JP2003306459A - Method for chlorinating 1,3-propanediol - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an industrially advantageous method for chlorinating a 1,3-propanediol of the formula(1) with hydrogen chloride in high yield. <P>SOLUTION: The method for chlorinating the 1,3-propanediol of formula(1) [wherein, R<SP>1</SP>and R<SP>2</SP>are each H or an optionally branched (substituted) 1-8 aliphatic hydrocarbon group or joined together to form an optionally branched bivalent 2-8C aliphatic hydrocarbon group] comprises introducing an effluent gas from a chlorination reaction liquid into a rectifier and returning the resultant condensate via the rectifier to a reaction vessel to keep useful components including the product and raw materials within the reaction system. By this method, the useful components, together with hydrochloric acid, can be kept from leaking out of the reaction system, thus enabling the chlorination of the 1,3-propanediol with the hydrogen chloride to be carried out in high yield. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for chlorinating 1,3-propanediol represented by the following formula (1), wherein the chlorine-substituted product of the formula (1) obtained is an organic synthetic intermediate. And is used as an intermediate raw material of an oxetane compound which is a monomer capable of ring-opening polymerization.

[0002]

[Chemical 2]

In the formula (1), R¹And R²Are different
Charcoal that may have hydrogen atoms or substituents
An aliphatic hydrocarbon group which may have a branch number of 1 to 8 or
Is R ¹And R²And are combined to form a divalent C2-C8 branch.
Represents an aliphatic hydrocarbon group which may have.

[0004]

2. Description of the Related Art As a method for chlorinating 1,3-propanediols with hydrogen chloride, 160-
A method of reacting trimethylolpropane with hydrogen chloride gas under heating conditions of 180 ° C. is disclosed in JP-A-10-139.
No. 700 publication. The method described in this patent distills gas mainly containing xylene, water and hydrogen chloride, condenses it in a condenser, separates the condensate into an organic liquid consisting of xylene and hydrochloric acid, and an organic liquid. Is returned to the reactor to carry out the reaction while removing water produced from the reaction system. However, according to this method, 2-chloromethyl-
As a result of examining that useful components such as 2-ethyl-1,3-propanediol and 2,2-bis (chloromethyl) butan-1-ol are contained, it became clear as a result. When chlorination of 2,2-dimethyl-1,3-propanediol is carried out by the same method, 2,2
As a result of examining the fact that dimethyl-3-chloropropanol was contained in the separated hydrochloric acid, it became clear. Therefore, in the conventional method, the raw material and the product go out of the reaction system together with the removed hydrochloric acid, and a sufficient yield cannot be obtained.

[0005]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the problems of the prior art described above, and chlorine of 1,3-propanediol represented by the above formula (1) by hydrogen chloride. The object of the present invention is to provide an industrially advantageous method which can be used in a high yield.

[0006]

The inventors of the present invention have conducted extensive studies to solve the above-mentioned problems, and as a result, have chlorinated 1,3-propanediol represented by the above formula (1) with hydrogen chloride. In the method, the distillate gas from the chlorination reaction liquid is introduced into a column having a rectification capacity (rectification column), the reaction product water is removed from the condensate of the distillate gas, and this condensate is stored in the rectification column. The present inventors have found a production method in which useful components such as raw materials and products are retained in the reaction system by returning them to the reaction tank through. By this method, useful components such as products and raw materials can be prevented from leaking out of the reaction system together with hydrochloric acid,
The inventors have found that chlorination of 1,3-propanediols with hydrogen chloride can be performed in good yield, and have completed the present invention.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, 1,3-propanediol represented by the above formula (1), which is a raw material, has a branch having 1 to 8 carbon atoms represented by R ¹ and R ^2. Examples of the aliphatic hydrocarbon group also include an alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, an amyl group, an isoamyl group, a hexyl group, and an octyl group. Alternatively, a cycloalkyl group such as a cyclopentyl group or a cyclohexyl group can be used. Examples of the aliphatic hydrocarbon group in which R ¹ and R ² are united and which may have a divalent C 2-8 branched chain include, for example, a trimethylene group, a tetramethylene group, a hexamethylene group and the like. Can be mentioned. And
As the substituent which these aliphatic hydrocarbon groups may have, any substituent may be used as long as it does not adversely affect the chlorination reaction, for example, a hydroxyl group, a fluorine atom, a halogen atom such as chlorine, bromine and iodine, Examples thereof include alkoxy groups such as methoxy group and ethoxy group, and cycloalkyl groups such as cyclopentyl group and cyclohexyl group.

Specific examples of 1,3-propanediols used in the present invention include 1,3-propanediol, 2-methyl-1,3-propanediol, 2,
2-dimethyl-1,3-propanediol, 2-methyl-2-hydroxymethyl-1,3-propanediol (also known as trimethylolethane), 2-ethyl-2-hydroxymethyl-1,3-propanediol ( Alias: trimethylolpropane), 2,2-bis (hydroxymethyl) -1,3-propanediol (alias: pentaerythritol), 2-chloromethyl-2-ethyl-1,3
-Propanediol, cyclohexane-1,1-dimethanol, 2-methyl-cyclohexane-1,1-dimethanol and the like.

The present invention relates to a method of chlorinating 1,3-propanediol represented by the above formula (1) with hydrogen chloride, for example, by using a compound which forms an azeotropic mixture with water as a solvent. Water generated during the process is distilled off from the chlorination reaction system. When carrying out this chlorination, in a column having a rectification capacity (rectification column), a gas distilled from the reaction system and a solvent obtained by removing water from a condensed liquid of the distilled gas are countercurrently contacted. As a result, useful components such as 1,3-propanediol and its chlorinated product are recovered in the solvent in the rectification column and returned to the chlorination reaction tank (also referred to as reaction tank) to carry out the chlorination reaction. To do. The rectification column used may be a plate column type, a packed column type, or the like, and may be an industrially used rectification column. Further, the rectification temperature may be controlled.

Since this reaction is carried out while distilling water produced during the chlorination reaction together with a solvent, hydrogen chloride, etc., it is desirable to carry out the reaction under the temperature and pressure conditions at which the produced water evaporates. This temperature is 50 ℃ ~ 250 ℃
And the preferred temperature is 100 ° C to 200 ° C. Fifty
It cannot be said that a sufficient reaction rate can be obtained at a temperature lower than 0 ° C, while on the other hand, at a temperature higher than 250 ° C, by-products such as oligomeric substances may increase. Further, when the temperature is higher than the temperature at which water evaporates, it is not necessary to use a solvent that forms an azeotropic mixture with water.

This reaction can be carried out in the presence of a carboxylic acid in order to improve the reaction rate. Examples of the carboxylic acid to be used include acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid and benzoic acid. preferable. The amount used is preferably 0.01 to 0.5 mol times the 1,3-propanediol starting material.

In the present invention, the solvent used in the reaction may be a compound which is inactive to the raw materials and the reaction product. As the solvent, compounds that form an azeotropic mixture with water as described above are suitable, and among them, organic compounds except alcohols and esters are particularly suitable. This makes it easy to distill water,
The reaction can be carried out smoothly. Suitable solvents include
Examples thereof include benzene, toluene, xylene, ethylbenzene, chlorobenzene, 1,2-dichloroethane and tetrachloroethylene. The amount of the solvent is preferably 0.01 to 100 parts by weight, more preferably 0.05 to 10 parts by weight, based on 1 part by weight of the total amount of the raw material and the reaction product in the reactor. If it exceeds 100 parts by weight, the yield per unit volume decreases, that is, a large reaction container is required, and the energy required for recovering the solvent increases, which is not economical. On the other hand, if the amount is less than 0.01 part by weight, it may not be said that the effect of using the solvent is exhibited.

The reaction mode of the chlorination reaction may be either a batch system or a continuous system. In the batch system, 1,3-propanediol represented by the above formula (1), a carboxylic acid and a solvent as needed are charged into a reactor, and then hydrogen chloride gas is supplied to generate water in the reaction system. Chlorination is carried out while distilling off. At this time, the gas distilled from the reaction system to the rectification column and water from the condensed liquid of the distilled gas (becomes hydrochloric acid because hydrogen chloride is dissolved)
Countercurrent contact is made with the solvent etc. As a result, the useful component is recovered in the solvent in the rectification column and returned to the reactor to carry out the chlorination reaction, and the reaction is terminated when a predetermined amount of water is distilled.

In the continuous type, 1, represented by the above formula (1),
Chlorination is performed while continuously supplying 3-propanediols, a carboxylic acid and a solvent, and hydrogen chloride gas as needed to the reactor, and distilling the produced water from the reaction system.
At this time, countercurrent contact is made between the gas distilled from the reaction system in the rectification column and a solvent, etc., in which water (which has become hydrochloric acid because hydrogen chloride is dissolved) has been removed from the condensed liquid of the distilled gas. By doing so, the useful components are recovered in the solvent in the rectification column and returned to the reactor to carry out the reaction. At this time, the reaction liquid may be extracted according to the amount of the raw material supplied.

As these reactors, a tank type, a tube type, or a column type (which may be filled with packing) in which the reaction liquid and hydrogen chloride gas are brought into countercurrent or cocurrent contact can be used.

The reaction solution obtained by the above production method is a solvent,
When a raw material, a monochloro-substituted product, a dichloro-substituted product, and a carboxylic acid, which are reaction products, are used, it is a mixed solution containing the ester thereof. The reaction product such as a monochloro-substituted product or a dichloro-substituted product can be separated by an operation such as distillation or crystallization. In the production method of the present invention, the content ratio of the monochloro substitution product (the ester form) and the dichloro substitution product (the ester form) can be adjusted by changing the reaction time or the residence time, and the monochloro substitution can be performed at a desired ratio. (The ester form) and the dichloro-substituted form (the ester form) can be produced. In the chlorination reaction of the formula (1), the treatment of the waste liquid removed as hydrochloric acid is mitigated by using the production method of the present invention because the waste liquid contains no or very little organic components such as useful components ( For example, neutralization treatment only).

The present invention is a method for producing a chlorine-substituted compound of the formula (1), characterized in that a reaction tank equipped with a rectification column is used, wherein the distillate gas condensed from the chlorination reaction solution in the reaction tank is condensed. A method for producing a chlorine-substituted product, characterized in that the reaction product water (which becomes hydrochloric acid because hydrogen chloride dissolves) is removed from the liquid, and the condensate from which this hydrochloric acid is removed is returned from the upper part of the rectification column to the reaction tank. The production method is characterized by using a solvent that forms an azeotropic mixture with water when carrying out this chlorination reaction.

The chlorination of formula (1) has been described, but the use of hydrogen bromide instead of hydrogen chloride will yield the bromide of formula (1). And the bromide of formula (1) can be used for the same purpose as the chlorinated compound of formula (1).

[0019]

EXAMPLES The present invention will be specifically described below with reference to examples.

<Embodiment 1> As shown in the schematic diagram of FIG. 1, a stirrer, a gas blowing pipe, a thermometer, a water dividing tank, a condenser, and a rectification tower (25 mmφ × 300 mmL, filled with 100 cc of glass helicopter coil) were installed. 2,2-Dimethyl-1,3-in a glass 1,000 ml flask equipped.
624.9 g of propanediol (hereinafter abbreviated as NPG)
(6.0 mol), 90.0 g (1.5 mol) of acetic acid, and 80 g of toluene (hereinafter abbreviated as TOL) were charged and heated with stirring until TOL refluxed. Then, under the reflux of TOL, hydrogen chloride gas was supplied into the flask / reactor at a flow rate of 134.4 liter / hour. The gas distilled from the reactor was cooled and condensed by a condenser through a rectification column, hydrochloric acid was removed from the condensate in a water dividing tank, and hydrogen chloride-containing TOL was returned to the reaction system through the rectification column. This reaction was carried out for 6 hours. The reaction temperature was gradually raised while observing the reflux state of TOL, and finally the reaction liquid temperature increased to 158 ° C. After completion of the reaction, dissolved hydrochloric acid was removed by nitrogen to obtain 841 g of a chlorination reaction solution. The composition of this reaction solution is gas chromatography (hereinafter abbreviated as GC. Analysis conditions are: capillary column: TC-WAX).
(GL Science Co., Ltd.), column temperature: 80 to 24
Temperature rise to 0 ℃, Carrier gas: Helium, Detection: FI
Analysis by D) showed that 3-chloro-2,2-dimethylpropanol (hereinafter abbreviated as CNP) was 61.6% by weight, and CNP acetate body (hereinafter abbreviated as CNPE) was 2%.
1.3% by weight, 2.6% by weight of NPG, 2.3% by weight of acetate of NPG (hereinafter abbreviated as NPGE), TOL
Was contained by 8.6% by weight. Also, 202 g of hydrochloric acid was distilled out, and the useful component amount contained in the hydrochloric acid was changed to GC.
It was found to contain 0.2% by weight of CNP. From this result, the reaction yield of CNP and CNPE is
It was 88.6%. Reaction yield (%) of CNP and CNPE = (CN in the reaction solution
P amount (mol) + CNPE amount (mol)) x 100 / prepared N
PG amount (mol)

<Comparative Example 1> A chlorination reaction was carried out for 6 hours in the same apparatus and conditions as in Example 1 except that the rectification column shown in FIG. 1 was removed. The reaction temperature was gradually raised while observing the reflux state of TOL, and finally the reaction liquid temperature rose to 158 ° C. After completion of the reaction, dissolved hydrochloric acid was expelled with nitrogen to obtain 787 g of a chlorination reaction solution. The composition of this reaction solution was analyzed by GC to find that CNP was 58.7% by weight, CNPE was 22.0% by weight, NPG was 3.3% by weight, NPGE was 2.8% by weight, and TOL was 9.1% by weight. % Was included. Further, 254 g of hydrochloric acid was distilled out, and the amount of useful components contained in the hydrochloric acid was analyzed by GC. As a result, NPG was 9.8% by weight, NPGE was 1.7% by weight, and CNP was 9.8% by weight. Was included. From this result, the reaction yield of CNP and CNPE was 80.3%.

In Comparative Example 1, some of the raw materials and the target compound were distilled, but in Example 1, it was found that they were hardly distilled and remained in the reaction solution. From this, the yield can be improved and the waste liquid treatment can be reduced.

Example 2 Using the apparatus shown in FIG. 1 as in Example 1, 805 g (6.0 mol) of trimethylolpropane (hereinafter abbreviated as TMP) and 90.0 g of acetic acid were used.
(1.5 mol) and 110 g of meta-xylene (abbreviated as XYL below) were charged, heated with stirring until XYL refluxed, and under reflux of XYL, hydrogen chloride gas was supplied at a flow rate of 134.4 liters / hour. did. Hydrochloric acid distilled with XYL was separated in a water diversion tank, and a chlorination reaction was carried out for 12 hours while extracting this from the lower part of the water diversion tank. The reaction temperature was gradually increased while watching the reflux state of XYL, and finally the reaction liquid temperature was raised to 180 ° C. After completion of the reaction, dissolved hydrochloric acid was expelled with nitrogen to obtain 1177 g of a chlorination reaction solution. When the composition of this reaction solution was analyzed by GC, it was found that 2,2-bis (chloromethyl) butan-1-ol (hereinafter abbreviated as BCP) was 59.8% by weight and 2- (chloromethyl) -2-ethylpropane. 0.3% by weight of -1,3-diol (hereinafter abbreviated as MCP), 26.8% by weight of BCP acetate body (hereinafter abbreviated as BCPE), and 0.1% of MCP acetate body (hereinafter abbreviated as MCPE). weight%,
It contained 8.5% by weight of XYL. Also, 368g
Hydrochloric acid was distilled off, and the amount of useful components contained in the hydrochloric acid was analyzed by GC to find that TMP, MCP, BCP
Neither was detected. From this result, BCP and BC
The reaction yield of PE was 93.2%. Reaction yield (%) of BCP and BCPE = (BC in the reaction solution
P amount (mol) + BCPE amount (mol)) x 100 / prepared T
MP amount (mol)

Comparative Example 2 The rectification column was removed from the apparatus shown in FIG. 1 and the reaction was performed under the same chlorination conditions as in Example 2.
I went on time. The reaction temperature was gradually increased while observing the reflux state of XYL, and finally the reaction liquid temperature increased to 178 ° C. After completion of the reaction, expel dissolved hydrochloric acid with nitrogen,
1168 g of chlorinated reaction liquid was obtained. When the composition of this reaction solution was analyzed by GC, BCP was 57.9% by weight,
1.5% by weight of MCP, 26.5% by weight of BCPE, M
It contained 0.8% by weight of CPE and 8.6% by weight of XYL. Further, when 348 g of hydrochloric acid was distilled out and the amount of useful components contained in the hydrochloric acid was analyzed by GC,
TMP 0.4% by weight, MCP 0.9% by weight, BCP
Was contained in an amount of 0.5% by weight. From this result, the reaction yield of BCP and BCPE was 90.1%.

In Comparative Example 2, some of the raw materials and the target compound were distilled out, but in Example 2, it was found that they were hardly distilled out and remained in the reaction solution. From this, the yield can be improved and the waste liquid treatment can be reduced.

[0026]

By using the manufacturing method of the present invention,
This is an economically advantageous production method because chlorination of 1,3-propanediol represented by the formula (1) with hydrogen chloride can be carried out in good yield.

[0027]

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a chlorination device for hydrogen chloride of 1,3-propanediol represented by the formula (1) Condenser: Distilled organic solvent, generated water and gases such as hydrogen chloride are condensed. Water separation tank: Hydrochloric acid is separated from the organic solvent condensed by the condenser and the water produced by the reaction (hydrogen chloride dissolves to become hydrochloric acid), and the organic solvent is returned to the chlorination reaction system (reaction tank) through the rectification tower. Detoxification tower: Waste liquid treatment to neutralize and remove harmful substances such as hydrogen chloride.

Claims (4)

[Claims] 1. A reaction vessel equipped with a rectification column is used.
A method for producing a chlorine-substituted compound represented by the following formula (1): [Chemical 1] (In the formula (1), R¹And R²Can be different
1 to 8 carbon atoms which may have a hydrogen atom or a substituent
An aliphatic hydrocarbon group optionally having R or R ¹And R²
And has a divalent C2-C8 branch.
Represents a good aliphatic hydrocarbon group. ) 2. The method according to claim 1, wherein hydrochloric acid is removed from the condensate of the distillate gas from the chlorination reaction solution, and the condensate from which the hydrochloric acid has been removed is returned from the upper part of the rectification column into the reaction tank. Manufacturing method. 3. The chlorination of the formula (1) is carried out by contacting the distillate gas with the condensate from which hydrochloric acid is removed in the rectification column to prevent the useful component from leaking out of the system. Claim 1
Or the manufacturing method according to 2. 4. The production method according to each of claims 1 to 3, wherein a solvent which forms an azeotropic mixture with water is used.