阅读说明：本技术 红玉酯化液及红玉酯化液的制备方法 (Hongyu esterified liquid and preparation method thereof ) 是由 李茂� 王志刚 余自琳 杜佳栋 王养冠 于 2021-06-28 设计创作，主要内容包括：本发明提供一种红玉酯化液及红玉酯化液的制备方法,所述红玉酯化液的制备方法包括以下步骤：以3-(N-N-二羟乙基)氨基乙酰苯胺和过量醋酸为原料,醋酸至少分两次加入并与3-(N-N-二羟乙基)氨基乙酰苯胺进行反应；其中,每次加入醋酸后,在与3-(N-N-二羟乙基)氨基乙酰苯胺的反应过程中分离出部分醋酸反应液。通过本发明合成的红玉酯化液在保证了产品中3-乙酰氨基-N,N-二乙酰氧乙基苯胺纯度的同时降低了生产成本,减少了反应副产物的生成,并且有效延长了保质期使其达到1年,对于产品的保存与运输有着重要的作用。(The invention provides a ruby esterified liquid and a preparation method thereof, wherein the preparation method of the ruby esterified liquid comprises the following steps: 3- (N-N-dihydroxyethyl) aminoacetanilide and excessive acetic acid are taken as raw materials, and the acetic acid is added at least twice and reacts with the 3- (N-N-dihydroxyethyl) aminoacetanilide; wherein, after each acetic acid addition, part of the acetic acid reaction liquid is separated during the reaction with the 3- (N-dihydroxyethyl) aminoacetanilide. The ruby esterified liquid synthesized by the method ensures the purity of the 3-acetamido-N, N-diacetoxyethylaniline in the product, reduces the production cost, reduces the generation of reaction byproducts, effectively prolongs the shelf life to reach 1 year, and plays an important role in the storage and transportation of the product.)

1. The preparation method of the ruby esterified liquid is characterized by comprising the following steps:

3- (N-N-dihydroxyethyl) aminoacetanilide and excessive acetic acid are taken as raw materials, and the acetic acid is added at least twice and reacts with the 3- (N-N-dihydroxyethyl) aminoacetanilide; wherein the content of the first and second substances,

after each addition of acetic acid, a portion of the acetic acid reaction was separated during the reaction with 3- (N-dihydroxyethyl) aminoacetanilide.

2. The process according to claim 1, wherein acetic acid is added in 3 to 6 times and reacted with 3- (N-dihydroxyethyl) aminoacetanilide, wherein,

after each addition of acetic acid, a portion of the acetic acid reaction was separated during the reaction with 3- (N-dihydroxyethyl) aminoacetanilide.

3. The method according to claim 1 or 2, wherein the molar ratio of 3- (N-dihydroxyethyl) aminoacetanilide to the total mass of acetic acid added is 1:2.5 to 6; wherein the content of the first and second substances,

the molar ratio of the 3- (N-N-dihydroxyethyl) aminoacetanilide to the acetic acid participating in the reaction is 1: 1.7-2.2.

4. The process according to claim 2 or 3, wherein in the first reaction of acetic acid with 3- (N-dihydroxyethyl) aminoacetanilide, the mass of acetic acid added is 35 to 55% of the total mass of acetic acid;

the mass of the separated acetic acid reaction liquid is 38 to 42 percent of the mass of the acetic acid added in the first reaction;

the reaction temperature in the first reaction is 100-110 ℃.

5. The preparation method according to claim 4, wherein in the last reaction of acetic acid and 3- (N-dihydroxyethyl) aminoacetanilide, the mass of the added acetic acid is 15-20% of the total mass of the acetic acid;

the mass of the separated acetic acid reaction liquid is 68-72% of the mass of the acetic acid added in the last reaction;

the temperature of the acetic acid reaction liquid separated in the last reaction is 135-145 ℃.

6. The preparation method according to claim 5, wherein in the intermediate reaction of acetic acid and 3- (N-dihydroxyethyl) aminoacetanilide, the mass of the added acetic acid is 30-45% of the total mass of the acetic acid;

the mass of the separated acetic acid reaction liquid is 78-82% of the mass of the acetic acid added in the middle reaction.

7. The production method according to claim 6, wherein the acetic acid added in the first reaction is an acetic acid having a mass fraction of 90% or more; in the last reaction, the added acetic acid is glacial acetic acid; in the intermediate reaction, the added acetic acid is acetic acid or glacial acetic acid with the mass fraction of more than 90%.

8. The method according to any one of claims 1 to 7, wherein the total reaction time of the method is 15 to 24 hours.

9. A ruby esterified liquid, which is prepared by the method according to any one of claims 1 to 8; preferably, the purity of the ruby esterified liquid is more than 95%, and the content of the perester is less than 1.5%.

10. The ruby esterified liquid according to claim 9, having a shelf life of more than 1 year.

Technical Field

The invention relates to a ruby esterified liquid and a preparation method thereof, belonging to the field of chemical synthesis, in particular to the field of dye synthesis.

Background

The disperse red series dyes take an important position in dye varieties, particularly C.I. disperse red 167, has wide acceptance in the dye market due to wide application in dyeing of polyester fibers, so that the synthesis of the intermediate 3-acetamido-N, N-diacetoxyethylaniline is very important.

The ruby esterified liquid is usually prepared by one-step esterification reaction of corresponding hydroxylate serving as a starting material and carboxylic acid or anhydride. The acid anhydride has stronger activity and can be used for esterification of alcoholic hydroxyl with small activity or larger steric hindrance, and in the traditional industrial production, the production of acetified liquor usually adopts acetic anhydride as an esterifying agent.

Citation 1 discloses a method for synthesizing 3-acetamido-N, N-diacetoxyethylaniline, which takes acetic anhydride and 3- (N-N-dihydroxyethyl) aminoacetanilide as raw materials, the acetic anhydride is added in two times, 60% -80% of the total mass of the acetic anhydride is added for the first time, then the reaction is carried out for 4-6 hours at 50-55 ℃, and then the rest acetic anhydride is added at 45-55 ℃ for the reaction for 8-10 hours; and finally adding acetic acid accounting for 20-26 percent of the mass of the 3- (N-N-dihydroxyethyl) aminoacetanilide into the reaction solution and cooling to obtain the 3-acetamido-N, N-diacetoxyethylanilide. The 3-acetamido-N, N-diacetoxyethylaniline synthesized by the method has the advantages of improving the purity of the product and prolonging the shelf life, but still has the problems of higher synthesis cost, more byproducts in the finished product, short shelf life (only half a year) and the like. The synthesis reaction equation is as follows:

citation 2 discloses a method for synthesizing an esterification liquid in a dye. The method comprises the following steps: adding dehydrated hydroxylate and acetic acid into the esterification kettle, wherein the dehydrated hydroxylate and the acetic acid are fed according to the mol ratio of the contained hydroxyethyl to the acetic acid of 1:1-1: 10; heating while stirring, and promoting esterification reaction by rectification and dehydration when the temperature is raised to 110-150 ℃; adding a molecular sieve with the channel aperture smaller than 9A into the esterification kettle after the esterification reaction, wherein the adding mass of the molecular sieve is 1-25% of the mass of the dehydrated hydroxylation, and continuing the reaction under the reflux state of 110-140 ℃ until the reaction is finished; after the esterification reaction is finished, separating the product from the molecular sieve to obtain high-purity esterified liquid; the separated molecular sieve is subjected to regeneration and activation treatment, and the regenerated and activated molecular sieve is recycled. However, the preparation process of the method is complex, a molecular sieve is required, the overall cost is high, and the shelf life of the obtained product is short.

Therefore, in order to solve the above problems, it is an urgent need to provide a new synthesis method that can reduce the synthesis cost, reduce the reaction by-products, and effectively prolong the shelf life of the product.

Cited documents:

cited document 1: CN104710322A

Cited document 2: CN106117073A

Disclosure of Invention

Problems to be solved by the invention

In view of the technical problems in the prior art, such as high synthesis cost, more side reaction products, short shelf life and the like; the invention firstly provides a preparation method of ruby esterified liquid, which can effectively reduce the synthesis cost, reduce the reaction by-products and prolong the shelf life.

Means for solving the problems

The invention provides a preparation method of ruby esterified liquid, which comprises the following steps:

3- (N-N-dihydroxyethyl) aminoacetanilide and excessive acetic acid are taken as raw materials, and the acetic acid is added at least twice and reacts with the 3- (N-N-dihydroxyethyl) aminoacetanilide; wherein the content of the first and second substances,

after each addition of acetic acid, a portion of the acetic acid reaction was separated during the reaction with 3- (N-dihydroxyethyl) aminoacetanilide.

The preparation method according to the invention, wherein acetic acid is added in 3 to 6 times and reacted with 3- (N-N-dihydroxyethyl) aminoacetanilide, wherein,

after each addition of acetic acid, a portion of the acetic acid reaction was separated during the reaction with 3- (N-dihydroxyethyl) aminoacetanilide.

The preparation method comprises the following steps of (1) mixing 3- (N-N-dihydroxyethyl) aminoacetanilide and acetic acid in a molar ratio of 1: 2.5-6; wherein the content of the first and second substances,

the molar ratio of the 3- (N-N-dihydroxyethyl) aminoacetanilide to the acetic acid participating in the reaction is 1: 1.7-2.2.

According to the preparation method, in the first reaction of acetic acid and 3- (N-N-dihydroxyethyl) aminoacetanilide, the mass of the added acetic acid is 35-55% of the total mass of the acetic acid;

the mass of the separated acetic acid reaction liquid is 38 to 42 percent of the mass of the acetic acid added in the first reaction;

the reaction temperature in the first reaction is 100-110 ℃.

According to the preparation method, in the last reaction of acetic acid and 3- (N-N-dihydroxyethyl) aminoacetanilide, the mass of the added acetic acid is 15-20% of the total mass of the acetic acid;

the mass of the separated acetic acid reaction liquid is 68-72% of the mass of the acetic acid added in the last reaction;

the temperature of the acetic acid reaction liquid separated in the last reaction is 135-145 ℃.

According to the preparation method, in the intermediate reaction of acetic acid and 3- (N-N-dihydroxyethyl) aminoacetanilide, the mass of the added acetic acid is 30-45% of the total mass of the acetic acid;

the mass of the separated acetic acid reaction liquid is 78-82% of the mass of the acetic acid added in the middle reaction.

According to the preparation method, in the first reaction, the added acetic acid is acetic acid with the mass fraction of more than 90%; in the last reaction, the added acetic acid is glacial acetic acid; in the intermediate reaction, the added acetic acid is acetic acid or glacial acetic acid with the mass fraction of more than 90%.

The preparation method provided by the invention has the advantage that the total reaction time of the preparation method is 15-24 hours.

The invention also provides a ruby esterified liquid, which is prepared by the preparation method; preferably, the purity of the ruby esterified liquid is more than 95%, and the content of the perester is less than 1.5%.

The ruby esterified liquid of the present invention has a shelf life of 1 year or more.

ADVANTAGEOUS EFFECTS OF INVENTION

The ruby esterified liquid synthesized by the method ensures the purity of the 3-acetamido-N, N-diacetoxyethylaniline in the product, reduces the production cost, reduces the generation of reaction byproducts, effectively prolongs the shelf life to reach 1 year, and plays an important role in the storage and transportation of the product.

Detailed Description

The present invention will be described in detail below. The technical features described below are explained based on typical embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples.

Furthermore, in the following detailed description, numerous specific details are set forth in order to provide a better understanding of the present invention. It will be understood by those skilled in the art that the present invention may be practiced without some of these specific details. In other instances, methods, means, devices and steps which are well known to those skilled in the art have not been described in detail so as not to obscure the invention.

It should be noted that:

in the present specification, the numerical range represented by "numerical value a to numerical value B" means a range including the end point numerical value A, B.

All units used in the present invention are international standard units unless otherwise stated, and numerical values and numerical ranges appearing in the present invention should be understood to include errors allowed in industrial production.

In the present specification, reference to "some particular/preferred embodiments," "other particular/preferred embodiments," "embodiments," and the like, means that a particular element (e.g., feature, property, and/or characteristic) described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it is to be understood that the described elements may be combined in any suitable manner in the various embodiments.

The invention provides a preparation method of ruby esterified liquid, which comprises the following steps:

3- (N-N-dihydroxyethyl) aminoacetanilide and excessive acetic acid are taken as raw materials, and the acetic acid is added at least twice and reacts with the 3- (N-N-dihydroxyethyl) aminoacetanilide; wherein the content of the first and second substances,

after each addition of acetic acid, a portion of the acetic acid reaction was separated during the reaction with 3- (N-dihydroxyethyl) aminoacetanilide.

The reaction synthesis route of the invention is as follows:

the inventor finds that the ruby esterified liquid prepared by the method of the invention reduces the production cost and the generation of reaction by-products while ensuring the purity of the 3-acetamido-N, N-diacetoxyethylaniline, effectively prolongs the shelf life to 1 year, and plays an important role in the storage and transportation of products.

In the present invention, the mode of mixing 3- (N-N-dihydroxyethyl) aminoacetanilide with an excess of acetic acid is not particularly limited, and may be any mode commonly used in the art, for example, a mode in which acetic acid is added dropwise to 3- (N-N-dihydroxyethyl) aminoacetanilide.

In some embodiments, acetic acid may be added in 3 to 6 portions and reacted with 3- (N-dihydroxyethyl) aminoacetanilide, wherein,

after each addition of acetic acid, a portion of the acetic acid reaction was separated during the reaction with 3- (N-dihydroxyethyl) aminoacetanilide.

The inventor finds that the purity of the 3-acetamido-N, N-diacetoxyethylaniline in the ruby esterified liquid can be greatly improved by adding acetic acid for multiple times and then separating out partial acetic acid reaction liquid, the generation of side reactions is reduced, and the shelf life of the ruby esterified liquid prepared by the method can reach 1 year and more than 1 year.

The method for separating a part of the acetic acid reaction solution is not particularly limited, and may be any of those commonly used in the art, for example: distillation, and the like. Namely, the temperature can be properly raised in the reaction process, and some acetic acid reaction liquid can be distilled.

Further, the molar ratio of the 3- (N-dihydroxyethyl) aminoacetanilide to the total mass of the added acetic acid is 1: 2.5-6, for example: 1:2.7, 1:3, 1:3.2, 1:3.5, 1:3.8, 1:4, 1:4.2, 1:4.5, 1:4.8, 1:5, 1:5.2, 1:5.5, 1:5.8, etc.; wherein the molar ratio of the 3- (N-N-dihydroxyethyl) aminoacetanilide to the acetic acid participating in the reaction is 1: 1.7-2.2, for example: 1:1.8, 1:1.9, 1:2, 1:2.1, etc.

In the invention, the total amount of the added acetic acid is excessive, and the excessive addition of the acetic acid can ensure that the esterification reaction is balanced and moved forward in the reaction process, so that the reaction of hydroxylate is more complete; meanwhile, excessive acetic acid is continuously evaporated in the subsequent reaction process, so that the aim of saving resources can be fulfilled.

In some embodiments, in the first reaction of acetic acid with 3- (N-dihydroxyethyl) aminoacetanilide, the mass of acetic acid added is between 35% and 55% of the total mass of acetic acid, for example: 38%, 40%, 42%, 45%, 48%, 50%, 52%, etc. In the first reaction, the addition of more acetic acid can promote the contact area of the 3- (N-N-dihydroxyethyl) aminoacetanilide and the acetic acid in the reaction to be increased, so that the raw materials are reacted fully, and the reaction speed is accelerated.

In the first reaction of the invention, the mass of the separated acetic acid reaction liquid is 38 to 42 percent of the mass of the acetic acid added in the first reaction; most of the acetic acid added in the first reaction participates in the reaction, so the amount of the acetic acid reaction liquid separated in the reaction is small; meanwhile, as the reaction proceeds, new acetic acid can be added after separating out part of acetic acid reaction liquid which does not participate in the reaction, so as to promote the reaction equilibrium to move forward.

The reaction temperature in the first reaction is 100 to 110 ℃, for example, 101 ℃, 102 ℃, 103 ℃, 104 ℃, 105 ℃, 106 ℃, 107 ℃, 108 ℃, 109 ℃ and the like. The reason is that the boiling point of the acetic acid is 117.9 ℃ and the boiling point of the acetic acid is not reached at 100-110 ℃, so the acetic acid can participate in the reaction at the temperature and can not be separated.

In the first reaction of the present invention, the temperature at which acetic acid is separated by raising the temperature is not particularly limited in the present invention, and may be determined depending on the separation, and may be, for example, 120 ℃ or higher.

Further, in the invention, the acetic acid reaction liquid separated in the first reaction can be recycled to the reaction after being rectified by a hypergravity rectifying device.

In some specific embodiments, the mass of acetic acid added in the last reaction of acetic acid and 3- (N-dihydroxyethyl) aminoacetanilide is 15-20% of the total mass of acetic acid; in the last reaction, the esterification reaction is already at the final reaction stage, most of the 3- (N-N-dihydroxyethyl) aminoacetanilide is reacted in the former stage, so the addition amount of the acetic acid is less. Specifically, in the last reaction of acetic acid and 3- (N-N-dihydroxyethyl) aminoacetanilide, the mass of the added acetic acid can be 16%, 17%, 18%, 19% and the like based on the total mass of the acetic acid.

In the last reaction of the invention, the mass of the separated acetic acid reaction liquid is 68-72% of the mass of the acetic acid added in the last reaction, such as: 69%, 70%, 71%, etc.; in the last reaction, the esterification reaction reaches the end of the reaction, and less 3- (N-N-dihydroxyethyl) aminoacetanilide does not participate in the reaction; meanwhile, a small amount of moisture generated by the reaction, namely acetic acid reaction liquid, can be separated while acetic acid is separated in the process, so that the reaction equilibrium can be accelerated to move in the positive direction.

The temperature after the acetic acid reaction liquid is separated in the last reaction is 135-145 ℃, for example: 136 deg.C, 137 deg.C, 138 deg.C, 139 deg.C, 140 deg.C, 141 deg.C, 142 deg.C, 143 deg.C, 144 deg.C, etc. When the temperature of the acetic acid reaction liquid separated in the last reaction is 135-145 ℃, the acetic acid reaction liquid formed by acetic acid which does not participate in the reaction and a small amount of moisture generated in the reaction can be completely separated, and the purity of the product is improved.

Further, in the invention, the mass fraction of acetic acid in the acetic acid reaction solution separated from the last reaction can reach more than 90%, so that the acetic acid reaction solution can be directly recycled to the reaction.

In some embodiments, the mass of acetic acid added in the intermediate reaction between acetic acid and 3- (N-dihydroxyethyl) aminoacetanilide is 30% to 45% of the total mass of acetic acid, for example: 32%, 35%, 40%, 42%, etc.; in the intermediate reaction, the reaction can be promoted to continue by adding a small amount of acetic acid.

In the intermediate reaction of the present invention, the mass of the separated acetic acid reaction solution is 78% to 82% of the mass of the acetic acid added in the intermediate reaction, for example: 79%, 80%, 81%, etc. Because a small amount of moisture is generated in the esterification reaction process, the method of the invention can separate the small amount of moisture generated in the reaction process along with the acetic acid which does not participate in the reaction (namely, the acetic acid reaction solution), thereby promoting the reaction direction to move forward and accelerating the reaction rate.

In the intermediate reaction of the present invention, the temperature at which acetic acid is separated by raising the temperature is not particularly limited in the present invention, and may be determined depending on the separation, and may be, for example, 120 ℃ or higher.

Further, the acetic acid reaction liquid separated from the intermediate reaction can be recycled to the reaction after being rectified by a hypergravity rectifying device or directly recycled to the reaction according to the condition.

In some specific embodiments, in the first reaction, the acetic acid added is acetic acid with a mass fraction of 90% or more; in the last reaction, the added acetic acid is glacial acetic acid; in the intermediate reaction, the added acetic acid is acetic acid or glacial acetic acid with the mass fraction of more than 90%.

In some specific embodiments, the present invention employs 3 reactions to complete the entire process of the preparation method, specifically:

in the first reaction, in the first reaction of acetic acid and 3- (N-N-dihydroxyethyl) aminoacetanilide, the mass of the added acetic acid is 35 to 55 percent of the total mass of the acetic acid;

the mass of the separated acetic acid reaction liquid is 38 to 42 percent of the mass of the acetic acid added in the first reaction;

the reaction temperature in the first reaction is 100-110 ℃.

Further, in the invention, the acetic acid reaction liquid separated in the first reaction can be recycled to the reaction after being rectified by a hypergravity rectifying device.

In the second reaction (intermediate reaction), the mass of the added acetic acid is 30-45% of the total mass of the acetic acid in the second reaction of the acetic acid and the 3- (N-dihydroxyethyl) aminoacetanilide;

the mass of the separated acetic acid reaction liquid is 78-82% of the mass of the acetic acid added in the second reaction.

Further, the acetic acid reaction liquid separated in the second reaction can be rectified by a hypergravity rectifying device according to the condition and then recycled to the reaction.

In the third reaction (the last reaction), in the third reaction of acetic acid and 3- (N-N-dihydroxyethyl) aminoacetanilide, the mass of the added acetic acid is 15 to 20 percent of the total mass of the acetic acid;

the mass of the separated acetic acid reaction liquid is 68-72% of the mass of the acetic acid added in the third reaction;

the temperature of the acetic acid reaction liquid separated in the third reaction is 135-145 ℃.

Further, in the invention, the mass fraction of acetic acid in the acetic acid reaction solution separated in the third reaction can reach more than 90%, so that the acetic acid reaction solution can be directly recycled to the reaction.

In the first reaction, the added acetic acid is acetic acid with the mass fraction of more than 90%; in the second reaction, the added acetic acid is acetic acid or glacial acetic acid with the mass fraction of more than 90%; in the third reaction, the added acetic acid is glacial acetic acid.

In other specific embodiments, the present invention utilizes 4 reactions to complete the entire process of the preparation process, specifically:

in the first reaction, in the first reaction of acetic acid and 3- (N-N-dihydroxyethyl) aminoacetanilide, the mass of the added acetic acid is 35 to 55 percent of the total mass of the acetic acid;

the mass of the separated acetic acid reaction liquid is 38 to 42 percent of the mass of the acetic acid added in the first reaction;

the reaction temperature in the first reaction is 100-110 ℃.

Further, in the invention, the acetic acid reaction liquid separated in the first reaction can be recycled to the reaction after being rectified by a hypergravity rectifying device.

In the second reaction (intermediate reaction), the mass of the added acetic acid is 15 to 25 percent of the total mass of the acetic acid in the second reaction of the acetic acid and the 3- (N-dihydroxyethyl) aminoacetanilide;

the mass of the separated acetic acid reaction liquid is 78-82% of the mass of the acetic acid added in the second reaction.

Further, the acetic acid reaction liquid separated in the second reaction can be rectified by a hypergravity rectifying device according to the condition and then recycled to the reaction.

In the third reaction (middle reaction), the mass of the added acetic acid is 15-20% of the total mass of the acetic acid in the third reaction of the acetic acid and the 3- (N-dihydroxyethyl) aminoacetanilide;

the mass of the separated acetic acid reaction liquid is 78-82% of the mass of the acetic acid added in the third reaction.

Further, the mass fraction of acetic acid in the acetic acid reaction solution separated in the third reaction can reach more than 90%, so that the acetic acid reaction solution can be directly recycled to the reaction.

In the fourth reaction (the last reaction), in the fourth reaction of acetic acid and 3- (N-N-dihydroxyethyl) aminoacetanilide, the mass of the added acetic acid is 15 to 20 percent of the total mass of the acetic acid;

the mass of the separated acetic acid reaction liquid is 68-72% of the mass of the acetic acid added in the fourth reaction;

the temperature of the acetic acid reaction liquid separated in the fourth reaction is 135-145 ℃.

Further, in the invention, the mass fraction of acetic acid in the acetic acid reaction solution separated in the fourth reaction can reach more than 90%, so that the acetic acid reaction solution can be directly recycled to the reaction.

In the first reaction, the added acetic acid is acetic acid with the mass fraction of more than 90%; in the second reaction, the added acetic acid is acetic acid with the mass fraction of more than 90%; in the third reaction, the added acetic acid is glacial acetic acid in mass fraction; in the fourth reaction, the added acetic acid is glacial acetic acid.

In further specific embodiments, the present invention employs 5 reactions to complete the entire process of the preparation method, specifically:

in the first reaction, in the first reaction of acetic acid and 3- (N-N-dihydroxyethyl) aminoacetanilide, the mass of the added acetic acid is 35 to 55 percent of the total mass of the acetic acid;

the mass of the separated acetic acid reaction liquid is 38 to 42 percent of the mass of the acetic acid added in the first reaction;

the reaction temperature in the first reaction is 100-110 ℃.

Further, in the invention, the acetic acid reaction liquid separated in the first reaction can be recycled to the reaction after being rectified by a hypergravity rectifying device.

In the second reaction (intermediate reaction), in the second reaction of acetic acid and 3- (N-N-dihydroxyethyl) aminoacetanilide, the mass of the added acetic acid is 10 to 15 percent of the total mass of the acetic acid;

the mass of the separated acetic acid reaction liquid is 78-82% of the mass of the acetic acid added in the second reaction.

Further, the acetic acid reaction liquid separated in the second reaction can be rectified by a hypergravity rectifying device according to the condition and then recycled to the reaction.

In the third reaction (middle reaction), the mass of the added acetic acid is 10-15% of the total mass of the acetic acid in the third reaction of the acetic acid and the 3- (N-dihydroxyethyl) aminoacetanilide;

the mass of the separated acetic acid reaction liquid is 78-82% of the mass of the acetic acid added in the third reaction.

Further, the acetic acid reaction liquid separated from the third reaction can be directly recycled to the reaction.

In the fourth reaction (intermediate reaction), in the fourth reaction of acetic acid and 3- (N-N-dihydroxyethyl) aminoacetanilide, the mass of the added acetic acid is 10 to 15 percent of the total mass of the acetic acid;

the mass of the separated acetic acid reaction liquid is 78-82% of the mass of the acetic acid added in the fourth reaction.

Furthermore, the acetic acid reaction liquid separated from the fourth reaction can be directly recycled to the reaction.

In the fifth reaction (the last reaction), in the fifth reaction of acetic acid and 3- (N-N-dihydroxyethyl) aminoacetanilide, the mass of the added acetic acid is 15-20% of the total mass of the acetic acid;

the mass of the separated acetic acid reaction liquid is 68-72% of the mass of the acetic acid added in the fifth reaction;

the temperature after the acetic acid reaction liquid is separated in the fifth reaction is 135-145 ℃.

Further, in the present invention, the acetic acid reaction solution separated in the fifth reaction can be directly recycled to the present reaction.

In the first reaction, the added acetic acid is acetic acid with the mass fraction of more than 90%; in the second reaction, the added acetic acid is acetic acid with the mass fraction of more than 90%; in the third reaction, the added acetic acid is acetic acid or glacial acetic acid with the mass fraction of more than 90%; in the fourth reaction, the added acetic acid is glacial acetic acid in mass fraction; in the fifth reaction, the acetic acid added is glacial acetic acid.

Further, the total reaction time of the preparation method is 15-24 hours. And when the total reaction time is 15-24 hours, obtaining the ruby esterified liquid with excellent performance.

The invention also provides a ruby esterified liquid, which is prepared by the preparation method; preferably, the purity of the ruby esterified liquid is more than 95%, and the content of the perester is less than 1.5%. Furthermore, the shelf life of the ruby esterified liquid is more than 1 year.

Examples

Embodiments of the present invention will be described in detail below with reference to examples, but those skilled in the art will appreciate that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.

Example 1

Heating 238g of 3- (N-N-dihydroxyethyl) aminoacetanilide to 110 ℃ while stirring in a 1000mL three-necked flask, dropwise adding 106g of acetic acid with the mass fraction of 95%, simultaneously starting heating distillation to recover an acetic acid reaction solution, starting adding 48g of acetic acid (with the mass fraction of 95%) when the mass of the recovered acetic acid reaction solution is 44g, simultaneously starting heating distillation to recover the acetic acid reaction solution, starting adding 45g of acetic acid (glacial acetic acid) when the mass of the acetic acid reaction solution recovered for the second time is 38g, simultaneously starting distillation to recover the acetic acid reaction solution, starting adding 45g of acetic acid (glacial acetic acid) for the fourth time when the mass of the acetic acid reaction solution recovered for the third time is 36g (with the mass fraction of the acetic acid recovered at the moment being not less than 90%), continuing distillation to recover the acetic acid reaction solution when the acetic acid reaction solution for the fourth time is recovered to 32g (with the mass fraction of the acetic acid recovered at the moment being not less than 90%) and the temperature of the reaction system at the moment being not less than 90% Cooling to 145 deg.C to room temperature to obtain ruby esterified solution, labeled as S1.

Example 2

Heating 238g of 3- (N-N-dihydroxyethyl) aminoacetanilide to 100 ℃ while stirring in a 1000mL three-necked flask, dropwise adding 121g of 95% by mass acetic acid (part of the acetic acid recovered in the third and fourth times in example 1) while starting heating and distilling to recover an acetic acid reaction solution, starting adding 41g of the second acetic acid (95%) when the mass of the recovered acetic acid reaction solution is 48g, starting heating and distilling to recover the acetic acid reaction solution, starting adding 45g of the third acetic acid (glacial acetic acid) when the mass of the acetic acid reaction solution recovered in the second time is 33g, starting distilling and recovering the acetic acid reaction solution, starting adding 45g of the fourth acetic acid (glacial acetic acid) when the mass of the acetic acid reaction solution recovered in the third time is 36g (the mass fraction of the recovered acetic acid is not less than 90%), and continuing distilling and recovering the acetic acid reaction solution, when the fourth acetic acid reaction solution is recovered to 32g (the mass fraction of the recovered acetic acid is more than or equal to 90 percent) and the temperature of the reaction system is 143 ℃, the temperature is reduced to room temperature, and the ruby esterification solution is obtained, and is marked as S2.

Example 3

Heating 100g of 3- (N-N-dihydroxyethyl) aminoacetanilide to 105 ℃ while stirring in a 250mL three-necked flask, dropwise adding 56g of 95% by mass acetic acid (part of the acetic acid recovered in the third and fourth times in example 2) while starting heating and distilling to recover an acetic acid reaction solution, starting adding 22g of the second acetic acid (mass fraction of 95%) when the mass of the recovered acetic acid reaction solution is 23g, starting heating and distilling to recover the acetic acid reaction solution, starting adding 21g of the third acetic acid (glacial acetic acid) when the mass of the acetic acid reaction solution recovered in the second time is 18g, starting distilling to recover the acetic acid reaction solution, starting adding 20g of the fourth acetic acid (glacial acetic acid) when the mass of the acetic acid reaction solution recovered in the third time is 17g (the mass fraction of the recovered acetic acid is not less than 90%), and continuing distilling to recover the acetic acid reaction solution, when the fourth acetic acid reaction solution is recovered to 14g (the mass fraction of the recovered acetic acid is more than or equal to 90 percent) and the temperature of the reaction system is 140 ℃, the temperature is reduced to room temperature, and the ruby esterification solution is obtained, and is marked as S3.

Example 4

Heating 100g of 3- (N-N-dihydroxyethyl) aminoacetanilide to 108 ℃ while stirring in a 250mL three-necked flask, dropwise adding 53g of 95% acetic acid (part of the acetic acid recovered in the third and fourth times in example 3) while starting heating, distilling and recovering the acetic acid reaction solution, starting adding 22g of the second acetic acid (mass fraction of 95%) when the recovered acetic acid reaction solution is 21g, starting heating, distilling and recovering the acetic acid reaction solution, starting adding 18g of the third acetic acid (mass fraction of 95%) when the acetic acid reaction solution recovered for the second time is 18g, starting heating, distilling and recovering the acetic acid reaction solution, starting adding 18g of the fourth acetic acid (glacial acetic acid) when the acetic acid reaction solution recovered for the third time is 15g (mass fraction of the acetic acid recovered at the moment is not less than 90%), and continuing distilling and recovering the acetic acid reaction solution, when the fourth acetic acid reaction solution is recovered to 13g (the mass fraction of the recovered acetic acid is more than or equal to 90 percent) and the temperature of the reaction system is 136 ℃, the temperature is reduced to room temperature, and the ruby esterification solution is obtained, wherein the label is S4.

Comparative example 1

Taking 238g of 3- (N-N-dihydroxyethyl) aminoacetanilide, stirring and heating to 110 ℃ while raising the temperature, adding 300g of acetic acid with the mass fraction of 95%, starting to react, starting to distill and recover the acetic acid reaction liquid until the mass of the recovered acetic acid reaction liquid reaches 200g, and then cooling to room temperature to obtain a ruby esterified liquid, wherein the label is D1.

Comparative example 2

Taking 115g of 3- (N-N-dihydroxyethyl) aminoacetanilide, stirring and heating to 50 ℃ while heating, adding 75g of acetic acid with the mass fraction of 95%, starting to react, starting to distill and recover acetic acid reaction liquid until the mass of the recovered acetic acid reaction liquid reaches 80g, and cooling to room temperature to obtain ruby esterified liquid, wherein the label is D2.

Comparative example 3 dehydrated 3- (N-dihydroxyethyl) aminoacetanilide 115g and acetic acid 100g are put into an esterification kettle, the temperature is raised while stirring until the temperature in the reaction kettle reaches 110-.

Performance testing

1. Purity test

Purity testing was performed using HPLC.

2. Content of perester

Ester content testing was performed using HPLC.

3. Shelf life

The ruby esterified solutions of examples 1 to 4 and comparative examples 1 to 3 were stored at normal temperature and pressure, and sampled every 1 month, and the product purity was tested by HPLC, and the product purity was found to be less than or equal to 65% and was regarded as expired.

The results of quality tests of the inventive examples and comparative examples are shown in table 1.

TABLE 1

Item	S1	S 2	S 3	S 4	D1	D2	D3
								Purity (%)	95.81	96.37	95.33	96.52	90.51	75.38	94.53
Perester content (%)	1.35	1.28	1.12	0.97	4.53	1.86	2.47
								Shelf life	1 year	1 year	1 year	1 year	1 month	1 month	6 months old

As can be seen from Table 1, the ruby esterified liquid prepared in examples 1 to 4 of the present invention is significantly different from the ruby esterified liquid prepared in comparative examples 1 to 3 in terms of purity, ester content and shelf life.

The purity of the products represented by examples 1-4 is higher than that of comparative examples 1-3, and the content of the perester is lower than that of comparative examples 1-3, which shows that the method provided by the invention can effectively ensure the purity of the products and reduce the content of the perester by using acetic acid to participate in the esterification reaction, and simultaneously, the cost of raw materials can be effectively reduced by using the acetic acid to participate in the reaction. And the acetic acid recovered in the reaction process can be rectified again by the hypergravity rectifying equipment and recycled to the reaction, which is beneficial to the reutilization of resources.

In terms of shelf life, the ruby esterified liquid prepared in the examples 1 to 4 of the present invention can effectively prolong the shelf life of the product to one year, while the ruby esterified liquid prepared in the comparative examples 1 to 2 has a shelf life of only 1 month, and the ruby esterified liquid prepared in the comparative example 3 has a shelf life of 6 months.

In summary, the synthesis method brings great convenience to the production, storage and transportation of the ruby esterified liquid.

The above examples of the present invention are merely examples for clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.