

In order to achieve the purpose, the technical scheme of the invention is as follows: a method for producing vanillin isobutyrate is characterized in that: mixing vanillin and isobutyric anhydride under the protection of nitrogen in the vacuum environment and the whole process, carrying out synthesis reaction under the condition of constant temperature, carrying out reduced pressure distillation to recover the unreacted isobutyric anhydride and isobutyric acid mixture after sampling is qualified, and continuously carrying out reduced pressure distillation on the rest product to obtain vanillin isobutyrate with the gas analysis content of more than 98.5% and the yield of more than 90%.

Further, the content of vanillin is more than 99%, the content of water is less than 0.1%, the content of isobutyric anhydride is more than 99%, and the content of water is less than 0.1%, wherein the weight ratio of vanillin to isobutyric anhydride is 1: 1-1: 8.

Further, the weight ratio of vanillin to isobutyric anhydride is 1: 3-1: 5.

Furthermore, the vacuum degree of the vacuum environment is 500-1500 pa.

Further, a container made of 316L, Hastelloy plates or an enamel kettle is used as a reaction kettle for vanillin and isobutyric anhydride, before reaction, the reaction kettle is cleaned, and the reaction kettle and a condensing device thereof are dewatered to ensure that the water content of the whole system is lower than 100 ppm.

Further, before the reaction, cooling the reaction kettle, adding vanillin and isobutyric anhydride, and heating to the constant temperature of 30-100 ℃.

Further, the constant temperature is 40-60 ℃.

Further, the reaction time is 6-12 h.

Further, in the reduced pressure distillation process, the distillation temperature is 135-180 ℃, and the distillation vacuum is 50-200 pa.

Further, in the reduced pressure distillation process, the distillation temperature is 140-155 ℃.

The invention has the beneficial effects that: the vanillin and isobutyric anhydride are directly synthesized under the protection of vacuum and nitrogen for reaction without a catalyst, the water content in the reaction process is controlled, the conversion rate and the reaction rate of vanillin isobutyrate are improved, the reaction process is simple and easy to control, and the purification effect is good.

Detailed Description

The present invention will be described in further detail with reference to the following examples.

Under the protection of nitrogen in the whole process in a vacuum environment, mixing vanillin and isobutyric anhydride, carrying out synthesis reaction under the condition of constant temperature, after sampling is qualified, carrying out reduced pressure distillation to recover the unreacted isobutyric anhydride and isobutyric acid mixture, and continuously carrying out reduced pressure distillation on the rest product to obtain vanillin isobutyrate with the gas phase analysis content of more than 98.5% and the yield of more than 90%.

Specifically, because whole reaction system is the acidity, can produce the corruption, and isobutyric acid vanillin ester can turn red when meeting iron, so adopt the reaction kettle of vanillin and isobutyric anhydride as the container that 316L, hastelloy board or enamel kettle made, before the reaction, wash the reaction kettle to with reaction kettle and condensing equipment dewatering make whole system water content be less than 100ppm, improve the conversion, avoid too much moisture to exist and can make isobutyric anhydride decompose, and then reduce reaction conversion. Meanwhile, the raw materials, namely the vanillin, the water content and the isobutyric anhydride are more than 99%, less than 0.1%, more than 99% and less than 0.1%.

In the process, nitrogen is used as protective gas in the whole process, so that oxidation is reduced.

Vanillin and isobutyric anhydride are added in sequence in the reaction process, the weight ratio of vanillin to isobutyric anhydride is 1: 1-1: 8, the preferable weight ratio is 1: 3-1: 5, and excess isobutyric anhydride is required in the reaction process, but not excessive, so that the yield of unit volume of a reaction kettle is reduced, and the production cost of vanillin isobutyrate is increased.

In the reaction process, the vacuum degree of the vacuum environment is 500-1500 pa, so that isobutyric acid produced by conversion is removed, the reaction is facilitated to be carried out in the forward direction, the product is more facilitated to be generated, the reaction rate is improved, the vacuum degree is too high, the requirement on equipment is high, unnecessary waste is caused, and if the vacuum degree is insufficient, the acid removal effect is poor, and the product is not facilitated to be generated.

Before the reaction, cooling the reaction kettle, sequentially adding vanillin and isobutyric anhydride, heating to a constant temperature which is set to be 30-100 ℃, preferably 40-60 ℃, for 6-12 h, and obtaining a gas phase detection result through tests, wherein the content of vanillin isobutyrate after the reaction is finished is more than 98%.

The invention adopts a reduced pressure distillation mode to recover the unreacted isobutyric anhydride and the isobutyric acid, and the recovered isobutyric anhydride and isobutyric acid mixture can be directly used for being mixed with the new isobutyric anhydride to react with vanillin so as to produce vanillin isobutyrate without any influence on the production. This reduces the consumption of isobutyric anhydride and thus the production costs.

And after the recovery of isobutyric anhydride and isobutyric acid is finished, continuously distilling vanillin isobutyrate under reduced pressure, wherein the distillation temperature is 135-180 ℃, preferably 140-155 ℃, and the distillation vacuum is 50-200 pa. The vacuum degree is lower than 50Pa, the distillation temperature is low, the distillation speed is high, the product fragrance is good, but the requirement on equipment is high; when the vacuum degree is higher than 200pa, the distillation temperature is high, the product is easy to polymerize, the product is easy to coke, and the fragrance is poor.

The technical solutions provided by the embodiments of the present invention are described in detail above, and the principles and embodiments of the present invention are explained herein by using specific examples, and the descriptions of the embodiments are only used to help understanding the principles of the embodiments of the present invention; meanwhile, for a person skilled in the art, according to the embodiments of the present invention, there may be variations in the specific implementation manners and application ranges, and in summary, the content of the present description should not be construed as a limitation to the present invention.

Claims

1. A method for producing vanillin isobutyrate is characterized in that: mixing vanillin and isobutyric anhydride under the protection of nitrogen in the vacuum environment and the whole process, carrying out synthesis reaction under the condition of constant temperature, carrying out reduced pressure distillation to recover the unreacted isobutyric anhydride and isobutyric acid mixture after sampling is qualified, and continuously carrying out reduced pressure distillation on the rest product to obtain vanillin isobutyrate with the gas analysis content of more than 98.5% and the yield of more than 90%.

2. The method of claim 1, wherein: the vanillin content is more than 99%, the water content is less than 0.1%, the isobutyric anhydride content is more than 99%, and the water content is less than 0.1%, wherein the weight ratio of vanillin to isobutyric anhydride is 1: 1-1: 8.

3. The method of claim 2, wherein: the weight ratio of vanillin to isobutyric anhydride is 1: 3-1: 5.

4. The method of claim 1, wherein: the vacuum degree of the vacuum environment is 500-1500 pa.

5. The method of claim 1, wherein: a container made of 316L, Hastelloy plates or an enamel kettle is used as a reaction kettle for vanillin and isobutyric anhydride, before reaction, the reaction kettle is cleaned, and the reaction kettle and a condensing device thereof are dewatered to ensure that the water content of the whole system is lower than 100 ppm.

6. The method of claim 5, wherein: before reaction, cooling the reaction kettle, adding vanillin and isobutyric anhydride, and heating to the constant temperature of 30-100 ℃.

7. The method of claim 6, wherein: the constant temperature is 40-60 ℃.

8. The method of claim 1, wherein: the reaction time is 6-12 h.

9. The method of claim 1, wherein: in the reduced pressure distillation process, the distillation temperature is 135-180 ℃, and the distillation vacuum is 50-200 pa.

10. The method of claim 9, wherein: in the reduced pressure distillation process, the distillation temperature is 140-155 ℃.