Preparation method of trimethylolpropane diallyl ether

Abstract

The invention belongs to the technical field of chemical production, and particularly relates to a preparation method of trimethylolpropane diallyl ether, which comprises the following steps: S1, adding trimethylolpropane into acetone, and reacting to obtain an oil layer as a first intermediate; s2, adding the first intermediate into dihydropyran, and reacting to obtain a second intermediate; s3, adding water, basic potassium permanganate and a phase transfer catalyst into the second intermediate, and reacting to obtain an oil layer which is a third intermediate; s4, mixing the third intermediate, chloropropene, basic hydroxide and polyethylene glycol, and reacting to obtain a fourth intermediate; and S5, adding the fourth intermediate into diluted hydrochloric acid, and carrying out reduced pressure rectification on the obtained oil layer to obtain a trimethylolpropane diallyl ether finished product. According to the present invention, the protection group is introduced during the preparation process, such that the trimethylolpropane triallyl ether cannot be generated during the reaction under the high reaction activity condition so as to substantially improve the yield of the trimethylolpropane diallyl ether.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical production, and particularly relates to a method for preparing trimethylolpropane diallyl ether. Background Art

[0002] Trimethylolpropane diallyl ether is an important organic compound, which is widely used in resin, coating and other fields.

[0003] At present, the main preparation method of trimethylolpropane diallyl ether is mainly to use trimethylolpropane and allyl chloride as raw materials, react under the action of a catalyst, and then separate the oil phase and obtain the finished product after vacuum distillation.

[0004] The main reaction product of trimethylolpropane and allyl chloride is trimethylolpropane diallyl ether. However, one or three hydroxyl groups of some trimethylolpropane are replaced to generate impurity trimethylolpropane monoallyl ether or impurity trimethylolpropane triallyl ether. Moreover, the three products are difficult to separate, which makes it difficult to achieve high purity of trimethylolpropane diallyl ether.

[0005] In order to improve the yield of trimethylolpropane diallyl ether, it is necessary to strictly control various parameters such as the concentration, proportion, reaction temperature, etc. of the raw materials. Any change in any parameter may lead to a decrease in yield. When the reaction activity is low, it will promote the formation of trimethylolpropane monoallyl ether. When the reaction activity is high, it will promote the formation of trimethylolpropane triallyl ether. However, it is difficult to accurately control the production parameters of each link in the actual production process, resulting in an unstable and low yield of trimethylolpropane diallyl ether actually produced. Summary of the invention

[0006] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a method for preparing trimethylolpropane diallyl ether. By introducing a protecting group during the preparation process and carrying out the reaction under the condition of high reactivity, the formation of trimethylolpropane monoallyl ether is suppressed and trimethylolpropane triallyl ether is not produced, thereby greatly improving the yield of trimethylolpropane diallyl ether.

[0007] The specific technical solution adopted by the present invention is: A method for preparing trimethylolpropane diallyl ether comprises the following steps: S1, adding trimethylolpropane to excess acetone, reacting under acidic conditions, adding water and stirring after the reaction, standing and separating, and the obtained oil layer is the first intermediate; S2, adding the first intermediate to an excess of dihydropyran, reacting under the action of an acidic catalyst, filtering to remove the acidic catalyst after the reaction, and removing the dihydropyran by vacuum distillation to obtain a second intermediate; S3, adding the second intermediate into water, then adding alkaline potassium permanganate and a phase transfer catalyst, filtering to remove the phase transfer catalyst after the reaction, then standing to separate, and the obtained oil layer is the third intermediate; S4, mixing the third intermediate, allyl chloride and alkaline hydroxide, and then adding polyethylene glycol to react to obtain a fourth intermediate; S5. Add the fourth intermediate into dilute hydrochloric acid for reaction, then stand for separation, and perform vacuum distillation on the obtained oil layer to obtain the finished product of trimethylolpropane diallyl ether.

[0008] Furthermore, the acidic catalyst in step S2 includes any one of acidic montmorillonite, kaolin, and ZSM-5 molecular sieve.

[0009] Furthermore, the phase transfer catalyst described in step S3 is a quaternary ammonium salt phase transfer catalyst.

[0010] Furthermore, the reaction temperature in step S3 is 2-8°C, and the reaction time is 3-4h.

[0011] Furthermore, the two intermediates, alkaline potassium permanganate and phase transfer catalyst described in step S3 are 1 part, 2.0-2.2 parts and 0.05-0.06 parts by molar mass, respectively.

[0012] Furthermore, the alkaline hydroxide described in step S4 includes sodium hydroxide or potassium hydroxide.

[0013] Furthermore, the third intermediate, allyl chloride, alkaline hydroxide and polyethylene glycol described in step S4 are 1 part, 2.0-2.2 parts, 3.0-4.0 parts and 0.08-0.10 parts respectively in terms of molar mass fractions.

[0014] Furthermore, the reaction temperature in step S4 is 100-120° C., and the reaction time is 4-8 h.

[0015] Furthermore, the concentration of the dilute hydrochloric acid in step S5 is 10-15%.

[0016] The beneficial effects of the present invention are: 1. In order to stabilize the yield of trimethylolpropane diallyl ether at a high level in the present invention, acetone is first reacted with the 1,2-o-dihydroxyl group of trimethylolpropane to form a five-membered ring protecting group to form a first intermediate, and then dihydropyran is reacted with the 3-hydroxyl group to form a tetrahydropyran protecting group to form a second intermediate. The five-membered ring protecting group is then reduced and deprotected to restore to the 1,2-o-dihydroxyl group to form a third intermediate.

[0017] Since the tetrahydropyran protecting group is relatively stable under alkaline conditions, the tetrahydropyran protecting group will not react during the reaction of the 1,2-o-dihydroxyl group of the third intermediate with allyl chloride. After the reaction, the tetrahydropyran protecting group can be reduced to 3-hydroxyl. Therefore, when the third intermediate reacts with allyl chloride under conditions of high reactivity, the 3-hydroxyl group will not be replaced.

[0018] That is, by adopting the preparation method of the present invention, the reaction is carried out under the condition of high reaction activity, the generation of trimethylolpropane monoallyl ether is suppressed and trimethylolpropane triallyl ether is not generated, thereby greatly improving the yield of trimethylolpropane diallyl ether. At the same time, since various reaction parameters only need to ensure that the reaction activity is at a high level, there is no need to strictly control the production parameters, so that the difficulty of actual production is reduced, and the yield stability of trimethylolpropane diallyl ether is guaranteed. DETAILED DESCRIPTION

[0019] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. 1. Specific embodiments Example 1 S1, adding 1 mol mass fraction of trimethylolpropane to 2.5 mol mass fraction of acetone, reacting for 2 hours at pH = 4, adding water after the reaction, stirring, standing and separating, and the obtained oil layer is the first intermediate; S2, adding 1 mol of the first intermediate to 1.5 mol of dihydropyran, then adding 0.05 mol of acidic montmorillonite, reacting at room temperature for 1 h, filtering the acidic montmorillonite after the reaction, and removing the dihydropyran by vacuum distillation to obtain a second intermediate; S3, adding 1 mol of the second intermediate into water, and then adding 2.1 mol of dilute cold alkaline potassium permanganate and 0.06 mol of octadecyltrimethylammonium bromide, reacting at 5° C. for 4 h, filtering to remove the phase transfer catalyst after the reaction, and then standing to separate, the obtained oil layer is the third intermediate; S4, mixing 1 mol of the third intermediate, 2.8 mol of allyl chloride and 4 mol of sodium hydroxide, adding 0.1 mol of polyethylene glycol, and reacting at 120° C. for 8 h to obtain a fourth intermediate; S5. Add 1 mol mass fraction of the fourth intermediate to 1.2 mol mass fraction of dilute hydrochloric acid, react at 50° C. for 4 hours, then stand for separation, and perform vacuum distillation on the obtained oil layer to obtain the finished product of trimethylolpropane diallyl ether.

[0021] Example 2 S1, adding 1 mol of trimethylolpropane to 2.4 mol of acetone, reacting for 2 h at pH = 4, adding water after the reaction, stirring, standing and separating, and the obtained oil layer is the first intermediate; S2, adding 1 mol of the first intermediate to 1.4 mol of dihydropyran, then adding 0.06 mol of acidic montmorillonite, reacting at room temperature for 1 hour, filtering the acidic montmorillonite after the reaction, and removing dihydropyran by vacuum distillation to obtain a second intermediate; S3, adding 1 mol of the second intermediate into water, and then adding 2.2 mol of dilute cold alkaline potassium permanganate and 0.05 mol of octadecyltrimethylammonium bromide, reacting at 5° C. for 4 h, filtering to remove the phase transfer catalyst after the reaction, and then standing to separate, the obtained oil layer is the third intermediate; S4, mixing 1 mol of the third intermediate, 2.5 mol of allyl chloride and 3 mol of sodium hydroxide, adding 0.08 mol of polyethylene glycol, and reacting at 100° C. for 4 h to obtain a fourth intermediate; S5. Add 1 mol mass fraction of the fourth intermediate to 1.2 mol mass fraction of dilute hydrochloric acid, react at 50° C. for 4 hours, then stand for separation, and perform vacuum distillation on the obtained oil layer to obtain the finished product of trimethylolpropane diallyl ether.

[0022] Example 3 S1, adding 1 mol mass fraction of trimethylolpropane to 2.5 mol mass fraction of acetone, reacting for 2 hours at pH = 4, adding water after the reaction, stirring, standing and separating, and the obtained oil layer is the first intermediate; S2, adding 1 mol of the first intermediate to 1.5 mol of dihydropyran, then adding 0.05 mol of acidic montmorillonite, reacting at room temperature for 1 h, filtering the acidic montmorillonite after the reaction, and removing the dihydropyran by vacuum distillation to obtain a second intermediate; S3, adding 1 mol of the second intermediate into water, then adding 2.1 mol of dilute cold alkaline potassium permanganate and 0.06 mol of octadecyltrimethylammonium bromide, reacting at 5° C. for 3 h, filtering to remove the phase transfer catalyst after the reaction, and then standing to separate, the obtained oil layer is the third intermediate; S4, mixing 1 mol of the third intermediate, 2.6 mol of allyl chloride and 3.5 mol of sodium hydroxide, adding 0.1 mol of polyethylene glycol, and reacting at 110° C. for 6 h to obtain a fourth intermediate; S5. Add 1 mol mass fraction of the fourth intermediate to 1.2 mol mass fraction of dilute hydrochloric acid, react at 50° C. for 4 hours, then stand for separation, and perform vacuum distillation on the obtained oil layer to obtain the finished product of trimethylolpropane diallyl ether.

[0023] Example 4 S1, adding 1 mol mass fraction of trimethylolpropane to 2.5 mol mass fraction of acetone, reacting for 2 hours at pH = 4, adding water after the reaction, stirring, standing and separating, and the obtained oil layer is the first intermediate; S2, adding 1 mol of the first intermediate to 1.5 mol of dihydropyran, then adding 0.05 mol of acidic montmorillonite, reacting at room temperature for 1 h, filtering the acidic montmorillonite after the reaction, and removing the dihydropyran by vacuum distillation to obtain a second intermediate; S3, adding 1 mol of the second intermediate into water, and then adding 2.0 mol of dilute cold alkaline potassium permanganate and 0.06 mol of octadecyltrimethylammonium bromide, reacting at 2° C. for 4 h, filtering to remove the phase transfer catalyst after the reaction, and then standing to separate, the obtained oil layer is the third intermediate; S4, mixing 1 mol of the third intermediate, 2.8 mol of allyl chloride and 3.8 mol of sodium hydroxide, adding 0.08 mol of polyethylene glycol, and reacting at 105° C. for 8 h to obtain a fourth intermediate; S5. Add 1 mol mass fraction of the fourth intermediate to 1.2 mol mass fraction of dilute hydrochloric acid, react at 50° C. for 4 hours, then stand for separation, and perform vacuum distillation on the obtained oil layer to obtain the finished product of trimethylolpropane diallyl ether.

[0024] Example 5 S1, adding 1 mol mass fraction of trimethylolpropane to 2.5 mol mass fraction of acetone, reacting for 2 hours at pH = 4, adding water after the reaction, stirring, standing and separating, and the obtained oil layer is the first intermediate; S2, adding 1 mol of the first intermediate to 1.5 mol of dihydropyran, then adding 0.05 mol of acidic montmorillonite, reacting at room temperature for 1 h, filtering the acidic montmorillonite after the reaction, and removing the dihydropyran by vacuum distillation to obtain a second intermediate; S3, adding 1 mol of the second intermediate into water, and then adding 2.0 mol of dilute cold alkaline potassium permanganate and 0.06 mol of octadecyltrimethylammonium bromide, reacting at 2° C. for 4 h, filtering to remove the phase transfer catalyst after the reaction, and then standing to separate, the obtained oil layer is the third intermediate; S4, mixing 1 mol of the third intermediate, 2.6 mol of allyl chloride and 3.2 mol of sodium hydroxide, adding 0.1 mol of polyethylene glycol, and reacting at 110° C. for 6 h to obtain a fourth intermediate; S5. Add 1 mol mass fraction of the fourth intermediate to 1.2 mol mass fraction of dilute hydrochloric acid, react at 50° C. for 4 hours, then stand for separation, and perform vacuum distillation on the obtained oil layer to obtain the finished product of trimethylolpropane diallyl ether.

[0025] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that no protecting group is generated during the preparation process in Comparative Example 1, and trimethylolpropane is directly reacted with allyl chloride. The specific steps are as follows: S1, 1 mol of trimethylolpropane, 2.8 mol of allyl chloride and 4 mol of sodium hydroxide were mixed, and then 0.1 mol of polyethylene glycol was added, and the mixture was reacted at 120° C. for 8 h to obtain a crude product of trimethylolpropane diallyl ether; S2, allowing the crude trimethylolpropane diallyl ether to stand for separation, and subjecting the obtained oil layer to vacuum distillation to obtain the finished trimethylolpropane diallyl ether.

[0026] Comparative Example 2 The difference between Comparative Example 2 and Comparative Example 1 is that a lower reaction activity is used in Comparative Example 1, and the specific steps are as follows: S1, 1 mol of trimethylolpropane, 2.2 mol of allyl chloride and 2.5 mol of sodium hydroxide were mixed, and 0.05 mol of polyethylene glycol was added, and the mixture was reacted at 80° C. for 4 h to obtain a crude product of trimethylolpropane diallyl ether; S2, allowing the crude trimethylolpropane diallyl ether to stand for separation, and subjecting the obtained oil layer to vacuum distillation to obtain the finished trimethylolpropane diallyl ether.

[0027] 2. Performance Test The finished trimethylolpropane diallyl ether products obtained in Examples 1-3 and Comparative Examples 1-2 were subjected to purity testing to measure the total ether content, trimethylolpropane diallyl ether content, impurity trimethylolpropane monoallyl ether content, and trimethylolpropane triallyl ether content. The test results are shown in Table 1.

[0028] Table 1 As can be seen from Table 1, the yield of trimethylolpropane diallyl ether in the products obtained in Examples 1-5 is above 95%, and the yield is relatively stable even within a larger range of process parameters. In addition, the content of trimethylolpropane monoallyl ether and trimethylolpropane triallyl ether as impurities in the products is low, especially the yield of trimethylolpropane triallyl ether as an impurity is less than 0.5%.

[0029] The other ether impurities in Examples 1-5 are intermediates and reactants that are not completely separated during the reaction, such as dihydropyran and intermediates containing tetrahydropyran protective groups.

[0030] During the preparation of Comparative Examples 1 and 2, due to the lack of protection of the hydroxyl group by the protecting group, a large amount of impurities trimethylolpropane monoallyl ether and trimethylolpropane triallyl ether were generated during the production process, resulting in a trimethylolpropane diallyl ether yield of only about 85%.

[0031] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing trimethylolpropane diallyl ether, characterized in that: The following steps are involved: S1, adding trimethylolpropane to excess acetone, reacting under acidic conditions, adding water and stirring after the reaction, standing and separating, and the obtained oil layer is the first intermediate; S2, adding the first intermediate to an excess of dihydropyran, reacting under the action of an acidic catalyst, filtering to remove the acidic catalyst after the reaction, and removing the dihydropyran by vacuum distillation to obtain a second intermediate; S3, adding the second intermediate into water, then adding alkaline potassium permanganate and a phase transfer catalyst, filtering to remove the phase transfer catalyst after the reaction, then standing to separate, and the obtained oil layer is the third intermediate; S4, mixing the third intermediate, allyl chloride and alkaline hydroxide, and then adding polyethylene glycol to react to obtain a fourth intermediate; S5. Add the fourth intermediate into dilute hydrochloric acid for reaction, then stand for separation, and perform vacuum distillation on the obtained oil layer to obtain the finished product of trimethylolpropane diallyl ether.

2. The method for preparing trimethylolpropane diallyl ether according to claim 1, characterized in that: The acidic catalyst described in step S2 includes any one of acidic montmorillonite, kaolin, and ZSM-5 molecular sieve.

3. The method for preparing trimethylolpropane diallyl ether according to claim 1, characterized in that: The phase transfer catalyst described in step S3 is a quaternary ammonium salt phase transfer catalyst.

4. The method for preparing trimethylolpropane diallyl ether according to claim 1, characterized in that: The reaction temperature in step S3 is 2-8°C and the reaction time is 3-4h.

5. The method for preparing trimethylolpropane diallyl ether according to claim 1, characterized in that: The two intermediates, alkaline potassium permanganate and phase transfer catalyst described in step S3 are 1 part, 2.0-2.2 parts and 0.05-0.06 parts by molar mass, respectively.

6. The method for preparing trimethylolpropane diallyl ether according to claim 1, characterized in that: The alkaline hydroxide described in step S4 includes sodium hydroxide or potassium hydroxide.

7. The method for preparing trimethylolpropane diallyl ether according to claim 1, characterized in that: The third intermediate, allyl chloride, alkaline hydroxide and polyethylene glycol described in step S4 are 1 part, 2.5-2.8 parts, 3.0-4.0 parts and 0.08-0.10 parts respectively in terms of molar mass fractions.

8. The method for preparing trimethylolpropane diallyl ether according to claim 1, characterized in that: The reaction temperature in step S4 is 100-120° C., and the reaction time is 4-8 h.

9. The method for preparing trimethylolpropane diallyl ether according to claim 1, characterized in that: The concentration of the dilute hydrochloric acid in step S5 is 10-15%.

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