JPS60123443A - Production of 2-(4-hydroxyphenoxy)alkanoic acid - Google Patents

Abstract

PURPOSE:To obtain the titled compound useful as an intermediate for herbicides, etc. easily in high selectivity, by reacting a hydroquinone with an alpha-chloro(or bromo)carboxylic acid in the presence of an alkali metallic hydroxide in a solvent. CONSTITUTION:Hydroquinone or salt thereof is reacted with a compound expressed by the formula (X is Cl or Br, preferably Cl; R is H or lower alkyl), e.g. alpha-chloropropionic acid, in the presence of an alkali metallic hydroxide, particularly sodium hydroxide in a molar amount of 2 times or more, preferably 2.8 times or more of that of the compound expressed by the formula in one or more solvents selected from preferably methanol, ethanol, methyl cellosolve, ethyl cellosolve or water to give industrially and advantageously the aimed 2-(4-hydroxyphenoxy)alkanoic acid, particulary 2-(4-hydroxyphenoxy)propionic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing 2-(4-hydroxyphenoxy)alkanoic acids. More details.

The present invention relates to hydroquinone or a salt of hydroquinone, and a compound represented by the general formula (1) (wherein, X represents a chlorine or bromine atom, and R represents hydrogen or a lower alkyl group). 2-(4-
The present invention relates to a method for producing hydroxyphenoxy)alkanoic acid.

2-(4-hydroxyphenoxy)alkanoic acid esters are disclosed in JP-A-56-16475 and JP-A-54-. 2
It is useful as an intermediate for compounds disclosed in JP-A-2371, JP-A-53-40767, and the like. For example, it is useful as a raw material for producing a highly effective herbicide containing a heterocyclic ether phenoxy fatty acid derivative as an active ingredient, as described in JP-A-56-16475.

As a method for producing 2-(4-hydroxyphenoxy)alkanoic acid esters, there is, for example, a method shown in the following reaction formula disclosed in JP-A-56-59718.

There is also a method shown by the following reaction formula disclosed in Publication No. 1 International Application Publication No. 82/(1).

Furthermore, there is a method shown in the following reaction formula disclosed in European Patent No. 82413.

(In the formula, X represents a chlorine or bromine atom, and R represents a lower alkyl group.) The melting point is 228-230'C, whereas the melting point of 2-(4-hydroxyphenoxy)propionic acid required by the present inventors is 147-15-0C.

In addition, the method disclosed in International Application Publication No. 82100639 has a low production rate in the step of synthesizing persulfate ester and requires a large number of steps, so it is not industrially preferred.

Furthermore, the reaction disclosed in European Patent No. 82413 has insufficient selectivity, and unless the conversion of hydroquinone is kept within 50%, a large amount of dimer is produced. Therefore, industrially, a large amount of hydride 1j quinone must be recovered and produced, which increases the cost. In addition, the reaction rate is reduced because unreacted hydride quinone is not reduced.

(In the formula, 2 indicates the reaction rate, and 1 indicates a lower alkyl group.) If the reaction rate is increased, the production rate of dimers increases and the yield decreases significantly.

Since these methods are not industrially advantageous, the present invention'tF et al. conducted conceptual research into an excellent method for producing 2-(4-hydroxyphenoxy)alkanoic acid.

Overcoming the drawbacks of the conventional method, it is easy and highly selective for 2-(
4-Human I:Jxophenoxy))'Lucanoic acid! 11
1. ! The present invention was completed by discovering a method for manufacturing.

Zunawara 1 The present invention provides α-ri iJ lubricant with a selectivity of < 2-(4-human[J This is a method for producing 17 acids.

In the general formula (1): The amount used is usually equimolar to that of hydroquinone, but if particularly high selectivity is required, it may be used in a molar amount of 70 to 80%.

As the solvent, alcohols such as methanol, ethanol, isopropanol, ethylene glycol, and cellosolders, or water are used. The amount used varies depending on the type of each solvent and the reaction temperature and is not limited. As the alkali metal hydroxide, lithium hydroxide, sodium hydroxide, and potassium hydroxide are used, but mono-lithium hydroxide is most preferable in consideration of economical efficiency. The amount used is at least twice the mole of the raw material, Zunawaji, XCHIN C00II (in the formula, R represents hydrogen or a lower alkyl method), but from the viewpoint of selectivity, it is preferably 2.8 moles or more. However, when using the thorium salt of hydroquinone, the amount may be equivalent to the same molar amount or more. The sodium salt of hydroquinone may be prepared in advance in the system by adding sodium 1-lium methylate or sodium ethylate, or it can be prepared by reacting hydroquinone with an equivalent mole to twice the amount of alkali hydroxide. ,
Single A1 may be used.

The reaction temperature varies depending on the raw materials used, the alkali metal, the type of T8 medium, etc., but is preferably 0 to 100°C. In consideration of reaction rate 2 selectivity, the temperature is most preferably 50 to 80°C. The produced acid is mostly used as an ester, so the esterified acid is steamed1ii71. The bipods can be separated and purified.

In addition, if the reaction solvent has the same alkyl group as the desired ester, it is also possible to obtain the ester by acidifying it with hydrogen chloride gas, concentrated sulfuric acid, or fuming sulfuric acid, and then performing the usual post-treatment with fish oil to obtain the ester. .

To obtain 2-(4-hydroxyphenoxy)propionic acid with good purity, tube! Hydrolyze ethyl 2-(4-hydroxyphenoxy)pionate using at least twice the molar amount of sodium hydroxide, acidify it with hydrochloric acid, cool and separate the resulting solid by filtration, and dilute with aqueous solvent. All you have to do is recrystallize. The melting point of the white solid thus obtained was 147-150'C.

This will be explained in more detail below with reference to Examples.

The present invention is not limited to these.

Disaster 22g of hydroquinone, 120g of ethanol and α-
Prepare 21.7g of chloropropionic acid.

After purging with nitrogen, 28 g of sthorium hydroxide was added.

The mixture was stirred at 60°C for 4 hours. 200 g of water was added, the pH was adjusted to pH1 with hydrochloric acid, and the mixture was extracted twice with 200 g of ethyl acetate, and the ethyl acetate was distilled off. The obtained solid was methylated with diazomethane to obtain the following composition.

Hydroquinone---13, 6 mol% Methyl 2-(4-hydroxyphenoxy) propionate---77, 8 mol% diform---
−−−−−−−−−−−−−−−−−−−−−−−−−
8.6 mol% To this composition, 100 g of ethanol and 1 g of concentrated sulfuric acid were added and refluxed for 1 hour, then the ethanol was distilled off, 100 g of water and 100 g of I-toluene were added, and insoluble matter was filtered off.

The liquid was separated, and the l.toluene layer was washed twice with water and toluene was distilled off. The residue was filtered under reduced pressure to obtain ethyl 2-(4-hydroxyphenoxy)propionate as a light brown liquid at 30.2
I got g.

Boiling point: 135-140°C/l mm11g.

1 88g of water, 1g of hydroquinone, 1g of sodium hydroxide
2 g and 7.6 g of α-lyl colpropionic acid were added and the reaction between 411M and 7.6 g of α-lyl colpropionic acid was carried out at 60° C. under a nitrogen atmosphere.The total reaction was one. After the reaction was completed, hydrochloric acid was added to adjust the pH to l, and the mixture was extracted twice with 200 g of ethyl acetate, and the ethyl acetate was distilled off.

The iq solid was methylated with diazomethane to obtain the following composition.

Hydroquinone, ---------36, 1
Mol% 2-(4-Hydroxy)methyl propionate-60.5 Mol% dimer ---, --, --
---------1 to -4,8 mol% The same post-treatment as in Example 1 was carried out, and ethyl 2-(4-hydroxyphenoxy)propionate was converted into a light brown liquid by thin grooves under reduced pressure. It was 11.5g17.

Boiling point: l 35-140'C/1mm1lH.

Under a fresh nitrogen atmosphere, 88 g of hydroquinone lI[r, methyl cellosolve, 12 g of hydroxide, 12 g of hydroxide, and 7.6 g of α-chloropropionic acid were added, and the reaction was carried out at 60° C. for 4 hours. After the reaction is complete, add hydrochloric acid and add 200g of ethyl acetate.
Extract twice with i! Ethyl itate was distilled off. The obtained solid was methylated with diazomethane.

As a result of the gas chromatography analysis, the following composition was shown.

Hydroquinone---111-1----1
9,2 mol% 2- (4-hydroxyphenoxy) methyl propionate --- 73, 1 mol% di-
−−−−−−−−−−−−−−−−−−−−−7,
7 mol% The same post-treatment as in Example 1 was carried out, and ethyl 2-(4-hydroxyphenoxy)p1'pionate was converted into a light brown liquid by vacuum thin grooves to yield 14.3 gf! It's 7.

Boiling point: 135-140°C / 1 mm 11 g 0'' (under nitrogen atmosphere, Hydreki 2F 11 g, ethanol 88
g, sodium hydroxide 12 [and chloroacetic acid 9.5 g
411 at 60'C. +J reaction was performed.

After finishing the anti-Lw +, add hydrochloric acid and add 200 g of ethyl acetate to 21
The mixture was extracted and ethyl acetate was distilled off. (The resulting solid was methylated with diazomethane, and gas chroma I/graph analysis showed the following composition.

Hytroquinone---20.2 mol% 2-(4-hydroxyphenoxy) methyl propionate-16.9 mol% dimer---
----------1--2, 9 pieces of morsilicate under nitrogen atmosphere, 1 g of hydroquinone, 1 g of ethanol, 1 g of ethanol (1 g)
8g of sodium hydroxide, 14g of sodium hydroxide, and 15.3g of α-propionic acid were added, and the reaction was carried out at 60°C for 4 hours. Upon completion of the reaction, phosphoric acid was added, and the mixture was extracted twice with 200 g of ethyl acetate, and the ethyl acetate was distilled off. The obtained solid was methylated with diazomethane, and gas chromatography analysis showed the following composition.

Hydroquinone---15, 4 mol% 2-(4
-Hydroxyphenoxy) Methyl propionate - 73.8 mol% 2M form - 10, 8 mol% Patent applicant Nissan Chemical Industries, Ltd. Procedural amendment (voluntary) 1988 3 March 30th 1 Display of the case 1982 Patent Application No. 230787' 2 Title of the invention 2 Process for producing -(4-hydroxyphenoxy)alkanoic acid 3 ? Relationship with the I-correction case Patent applicant address 3-7-1 Nishikicho, 1 Kamiguchi, Chiyoda-ku, Tokyo 101
4 Claims column of the specification to be amended and Detailed explanation of the invention column 5 Contents of the amendment (1) As shown in the attached sheet.

(2) rX stated on page 2, line 9 of the specification
CHRCOOR (1) (wherein, X represents a chlorine or bromine atom, and R represents hydrogen or a lower alkyl group).

r

(3) Specifications■Described in the reaction formula in the second half of page 3'
2320J to.

'ni 2 S2013 J Correct to.

(4) “α-
Chlorpropion @j.

``The compound represented by the general formula (1) and hydroquinone or a salt of hydroquinone'' is corrected to 1.

(5) Delete "2 moles or more" written in the first line of page 6 of the Memorandum of Understanding.

(6) 'X stated on page 6, line 4 of the specification
CHRCOOR(1)J.

'XCHR' C0OR” [1) Correct to J.

(7) Page 6 of the specification, between line 81j and line 9.

"Also, when R2 is hydrogen in the general formula [1], it first becomes an alkali metal salt in the system and reacts from °ζ. Add J.

(8) r stated on page 6, line 17 of the specification
X CHRCOOH (wherein R represents hydrogen or a lower alkyl group).

rXcHRI COOR2 (wherein, X represents a chlorine or bromine atom, R1 represents hydrogen or a lower alkyl group, and R2 represents a hydrogen or alkali metal atom) J.

(9) '?' stated on page 10, line 6 of the specification?
, 6J '10. Corrected to 8J.

(10) Next to the 4th line on page 12 of the specification.

Example 6 Under nitrogen atmosphere, 11 g of hydroquinone, 88 g of ethanol
g, 10 g of sodium hydroxide, and 3.0 g of the sodium salt of α-chloropropionic acid 1' were added, and the reaction was carried out at 60° C. for 4 hours. After the reaction is complete, add hydrochloric acid and add ethyl acetate.
00g twice and ethyl acetate was distilled off. The obtained solid was methylated with diazomethane and gas chromatography showed the following composition.

Hydroquinone--------
-14, 5 mol% dimer -------11--
−−−−−−−・−・−−−−−−−−−−5.7 mol %'' is added.

Attachment 2, Claims (1) Hydroquinone or a salt of hydroquinone and the general formula [1
] XCHRI GOOR” (1) (wherein, 2-(
A method for producing 4-hydroxyphenoxy)alkanoic acid.

(2) The manufacturing method according to claim 1, wherein the solvent is one or more of methanol, ethanol, methyl cellosolve, ethyl cellosolve, or water.

Claims (3)

[Claims] (1) Salt of hydroquinone or H-1-quinone and general formula (1) % formula % (1) (wherein, X represents chlorine or bromine atom, R represents hydrogen or lower alkyl group) 2-(
A method for producing 4-hydroxyphenoxy)chilucanoic acid. (2) l medium is methanol, ethanol, methyl cellosolve,
The manufacturing method according to claim 1, wherein one or more types of ethyl cellosolve or water are used. (3) The manufacturing method according to claim 1, wherein the solvent is ethanol.