A preparation method of 2,4-d 2-ethylhexyl ester

Abstract

The present invention relates to a method for preparing 2,4 drops of isooctyl ester with high purity and low acidity, wherein 2,4 drops of acid and isooctyl alcohol are reacted under catalyst conditions to generate 2,4 drops of isooctyl ester, the mol ratio of 2,4 drops of acid and isooctyl alcohol is 1: 1.35-1.355, and the reaction time is 9-11 hours. It is characterized in that the catalyst is sodium bisulfate and hydrochloric acid, and sodium bisulfate and hydrochloric acid are not added at the same time; the order of addition is, first, sodium bisulfate is added, catalytic reaction is carried out for a period of time, and then hydrochloric acid is added. The present application changes the product appearance color, improves product purity, and reduces the acidity of the product.

Description

Technical Field

[0001] The invention relates to a method for preparing 2,4-diisooctyl ester. Background Art

[0002] 2,4-Dichlorophenoxyacetic acid 2,4-ethylhexyl ester is a phenoxycarboxylic acid herbicide. It contains 96% active ingredient, and is an amber liquid with a density of 1.15g / cm3.

[0003] Boiling point: 396.9°C (760 mmHg), flash point: 137°C, vapor pressure: 1.65 × 10-6 mmHg (25°C); solubility: sparingly soluble in water, readily soluble in organic solvents such as toluene, xylene, and chloroform. Herbicidal properties: A selective post-emergence contact herbicide for foliar treatment. Suitable crops: soybeans, corn, and wheat.

[0004] Target weeds: annual or perennial broadleaf weeds such as thistle, endive, dayflower, horsetail, quinoa, polygonum, rice pot, nightshade, velvet, ion grass, chickweed, amaranth, humulus, cocklebur, and field bindweed.

[0005] Structural formula:

[0006] .

[0007] Existing technology:

[0008] 1. Sulfuric acid is used as a catalyst in the production process. Sulfuric acid has a high boiling point and is not easy to remove, which affects the acidity of the product and is not conducive to crop protection. It also requires tedious steps of water washing and dehydration, which increases costs.

[0009] 2. Sulfuric acid is a strong oxidizing agent and affects the appearance, color and quality of the product.

[0010] 3. The content is about 96%. A low content contains more impurities and solvents, which is not conducive to solvent recovery. Summary of the Invention

[0011] The invention provides a preparation method of 2,4-diisooctyl ester, which solves the technical problem of changing the appearance color of the product, improving the purity of the product and reducing the acidity of the product.

[0012] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0013] A method for preparing 2,4-diisooctyl ester comprises reacting 2,4-diisooctyl acid and isooctyl alcohol under catalyst conditions to generate 2,4-diisooctyl ester, wherein the molar ratio of 2,4-diisooctyl acid to isooctyl alcohol is 1:1.35-1.355, the reaction temperature is 0-155° C., and the reaction time is 9-11 hours. The catalysts are sodium bisulfate and hydrochloric acid, and the order of adding sodium bisulfate and hydrochloric acid is to first add sodium bisulfate for catalytic reaction and then add hydrochloric acid for catalytic reaction.

[0014] The mass of sodium bisulfate added accounts for 0.1% of the total mass of isooctyl alcohol; the mass of hydrochloric acid added accounts for 1% of the total mass of isooctyl alcohol.

[0015] The catalytic reaction time of sodium bisulfate is 1.5 to 2 hours; the catalytic reaction time of hydrochloric acid is 3 to 4 hours.

[0016] The method further includes introducing nitrogen at a temperature of 145 to 150° C. and maintaining the temperature at a vacuum degree of 0.095 to 0.1 MPa for 1 to 2 hours.

[0017] The invention has the following beneficial technical effects:

[0018] This application changes the appearance color of the product, improves the product purity, and reduces the acidity of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The product images are for comparison 1 and example 1; DETAILED DESCRIPTION

[0020] The present invention is further described below with reference to specific examples. Example 1

[0021] A method for preparing 2,4-diisooctyl ester comprises reacting 2,4-diisooctyl acid and isooctyl alcohol in the presence of a catalyst to generate 2,4-diisooctyl ester, wherein the molar ratio of the 2,4-diisooctyl acid to the isooctyl alcohol is 1:1.35. The reaction temperature is 145° C., the reaction time is 9 hours, nitrogen is introduced to achieve a vacuum degree of 0.095-0.1 MPa, and the vacuum is maintained for 1 hour to obtain 2,4-diisooctyl ester. The catalysts are sodium bisulfate and hydrochloric acid, and the order of adding the sodium bisulfate and the hydrochloric acid is first adding the sodium bisulfate for catalytic reaction, and then adding the hydrochloric acid for catalytic reaction.

[0022] The mass of sodium bisulfate added accounts for 0.1% of the total mass of isooctyl alcohol; the mass of hydrochloric acid added accounts for 1% of the total mass of isooctyl alcohol.

[0023] The reaction time of sodium bisulfate catalysis is 1.5h; the reaction time of hydrochloric acid catalysis is 3h. Example 2

[0024] A method for preparing 2,4-diisooctyl ester comprises reacting 2,4-diisooctyl acid and isooctyl alcohol under catalyst conditions to generate 2,4-diisooctyl ester, wherein the molar ratio of 2,4-diisooctyl acid to isooctyl alcohol is 1:1.355, the reaction temperature is 140° C., the reaction time is 10 hours, nitrogen is introduced to achieve a vacuum degree of 0.095-0.1 MPa, and the vacuum is maintained for 1 hour to obtain 2,4-diisooctyl ester, wherein the catalysts are sodium bisulfate and hydrochloric acid, and the order of adding the sodium bisulfate and the hydrochloric acid is first adding the sodium bisulfate for catalytic reaction, and then adding the hydrochloric acid for catalytic reaction.

[0025] The mass of sodium bisulfate added accounts for 0.1% of the total mass of isooctyl alcohol; the mass of hydrochloric acid added accounts for 1% of the total mass of isooctyl alcohol.

[0026] The reaction time of sodium bisulfate catalysis is 1.8h; the reaction time of hydrochloric acid catalysis is 3.5h. Example 3

[0027] A method for preparing 2,4-diisooctyl ester comprises reacting 2,4-diisooctyl acid and isooctyl alcohol under catalyst conditions to generate 2,4-diisooctyl ester, wherein the molar ratio of 2,4-diisooctyl acid to isooctyl alcohol is 1:1.35, the reaction temperature is 150° C., the reaction time is 11 hours, nitrogen is introduced to achieve a vacuum degree of 0.095-0.1 MPa, and the vacuum is maintained for 1 hour to obtain 2,4-diisooctyl ester. The catalysts are sodium bisulfate and hydrochloric acid, and the order of adding the sodium bisulfate and the hydrochloric acid is first adding the sodium bisulfate for catalytic reaction, and then adding the hydrochloric acid for catalytic reaction.

[0028] The mass of sodium bisulfate added accounts for 0.1% of the total mass of isooctyl alcohol; the mass of hydrochloric acid added accounts for 1% of the total mass of isooctyl alcohol.

[0029] The reaction time of sodium bisulfate catalysis is 1.8h; the reaction time of hydrochloric acid catalysis is 3.5h. Example 4

[0030] A method for preparing 2,4-diisooctyl ester comprises reacting 2,4-diisooctyl acid and isooctyl alcohol under catalyst conditions to generate 2,4-diisooctyl ester, wherein the molar ratio of 2,4-diisooctyl acid to isooctyl alcohol is 1:1.35, the reaction temperature is 145° C., the reaction time is 11 hours, nitrogen is introduced to achieve a vacuum degree of 0.095-0.1 MPa, and the vacuum is maintained for 1 hour to obtain 2,4-diisooctyl ester. The catalysts are sodium bisulfate and hydrochloric acid, and the order of adding the sodium bisulfate and the hydrochloric acid is first adding the sodium bisulfate for catalytic reaction, and then adding the hydrochloric acid for catalytic reaction.

[0031] The mass of sodium bisulfate added accounts for 0.1% of the total mass of isooctyl alcohol; the mass of hydrochloric acid added accounts for 1% of the total mass of isooctyl alcohol.

[0032] The reaction time of sodium bisulfate catalysis is 1.6h; the reaction time of hydrochloric acid catalysis is 3.2h.

[0033] Comparison 1 (except that nitrogen is omitted and the vacuum degree reaches 0.095-0.1 MPa and is maintained for 1 hour, the others are consistent with Example 1), Comparison 2 (except that nitrogen is omitted and the vacuum degree reaches 0.095-0.1 MPa and is maintained for 1 hour, the others are consistent with Example 2), Comparison 3 (except that nitrogen is omitted and the vacuum degree reaches 0.095-0.1 MPa and is maintained for 1 hour, the others are consistent with Example 3) and Example 4 (except that nitrogen is omitted and the vacuum degree reaches 0.095-0.1 MPa and is maintained for 1 hour, the others are consistent with Example 2) are compared with the data of Example 1, Example 2, Example 3 and Example 4. See Table 1 and Table 2

[0034] Table 1

[0035]

[0036] Table 2

[0037]

[0038] From the comparison of the data in Table 1 and Table 2, it can be seen that the present application can improve the purity of 2,4 drops of isooctyl ester, reduce the acidity, and significantly improve the appearance by introducing nitrogen to make the vacuum degree reach 0.095~0.1Mpa and maintaining it for 1h.

[0039] The effect of the order of catalyst addition on the reaction time. In Table 3, except for the order of catalyst addition, all other conditions are the same. Table 4 compares the purity and acidity of 2,4 drops of isooctyl ester obtained at the same reaction time as in Example.

[0040] Table 3

[0041]

[0042] Table 4

[0043]

[0044] From the comparison of the data in Table 3 and Table 4, it can be seen that the order of adding the catalysts not only affects the reaction time, but also affects the purity and acidity of the product under the same conditions.

Claims

1. A method for preparing 2,4-diisooctyl ester, characterized in that: 2,4 drops of acid and isooctyl alcohol are reacted under catalyst conditions to generate 2,4 drops of isooctyl ester, the molar ratio of 2,4 drops of acid to isooctyl alcohol is 1:1.35-1.355, the reaction temperature is 140-155° C., and the reaction time is 9-11 hours. The catalysts are sodium bisulfate and hydrochloric acid, and the order of adding sodium bisulfate and hydrochloric acid is to first add sodium bisulfate to carry out the catalytic reaction and then add hydrochloric acid to carry out the catalytic reaction; The method further includes introducing nitrogen at a temperature of 145 to 150° C. and maintaining the temperature at a vacuum degree of 0.095 to 0.1 MPa for 1 to 2 hours.

2. The method for preparing 2,4 drops of isooctyl ester as claimed in claim 1, characterized in that: The mass of the added sodium bisulfate accounts for 0.1% of the total mass of the isooctyl alcohol; the mass of the added hydrochloric acid accounts for 1% of the total mass of the isooctyl alcohol.

3. The method for preparing 2,4 drops of isooctyl ester as claimed in claim 1, characterized in that: The sodium bisulfate catalytic reaction time is 1.5 to 2 hours; the hydrochloric acid catalytic reaction time is 3 to 4 hours.

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