Preparation process of 2,2, 4-trimethyl-3-hydroxypentanoic acid
阅读说明：本技术 2,2,4-三甲基-3-羟基戊酸的制备工艺 (Preparation process of 2,2, 4-trimethyl-3-hydroxypentanoic acid ) 是由 卢小松 张世元 姜明秋 王永成 张润赟 于 2019-10-31 设计创作，主要内容包括：本发明涉及精细化工技术领域,具体涉及一种2,2,4-三甲基-3-羟基戊酸的制备工艺。本发明的2,2,4-三甲基-3-羟基戊酸的制备工艺,包括以下步骤：1)异丁醛在碱性催化剂作用下发生羟醛缩合反应,生成2,2,4-三甲基-3-羟基戊醛；2)将步骤1)得到的2,2,4-三甲基-3-羟基戊醛与H<Sub>2</Sub>O<Sub>2</Sub>发生氧化反应得到2,2,4-三甲基-3羟基戊酸。本发明的2,2,4-三甲基-3-羟基戊酸的制备工艺反应产物单一,无需进行多步分离,操作简单。(The invention relates to the technical field of fine chemical engineering, in particular to a preparation process of 2,2, 4-trimethyl-3-hydroxypentanoic acid. The preparation process of the 2,2, 4-trimethyl-3-hydroxypentanoic acid comprises the following steps: 1) isobutyraldehyde is subjected to aldol condensation reaction under the action of an alkaline catalyst to generate 2,2, 4-trimethyl-3-hydroxypentanal; 2) mixing the 2,2, 4-trimethyl-3-hydroxypentanal obtained in the step 1) with H 2 O 2 Oxidation reaction is carried out to obtain 2,2, 4-trimethyl-3-hydroxy valeric acid. The preparation process of the 2,2, 4-trimethyl-3-hydroxypentanoic acid has single reaction product, does not need to carry out multi-step separation, and is simple to operate.)
1. A preparation process of 2,2, 4-trimethyl-3-hydroxypentanoic acid is characterized by comprising the following steps:
1) isobutyraldehyde undergoes aldol condensation reaction under the action of an alkaline catalyst to generate 2,2, 4-trimethyl-3-hydroxypentanal, and the reaction formula is as follows:
2) mixing the 2,2, 4-trimethyl-3-hydroxypentanal obtained in the step 1) with H2O2Oxidation takes place to give 2,2, 4-trimethyl-3-hydroxyvaleric acid, the reaction scheme being:
2. the process for preparing 2,2, 4-trimethyl-3-hydroxypentanoic acid according to claim 1, wherein H in step 2) is2O2Derived from hydrogen peroxideH in the hydrogen peroxide2O2The mass fraction of (A) is 5-70%.
3. The process for preparing 2,2, 4-trimethyl-3-hydroxypentanoic acid according to claim 1, wherein H in step 2) is2O2The mass ratio of the 2,2, 4-trimethyl-3-hydroxypentanal to the 2,2, 4-trimethyl-3-hydroxypentanal is 1: 3.26-4.23.
4. The preparation process of 2,2, 4-trimethyl-3-hydroxypentanoic acid according to claim 2, wherein in the step 2), the 2,2, 4-trimethyl-3-hydroxypentanal obtained in the step 1) is added into a reaction kettle, the temperature is increased to 50-90 ℃, hydrogen peroxide is dropwise added while reaction is carried out, and the reaction lasts for 2-5 hours.
5. The process for preparing 2,2, 4-trimethyl-3-hydroxypentanoic acid according to claim 1, wherein in step 1), isobutyraldehyde and a basic catalyst are respectively added into a reaction kettle, the pH value is adjusted to 10-12, and the mixture is stirred and heated to 30-65 ℃ for reaction for 2-7 hours.
6. The process for preparing 2,2, 4-trimethyl-3-hydroxypentanoic acid according to claim 1, wherein the basic catalyst used in step 1) is NaOH, KOH, Ca (OH)2,BA(OH)2And LiOH.
7. The process according to claim 1, wherein the mass ratio of isobutyraldehyde to the basic catalyst is 100:1 to 3.
Technical Field
The invention relates to the technical field of fine chemical engineering, in particular to a preparation process of 2,2, 4-trimethyl-3-hydroxypentanoic acid.
Background
2,2, 4-trimethyl-3-hydroxypentanoic acid is an important organic chemical raw material, however, in the prior art, the preparation process of 2,2, 4-trimethyl-3-hydroxypentanoic acid is complex in operation, the generated species are various, and multi-step separation and purification are required. For example, the document (Chemical Communications, United Kingdom, 49 (52)), 5889-2O2The mixture of 2,2, 4-trimethyl-3-hydroxypentanal, 2, 4-trimethyl-3-hydroxypentanal and 2,2, 4-trimethyl-1-hydroxypentanal is obtained simultaneously by catalytic reaction, and the 2,2, 4-trimethyl-3-hydroxypentanal can be obtained by separating and purifying the reaction mixture for many times. Furthermore, the literature (ChemSusChem,6(9), 1774-1778; 2013) discloses the use of 2,2, 4-trimethyl-1, 3-pentanediol as starting material, Me (O ═ CC ═ O) Me and H2O2The reaction is carried out as a catalyst to obtain a mixture of 2,2, 4-trimethyl-1, 3-glutaraldehyde, 2, 4-trimethyl-3-hydroxypentanoic acid and 2,2, 4-trimethyl-1-hydroxypentanal, and the reaction mixture also needs to be separated and purified for many times to obtain 2,2, 4-trimethyl-3-hydroxypentanoic acid; and another document (Journal of Natural Products,66(3), 344-; the prior art disclosed above also has problems of raw material not being easily available, low conversion rate of raw material and serious pollution of catalyst.
Disclosure of Invention
The invention aims to provide a preparation process of 2,2, 4-trimethyl-3-hydroxypentanoic acid with a simplified process.
In order to achieve the purpose, the technical scheme of the invention is as follows:
a preparation process of 2,2, 4-trimethyl-3-hydroxypentanoic acid comprises the following steps:
1) isobutyraldehyde undergoes aldol condensation reaction under the action of an alkaline catalyst to generate 2,2, 4-trimethyl-3-hydroxypentanal, and the reaction formula is as follows:
2) mixing the 2,2, 4-trimethyl-3-hydroxypentanal obtained in the step 1) with H2O2Oxidation takes place to give 2,2, 4-trimethyl-3-hydroxyvaleric acid, the reaction scheme being:
h in the step 2)2O2Derived from hydrogen peroxide, H in the hydrogen peroxide2O2The mass fraction of (A) is 5-70%.
H in the step 2)2O2The mass ratio of the 2,2, 4-trimethyl-3-hydroxypentanal to the 2,2, 4-trimethyl-3-hydroxypentanal is 1: 3.26-4.23.
Adding the 2,2, 4-trimethyl-3-hydroxypentanal obtained in the step 1) into a reaction kettle in the step 2), heating to 50-90 ℃, dropwise adding hydrogen peroxide while reacting, and reacting for 2-5 hours.
In the step 1), isobutyraldehyde and a basic catalyst are respectively added into a reaction kettle, the pH value is adjusted to 10-12, the mixture is stirred and heated to 30-65 ℃, and the reaction lasts for 2-7 hours.
The alkaline catalyst used in the step 1) is NaOH, KOH, Ca (OH)2,BA(OH)2And LiOH.
The alkaline catalyst used in the step 1) is derived from an aqueous solution of an alkaline catalyst, and the mass fraction of the alkaline catalyst in the aqueous solution of the alkaline catalyst is 20-40%.
The mass ratio of the isobutyraldehyde to the basic catalyst is 100: 1-3.
The preparation process of the 2,2, 4-trimethyl-3-hydroxypentanoic acid has the beneficial effects that:
the preparation process of 2,2, 4-trimethyl-3-hydroxy valeric acid provided by the invention comprises the step of generating isobutyraldehyde through aldol condensation reaction under the action of a basic catalystTo 2,2, 4-trimethyl-3-hydroxypentanal, then 2,2, 4-trimethyl-3-hydroxypentanal with H2O2The oxidation reaction is carried out to generate crude 2,2, 4-trimethyl-3 hydroxypentanoic acid, and the recrystallization is carried out to obtain the high-purity 2,2, 4-trimethyl-3 hydroxypentanoic acid, the reaction product is single, multi-step separation is not needed, the production process is simplified, the yield of the 2,2, 4-trimethyl-3 hydroxypentanoic acid is high, reactants and a catalyst are common chemical raw materials, and the production cost is low.
Detailed Description
A preparation process of 2,2, 4-trimethyl-3-hydroxypentanoic acid comprises the following steps:
1) isobutyraldehyde undergoes aldol condensation reaction under the action of an alkaline catalyst to generate 2,2, 4-trimethyl-3-hydroxypentanal, and the reaction formula is as follows:
2) mixing the 2,2, 4-trimethyl-3-hydroxypentanal obtained in the step 1) with H2O2Oxidation takes place to give 2,2, 4-trimethyl-3-hydroxyvaleric acid, the reaction scheme being:
h in the step 2)2O2Derived from hydrogen peroxide, H in the hydrogen peroxide2O2The mass fraction of the active carbon is 5 to 70 percent; h2O2The mass ratio of the 2,2, 4-trimethyl-3-hydroxypentanal to the 2,2, 4-trimethyl-3-hydroxypentanal is 1: 3.26-4.23; adding the 2,2, 4-trimethyl-3-hydroxypentanal obtained in the step 1) into a reaction kettle in the step 2), heating to 50-90 ℃, dropwise adding hydrogen peroxide while reacting, and reacting for 2-5 hours.
In the step 1), isobutyraldehyde and a basic catalyst are respectively added into a reaction kettle, the pH value is adjusted to 10-12, the mixture is stirred and heated to 30-65 ℃, and the reaction lasts for 2-7 hours. The alkaline catalyst used in the step 1) is NaOH, KOH, Ca (OH)2、BA(OH)2And LiOH.
The alkaline catalyst used in the step 1) is derived from an aqueous solution of an alkaline catalyst, and the mass fraction of the alkaline catalyst in the aqueous solution of the alkaline catalyst is 20-40%. The mass ratio of the isobutyraldehyde to the basic catalyst is 100: 1-3.