JPH0211565A - Preparation of metachloroperbenzoic acid - Google Patents

Abstract

PURPOSE:To provide the objective compound in a short time and in a high yield by reacting metachlorobenzoic acid chloride in a mixture comprising a specific ratio of an alkali metal hydroxide, hydrogen peroxide, a lower alcohol and an inert solvent capable of dissolving the resulting metachlorobenzoyl peroxide. CONSTITUTION:When metachlorobenzoic acid chloride (I) is mixed with an alkali metal hydroxide (II), H2O2 (III), a <=3C alcohol and a solvent capable of dissolving the resulting metachlorobenzoyl peroxide and subsequently reacted with the H2O2 to provide the subject compound, the reaction is carried out at 5-25 deg.C under conditions wherein the mol ratios of the compounds (II):(I) and the compounds (III):(I) are (2.5-5.5):1 and (4-6):1, respectively, and the amount of the compound IV is 25-50wt.% based on the aqueous phase. The inert solvent includes dichloromethane, trichloroethylene, etc., and the employment of the inert solvent permits the reduction of the metachlorobenzoyl peroxide remained in the product. Side products are also reduced.

Description

[Detailed Description of the Invention] (Industrial Application Field) Among organic peracids, metachloroperbenzoic acid can be used in organic synthesis reactions, such as epoxidation reactions, Bayer-Villiger oxidation reactions, and N-oxidation reactions. From fine chemicals such as medicine and agricultural chemicals! It is widely used as a bleaching agent and a bleaching agent. Additionally, many organic peracids are unstable and cannot be stored for long periods of time, whereas metachloroperbenzoic acid is a very stable crystal even at room temperature, making it easy to handle.

There is almost no decrease in purity even when stored at room temperature for several months, and in terms of reactivity, numerous advantages have been found compared to peracetic acid, monoperphthalic acid, etc. The purpose of the invention is to establish a technology for producing metachloroperbenzoic acid and to make it widely available to the public.

(Prior art) Regarding the production technology of metachloroperbenzoic acid using metachlorobenzoic acid chloride as a raw material, US Patent jI3231
No. 605, No. 3232979, No. 3485869, etc., it is said that it is obtained by reacting metachlorobenzoic acid chloride with hydrogen peroxide, sodium hydroxide, or potassium hydroxide in the presence of t-butyl alcohol. All of the above patents are characterized in that t-butyl alcohol is used, and products are obtained by removing t-butyl alcohol by distillation under reduced pressure. However, t-butyl alcohol has a high boiling point of 82.5°C (760 mmHg) and a melting point of 25.6°C, so it is difficult to distill t-butyl alcohol from a peracid aqueous solution, which is a thermally unstable reaction liquid. involves danger or difficulty;

In US Pat. No. 1,346,2480, since the peracid produced is unstable, the peracid is produced in the presence of a special stabilizer such as nitrilotriacid. Also, Soviet literature Zh, P r i k 1.

Khim, 1986.59 (2), 388-91 also reported that the reaction conditions were investigated in the presence of oxyethylidene diphosphoric acid as a stabilizer and a product with a peracid purity of 85 to 90% was obtained. The product is said to contain benzoyl metachloroperoxide, a reaction intermediate.

(Problems to be solved by the invention) That is, in the conventional technology, since peracid is unstable in the reaction solution, it is necessary to add a special stabilizer, and a large amount of alcohol is used. This not only results in the formation of esters of metachlorobenzoic acid, but also reduces the yield.
There is a problem of lowering the purity of product a. In addition, in conventional technology, the boiling point of the alcohol used is high,
There are problems such as the high freezing point, which makes it dangerous to distill off the alcohol.

(Means and effects for solving the problems) As a result of intensive research into methods for solving the above-mentioned problems, the present inventors found that metachlorobenzoic acid chloride (1) was converted into alkali metal hydroxide (II), peroxidized When reacting by mixing hydrogen (■), an alcohol having 3 or less carbon atoms (rV), and an inert solvent in which metachlorobenzoyl peroxide is soluble (ff): (1
) in a molar ratio of 2.5:1 to 5.5:1,
(III): (1) is used in a molar ratio of 4=1 to 6:1, and (IV) is used in an amount of 25 to 50% by weight with respect to the aqueous phase, and the reaction temperature is 5 to 25°C. The inventors discovered a characteristic method for producing metachloroperbenzoic acid and completed the present invention.

The present invention will be described in more detail below by describing a reaction formula for the case where potassium hydroxide is used as the alkali metal hydroxide and methanol is used as the alcohol having 3 or less carbon atoms.

2 CI C, H4C0C1+ 2 KOH+H,
0x(1) (n) CII
I)→CI CmH4C0-00-OCCaH4Cl(
benzoyl metachloroperoxide) +2 K Cl + 2 Hz○ ... (A) CI
CaH4G O-00-OCCaHaC1+2KO
H+H! 0. -) 2CIC, H, +2H to C0-00,
O・・(B) Side reaction CI Ca H4COCl + CH10H+ K O
H→CI Ca H4CO-OCHL + K Cl
＋H! 0 (methyl metachlorobenzoate)...
・(C) Metachloroperbenzoic acid reacts with (A) and (B)
It is known that the compound is synthesized through the formula (A).

From (B), the theoretical molar ratio of potassium hydroxide and hydrogen peroxide to metachlorobenzoic acid chloride is (III):
(ff): (1)=1:2:1. or.

In the reaction of formula (B), it is difficult to proceed equivalently unless in the presence of an alcohol, as shown in the literature Tetrahedron, 23.3327 (1
967). However, when only alcohol is added in the synthesis reaction of metachloroperbenzoic acid, several percent of benzoyl metachloroperoxide, which is a reaction intermediate, remains in the product. This is because benzoyl metachloroperoxide is insoluble and difficult to react with the aqueous reaction solution. Therefore, in the present invention, it has been discovered that the amount of metachlorobenzoyl peroxide remaining in the product can be reduced by adding a solvent in which metachlorobenzoyl peroxide is soluble and inert in the reaction solution. or.

At the same time, since the amount of alcohol added can be done without ψ, the secondary pressure (C
) formula is slow to proceed, and the formation of esters such as methyl metachlorobenzoate, which are by-products, can be suppressed.Firstly, in the present invention, the alkali metal hydroxide (n) and peroxide relative to metachlorobenzoic acid chloride (1) can be suppressed. Hydrogen oxide (III
) of an alkali metal hydroxide having a molar ratio in the following specific range in excess of the theoretical value, that is, (n): (1) = 2.5: 1 to 5.5: 1. frowned.

(III): By using hydrogen peroxide at a molar ratio of (1)=4:1 to 6=1, the yield can be improved, w
The objectives of the present invention, such as the suppression of the J product and the raw material of the reaction time, can be achieved. Moreover, the alcohol having 3 or less carbon atoms here refers to methanol, ethanol, or propatool, and the purpose can be achieved by using the alcohol in an amount of 25 to 50% by weight of the aqueous phase in the reaction solution. Further, the solvents in which benzoyl metachloroperoxide is soluble are dichloromethane and chloroform.

Halogenated hydrocarbons such as carbon tetrachloride, dichloroethane, trichloroethylene, or benzene.

Aromatic hydrocarbons such as toluene and xylene are cited. The object of the present invention can be achieved if the amount of alcohol added is slightly larger than the amount of alcohol mentioned above in terms of solubility in benzoyl metachloroperoxide and ease of solvent distillation. In addition, as a stabilizer for peracid, which has been a particular problem in the past, magnesium sulfate, which is available at low cost, is sufficient without using special stabilizers such as nitrilotriacetic acid or oxyethylidene diphosphoric acid. This is because the present invention uses a sufficiently excessive amount of alkali metal hydroxide and hydrogen peroxide relative to metachlorobenzoyl chloride, and the addition of a solvent in which metachlorobenzoyl peroxide is soluble. This seems to be because the reaction can be completed in a short time.According to the study by the present inventors, in the conventionally known reaction method, benzoyl metachloroperoxide is difficult to dissolve in the reaction solution, so the reaction of Formula 9 (B) The reaction is slow and it is necessary to react for several hours in order to reduce the residual amount of metachlorobenzoyl peroxide to 2% or less, during which time the peracid decomposes and causes a decrease in purity. Since some metachlorobenzoyl peroxide is solubilized by the solvent, the reaction time is short.

For example, during the reaction time of 2 to 4 hours, the remaining amount of benzoyl metachloroperoxide becomes 2% or less, indicating that one reaction is almost completed.

(Effects of the Invention) Since the method for producing metachloroperbenzoic acid of the present invention is configured as described above, it has several advantages as shown below.

First, in the present invention, since a solvent in which benzoyl metachloroperoxide, which is a reaction intermediate, is soluble is added, the reaction can be completed in a high yield and in a short time. Moreover, there is no need to add special stabilizers for this purpose.

By adding a solvent in which secondary metachlorobenzoyl peroxide is soluble, the amount of alcohol used can be reduced compared to conventionally known methods, and therefore the removal of metachlorobenzoic acid ester can be significantly suppressed.

Thirdly, by using the amount of the reaction reagent within a specific range, the objectives of the present invention, such as improving the yield, suppressing W1 raw materials, and shortening the reaction time, can be achieved.

Fourth, since t-butyl alcohol is not used, t-butyl alcohol is not used.
- There are no problems such as danger associated with distilling off butyl alcohol.

(Example) Next, an example and a comparative example will be given and explained, but all are for illustrative purposes and the present invention is not limited to them.

(Example 1) In an IL flask equipped with a thermometer, stirrer (paddle type 3 blades), and cooling bath, 70.5 g of 30% potassium hydroxide aqueous solution, 61.1 g of 35% hydrogen peroxide aqueous solution + 70 g of dichloromethane* After mixing 46 g of methanol and 0.5 g of magnesium sulfate and cooling to 10°C, 22 g of metachlorobenzoic acid chloride (distilled product) was added and stirred.

After the reaction was completed for 2 hours, 20% sulfuric acid 280
280 g of dichloromethane was added and metachloroperbenzoic acid was extracted into the dichloromethane phase under acidic conditions. Next, dichloromethane was distilled off from the extract under reduced pressure using a rotary evaporator to obtain 20.1 g of a needle-shaped crystal product. Ta.

This product has 94.3% methacrylic acid based on the iodometry method! It contained 2. Also, i! ! Analysis by body chromatography revealed that the content of metachlorobenzoyl peroxide was 0.1% and the content of methyl metachlorobenzoate was 1.4%. Note that the product yield was 92.6%.

(Example 2) The reaction was carried out in exactly the same manner as in Example 1, except that 50.3 g of a 30% sodium hydroxide aqueous solution was used instead of the 30% potassium hydroxide aqueous solution in Example 1, and 20.2 g of a needle-shaped crystal product was obtained. The obtained 0 analysis result is methacrylate perbenzoin 12
95.1%, metachlorobenzoyl peroxide 0.2%,
The content of methyl metachlorobenzoate was 1.0%. Incidentally, the I1 item count rate was 93.1%.

(Example 3) The reaction was carried out in exactly the same manner as in Example 1, except that chloroform was used instead of dichloromethane in Example 1, and 20.1 g of a needle-like crystal product was obtained.

The analysis results showed that the content of metachloroperbenzoic acid was 93.2%, the content of metachlorobenzoyl peroxide was 0.9%, and the content of methyl metachlorobenzoate was 1.2%.

Note that the product yield was 92.6%.

(Example 4) The reaction was carried out in exactly the same manner as in Example 1 except that ethanol was used instead of methanol in Example 1. The result is a needle-shaped crystal product19. The results of the 6 analysis obtained for ag were 86.0% metachloroperbenzoic acid and 1.7% metachlorobenzoyl peroxide.

The content of ethyl metachlorobenzoate was 0.9%. Furthermore, the acceptance rate of II items was 88.9%.

(Examples 5 to 6) and (Comparative Examples 1 to 2) Next, Table 1 shows the results for Examples and Comparative Examples that were reacted under the same conditions as Example 1 except that the reaction temperature was changed. summarized in.

Table 1.

Table 2 shows the results of an experiment conducted in the same manner as in Example 1 except for the feeding amount. summarized in.

Table 2.

FA is methacrylic hyperbenzoin 11. MCBPO means metachlorobenzoyl peroxide.As shown in the results in Table 1, in Comparative Example 2 where the reaction temperature was high, metachloroperbenzoic acid decomposed and the purity decreased markedly.
In C, a large amount of the intermediate metachlorobenzoyl peroxide remains and the reaction is slow.

(Examples 7 to 13) Next, the preparation of hydrogen peroxide and alkali metal hydroxide (Comparative Examples 3 to 9) Next, the same method as in Example 1 except for the amount of hydrogen peroxide and alkali metal hydroxide added. Table 3 shows the results for comparative examples tested in 3. summarized in.

table It can be seen that the amount of contamination in the product is extremely low.

(Examples 14 to 17) and (Comparative Examples 10 to 13) Next,
The reaction was carried out in the same manner as in Example 1 except for the amount of methanol added, and the amount was 18 to 21 g for both the Example and Comparative Example.
of products were obtained. Table 4 shows the product analysis results of Examples and Comparative Examples. summarized in.

Table 4.

Table 2. and Table 3. m:n:x means the molar ratio of hydrogen peroxide:alkali metal hydroxide:metachlorobenzoic acid chloride. Also, PA means metachloroperbenzoic acid and MCBPO means metachlorobenzoyl peroxide.Table 3. Therefore, the remaining amount of MCBPO was 20% or more in Comparative Examples 3 to 9. Examples 7-1 in
In No. 3, the island was 2% or less, and in the example, MCBP
OPA means metachloroperbenzoic acid, MCBPO means metachlorobenzoyl peroxide, and MB means methyl metachlorobenzoate. The amount of methanol referred to here is expressed in weight% with respect to the aqueous phase in the reaction solution.Table 4 shows that when the amount of methanol added is 20% or less, a large amount of MEC 00 benzoyl peroxide remains, and when the amount of methanol added is 60%, methanol peroxide remains. It can be seen that as the acid purity decreases, more methyl metachlorobenzoate is produced.

(Comparative Example 14) The reaction was carried out in exactly the same manner as in Example 1, except that dichloromethane, which was added during the reaction in Example 1, was not added.

As a result, 19.4 g of product was obtained.

The analysis results are methacrylic hyperbenzoin! 151.2%, benzoyl metachloroperoxide 30.7%, and methyl metachlorobenzoate 4.1%.0 If dichloromethane is not added during the reaction, the purity of metachloroperbenzoic acid is low, and the purity of benzoyl metachloroperoxide and methyl metachlorobenzoate is low. It was found that a large amount of methyl was produced.

Claims (2)

[Claims] (1) Metachlorobenzoic acid chloride (I) is combined with alkali metal hydroxide (II), hydrogen peroxide (III), and carbon number 3
When reacting by mixing the following alcohol (IV) and an inert solvent in which benzoyl metachloroperoxide is soluble (II):
(I) was used in a molar ratio of 2.5:1 to 5.5:1, (III): (I) was used in a molar ratio of 4:1 to 6:1 and (IV) was added to the aqueous phase. A method for producing metachloroperbenzoic acid, which comprises using 25 to 50% by weight of metachloroperbenzoic acid and reacting at a reaction temperature of 5 to 25°C. (2) The method according to claim 1, in which halogenated hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride, dichloroethane, and trichloroethylene are used as the inert solvent in which benzoyl metachloroperoxide is soluble.