JPS60209548A - Production of 2-(4-hydroxyphenoxy)propionic ester - Google Patents

Abstract

PURPOSE:The reaction between hydroquinone and alkali metal hydroxide is carried out in the presence of a solvent which forms an azeotropic mixture with water to remove water, then the product is allowed to react with 2-halopropionic acid ester in the presence of an alcohol to achieve high-yield production of the titled compound. CONSTITUTION:In the production of 2-(4-hydroxyphenoxy)propionic ester by reaction between hydroquinone and 2-halopropionic ester, the hydroquinone is allowed to react with alkali metal hydroxide in the presence of a solvent which forms an azeotropic mixture with water to remove water. Then, the product is allowed to react with 2-halopropionic ester such as ethyl 2-chloropropionate in the presence of an alcohol, preferably the same alcohol as the ester moiety of the 2-halopropionate ester to give the objective compound. USE:A starting material of agricultural chemicals.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing 2-(4-hydroxyphenoquine)propio/acid ester.

2-(4-hydroxyphenoxy) obtained by this invention
Propio/acid esters are important compounds as raw materials for agricultural chemicals.

This compound is usually obtained by reacting hydroquinone with a 2-halopropionic ester under basic conditions, but in this method, both of the two hydroxyl groups of hydroquinone are reacted with the 2-halopropionic ester, or the 1 ester is The desired product, 2-(4-hydroxyphenoxy)propionic acid ester, could only be obtained in low yield due to side reactions in which bonds were hydrolyzed. Japanese Patent Application Publication No. 5
No. 4-19925 describes a method in which hydroquinone is reacted with Ij acetate in the presence of 2 mol of alkali metal alkoxide per 1 mol of hydroquinone. However, in this method, 2 moles of alkali metal alkoxide, which is an expensive reagent, must be used per 1 mole of hydroquinone, and it cannot be said to be an economical method. Further, West German Patent Publication No. 3,150,233 describes that ethyl 2-(4-hydroxyphenoxy)propionate can be obtained by reacting hydroquinone and ethyl 2-bromopropionate in the presence of calcium hydroxide. However, when the reaction is carried out using hydroquinone and ethyl 2-chloropropionate, which is cheaper than ethyl 2-bromopropionate, in the presence of calcium hydroxide according to this method, the reactivity is extremely low (,2, It is difficult to obtain ethyl -(4-hydroxyphenoxy)propionate in high yield.

In view of these current circumstances, the present inventor has conducted extensive studies with the aim of developing an industrial manufacturing method that can advantageously produce 2-(4-hydroxyphenoquine) propionate, and as a result, has found that hydroquinone and After removing water by reacting the alkali metal hydroxide in the presence of a solvent that is azeotropic with water.

It has been discovered that the target product, 2-(4-hydroxyphenoxy)propionic ester, can be obtained in high yield by reacting with 2-halopropionic ester in the presence of alcohol, and the above object can be achieved. It has arrived.

The present invention provides a method for producing 2-(4-hydroxytwo-enoxy)propionate by reacting hydroquinone with 2-halopropionate, in which hydroquinone is reacted with an alkali metal in the presence of a solvent that is azeotropic with water. The present invention relates to a method for producing 2-(4-hydroxyphenoxy)propionic acid ester, which comprises reacting with a hydroxide to remove water, and then reacting with a 2-halopropionic acid ester in the presence of an alcohol.

The 2-halopropionic acid ester used in the present invention has the formula % (wherein, X represents Ct or Br, and R represents c1 to c1
゜ straight or branched alkyl group, cycloalkyl group,
Or represents an aralkyl group. ).

Representative examples of the 2-halopropionate represented by the formula [■] include methyl 2-chloropropionate, ethyl 2-chloropropionate, and n-propyl 2-chloropropionate.

1--j-ropyl 2-chloropropionate, n-butyl 2-chloropropionate, i-butyl 2-chloropropionate, S-butyl 2-chloropropionate, t-butyl 2-chloropropionate, 2-chloro , cyclohexyl chloropropionate, 2 l hensyl chloropropionate, 2-
Methyl bromopropionate, ethyl 2-bromopropionate, n-7' pill of 2-bromopropionate, 2-
7' bromopropionate i 7' pill, n-butyl 2-bromopropionate 1-butyl 12-bromopropionate.

Examples include 2-bromopropion e B -phthyl, t-butyl 2-bromopropionate, cyclohexyl 2-bromopropionate, and benodyl 2-bromopropionate. The amount of these 2-halopropionic acid esters used is 0.5 to 2
．． 0 mol, especially 0.6 to 16 mol is wise.

The alkali metal hydroxides used in the present invention include sodium hydroxide, potassium hydroxide, and lithium hydroxide, and these can be used in any form such as solid, aqueous solution, or alcoholic solution. It's okay. The amount of alkali metal hydroxide used is preferably 10 to 2.2 mol, particularly 1.5 to 2.0 mol, per 1 mol of hydroquinone.

In the present invention, solvents that are azeotropic with water include benzene,
Aromatic hydrocarbons such as toluene or xylene, pentane, hexane, cyclohexane, saturated hydrocarbons such as octane, ethanol, 1-propanol, 2-
Alcohols such as propatool, 1-butanol, 2-butanol, inbutanol or cyclohexanol.

and ethyl methyl ketone, cyclopentanone.

Examples include cyclohexanone and other ketones such as methyl isobutyl ketone, and these may be used in appropriate combinations. The amount of the solvent is not particularly limited, as long as it is a commercially available amount necessary to theoretically remove the existing water.

The reaction between hydroquinone and an alkali metal hydroxide may be carried out under normal pressure at a temperature above the azeotropic temperature with water, or may be carried out under reduced pressure at a temperature below this temperature.

In the present invention, the alcohol used in reacting the reaction product of hydroquinone and an alkali metal hydroxide with the 2-halopropionic acid ester is as follows.

It is preferable to use the same alcohol as the ester portion of the 2-halopropionic acid ester. When carrying out the reaction with 2-halopropionic acid ester in the presence of alcohol, if the solvent is a mixture of hydroquinone and Earl, the reaction can be carried out directly with the 2-halopropionic acid ester without adding any alcohol. be able to. It is also possible to add the azeotropic solvent and then react with the 2-halopropionic acid ester. The amount of alcohol is preferably 2 to 20 parts by weight per 71 parts by weight of hydroxyl used. 2-...The reaction temperature and time with lopropionic acid ester are 0 to 150°C and 0.5 to
10 hours is appropriate.

After completion of the reaction, the target product is isolated by conventional methods such as distillation after making the reaction solution neutral to slightly chivalrous with an organic acid such as acetic acid or propionic acid or a mineral acid such as hydrochloric acid, sulfuric acid, or phosphoric acid. It can be obtained by manipulation.

EXAMPLES Below, the present invention will be explained more specifically by way of examples. The reaction solution was quantified by gas chromatography analysis. The reaction rate of hydroquinone, the yield of ethyl 2-(4-hydroxyphenoxy)propionate, and the selectivity are in accordance with the following definitions.

Example 1 Hydroquinone 11.0@, 16.7 g of a 48% sodium hydroxide aqueous solution and 100 g of toluene were placed in a flask with a Dean-Stark trap and heated under a nitrogen atmosphere for an hour until the water became almost azeotropic. The reaction was carried out by heating and stirring (12.2% of water was separated). The trap was removed, the toluene was removed under reduced pressure, anhydrous ethanol 100+a/+ was added to the residue, and the mixture was heated for 30 minutes with vigorous stirring.
Warm to ℃.

16.71 ethyl 2-chloropropionate were added in one portion. After reacting for 5 hours, 8 me of glacial acetic acid was added to stop the reaction. As a result, the reaction rate of hydroquinone was 78%, and the amount of ethyl 2-(4-hydroxyphenoxy)propionate produced was 1,517 (yield and selectivity: 72:1 and 92:1).

Example 2 The same procedure as in Example 1 was carried out except that the reaction of ethyl 2-chloropropionate was carried out at 15° C. for 4 hours.

As a result, the reaction rate of hydroquinone was 62%.

The amount of ethyl 2-(4-hydroxyphenoxy/)propionate produced was 12.47 (11M rate and selectivity were 59% and 95%).

Examples 4 and 4 The same procedure as in Example 1 was carried out, except that the solvents listed in Table 1 were used in place of toluene in Example 1, and the mixture was heated and stirred until water no longer azeotroped. The results are shown in Table 1.

Table 1 1) Time required until water ceases to azeotrope Example 5 Hydroquinone 4297 and 12 g of toluene 50 m/? 'l:1. The mixture was heated to about 100°C to cause a reaction, and the azeotropic water was separated in the same manner as in Example 1. Water separation was carried out for approximately 3 hours m]K.

After cooling, remove toluene under reduced pressure and add 30% absolute ethanol.
mg was added. The resulting suspension was warmed to 30°C, 4.11ji' of ethyl 2-chloropropionate was added at once,
After reacting for 3 hours, the same post-treatment as in Example 1 was performed. As a result, the reaction rate of hydroquinone was 67%, 1,2-(
The amount of ethyl 4-hydroxyphenoxy)propionate produced was 50 g (yield and selectivity were 61% and 91%).

Example 6 Hydroquinone 3.31i' and sodium hydroxide 2.42
were reacted by heating in 50 ml of 1-butanol, and the resulting water was removed by azeotropy with 1-butanol over 2.5 hours. After cooling, 4.9 g of butyl 2-chloropropionate was added and reacted at 25° C. for 4 hours, followed by the same post-treatment as in Example 1. As a result, the reaction rate of hydroquinone was 8
5%, and the amount of butyl 2-(,4-hydroxyphenoxy)propionate produced was 5.6''? (yield and selectivity were 78% and 92%).

Patent applicant Ube Industries Co., Ltd.

Claims (1)

[Claims] A method for producing 2-(4-hydroxyphenoquine)propio/acid ester by reacting hydroquinone with nisder 2-halopropionate. A 2-( A method for producing 4-hydroxyphenoquine) propionate.