阅读说明：本技术 一种氢甲酯化反应催化剂及制备异壬酸的方法 (Catalyst for methyl hydrogen esterification reaction and method for preparing isononanoic acid ) 是由 刘振峰 袁帅 曹善健 王中华 董龙跃 黄少峰 吕艳红 任亚鹏 赵聪 黎源 于 2018-06-15 设计创作，主要内容包括：本发明公开一种氢甲酯化反应催化剂及制备异壬酸的方法。所述催化剂包含活性金属和配体,所述活性金属为含钴和/或铑的化合物；所述配体的结构式为<Image he="249" wi="319" file="DDA0001697096220000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>其中X<Sub>1</Sub>、X<Sub>2</Sub>、X<Sub>3</Sub>相同或不同,均为含氮杂环基团。所述催化剂适用于二异丁烯、甲醇、一氧化碳为原料进行氢甲酯化反应制备得到异壬酸甲酯,然后进一步水解得到异壬酸。所述催化剂可提高转化率和目标产物的选择性,异壬酸产品收率达92.9％。该方法流程较简单,原料成本低廉,安全性高,而且产品收率较高,具有较好的应用前景。(The invention discloses a catalyst for methyl hydrogenation esterification and a method for preparing isononanoic acid. The catalyst comprises an active metal and a ligand, wherein the active metal is a compound containing cobalt and/or rhodium; the structural formula of the ligand is Wherein X 1 、X 2 、X 3 The same or different, are nitrogen-containing heterocyclic groups. The above-mentionedThe catalyst is suitable for carrying out methyl hydrogenation esterification reaction on diisobutylene, methanol and carbon monoxide serving as raw materials to prepare methyl isononanoate, and then further hydrolyzing to obtain isononanoic acid. The catalyst can improve the conversion rate and the selectivity of a target product, and the yield of the isononanoic acid product reaches 92.9 percent. The method has the advantages of simple process, low raw material cost, high safety, high product yield and good application prospect.)

1. A catalyst for methyl hydrogen esterification reaction comprises a main catalyst and a ligand, wherein the active metal is a compound containing cobalt and/or rhodium; the structural formula of the ligand isWherein X₁、X₂、X₃The same or different, are nitrogen-containing heterocyclic groups.

2. The catalyst according to claim 1, wherein the procatalyst is selected from one or more of rhodium carbonyl, rhodium acetate, rhodium octanoate, rhodium acetylacetonate carbonyl and cobalt carbonyl, preferably one or more of rhodium acetate, rhodium octanoate and cobalt carbonyl.

3. Catalyst according to claim 1 or 2, characterized in that said X₁、X₂、X₃Independently of each other selected from

4. A catalyst according to any one of claims 1 to 3, wherein the ligand is prepared by a process comprising the steps of: adding the compound containing the nitrogenous heterocyclic group into a solvent, uniformly mixing, heating to 50-80 ℃, then dropwise adding phosphorus trihalide into the system, and stirring for 50-100min to obtain a solution containing the ligand.

5. The catalyst according to any one of claims 1 to 4, wherein the molar ratio of the metal element to the ligand in the main catalyst is 1:1 to 1:200, preferably 1:10 to 1: 100.

6. A preparation method of isononanoic acid comprises the following steps:

a) under the inert gas atmosphere, uniformly mixing diisobutylene, methanol and the catalyst of any one of claims 1 to 5, then heating, and introducing carbon monoxide for reaction to obtain a reaction solution a;

b) distilling the reaction liquid a obtained in the step B) to obtain a methyl isononanoate crude product, mixing the methyl isononanoate crude product with water, and reacting under the action of a catalyst B to obtain a reaction liquid B;

c) standing the reaction liquid b obtained in the step b), and distilling supernatant liquid to obtain isononanoic acid.

7. The process according to claim 6, wherein the mass concentration of the metal element in the catalyst of step a) relative to diisobutylene is from 0.0005 to 2 wt.%, preferably from 0.01 to 0.5 wt.%.

8. The method according to claim 6 or 7, wherein in step a), the temperature is raised to 80 to 180 ℃, preferably 100 to 150 ℃.

9. The process according to any one of claims 6 to 8, wherein in step a), the carbon monoxide gas is introduced at a gauge pressure of 2 to 15MPa, preferably 8 to 12 MPa; the reaction time is 1-8 h, preferably 4-6 h.

10. The method according to any one of claims 6 to 9, wherein in step B), the catalyst B is selected from one or more of organic acid, inorganic acid and solid acid, preferably, the catalyst B is selected from one or more of dilute acetic acid, dilute sulfuric acid, acidic alumina and strong acidic resin.

Technical Field

The invention relates to a catalyst for methyl hydrogenation esterification reaction and a preparation method of isononanoic acid, belonging to the technical field of chemical raw material preparation.

Background

Isononanoic acid (3,5, 5-trimethylhexanoic acid) having the structureThe modified alkyd resin has wide application, can be used as a raw material of a synthetic lubricant, a medical intermediate, a raw material of metal soap and metal processing liquid, is also suitable for modifying alkyd resin, can improve yellowing resistance and impact resistance, can be used for producing various isononanoate, can be used in the field of cosmetics, and can be used for different applications such as a paint drier, a vinyl stabilizer, a polyvinyl chloride stabilizer, a preservative, a tire bonding aid and the like.

The preparation of isononanoic acid by aldehyde oxidation is the main production process at present, and the isononanoic aldehyde (3,5, 5-trimethylhexanal) is prepared by the hydroformylation of diisobutylene, hydrogen and carbon monoxide) The isononanal further reacts with oxygen to produce isononanoic acid, the hydroformylation pressure in the production method is high, and the isononanal oxidation process reacts with oxygen, so that the risk of combustion and explosion exists.

Patent CN104379543A discloses that 2-ethylhexanol is used as a raw material, and 2-ethylhexanol is dehydrated to produce octene, and then hydroformylated to produce isononanoic acid, and then oxidized to produce isononanoic acid, and the method uses 2-ethylhexanol as an octene source to provide isononanoic acid based on propylene, but the method has a complicated flow, the hydroformylation reaction requires synthesis gas at a pressure of 10-30MPa, the reaction pressure is high, the risk is high, and the oxygen oxidation reaction is involved, and there is an inherent explosion risk.

Common ligands in current oxo catalyst systems include: phosphanes (phosphanes) (phosphines), phosphinites (phosphites), phosphites (phosphites), etc., which form metal complexes having a six-membered ring transition state structure with transition metals, are widely used in various types of catalytic reactions (Synthesis 2006, No.10, 1557-1571). The conventional phosphorus compounds based on P-C bond structure have poor hydroformylation reactivity and selectivity when used as ligands due to the influence of electron and space effects.

In summary, the conventional method for preparing isononanoic acid by oxidizing isononanoic aldehyde has explosion risk, and the activity and selectivity of the conventional phosphorus compound serving as a ligand in the hydrogen methyl esterification method are low, so that a new hydrogen methyl esterification catalyst with high activity and high selectivity needs to be developed.

Disclosure of Invention

The invention aims to provide a hydrogen methyl esterification catalyst. The catalyst is used for catalyzing diisobutylene methyl hydrogen esterification reaction to prepare methyl isononanoate, has high efficiency and can be recycled.

The invention also provides a preparation method of isononanoic acid, which has the advantages of simple process, low raw material cost, high safety, high product yield and good application prospect.

In order to achieve the purpose of the invention, the technical scheme adopted by the invention is as follows:

a hydromethyl esterification catalyst, the catalyst comprising a procatalyst and a ligand, the active metal being a cobalt and/or rhodium containing compound; the structural formula of the ligand isWherein X₁、X₂、X₃The same or different, are nitrogen-containing heterocyclic groups.

The main catalyst is selected from one or more of rhodium carbonyl, rhodium acetate, rhodium octoate, rhodium acetylacetonate carbonyl and cobalt carbonyl, preferably one or more of rhodium acetate, rhodium octoate and cobalt carbonyl, and more preferably one or more of rhodium acetate, rhodium octoate and cobalt carbonyl.

X of the invention₁、X₂、X₃Independently of each other selected from

A method for preparing the ligand of the invention, comprising the steps of: adding the compound containing the nitrogenous heterocyclic group into a solvent, uniformly mixing, heating to 50-80 ℃, then dropwise adding phosphorus trihalide into the system, and stirring for 50-100min to obtain a solution containing the ligand.

In the preparation method of the ligand, the molar ratio of the compound containing the nitrogen heterocyclic group to the phosphorus trihalide is 3-1: 1, preferably 2-1.2: 1.

The molar ratio of the metal element to the ligand in the main catalyst is 1: 1-1: 200, preferably 1: 10-1: 100.

A preparation method of isononanoic acid comprises the following steps:

a) under the inert gas atmosphere, diisobutylene, methanol and the catalyst are uniformly mixed, then the temperature is raised, and carbon monoxide is introduced for reaction to obtain reaction liquid a;

b) distilling the reaction liquid a obtained in the step B) to obtain a methyl isononanoate crude product, mixing the methyl isononanoate crude product with water, and reacting under the action of a catalyst B to obtain a reaction liquid B;

c) standing the reaction liquid b obtained in the step b), and distilling supernatant liquid to obtain isononanoic acid.

In step b), the methyl hydrogen esterification reaction is carried out, and the formula is as follows:

by adopting the technical route of the invention, diisobutylene is taken as a raw material, and is subjected to methyl esterification reaction with methanol and carbon monoxide, so as to obtain isononanoic acid through hydrolysis, thereby effectively avoiding the inherent explosion risk of isononanoic acid generated by firstly preparing isononanoic aldehyde and then oxidizing the isononanoic aldehyde in the common route. The diisobutylene has two isomers, 2,4, 4-trimethyl-1-penteneAnd 2,4, 4-trimethyl-2-penteneIn the methyl hydrogenation esterification reaction, 2,4, 4-trimethyl-2-pentene is firstly isomerized into 2,4, 4-trimethyl-1-pentene, and 2,4, 4-trimethyl-1-pentene is reacted with methanol and carbon monoxide to generate methyl isononanoate with two structures: 3,5, 5-Trimethylhexanoic acid methyl esterAnd methyl 2,2,4, 4-tetramethylvalerate

In step a) of the present invention, the main catalyst is a compound containing cobalt and/or rhodium, preferably one or more of rhodium carbonyl, rhodium acetate, rhodium octoate, rhodium acetylacetonate carbonyl and cobalt carbonyl, and more preferably one or more of rhodium acetate, rhodium octoate and cobalt carbonyl.

In the step a), the ligand has a structural formulaWherein X₁、X₂、X₃Identical or different, are each a nitrogen-containing heterocyclic group, preferably, X is₁、X₂、X₃Independently of each other selected from

In step a), the preparation method of the ligand comprises the following steps: adding the compound containing the nitrogenous heterocyclic group into a solvent, uniformly mixing, heating to 50-80 ℃, then dropwise adding phosphorus trihalide into the system, and stirring for 50-100min to obtain a solution containing a ligand; the solvent is one or more of alkane, arene and ether; preferably, the solvent is one or more of n-hexane, toluene and dichloromethane.

In step a) of the present invention, the mass concentration of the metal element in the main catalyst of the catalyst relative to diisobutylene is 0.0005 to 2 wt.%, preferably 0.01 to 0.5 wt.%.

In the step a), the molar ratio of methanol to diisobutylene is 1: 1-1: 20, preferably 1: 1.5-1: 10, and more preferably 1: 2-1: 4.

In the step a), the temperature is increased to 80-180 ℃, and preferably 100-150 ℃.

In the step a), the pressure of the introduced carbon monoxide gas is 2-15 MPa (gauge pressure), preferably 8-12 MPa (gauge pressure); the reaction time is 1-8 h, preferably 4-6 h.

In step B) of the present invention, the catalyst B is selected from one or more of organic acid, inorganic acid and solid acid, preferably, the catalyst B is selected from one or more of dilute acetic acid (mass fraction is 5-15%), dilute sulfuric acid (mass fraction is 5-10%), acidic alumina and strong acidic resin.

In the step b), the hydrolysis reaction temperature is 60-100 ℃, and the reaction time is 3-8 h.

Compared with the prior art, the invention has the following advantages:

1. at present, when a traditional phosphorus compound based on a P-C bond structure in a carbonyl synthesis catalytic system is used as a ligand, the activity and selectivity of a carbonylation reaction are poor due to the influence of electronic and space effects. The catalyst for catalyzing the methyl hydrogen esterification reaction adopts a catalyst containing a basic N heterocyclic groupThe ligand with a stable structure can form a stable complex with cobalt or rhodium, so that the stability of the catalyst can be obviously enhanced, the catalytic activity can be further improved, meanwhile, the complex is more stable, and the phenomena of decomposition and the like of the catalyst can be avoided in the subsequent rectification process; in the molecular structure of the phosphine ligand compound, the increase of the N atom number can enhance the alkalinity, the binding capacity of the ligand in the complex is stronger, and the ligand is not easy to dissociate from the complex, so that the selectivity of a linear chain product can be improved, meanwhile, if the ligand molecule is bigger, the space of the complex is more crowded, the substrate and the metal center are close to and coordinated with each other to have a certain space effect, and the selectivity of the target product 3,5, 5-trimethyl methyl hexanoate can be further improved.

2. In the step a), the conversion rate can reach 98%, the selectivity can reach 98.7%, and the final target product isononanoic acid yield can reach 92.9%.

Detailed Description

The present invention is further illustrated by the following examples, which should be construed as limiting the scope of the invention.

The analytical instruments and methods used in the examples are as follows:

nuclear magnetism: Varian-NMR 300;

gas chromatograph: agilent-7820;

gas chromatographic column: 0.25mm 30m DB-5 capillary column, detector FID, vaporizer temperature 280 deg.C, column box temperature 280 deg.C, FID detector temperature 300 deg.C, argon carrying capacity 2.1mL/min, hydrogen flow 30mL/min, air flow 400mL/min, and sample injection 1.0 μ L. The conversion of the olefin and the selectivity of the product were calculated using area normalization. Temperature rising procedure: preheating to 40 deg.C, holding for 5min, and heating at 15 deg.C/min from 40 deg.C to 280 deg.C, and holding for 2 min.