CN116354791A - A kind of method that chloroalkene prepares isopentenol - Google Patents

Abstract

The invention discloses a method for preparing isopentenol from chloroolefine, which takes chloroisopentene as a raw material, and adds a catalyst into an organic solvent to directly carry out hydrolysis reaction under alkaline conditions. After the hydrolysis is finished, the reactants are subjected to rectification, separation and purification. Wherein the chloroisoamylene: organic solvent: alkali: water: the mass ratio of the catalyst is 10-30: 8-25: 4-25: 5-30: 0.2 to 1. Compared with the existing process for producing the prenyl alcohol, the method has the advantages of simple process, obviously higher yield than the existing process, and considerable economic and social benefits.

Description

A kind of method that chloroalkene prepares isopentenol

technical field

The invention relates to a method for preparing prenol from chlorinated alkenes, in particular to a method for directly hydrolyzing chlorinated isopentene to prepare prenol, and the method does not need esterification before hydrolysis.

Background technique

Isopentenol, that is, 3-methyl-2-buten-1-ol, has a relative molecular weight of 86.13, a density of 0.848g/cm3, a boiling point of 140°C, and a flash point of 43°C. It is a colorless oily liquid with strong pungent odor. It is mainly used to synthesize important precursors of products such as citral, vitamin E, vitamin A, high-efficiency and low-surface toxicity pesticides such as pyrethroids.

At present, prenyl chloride is prepared from prenyl chloride by esterification with sodium acetate under the action of a phase transfer catalyst, and finally prenyl alcohol is hydrolyzed under alkaline conditions. In this process, the water content of sodium acetate is relatively high, and water needs to be removed before use, otherwise the selectivity of prenol will be reduced, and the process is complicated and the amount of waste water is relatively large.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for preparing isopentenol from chloroalkenes in view of the deficiencies in the prior art, which saves the steps of esterification and sodium acetate drying, simplifies the process, and reduces the amount of waste water .

In order to achieve the above object, the present invention adopts the following technical solutions:

A method for preparing isopentenol from chloroalkenes, using chlorinated isopentene as a raw material, adding a catalyst in an organic solvent under alkaline conditions, directly carrying out hydrolysis reaction, and performing rectification, separation and purification after the hydrolysis is completed.

In the above-mentioned technical scheme, described method specifically comprises the following steps:

(1) Add organic solvent, water, alkali and catalyst in the reaction kettle, dropwise add chlorinated isopentene in the system after heating up, keep warm after dropping and carry out hydrolysis reaction;

(2) After the hydrolysis reaction is finished, the temperature is lowered, and the material is filtered and passed into the rectification tower A for rectification separation and purification, to obtain the tower top material and the tower still material, and the tower still material is passed into the rectification tower B for rectification separation, Prenol is obtained overhead.

In the above technical solution, in step (1), the temperature rise refers to temperature rise to 20-100°C; the reaction conditions for the hydrolysis reaction are: the reaction temperature is 20-100°C, and the reaction pressure is normal pressure- 0.45MPa, the reaction time is 0.5h~5h.

In the above technical solution, in step (1), the mass ratio of the chlorinated isopentene:organic solvent:alkali:water:catalyst is 10～30:8～25:4～25:5～30:0.2～ 1.

In the above technical solution, in step (1), the organic solvent is selected from any one of acetonitrile, pyridine, and acetone, or a mixture of two or more mixed in any proportion.

In the above technical solution, in step (1), the alkali is any one of NaOH, potassium carbonate, and disodium hydrogen phosphate, or a mixture of two or more of them mixed in any proportion.

In the above technical solution, in step (1), the catalyst is a three-phase phase transfer catalyst, which is synthesized by grafting polyethylene glycol on polystyrene resin as a carrier.

In the above-mentioned technical scheme, described three-phase phase-transfer catalyst is specifically synthesized through the following steps:

Throw 0.4g of polyvinyl alcohol and 90g of water into the three-necked bottle, and heat up to 80°C. After they are fully dissolved, throw in 16.6g of styrene, and 0.3g of dibenzoyl peroxide is dissolved in the styrene; after 4 hours of reaction, heat up to Continue to react at 95°C for 2 hours to obtain polystyrene resin particles; put the obtained polystyrene resin particles into the reaction bottle, throw 12.8g of chloromethyl ether and 0.3g of aluminum trichloride, and react at 20°C for 12 After 4 hours, chloromethylated polystyrene white balls were prepared; the prepared white balls were dropped into 150g of solvent DMF, and after swelling for 4 hours, 10g of polyethylene glycol was put into the system, and reacted at 60°C for 8 hours to obtain the described three-phase phase transfer catalyst.

In the above technical scheme, in step (2), the material is filtered and passed into rectification tower A for rectification, separation and purification. It is normal pressure, and the reflux ratio at the top of the tower is controlled at 2 to 10, and the bottom material and the top material are harvested.

In the above technical scheme, in step (2), the material in the tower bottom is passed into the rectification tower B for rectification and separation, the temperature at the top of the tower is controlled at 130-143°C, the temperature at the bottom of the tower is controlled at 160-180°C, and the system The pressure is normal pressure, the reflux ratio at the top of the tower is controlled at 5-13, and refined prenol is extracted from the top of the tower.

In the method of the present invention, in the presence of a three-phase phase transfer catalyst in an organic solvent, the chlorinated isopentene is directly hydrolyzed to prepare the prenyl alcohol, thereby avoiding the esterification process and the sodium acetate water removal process. At the same time, the three-phase phase transfer catalyst can be separated and applied mechanically. The advantages of the present invention are very obvious, and the isopentenol can be synthesized more simply.

Detailed ways

The following describes in detail the specific implementation of the technical solution of the present invention, but the present invention is not limited to the following description:

Below in conjunction with specific embodiment, the present invention is set forth:

Embodiment 1～21:

A method for preparing prenol from chloroalkenes, comprising the following steps:

(1) The hydrolysis reaction is carried out in a 2L reaction kettle equipped with a mechanical stirring device, a thermometer, a pressure gauge, a heating device and a cooling device; add an organic solvent, water, alkali and a catalyst in the reaction kettle, and stir and heat up to the required temperature. Temperature, at this temperature, add chlorinated isopentene dropwise to the system, and after the dropwise addition, keep warm and carry out the hydrolysis reaction; the material ratio and reaction conditions in each embodiment are shown in Table 1;

The catalysts in all examples are prepared by the following method: throw 0.4g of polyvinyl alcohol and 90g of water into a three-necked bottle, raise the temperature to 80°C, and after it is completely dissolved, throw in 16.6g of styrene, and the styrene dissolves 0.3g dibenzoyl peroxide; after reacting for 4 hours, raise the temperature to 95°C, and continue to react for 2 hours to obtain polystyrene resin particles; put the prepared polystyrene resin particles into the reaction bottle, and throw 12.8g chlorine Methyl ether and 0.3g of aluminum trichloride were reacted at 20°C for 12 hours to obtain chloromethylated polystyrene white balls; put the prepared white balls into 150g of solvent DMF, and after swelling for 4 hours, put 10g into the system Polyethylene glycol was reacted at 60° C. for 8 hours to obtain the three-phase phase transfer catalyst.

(2) After the hydrolysis reaction is finished, the temperature is lowered, the material is transferred, the catalyst is filtered out, the mother liquor obtained after filtration is passed into rectification tower A for rectification separation and purification, and the obtained tower still material is passed into rectification tower B for further Separation by rectification, extraction of isopentenol by overhead rectification;

The operating conditions in the rectification tower A are as follows: the tower top temperature is controlled at 60-120°C, the tower bottom temperature is controlled at 100-150°C, the system pressure is normal pressure, and the tower top reflux ratio is controlled at 2-10; The conditions in are as follows: the tower top temperature is controlled at 130-143°C, the tower bottom temperature is controlled at 160-180°C, the system pressure is normal pressure, and the tower top reflux ratio is controlled at 5-13; the rectification conditions in each embodiment are detailed See Table 2; The yield of prenol in each embodiment is detailed in Table 2:

The reaction conditions of each embodiment step (1) of table 1

The reaction conditions and prenol yield of each embodiment step (2) of table 2

The above examples are only for illustrating the technical concept and technical characteristics of the present invention, and cannot limit the protection scope of the present invention. All equivalent changes or modifications made according to the essence of the present invention shall fall within the protection scope of the present invention.

Claims (10)

1. A process for preparing isopentenol from chloroolefine includes such steps as adding catalyst to the chloroisopentene in organic solvent under alkaline condition for hydrolysis reaction, rectifying, separating and purifying.

2. The method according to claim 1, characterized in that it comprises the following steps:

(1) Adding an organic solvent, water, alkali and a catalyst into a reaction kettle, heating, dropwise adding chloroisopentene into a system, and carrying out hydrolysis reaction after dropwise adding, and preserving heat;

(2) Cooling after the hydrolysis reaction is finished, filtering the materials, introducing the materials into a rectifying tower A for rectifying, separating and purifying to obtain tower top materials and tower bottom materials, introducing the tower bottom materials into a rectifying tower B for rectifying and separating, and obtaining the isopentenol at the tower top.

3. The method according to claim 2, wherein in step (1), the temperature is raised to 20-100 ℃; the hydrolysis reaction is carried out under the following reaction conditions: the reaction temperature is 20-100 ℃, the reaction pressure is normal pressure-0.45 MPa, and the reaction time is 0.5-5 h.

4. The method of claim 2, wherein in step (1), the chloroisoamylene: organic solvent: alkali: water: the mass ratio of the catalyst is 10-30: 8-25: 4-25: 5-30: 0.2 to 1.

5. The method according to claim 2, wherein in the step (1), the organic solvent is selected from the group consisting of acetonitrile, pyridine, and acetone, and a mixture of two or more of them in any ratio.

6. The method according to claim 2, wherein in the step (1), the alkali is a mixture of any one, two or more of NaOH, potassium carbonate and disodium hydrogen phosphate in any ratio.

7. The method according to claim 2, wherein in the step (1), the catalyst is a three-phase transfer catalyst, and is synthesized by grafting polyethylene glycol onto a polystyrene resin as a carrier.

8. The method according to claim 7, wherein the three-phase transfer catalyst is synthesized by the steps of:

adding 0.4g of polyvinyl alcohol and 90g of water into a three-port bottle, heating to 80 ℃, adding 16.6g of styrene after complete dissolution, wherein 0.3g of dibenzoyl peroxide is dissolved in the styrene; after reacting for 4 hours, heating to 95 ℃, and continuing to react for 2 hours to obtain polystyrene resin particles; putting the prepared polystyrene resin particles into a reaction bottle, adding 12.8g of chloromethyl ether and 0.3g of aluminum trichloride, and reacting for 12 hours at 20 ℃ to prepare chloromethylated polystyrene white balls; the prepared white balls are put into 150g of solvent DMF, swelled for 4 hours, then 10g of polyethylene glycol is put into the system, and the reaction is carried out for 8 hours at 60 ℃ to obtain the three-phase transfer catalyst.

9. The method according to claim 2, wherein in the step (2), the materials are filtered and then fed into a rectifying tower A for rectifying, separating and purifying, the tower top temperature is controlled to be 60-120 ℃, the tower bottom temperature is controlled to be 100-150 ℃, the system pressure is normal pressure, the tower top reflux ratio is controlled to be 2-10, and the tower bottom materials and the tower top materials are obtained through collection.

10. The method of claim 2, wherein in the step (2), the tower bottom material is introduced into a rectifying tower B for rectifying and separating, the tower top temperature is controlled to be 130-143 ℃, the tower bottom temperature is controlled to be 160-180 ℃, the system pressure is normal pressure, the tower top reflux ratio is controlled to be 5-13, and the refined isopentenol is extracted from the tower top.