SU824892A3 - Method of preparing phenoxypropionic acid derivatives - Google Patents

Abstract

The compounds of the general formula I can be used as herbicides. They are prepared by reacting a compound of the formula II with a phenol of the formula III. The symbols used in the formulae are defined in Claim 1. <IMAGE>

Description

in which R, R, R have the above values Xg or CHj-CgH SOg with inversion of configuration, at a temperature of 50-150 ° C, in the presence of a carbonate base or sodium methoxide, usually anhydrous sodium carbonate, followed by transesterification of the resulting ester if necessary , within the specified values in or by acid hydrolysis and isolation of the desired product in free form or in salt form. In the case of any stereo-specific process, the reaction conditions must be carefully selected and tested for each particular case. There is no effect on the optical integrity of the desired product. One of these conditions is the nature of the base present in the reaction. The base may be organic or inorganic, and specific examples are sodium carbonate or sodium methoxide. Particularly good results are obtained with anhydrous sodium carbonate. The phenol can be used as a solvent for this reaction. When preparing compounds of general formula 1, in which K is other than hydrogen, it may be advisable to introduce a keel substituent into the starting material, as an option, you can start with pilots (II R H) and invest in and replace R for more late stage or at the final stage of the process. For example, in the case of the preparation of esters with a long chain of phenoxy peonic acids, one can start with $ -. (+) -Lactic acid, or preferably, with S - (-) - ethyl lactate (P; RH or ethyl), and then The transesterification of ethyl ester R - (- i -) - phenoxypropionic acid. Found that a good exit; can also be obtained by using S - {-) - laneyl lactate as the starting material in the interaction of this compound. Example 1. Preparation of potassium salt R - (+) - 2- (4-chloro-2-methylphene si) -propionic acid, a). S - (-) - ethyl lactate mesylate loL - - 6 4, 89 ° is prepared with a yield of 79% from S - (-) - ethyl lactate, methanesulfonyl poride and pyridine at their molar ratio of 1: 1: 1.05. The resulting mesylate (6.0 mol) is stirred from 6.0 mol of 4-chloro-2-methylphenol with 3.3 mol of anhydrous sodium carbonate at 100-il4c for 17 hours. Then the mixture is cooled, filtered and washed several times with toluene, water 2, N NaOH, and then diluted sulfuric acid and water. The mixture is dehydrated by azeotropic distillation, the toluene is distilled off under vacuum. This gives 866 g (59%) of R - (+) - 2- (4-chloro-2-methylphenoxy) propionic acid ethyl ester having C3, methanol); Calculated;%: C 59.4; H 6.2; All 14.6. Found,%: C 59.8; H 6.4; Ce 14.3. The boiling point is 106 ° C at 0.25 mbar. The structure of the product is also confirmed by NMR spectrum data. b). A portion of R - (+) - (4-chloro-2-methylphenoxy) propionic acid ethyl ester is hydrolyzed with distilled formic acid and 2 mol of HC8 for 7 hours. Then the solution is poured into ice water and the precipitated solid is filtered off, washed with water , dissolved in diethyl ether and extracted with sodium bicarbonate in water. The aqueous solution is neutralized with concentrated hydrochloric acid to precipitate the acid, which is filtered, washed and dried. The output of R - (+) - 2- (4-chloro-2-methylphenoxy) propionic acid 83%, so pl. 8385 C, 14.62 ° (C 2, ethanol). Calculated,%: C 56.0; H 5.2, CE 16.5. Found,%: C 56.1; H 5.3; NE 16.6. Melting point 83-85 ° C. The structure of the product is confirmed by NMR data. AT-) . An aqueous solution of potassium salt R - (+) - 2- (4-chloro-2-methyl-phenoxy) propionic acid is obtained by adding 0.395 mol of acid to a stirred solution of potassium hydroxide (0.395 mol) in water (30 ml), with ice cooling. The resulting solution is poured into 121 ml of water to obtain a 70% w / v acidic equivalent solution. Salt has + 3.6 (NW, water). Example 2. Based on the R - (+) - 2- (4-chloro-2-methylphenoxy) propionic acid obtained in Example 16, derivatives are prepared using conventional methods for this. The compounds obtained, as well as their data on the rotation of the polarization plane, are listed in the table. Example 3. Obtaining linevolevo ether R - (+) - 2- (2,4-dichlorophenoxy) propionic acid through S - (-) - ethyl lactate. but). S - (-) - ethyl lactate atmesilate 41 -65,14 prepared in 81% yield from S - (-) - ethyl lactate, methanesulfonyl chloride and pyridine in a molar ratio of 1: 1: 1.05. 12 moles of the obtained mesylate are mixed with 12 moles of 2,4-dichlorophenol at -90-122 ° C for an hour. Anhydrous sodium carbonate (6.6 mol) is added in the first 5 hours in 5 portions in equal portions. The mixture is filtered and triturated with hot column (total volume 6 Jl). The combined organic layers are concentrated and then washed (2x120 ml) (2x1800 ml) with sulfuric acid, and then before the neutrons reaction. (4x1200 ml). The solution is dehydrated by azeotropic distillation and evaporated. The yield of ethyl ester of R - (+) - 2- (2,4-dichlorophenoxy) propioic acid 9.6 moles (80%) having, 5 ° (03, ethanol). Calculated,%: C 50.2; H 4.6; All 26.9. C S sCE-z Found,%: C 50.0; H 4.7; Ce 26, boiling point 117-119C (0.7 mb. The structure of the product was confirmed by NMR spectrum data. B). 5 mol of the ester obtained according to the example. 5.25 mol of lenevol (7-9) in 1300 ml of toluene are treated in the presence of 0.15 mol of concentrated, the mixture is removed with ethanol – tin azeotrope for 8 hours. The solution is cooled; washed with water (3x500 ml) and OC-zozhiva1ot by azeotropic distillation and the solvent is evaporated under vacuum. The output according to the linevol ester (esters) of R - () - 2- (2,4-lichlorophenoxy) propionic acid. 19.1 (C3, ethanol), With thin layer chromatography (SE3O, 5 feet, 239 ° C, gas flow 30 ml / min), the C – Cg component of the ester to ester ratio is 52.3: 33.1 : 14.6; After distillation, the main function (boiling point 131-156 ° C at 0.025 mbar), as it was found, similarly contains CT-, Cg-, ester compotents in a ratio of 36.0: 41.0: 23.0. Calculated,%: C 58.6; H 6.9, Found,%: C 58.3; H7.0. NMR spectrum: cG in CDCt multiplet, (J Hz) (number of protons) 0.65-1.9 wide multiplet (approximately 14.5 N), 1.67 doublet (6.5 Hz) (ZN) 4.15 quadruplet (6.5 Hz) (2H), 4.75 quadruplet (6.5 Hz) (1H), 6.65-7.35 multiplet (3N). HK-cneKTp9j, o, K.c (liquid film) 1757 (S) 1742 (S) 1481 (M) &amp; 68 (M) 802 (M) 736 (M) 651 (M) cm

X UN (SNE) 2.

L-levol is a mixture of primary alcohols,

Example 4, In Example 1.5), R - (+) - 2- (2,4-dichlorophenoxy propionic acid) is obtained by reacting ethyl ether R - (+) - 2- (2,4-dichlorophenoxy) propionic acid with formic acid at boiling point in the presence of 2N HC6; Free acid is obtained in a yield of 95.5%

Acid 1 (6) ioL + 6.9 ° (C2, ethanol)

anhydrous

HN (CH) 2

Melting point 121-122 ° C, o {.28 ° (C14, ethanol),. The resulting R - (+) - acid is used to prepare the corresponding derivatives, such as potassium salt, salt, dimethylammonium, tert-octylammonium salt, as well as the salts obtained

the interaction of R - (+) - 2- (2,4-dichlorophenoxy) propionic acid with .NHj-C (CH.), g- (CH.L- CiCHg), or with HjN- (cn). - not - sn - (shn „), - CHj. / 3,740, (NW, ethanol). Example 5. According to Example 1 a), S- {4 -) - 2- (2-4, 5-trichlorophenoxy) propionic acid ethyl ester is obtained by stirring - (-) - ethyl lactate mesylate with 2,4,5-trichlorophenol and atri carbonate for 2.5 hours at. After filtration, prog ing with water, NaOH, and again with water, an ethyl ester of R- (4-) -2-C2,4,5-trichlorophenokei) is obtained with propionic acid, melting point 39-42 ° C and 51, ethanol) Calculated: С 44.4; H 3.7, s-, n, Found,%: C 44.3 H 3.7. The structure of the product is confirmed by NMR-spectrum data. A part of the obtained compound was used to prepare the coigent of the corresponding linolic ester by transesterification. After heating the ethyl ester of R - (+) - 2- (2,4,5-trichlorophenoxy) propionic acid with a linzole in the presence of concentrated sulfuric acid for 10 hours at a boiling point. the solution is washed with water and the solvent is distilled off. The lignool ester is obtained in the form of milk with a quantitative yield of about (. +40.2 (C3, ethanol). At thin-layer chromatography (SE3O, 235 ° C, gas stream 30 ml / min), mole The ratios of the components of the Cj-Ca to Cd esters are 52.9: 33.5: 13.6. After distillation, the main fraction (m.p. 151-166 at 0.01 mbar), as it was found, also contains nents of esters in the ratio 46.6: 39.2: 14.2. Calculated,%: C 53.1; H 5.9. Found,%: C 53.9; H 6.1. The structure of the product is confirmed by NMR data -spectra, Example 6. Getting the line. volvoy ether R - (+) - 2- (4-chloro-2-methylphenoxy) propionic acid through S - (-) - linenelactate. A), S - (+) - lactic acid (1.5 mol), linenevol 79 ( 1 mol), benzene (250 ml) and concentrated sulfuric acid (0.05 mol) are boiled with azeotropic distillation of water for 2 x h. Then the benzene solution is washed with water (3x500 ml) until neutral reaction and dehydrated. azeotropic distillation, and the solvent is distilled off under vacuum. To obtain S - (-) - Li-lilactate with a yield of 76% .12.62 "Db) S - (- Lineneillactate (0.5 mol) triethylamine (0.54 mol) and toluene (2.00 ml) are stirred while adding methanesulfonyl chloride (0.54 mol) at a temperature maintained within 26-30 s. The toluene solution is washed with water (3x250 ml), 2N it (100 ml) and water until neutral, then dehydrated by azeotropic distillation, toluene is distilled off under vacuum and 3 - (- lineage lactate mesylate with a yield of 97% {ct || -40.34 ° (C2, ethanol); b5 8 - / - lineine lactate mesylate (0.4 mol) 4 chlorine-2 - methylphenol (0.4 mol), anhydrous carbonate sodium (0.4 mol) and toluene (40 ml) are stirred at 130-135 ° C for 8 hours. The organic solution is washed with water (2 x 300 ml), 2N sodium hydroxide (2 x 100 ml) and water until neutral. The solution is dehydrated by azeotropic distillation and evaporated in vacuo to give the R-(-} -) 2- (4-chloro-2-methylphenoxy) propionic acid linnelevate ester with a yield of 68%. ° C, a gas flow of 30 ml / min. The molar ratio of the components of the Cg and Cd esters is 44.9: 36.9: 18.2. Calculated,%: C 65.9; H 8.3. Found,%: C 66.3, H 8.3. Boiling point: 109-168 ° С (О, 4 mbar). Example 7. a) Preparation of S - (-) - ethyl lactate tosylate. S - (-) - ethyl lactate (0.08 mol) was dissolved in pyridine- (1.5 mol), p-toluenesulfonyl chloride (0.17 mol) was added to the solution, and the mixture was left at C for 16 hours. Pyridine is filtered off and the filtrate is added to ice / water (700 ml) and stirred for 30 minutes. The aqueous mixture is extracted with DIETHYL ETHER (2x100 ml). The combined ether solution was washed with 50% hydrochloric acid (2 x 125 ml) at ice temperature and water (3 x 250 ml) dried over potassium carbonate and sodium sulfate. The solvent is distilled off under vacuum. The resulting oil is placed in a minimum amount of white spirit at 40-C (1200 ml) and mixed with activated charcoal. After filtration, the solution is cooled to -20 ° C for 15 hours to obtain a white crystalline product S - (-) - toluene sulfoethyl lactate, the yield of which is 64% -55.2 (pure). Calculated,%: C 52.9 N 5.9; And, 8. Found,%: C 53.2; H 6.0; 11.5. b) Preparation of R - (+) - 2- (2,4-dichlorophenoxy) propionic acid ethyl ester. S - (-) - toluene sulfoethyl lactate (0.005 mol), 2,4-dichlor (

(0.0075 mol) anhydrous sodium carbonate (0.005 mol) and toluene (0.5 ml) are stirred at 130–135 ° C for b h. After toluene (15 ml) has been added, the organic solution is washed with water (2 x 15 ml ), IN with sodium hydroxide solution (10 ml) and water (3x20 ml) until neutral. The solution is subjected to azeotropic and then vacuum distillation. R - (+) - 2- (2,4-dichlorophenoxy) propionic acid ethyl ester is obtained in a yield of 58% and ctlff 31.3 (C3, ethanol).

Calculated,%: C 50.2; H 4.6.

with "

Found,%: C 49.9; H 4.6. Boiling point: 102-104 0 (0.13 mat.).

invention formula

Claims (2)

1. A process for the preparation of phenoxypropionic acid production, and the R-OR S-configuration of the general formula (I) where R is R CH-, p 0.1, m 1 - 3, R is H or alkyl C / 2.- C to or a mixture of compounds, where n-alkyl, CT-Cg or alkali metal ion or alkyl substituted ammonium, characterized in that, in order to increase the versatility of the process, the lactic acid derivative of the R or S configuration of the general formula CooR (II) subjected to interaction with phenol of General formula .her, ( /) in which R, R, R2 are as defined above, X or CHgCgH SOg with configuration inversion at a temperature of 50 -, in the presence of sodium carbonate or sodium methoxide base, followed by transesterification of the resulting ester, if necessary, within the specified values of R or acid hydrolysis and isolating the desired product in free form or as a salt. 2. The method according to claim 1, wherein the anhydrous sodium carbonate is used as the base. Sources of information taken into account in the examination 1. Patent of Great Britain 1114040, cl. C 2 C, pub. 1968