Process for producing itaconic acid chloride

Abstract

To provide a production method of itaconic acid chloride allowing production of itaconic acid chloride in good yield without handling dangerous reagents or wastes.SOLUTION: The production method of itaconic acid chloride comprises reacting itaconic acid or itaconic anhydride with a dichloromethyl alkyl ether represented by general formula (1) in the figure in the presence of a lewis acid catalyst. In the formula, R represents a C1-4 alkyl group.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for producing itaconic acid chloride.

Background Art

[0002] Itaconic acid is expected to be used as a plant-derived high molecular monomer. However, under the polymerization conditions of a polycondensation polymer using the carboxyl group of itaconic acid, it is difficult to produce a high molecular weight polymer while retaining the internal olefin of itaconic acid. On the other hand, since itaconic acid chloride is more reactive than itaconic acid, it is expected to relax the polymerization conditions and obtain a polycondensation polymer having an internal olefin.

[0003] For example, as a method for synthesizing itaconic acid chloride using itaconic acid as a raw material, a method using thionyl chloride as a chlorinating agent is described in Patent Document 1 or 2, and a method using phosphorus pentachloride as a chlorinating agent is described in Non-Patent Document 1. In addition, a document for synthesizing itaconic acid chloride by reacting phosphorus pentachloride with itaconic anhydride as a raw material is also known (Non-Patent Document 2). However, except for these methods, almost no production methods of itaconic acid chloride are known.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Non-Patent Documents

[0005]

Non-Patent Document 1

Non-Patent Document 2

[0006] However, as a result of the studies by the present inventors, it has been found that it is impossible to obtain itaconic acid chloride in good yield by the methods described in Patent Document 1 or 2 above (see Comparative Examples 2 and 3 in the specification of the present application). Further, even if itaconic acid chloride can be obtained in good yield through detailed condition studies, special equipment is required for the treatment of by-produced sulfur dioxide, which is not suitable for industrial implementation. Phosphorus pentachloride used in the methods described in Non-Patent Document 1 or 2 is designated as a poison and is difficult to handle in large quantities, and is not suitable for industrial implementation. The conventional methods for producing itaconic acid chloride have the above problems, and there is a demand for a new method for producing itaconic acid chloride from the viewpoint of industrial implementation.

[0007] Therefore, an object of the present invention is to provide a method for producing itaconic acid chloride that can obtain itaconic acid chloride in good yield without handling dangerous reagents or waste. Means for Solving the Problems

[0008] In view of the above problems, the present inventors have repeatedly studied the chlorination reaction of itaconic acid to obtain itaconic acid chloride from the viewpoints of chlorinating agents and catalysts. As a result, it has been found that when dichloromethyl alkyl ether is reacted with itaconic acid in the presence of a Lewis acid catalyst such as a zinc catalyst, high-purity itaconic acid chloride can be obtained in high yield. Further, it has been found that high-purity itaconic acid chloride can also be obtained in high yield when using anhydrous itaconic acid as a raw material by the method found by the present inventors. The present invention has been completed based on these findings.

[0009] That is, the above problems have been solved by the following means. [1] A method for producing itaconic acid chloride, comprising reacting itaconic acid or itaconic anhydride with a dichloromethyl alkyl ether represented by the following general formula (1) in the presence of a Lewis acid catalyst.

Chemical formula

[0010] In the present invention, the numerical range represented by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value.

Advantages of the Invention

[0011] According to the method for producing itaconic acid chloride of the present invention, itaconic acid chloride can be obtained in a good yield without handling dangerous reagents and wastes. In addition, according to the method for producing itaconic acid chloride of the present invention, the by-produced alkyl formate can be recovered and reused as a raw material for dichloromethyl alkyl ether.

Modes for Carrying Out the Invention

[0012] <Method for Producing Itaconic Acid Chloride> In the method for producing itaconic acid chloride of the present invention (hereinafter, also referred to as "the production method of the present invention"), as described above, in the presence of a Lewis acid catalyst, itaconic acid chloride (ClC(=O)C(=CH2)CH2C(=O)Cl) is produced in a good yield by a chlorination reaction of reacting itaconic acid or itaconic anhydride with a dichloromethyl alkyl ether represented by the following general formula (1). By the above chlorination reaction, itaconic acid chloride is usually obtained as a mixture of itaconic acid chloride, formic acid ester, and itaconic anhydride (hereinafter, also referred to as “reaction mixture”). By a simple purification process of distilling the reaction mixture of this chlorination reaction, high-purity itaconic acid chloride can be obtained in a high yield. The dichloromethyl alkyl ether represented by the general formula (1) (hereinafter, also simply referred to as “dichloromethyl alkyl ether”), the Lewis acid catalyst, the solvent that may be used in the above chlorination reaction, the reaction conditions in the chlorination reaction, and the distillation treatment used in the production method of the present invention will be described below.

[0013] (Dichloromethyl alkyl ether represented by the general formula (1))

Chemical formula

[0014] In the above formula, R represents an alkyl group having 1 to 4 carbon atoms. As the alkyl group having 1 to 4 carbon atoms that can be adopted as R, a primary alkyl group is preferable. Specific examples of the alkyl group having 1 to 4 carbon atoms that can be adopted as R include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an isobutyl group.

[0015] As a result of the above chlorination reaction, alkyl formate corresponding to the used dichloromethyl alkyl ether is by-produced together with the target itaconic acid chloride. Conventionally, dichloromethyl methyl ether has been widely used as a chlorinating agent or a formylating agent, and in that case, dichloromethyl methyl ether is converted into methyl formate. Methyl formate is a special flammable substance with a boiling point of 31 ° C and a flash point of minus 2C, and it is not preferable from the viewpoint of safety in industrial handling. From the viewpoint of raising the flash point of the by-produced alkyl formate and enabling safer handling in industrial implementation, it is preferable to use dichloromethyl propyl ether or dichloromethyl butyl ether.

[0016] Note that not all dichloromethyl alkyl ethers with similar structures exhibit the same reactivity. In fact, in the study of the formylation of benzene using dichloromethyl alkyl ether, the present inventors reported that as the alkyl group becomes longer, the yield of benzaldehyde decreases, and benzaldehyde can only be obtained in a very low yield with dichloromethyl propyl ether or dichloromethyl butyl ether (Warashina, T. et al., Tetrahedron, 2019, Vol. 75, p. 608 - 616.). That is, the fact that dichloromethyl propyl ether or dichloromethyl butyl ether is an effective chlorinating agent in the production method of the present invention is not an easily inferred result just because there is a similar reaction using dichloromethyl methyl ether. However, when a dichloromethyl alkyl ether in which R in the general formula (1) is a long-chain alkyl group having 5 or more carbon atoms is used, as shown in Comparative Examples 4 and 5 described later, the reactivity extremely decreases. For this reason, in the production method of the present invention, the upper limit value of R in the general formula (1) is 4 or less.

[0017] In the chlorination reaction using itaconic acid as a raw material, the amount of dichloromethyl alkyl ether used is preferably 2.0 to 3.0 equivalents, more preferably 2.3 to 2.8 equivalents, per 1 equivalent of itaconic acid. On the other hand, in the chlorination reaction using itaconic anhydride as a raw material, the amount of dichloromethyl alkyl ether used per 1 equivalent of itaconic anhydride is preferably 1.0 to 2.0 equivalents, more preferably 1.2 to 1.4 equivalents.

[0018] The above dichloromethyl alkyl ether can be produced in high yield and high purity by the method described in JP-A-2015-231961.

[0019] (Lewis acid catalyst) In the production method of the present invention, as described later, by carrying out the chlorination reaction using the above dichloromethyl alkyl ether as a chlorinating agent in the presence of a Lewis acid catalyst, itaconic acid chloride can be obtained. As the Lewis acid used as the Lewis acid catalyst, there is no particular limitation as long as it is a generally known Lewis acid and itaconic acid chloride can be obtained by the production method of the present invention. For example, zinc chloride, zinc oxide, titanium chloride, zirconium chloride, etc. may be mentioned. That is, in the production method of the invention, a Lewis acid such as zinc chloride, titanium chloride or zirconium chloride functions as a Lewis acid catalyst in the chlorination reaction using dichloromethyl alkyl ether as a chlorinating agent. Further, as will be described later, a Lewis acid such as zinc oxide changes into another Lewis acid by reaction with dichloromethyl alkyl ether, and the obtained Lewis acid functions as a Lewis acid catalyst in the chlorination reaction using dichloromethyl alkyl ether as a chlorinating agent. Among these, from the viewpoint of catalytic ability, zinc chloride or zinc oxide is preferable, and from the viewpoint of industrialization, zinc oxide is more preferable. Zinc chloride is generally produced by reacting zinc oxide with hydrogen chloride. Since zinc chloride has high deliquescence and hygroscopicity, it easily reacts with moisture in the air, easily blocks, and has a pungent odor when handled in large quantities. On the other hand, zinc oxide is a powder that is easy to handle because it has low reactivity with moisture in the air and is stable, and is inexpensive. The present inventors compared the catalytic abilities of zinc chloride and zinc oxide and found that the reaction is smoother when using zinc oxide, which is a fine powder. In addition, reference example 1 described later clarified circumstantial evidence that zinc oxide rapidly reacts with dichloromethyl alkyl ether and changes to zinc chloride. The experimental results also support that the surface activity of the zinc chloride catalyst generated in the reaction system is high because it is not in contact with the atmosphere containing moisture. This is a matter not described in any prior art documents. The amount of the Lewis acid catalyst used is selected from the range of 0.01 to 10 mol% based on 100 mol% of itaconic acid or itaconic anhydride. Usually, 1 to 2 mol% is sufficient.

[0020] (Solvent) In the production method of the present invention, it may be carried out without a solvent or a solvent may be used. When using a solvent, it can be used without particular limitation as long as it is a solvent stable under the reaction conditions of the present invention (a solvent that does not substantially react with the reaction reagent and itaconic acid chloride). For example, chlorinated hydrocarbon solvents (dichloromethane, trichloromethane, 1,2-dichloroethane, 1,2-dichloropropane, etc.) can be mentioned. These can be used either singly or in admixture of two or more. When using a solvent, the amount of the solvent used per mole of itaconic acid or itaconic anhydride as the raw material is preferably 100 ml or more, more preferably 200 to 2000 ml. Industrially, it is preferable not to use a solvent as it has better kettle efficiency, simpler post-treatment, and is more environmentally friendly.

[0021] (Reaction conditions for the chlorination reaction) In the chlorination reaction of reacting itaconic acid or itaconic anhydride with the above-mentioned dichloromethyl alkyl ether in the presence of a Lewis acid catalyst, the mixture of these raw materials and the catalyst is initially stirred in a slurry (suspension) state, but gradually becomes a homogeneous solution state. The reaction temperature in the above chlorination reaction can usually be carried out at 5 to 30 °C, preferably around room temperature (25 °C). If it is below the boiling points of the by-produced formic acid esters (boiling point of butyl formate: about 107 °C, boiling point of propyl formate: about 81 °C), it can be slightly heated, for example, it can be heated up to 40 to 60 °C. The reaction time in the above chlorination reaction varies depending on the reaction scale, the Lewis acid catalyst used, the type of the above dichloromethyl alkyl ether, the reaction temperature, etc., but is usually 1 to 30 hours.

[0022] (Distillation treatment) There is no particular limitation on the method of distillation treatment, and a usual method can be adopted. For example, alkyl formate and itaconic acid chloride can be easily separated by simple distillation, but if separation of itaconic anhydride and itaconic acid chloride is necessary, distillation under reduced pressure can be carried out using equipment equipped with a rectification column to separate itaconic acid chloride from the reaction mixture. In the production method of the present invention, by adjusting the reaction conditions, it is also possible to adjust so that only less than 4% of itaconic anhydride remains at the end of the reaction (the pure content of itaconic acid chloride in the reaction mixture is 96% or more). In this case, itaconic acid chloride with a purity of 98% or more, which is practically necessary, can be obtained by simple distillation.

[0023] The embodiments will be described in more detail below by dividing them into an embodiment using itaconic acid as a raw material (Embodiment 1) and an embodiment using itaconic anhydride as a raw material (Embodiment 2).

[0024] [Embodiment 1] [Chemical Formula]

[0025] In Embodiment 1 of the present invention, as shown in the above reaction scheme, itaconic acid chloride can be produced by stirring itaconic acid and 2 equivalents or more of the above dichloromethyl alkyl ether in the presence of a catalytic amount of a Lewis acid catalyst. In the reaction mixture (reaction solution) of the above chlorination reaction, in addition to the target itaconic acid chloride, an alkyl formate as a by-product and itaconic anhydride as a reaction intermediate are contained. By subjecting these reaction mixtures to distillation treatment, the target itaconic acid chloride can be easily separated and obtained in a high yield. Further, the alkyl formate separated by distillation can be reused as a raw material for synthesizing the above dichloromethyl alkyl ether as described in JP-A-2015-231961.

[0026] The method of using dichloromethyl methyl ether as a chlorinating agent to convert monocarboxylic acids into the corresponding carboxylic acid chlorides is itself known. For example, in Organic Syntheses, Coll. 1990, Vol. 7, p. 467, a method for the useful preparation of α-ketocarboxylic acid chloride is described, in which pyruvic acid is reacted with dichloromethyl methyl ether without using a catalyst to convert it into pyruvic acid chloride. It is also described that with common chlorinating agents such as thionyl chloride and phosphorus trichloride, pyruvic acid chloride can only be obtained in very low yields. However, even if the method for obtaining pyruvic acid chloride described above, that is, the method of reacting itaconic acid with dichloromethyl methyl ether without a catalyst, is applied to the method for producing itaconic acid chloride using itaconic acid, which is not a monocarboxylic acid of the present invention, as a starting material, no itaconic acid chloride can be obtained, and only itaconic anhydride can be obtained in quantitative yield (see Comparative Example 1 described later). Itaconic acid easily adopts a cyclic anhydride structure within the molecule, and it has become clear that the conversion of such dicarboxylic acids into acid chlorides does not succeed simply by applying known methods. Also, according to the descriptions in Patent Document 1 or 2, even when thionyl chloride and dimethylformamide (DMF) are allowed to act on itaconic acid, only a small amount of itaconic acid chloride is produced (see Comparative Example 2 described later). Further, even when zinc chloride or zinc oxide is added thereto, almost no itaconic acid chloride can be obtained. The same is true when oxalyl chloride, DMF, and zinc oxide are allowed to act on itaconic anhydride, and only 3% of itaconic acid chloride is produced (see Comparative Example 3 described later).

[0027] [Embodiment 2] [Chemical Formula]

[0028] As described in the above Embodiment 1, itaconic acid is easily converted to itaconic anhydride by dichloromethyl alkyl ether. It is presumed from Examples and Comparative Examples that when dichloromethyl alkyl ether is reacted with this itaconic anhydride in the presence of a Lewis acid catalyst, ring opening occurs and itaconic acid chloride is produced. Therefore, it is expected to reduce the amount of expensive dichloromethyl alkyl ether used by the production method of itaconic acid chloride using itaconic anhydride as a raw material. Therefore, in Embodiment 2 of the present invention, as shown in the above reaction scheme, itaconic acid chloride can be produced by stirring itaconic anhydride and 1 equivalent of the above dichloromethyl alkyl ether in the presence of a catalytic amount of a Lewis acid catalyst. Similar to the above Embodiment 1, by subjecting the reaction mixture of the chlorination reaction (a mixture of itaconic acid chloride, alkyl formate, and itaconic anhydride) to distillation treatment, the target itaconic acid chloride can be easily separated and obtained in a high yield. In the above Embodiment 1, hydrogen chloride is generated in an equivalent amount when forming itaconic anhydride, whereas the reaction of Embodiment 2 is preferable from the viewpoint that hydrogen chloride is not generated.

[0029] When two carboxy groups are present in the vicinity, there is a property that an acid anhydride is likely to be formed. Regarding attempts to open the ring of a cyclic acid anhydride and convert it to a dicarboxylic acid chloride, it has been studied by predecessors. For example, in F.M.Menge et.al, Angew.Chem.Int.Ed. 2002, Vol. 41, p.2581 - 2584, a method of converting all three carboxy groups of 1,3,5 - cis - cyclohexanetricarboxylic acid to acid chlorides and using them as raw materials for the target compound is described. The method is as follows: First, by reacting 1,3,5 - cis - cyclohexanetricarboxylic acid with thionyl chloride, a compound having one acid chloride and an acid anhydride structure in the molecule is obtained. Subsequently, by reacting this compound with dichloromethyl methyl ether in the presence of zinc chloride, 1,3,5 - cis - cyclohexanetricarboxylic acid chloride having three acid chlorides in the molecule is obtained. Also, according to F.Johnson et.al., J.Am.Chem.Soc. 1982, Vol. 104, p.2190 - 2198, by refluxing acetyl malic anhydride with dichloromethyl methyl ether in the presence of zinc chloride, the corresponding acid chloride is obtained in a yield of 80%. By applying the above reaction conditions to itaconic anhydride, the present inventors have found a reaction route for efficiently producing itaconic acid chloride from itaconic anhydride, which has not been known in the past for its synthesis method. Furthermore, the present invention has clarified that, from an industrial perspective, the part in the prior art literature referring to the ability to open the ring of an acid anhydride using zinc chloride and dichloromethyl methyl ether to synthesize a dicarboxylic acid can be changed to zinc oxide and dichloromethyl propyl ether or dichloromethyl butyl ether.

Examples

[0030] Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not construed as being limited thereto. Room temperature means 25°C. The itaconic acid chloride isolated in the examples of the present application had a purity of 98% or more except for Example 3. The measurement was carried out according to the method shown below. - Measurement of the composition ratio of the solution after the reaction - · Measuring device: Gas chromatography-mass spectrometry (GCMS) equipped with a mass spectrometer (detector: TCD) · Conversion rate and GC yield (%) = {(peak area of itaconic acid chloride) / (peak area of itaconic acid chloride + peak area of itaconic anhydride)} × 100

[0031] <Example 1> 6.50 g (50 mmol) of itaconic acid was suspended in 15 mL of dichloromethane, 134 mg (0.98 mmol) of zinc chloride and 18.3 g (159 mmol) of dichloromethyl methyl ether were added, and the mixture was stirred at room temperature (rt) for 3 hours. During the stirring, it gradually became a homogeneous solution. The solution after the reaction was distilled under reduced pressure to obtain 7.2 g of itaconic acid chloride (yield 86%). (Identification of itaconic acid chloride) bp: 74 - 75 °C / 2 torr. (Literature value bp: 71 - 72 °C / 2 torr. described in Non-Patent Document 1) GCMS: m / z = 131 (M + - Cl), 103 (base peak, M + - COCl). 300 MHz 1 1H-NMR (CDCl3): δ = 3.93 (J = 0.9 Hz, 2H), 6.32 (J = 0.9 Hz, 1H), 6.85 (J = 0.3 Hz, 1H) 75 MHz 13 13C-NMR (CDCl3): δ = 48.67, 136.43, 138.10, 167.70, 170.15. IR (neat): 1794 cm -1 , 1734 cm -1

[0032] A drop of methanol and pyridine was added to a part of the obtained itaconic acid chloride and stirred for 0.5 hour, and the formation of dimethyl itaconate was confirmed by GCMS. GCMS: m / z = 158 (M + ), 143 (M + - CH3), 127 (M + - OCH3), 99 (base peak, M+ -COOCH3).

[0033] <Example 2> 5.6 g (50 mmol) of itaconic anhydride, 135 mg (1.0 mmol) of zinc chloride, 7.27 g (71.5 mmol) of dichloromethyl methyl ether, and 20 mL of dichloromethane were placed in a 100 mL flask, stirred at room temperature (rt) for 0.5 hour, and then stirred at 40 °C for 2 hours. In the solution after completion of the reaction, the conversion rate was 96.0%. The solution after completion of the reaction was distilled to obtain 6.5 g (yield 78%) of itaconic acid chloride.

[0034] <Examples 3 to 8, Comparative Example 4> In accordance with Example 1, 1.95 g (15 mmol) of itaconic acid (ITA) was used, reacted under the conditions shown in Table 1 below, and distilled using a Kugelrohr (95 to 100 °C / 2 torr). The results are shown in Table 1.

[0035]

Table 1

[0036] <Examples 9 to 15, Comparative Example 5> In accordance with Example 2, 3.36 g (30 mmol) of itaconic anhydride (ITAH) was used, reacted under the conditions shown in Table 2 below, and distilled using a Kugelrohr (95 to 100 °C / 2 torr). The results are shown in Table 2.

[0037]

Table 2

[0038] (Note to the table) In the examples using a solvent, the solvent was used such that the raw material ITA or ITAH (mol) / solvent (L) = 3 M or 2.5 M. “-” in the column of GC or isolation of ITOC yield means that the confirmation by the method described in the corresponding column has not been performed. The value in the column of isolation of ITOC yield means the yield (%) of ITOC obtained by distillation treatment.

[0039] From the results of Tables 1 and 2 above and the results of Examples 16 and Comparative Examples 1 to 3 described below, the following can be understood. As shown in Comparative Example 1 described below, in the reaction with dichloromethyl alkyl ether without a catalyst, no itaconic acid chloride was obtained at all, and only itaconic anhydride was obtained in a quantitative yield. Further, even when thionyl chloride and dimethylformamide (DMF) were allowed to act on itaconic acid according to the method described in Patent Document 1 or 2, only a small amount of itaconic acid chloride was produced (Comparative Example 2), and even when oxalyl chloride, DMF, and zinc oxide were allowed to act on itaconic anhydride, only 3% of itaconic acid chloride was produced (Comparative Example 3). Also, as shown in Comparative Examples 4 and 5 above, when dichloromethyl hexyl ether was used, the reactivity was extremely reduced, and only a trace amount was observed by GC analysis. In contrast, in Examples 1 to 16 according to the production method of the present invention, it was confirmed that itaconic acid chloride as the target product was obtained in a good yield of 42% or more.

[0040] <Example 16: Large-scale synthesis> Itaconic anhydride (40 g, 0.36 mol), dichloromethyl n-butyl ether (72.3 g, 0.46 mol, 1.27 eq), and zinc oxide (0.58 g, 0.007 mol, 0.02 eq) were placed in a 200 mL flask and stirred at room temperature for 16 hours. As a result of GC analysis, the conversion rate was 97.8%. After completion of the reaction, the solution was distilled under reduced pressure (boiling point 73 to 74 °C / 4 to 5 torr) to obtain 72.8 g (yield 79%) of itaconic acid chloride. The purity of the isolated itaconic acid chloride by GC measurement was 99.3%.

[0041] <Comparative Example 1: Reaction without a catalyst> 1.34 g (10.3 mmol) of itaconic acid was suspended in 3 mL of dichloromethane, 3.48 g (30.3 mmol) of dichloromethyl methyl ether was added without adding a catalyst, and the mixture was stirred at room temperature for 2 hours and then further stirred at 40 °C for 1 hour and 15 minutes. Only itaconic anhydride was detected by GCMS. When the solvent was distilled off, 1.12 g of white crystals were obtained, and itaconic anhydride with a melting point of 64 - 68 °C was obtained in quantitative yield. GCMS: m / z = 112 (M + , relative intensity 0.12%), 68 (M + -CO2, relative intensity 68%), 40 (base peak).

[0042] <Comparative Example 2: Using thionyl chloride and DMF> 3.2 g (24.6 mmol) of itaconic acid was suspended in 6 mL of dichloromethane, and 1 drop of DMF was added. 7.18 g (60.3 mmol) of thionyl chloride was added at room temperature, and the mixture was stirred in an oil bath at 50 °C (with slight reflux) for 5 hours. As a result of analyzing the reaction solution by GCMS, a large amount of itaconic anhydride was detected, and only a trace amount of itaconic acid chloride was observed.

[0043] <Comparative Example 3: Using oxalyl chloride, DMF and zinc oxide> 3.36 g (30.0 mmol) of itaconic anhydride, 15 mg of zinc oxide, 5.0 g (40.0 mmol) of oxalyl chloride, and 1 drop of DMF were sequentially added, and the mixture was stirred at 50 °C for 3 hours. As a result of analyzing the brown reaction solution by GC, a large amount of itaconic anhydride remained, and only 3% of itaconic acid chloride was produced.

[0044] <Reference Example: Change of zinc oxide to zinc chloride in the reaction system> 162.7 mg (1.02 mmol) of dichloromethyl butyl ether was dissolved in 0.5 mL of anhydrous dichloromethane. 35 mg (0.43 mmol) of zinc oxide was added to this solution and stirred at room temperature for 10 minutes. When the reaction solution was analyzed by GC, 55% of butyl formate was produced in terms of the total area value. From this result, it can be estimated that zinc oxide changed rapidly to zinc chloride and the change was quantitative.

[0045] As described above, in the presence of a Lewis acid catalyst, by using dichloromethyl alkyl ether represented by the general formula (1) defined in the present invention as a chlorinating agent and carrying out the chlorination reaction of itaconic acid or itaconic anhydride, itaconic acid chloride as the target product is produced in a high yield, and by subjecting the solution after the reaction to a simple distillation treatment, itaconic acid chloride can be obtained in a high yield.

Claims

1. A method for producing itaconic acid chloride, comprising reacting itaconic acid or itaconic anhydride with a dichloromethyl alkyl ether represented by the following general formula (1) in the presence of a Lewis acid catalyst. 【Chemical 1】 In the above formula, R represents an alkyl group having 1 to 4 carbon atoms.

2. The method for producing itaconic acid chloride according to claim 1, wherein the Lewis acid catalyst is zinc chloride or zinc oxide.

3. The method for producing itaconic acid chloride according to claim 1 or 2, wherein the dichloromethyl alkyl ether represented by the general formula (1) is dichloromethyl propyl ether or dichloromethyl butyl ether.

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