CA1234142A

CA1234142A - Substituted 2-halogenopropionates as intermediates for herbicides

Info

Publication number: CA1234142A
Application number: CA000444790A
Authority: CA
Inventors: Koichi Moriya; Kazuomi Yasui; Junichi Saito; Kozo Shiokawa; Masahiro Aya
Original assignee: Nihon Tokushu Noyaku Seizo KK
Current assignee: Bayer CropScience KK
Priority date: 1981-06-25
Filing date: 1984-01-05
Publication date: 1988-03-15

Abstract

ABSTRACT OF THE DISCLOSURE
Novel substituted 2-halogenopropionates of the formula

Description

3~

The present invention relates to certain novel substituted

2-halogenopropionates, and to their use as intermediates for preparing certain herbicides.
It has been disclosed in United States Patent No.4,0~6,553 corresponding to Japanese Laid-open Patent Application No.51-106,735 that herbicidal activity is possessed by compounds of the general formula x2 Xl ~o-~ T l wherein xl and X each represents halogen, Y represents hydrogen or alkyl having 6 or less carbon atoms, and Z represents oxygen or sulfur, and the salts, esters, amides, and halides thereof.
I-t has been disclosed in Japanese Laid-open Patent Application No.52-131,545 corresponding to DE-OS ~German published specification) 2,617,804 that herbicidal activity is possessed by compounds of the general formula R CH3 CF:3~0~o-CH-C ~\

wherein R represents hydrogen or halogen, Rl represents:
(a) straight- or branched chain (Cl - C12) alkyl (which is substituted by cyclohexyl, halophenyl, nitrophenyl, (Cl - C6) alkylphenyl, phenoxy (which is mono- to tri-Nit 144 - 1 -~3~ 2 substituted in some cases with halogen and/or ~Cl - C4) alkyl), (C5 C6) alkoxy, ~C5 - C6)-alkoxy-(C2 - ~4) alkoxy, (Cl - C4) alkoxyethoxyethoxy, (Cl - C4~ acyl, a group rep-resented by the general ~ormula ~ R2 ~R2 -N or - - N-R3 Z a or~ in the R3 ~ R4 ~

2 position or a position remot from the carboxyl, mono- or poly-substituted by phenyl);
i - (b) cyclohexenyl or phenyl-(C3 - C4)alkenyl;
(c) (C3 - C.4)alkynyl (which is optionally mono- or di-10 substituted by straight or branched chain (Cl - C4~ alkyl, halogen, phenyl, halophenyl or (Cl - C4) alkylphenyl), provided that Rl does not represent unsubstituted propargyl or butynyl 3 (d) one of the groups represented by the following general formulae:

~ .
0 0 R~
-Rl-CH C~ Rl-0-C0-R5 ~ -Rl-0-C0-~ \ and , , ? 5 (IV) (V) (VI) Rl S~)n R6 (VII~
or (e) (Cl - C2)alkyl substituted by ~uryl, tetrahydro-furyl, pyridyl or oxiranyl, R2 represents hydrogen, (Cl - C~)alkyl or (Cl - C4)-20alkoxy, Nit 144 - ~ -,, .

~234~

R3 represents hydrogen, (Cl - C4)alkyl or phenyl, or R2 and R3 together form 4- or 5-membered, saturated or unsaturated alkylene chain one methyl- .
ene of which may optionally be replaced by -0-, -C- or -N-(Cl - C4)- alkyl, O
R4 represents hydro~en or (Cl - C4)alkyl, Z represents an inorganic or organic anion, R1 represents skraight or branched chain (Gl - C12)-alkylene, R5 represents hydro~en, tCl - C4)alkyl, (Cl - C4)-haloalkyl, phenyl optionally substituted by halogen~
.nitro and/or (Cl - C4) alkyly or group represented - by the formula -CH-0 ~ 0 ~ F3 ~VIII') or -CH-0 ~ 0 ~ Cl (IX') . CH3 Cl R~ represents (Cl - C4~alkyl, and n is 0, 1 or 2.
: It has been disclosed in Japanese Laid-open Patent Application No. 52-144,637 corresponding to DE-OS (German 20 published specification) 2,623,558 that herbicidal activity is possessed by compounds of the general formula (R)~ ~ 0-CH-C
wherein ~ Y-Rl each R represents t~e same or different group Nit 144 3 .; , _ selected from halogen, (Cl - C4~ alkyl, and (Cl - C4)alkoxy, Y represents 0 or S, n is 1 or 2, Rl represents:
- (a) straight or branched chain (Cl ~ Cl2)alkyl (which is substituted by cyclohexyl, halophenyl, nitrophenyl, (Cl - C4) alkylphenyl, or a group represented by the general formula "~ 2 " " R2 ~,R2 ~N \ ; -0-CH2-~H2-N \ 3 or ~ R4 J

(II ) (III ~ (IV 1l ) , or mono- or poly-substituted by the same or di~ferent group selected from hydroxy, halogen5 rhodanide, and phenyl, in ~-or mo~ distant position from Y);
(b) mono- or di-(Cl - C4)alkylcyclohexyl;
~c) cyclohexenyl or ~C3 - C4)alkenyl (which may be substituted by halogenJ hydroxy, phenyl, halophenyl or (Cl - C4)alkylphenyl), ~d~ naphthyl or phenyl (which is in some cases mono- or poly-substitùted by ~Cl - C4)alkyl; (Cl - C3)haloalkylJ
CF3, N02, CN, SCN~ CH0, (Cl - C3)alkoxy, (Cl - C3)-alkoxycarbonyl, aminocarbonyl~ di-(Cl - C4)alkylamino, or (Cl - C2)alkylthio, and which may further contain haloge~, or when Y is 0, Rl also represents:
(e) straight or branched chain tc3 - C6)alkynyl twhich i~
in some cases mono- or poly-substituted by tCl - C4)al.kyl, (Cl - c4)alkoxy, halogen, phenyl, halophenyl, or ~Cl - C4) alkylphenyl);
(f) halocyclohexyl optionally substituted by (Cl - C4)alkyl;

Nit 144 ~ 4 ~

~23~

(g) group represented by the formula o~ -O O
R1 0 R -R'-CH-CH2 , ~Rl-0-C0 R6 ~ 1 7 (V ) (VI ) (VII ) (VIII ) ,,~,R
-Rl-0-C0-N \ 7 , -Rl-C0-Rg , -Rl-0 S02-R7 or (IX ) (X ) (XI ) -Rl-S(O)p-R7 ;
~XII ) (h) (Cl - C2)alkyl substituted by a furyl, tetrahydro-furyl, pyridyl or by oxiranyl;
(i) (C2 - C4~alkyl substituted by 3 to 7 chlorine and~or fluorine, .or, when Y is S~ Rl represents:
(k) (C3 - C4)alkenyl, . R2 represents hydrogen, (Cl - C4)alkyl, (Cl - C4) alkoxy, hydroxyethyl or chloroethyl, R3 represents hydrogen, (Cl - C4)alkyl, chloroethyl, ! phenyl, halophenyl, (Cl - C4)alkylphenyl, hydroxy-: ethyl or aliphatic (Cl - C4)acyl, or, when taken together, R2 and R3 represents Z-, 4- or 5-membered, satur-ated or unsaturated hydrocarbon chain one,carbon atom of which may be replaced by -0-, -C0-, -N-, -NH- or -N-(Cl - C4)alkyl~
R4 represents hydroæen or (Cl - C4)alkyl, Z represents an inorganic or organic acid anion3 Rl.represents.a.straight ~hain or. branched.chain : Nlt 144 ~ 5 ~

~3~

~Cl - C`12) alkylene, R5 represents (Cl - C6)alkyl, (Cl ~ C4)haloalkyl, (C2 ~ C8)alkoxyalkyl, (C3 - Cl2)al~oxyalkoxy, hydroxyethyl or phenyl optionally mono- or di-subs~ituted by halogen and/or (Cl - C3)al~yl, R6 represents hydro~en, (Cl - C4)alkyl, (Cl - C4)-haloalkyl, phenyl optionally substituted by halogen, nitro and/or (Cl - C4)al~yl, or a group of the general formula -CH-O- ~ 0 ~ C~- -CH-0 ~ O ~ Cl or -C~ O- ~ 0 ~ Cl R7 represen~s (Cl - C4~alkyl, phenyl, halophenyl, ~ . nitrophenyl or (Cl ~ C4)alkylphenyl, :: ` R8 represents hydrogen, (Cl - C43alky1 or (Cl ~ C4)-; -. . alkoxy~ .
- Rg represents ~Cl - C4)alkyl~ and p is 0, l or 2.
It has further been disclosed in DE-OS (German pub-lished specification) 2,812~571, corresponding to Japanese Laid-open Patent Application No. 54-119,476, that herbicidal 20 activity is possessed by compounds of the general formula / R O
CF2X~o -~30-CH(CH2 )nCZ

wherein ~ X represents fluorine or chlorine, '~ Y represents hydrogen or chlorine, ~ .
Nit 144 - 6 -.. . - . ' ' ., .

~3~

R represents hydrogen, methyl or ethyl, n is 0 or 2, zl represents hydroxy, ~Cl - C6)alkoxy whose alkyl moiety is optionally substituted by 1 to 3 halogen, (Cl - C4)alkoxy-(Cl - C~)alkoxy, (C2 ~ C4) alkenyloxy, (C2 - C4)alkynyloxy, (C3 - C6) cycloalkyl whose cycloalkyl moiety is optionally substituted by (Cl - C~)alkyl~ (Cl - C4) alkoxycarbonyl-(Cl - C4)alkoxy, phenoxy whose phenyl moiety is optionally substituted by 1 to 3 halogen or (Cl - C4)alkyl, benzyloxy, glycidyloxy, (Cl -C4)alkylthio, (C2 - C4)alkenylthio, phenylthio whose phenyl moiety is optionally substituted by 1 to 3 halogen or (Cl - C4)alkyl, amino, (Cl - C4)-alkylamino, (Cl - C4)alkoxycarbonylmethylamino, hydroxycarbonyl-methylamino, anilino group whose phenyl moiety may optionally be substituted by 1 to 3 halogen, pyridin-2-ylamino, an -O- cation, or halogen.
The present invention now provides, as new compounds, cer~ain intermediates for preparing herbicidally active substituted phenoxypropionates of the general formula CH~ 0 R R2 Ar-O ~ O-CH _C-0-CH(Cil2)n-0-CH- ~ (I) in which Rl and R2 each independently represent a hydrogen atom or a Cl to C6 alkyl group, X represents a hydrogen or halogen atom or a nitro, Cl to C6 alkyl or Cl to C6 alkoxy group, a and n each independently are 1 or 2, and Ar represents a group of the general formula _ ~ or _ ~ b (Ia) (Ib) `~ Nit 144 - 7 -~3~

~herein Y represents a trifluoromethyl group~ a halogen atom or a nitro, cyano or Cl to C6 alkyl group, and b is 1, 2 or 3.
The invention thus provides a substituted propionic acid ester compound of the fo~mula W-C~I- C-O-CH(CH2) -O-C~I- ~ Xa (X) in which Rl and R2 each independently are a hydrogen atom or a Cl to C6 alkyl group, X is a hydrogen or halogen atom or a nitro, Cl to C6 alkyl or Cl to C6 alkoxy group, a and _ each independently are 1 or 2, and W is a halogen atom, or a 4-hydroxyphenoxy group, or alkali metal salt thereof.
The new intermediates fall into two classes, namely those in which N is halogen~ and those in which W is 4-hydroxyphenoxy or an alkali metal salt thereof.
The first class of intermediates i.e. those in which W is halogen, may be converted to herbicides of formula ~I) by a process in which a compound of the general formula Ar-O- ~ OM (II) in which Ar has the meaning given above, and M represents a hydrogen atom or an alkali metal atom, N t 144 - 8 -~23~

is reacted wi-th a compound of the general formula Zl-c~l-c-o-cH~cH2)n-o-cH- ~ Xa (III) in which Rl, R2, ~, a and n have the meanings given above, and zl represents a halogen atom.
The second class of intermediates i.e. those in which W is 4-hydroxy-phenoxy or an alkali metal salt thereof, may be converted to herbicides of formula ~I) by a process in which a compound of the general formula Ar _ zl (VI) in which Ar and zl have the meanings given above, is reacted with a compound of the general formula MO ~ OCH - C-O-CH~CH2)n-O-CH- ~ ~VII) in which Rl, R2, X, M, a and _ have the meanings given above. The herbicidally active substituted phenoxypropionate compounds of formula (I) can be synthesized by these reactions with ease in high yield, and are novel active compounds showing selective excellent herbicidal activity against gramineous weeds without causing substantial phytotoxicity on agricultural crops. The compounds of formula (I) show excellent properties which are not shown by structurally similar prior art compounds, in particular that, coupled with good toleration by useful plants, they show sufEicient herbicidal activity in low amounts, and that they control regeneration of weeds, especially perennial gramineous weeds, over a long period of time due to their excellent lasting effect.

Preferred compounds according to the present invention are those in Nit ]44 - 9 -which, alone or in combina*ion, Rl and R2 each independently represent a h-ydrogen atom or a methyl, ethyl, n-propyl, isopropyl, n-, iso-, sec- or tert-butyl group, and X represents a hydrogen atom, a fluorine, chlorine, bromine or iodine atom, a nitro, methyl, methoxy, ethyl/ ethoxy, n-propyl, n-propoxy, isopropyl, isopropoxy or n-, iso-, sec- or tert-butyl or -butoxy group, particularly hydrogen, fluoro, chloro, bromo, nitro, methyl or methoxy.
If 4-~4-trifluoromethylphenoxy)phenol and 2-benzyloxyethyl-2-bromo propionate are used as starting materials, a compound of formula ~I) may be produced cas illustrated by the following equation:

F3C ~ O ~ OH +

Br-CH - C-O-~CH2)2-O-CH2 ~

CH3 o ~ ~ O-CH - c-o-~C~l2)2-o-c~2 + HBr Nit 144 - 10 -~23~

If 4-tri~luoromethylphenylchloride and 2-~2-fluorob~nzyloxy)ethyl-2-(4-hydroxyphenoxy)propionate are used as starting materials, a compound of formula (I) may be produced as illustrated by the following equation-CH3 o F
F3C ~ Cl + ~IO ~ OCH- C-O-CHzCH20CH

F3C~30~oCH--C -CH2CH2CH2~

+ HCl Examples of the starting materials of the formula (III) are:
2-benzyloxyethyl-2-chloro~or bromo)propionate, 3-benzyloxypropyl-2-chloro~or bromo)propionate, l-methyl-2-benzyloxyethyl-2-chloro~or bromo)prop-ionate, 2-~-methylbenzyloxyethyl-2-chloro~or bromo?propionate~ 2-~2-fluoro-benzyloxy)ethyl-2-chloro~or bromo)propionate, 2-~4-fluorobenzyloxy)ethyl-2-chloro(or bromo)propionate, 2-(2-chlorobenzyloxy)ethyl-2-chloro~or bromo) propionate, 2-~4-chlorobenzyloxy)ethyl-2-chloro(or bromo)propionate, 2-~2,4-dichlorobenzyloxy)ethyl-2-chloro(or bromo)propionate, 2-~3,4-dichlorobenzyloxy) ethyl-2-chloro~or bromo)propionate, 2-(2,6-dichlorobenzyloxy)ethyl-2-chloro~or - bromo)propionate, 2-~2-methylbenzyloxy)ethyl-2-chloro~or bromo)propionate, 2-~3-nitrobenzyloxy)ethyl-2-chloro~or bromo)propionate, 2-~4-methoxybenzyloxy) ethyl-2-chloro~or bromo)propionate, 2-~4-bromobenzyloxy)ethyl-2-chloro~or bromo)propionate, l-methyl-2-~-methylbenzyloxyethyl-2-chloro(or bromo)-; 20 propionate, 2-~3-chlorobenzyloxy)ethyl-2-chloro~or bromo)propionate, 2-~2-bromobenzyloxy)ethyl-2-chloro~or bromo)propionate, 2-~3-fluorobenzyloxy) ethyl-2-chloro(or bromo) propionate, 1-methyl-2-(2-fluorobenzyloxy)ethyl-2-chloro(or bromo)-propionate, 3-(2-fluorobenzyloxy)propyl-2-chloro(or bromo) propionate, 2-(2-nitrobenzyloxy)ethyl-2-chloro(or bromo)propionate, ., .:.

Nit 144 ' ~ : :

~:3~ Z

2-(4-nitrobenzyloxy)ethyl-2-chloro(or bromo)propionate, 2-(4-methylbenzyloxy) ethyl-2-chloro(or bromo)propionate, 2-(2-methoxybenzyloxy)ethyl-2-chloro (or bromo)propionate, and 3-(4-fluorobenzyloxy)propyl-2-chloro (or bromo)propionate.
The reaction involving the intermediate of formula (III) is preferably carried out in a presence o a diluent. For this purpose, any inert solvents may be employed.
Example of such solvents and diluents include water; aliphatic, alicyclic and aromatic hydrocarbons - each of which may optionally be chlorinated (such as hexane, cyclohexane, petroleum ether, ligroin, benzene, toluene, xylene, methylene chloride, chloroform, carbon tetrachloride, ethylene chloride, tri-chloroethylene, and chlorobenzene), ethers (such as diethyl ether, methyl ethyl ether, di-isopropyl ether, dibutyl ether, propylene oxide, dioxane, and tetrahydrofuran), ketones (such as acetone, methyl ethyl ; ketone, methyl i-propyl ketone, and methyl isobutyl ketone), nitriles (such as acetonitrile, propionitrile, and acrylonitrile),alcohols (such as methanol, ethanol, iso-propanol, butanol, and ethylene glycol), esters (such as ethyl acetate and amyl acetate), acid amides (such as dimethylformamide and dimethy-lacetamide) sulfones and sulfoxides (such as dimethylsulfoxide and sulfolane) and bases (such as pyridine).
The reaction is preferably carried out in the presence of an acid-binding agent. As example of such acid-binding agents, there may be mentioned hydroxides, carbonates, bicarbonates and alcoholates of alkali metals, and tertiary amines such as triethylamine, diethylaniline, pyridine.
~ 1e reaction can be carried out over a wide range of temperatures.
Generally, it is carried out at a temperature between -20C and the boiling point cf the reaction mixture, preferably between 0C and 100C.
This reaction is preferably carried out under ambient pressure, Nit l44 - 12 -~:34~

although it can be effected under elevated or reduced pressure.
Examplc of the other starting materials of the formula (VII) are:
2-benzyloxyethyl-2-(4-hydroxyphenoxy)propionate, 3-benzyloxypropyl-2-~4-hydroxyphenoxy~propionate, 1-methyl-2-benzyloxyethyl-2-(4-hydroxyphenoxy) propionate. 2-~-methylbenzyloxyethyl-2-(4-hydroxyphenoxy)propionate, 2-(2-fluorobenzyloxy)ethyl-2-(4-hydroxyphenoxy)propionate, 2 ~4-fluorobenzyloxy) ethyl-2-(4-hydroxyphenoxy)propionate, 2-(2-chlorobenzyloxy)ethyl-2-(4-hydroxy-phenoxy)propionate, 2-(4-chlorobenzyloxy)ethyl-2-(4-hydroxyphenoxy)propionate, 2-(2,4-dichlorobenzyloxy)ethyl-2-(4-hydroxyphenoxy) propionate, 2-(3,4-dichlorobenzyloxy)ethyl-2-(4-hydroxyphenoxy)propionate,2-(2,6-dichlorobenzyl oxy)ethyl-2-(4-hydroxyphenoxy)propionate, 2-(2-methylbenzyloxy)ethyl-2-(4-hydroxyphenoxy)propionate, 2-(3-nitrobenzyloxy)ethyl-2-(4-hy~roxyphenoxy)prop-ionate, 2-(4-methoxybenzyloxy)-ethyl-2-(4-hydroxyphenoxy)propionate, 2-~4-bromobenzyloxy)-ethyl-2-(4-hydroxyphenoxy)propionate, 1-methyl-2-~-methyl-benzyloxyethyl-2-(4-hydroxyphenoxy)propionate, 2-(3-chlorobenzyloxy)ethyl-2-(4-hydroxyphenoxy)propionate, 2-~2-bromobenzyloxy)ethyl-2-~4-hydroxyphenoxy) propionate, 2-~3-fluorobenzyloxy)ethyl-2-~4-hydroxyphenoxy)propiona~e, l-methyl-2-~2-fluorobenzyloxy)ethyl-2-(4-hydroxyphenoxy)propiollate, 3-~2-fluorobenzyloxy) propyl-2-(4-hydroxyphenoxy)propionate, 2-(2-nitrobenzyloxy)ethyl-2-(4-hydroxy-phenoxy)propionate, 2-(4-nitrobenzyloxy)ethyl-2-(4-hydroxyphelloxy)propionate, 2-(2-methoxybenzyloxy)ethyl-2-(4-hydroxyphenoxy)propionclte, 3-(4-fluorobenzyloxy) propyl-2-(4-hydrophenoxy)propiollate, and 2-(4-methylbenzyloxy)ethyl-2-(4-hydroxyphenoxy)propionate.
In carrying out the reaction involvi.ng the intermediate of formula (VII) any of the inert solvents or diluents as described hereinbefore for the first reaction is preferably used to obtain the end product ~qith high puri.ty in Nit 144 - 13 -~23~

high yield. Likewise, this second reaction is preferably carried out in the presence of an acid-binding agent as described hereinbefore.
This second reaction can be carried within the same reaction conditions of temperature and pressure as those mentioned hereinbefore.
The intermediate compound of the formula (III), may also be used as an intermediate in the production of intermediates of the formula (VII~.
According to the invention, there is also provided a process Eor preparing a compound of formula ~X) which comprises reacting a compound of the formula CH3 O

Zl-CH_ C zl in which each zl independently represents a halogen atom, with a compound of the formula Rl R2 HO-CH(CH2)nOCH ~ Xa in which Rl, R2, X, a and n are as d0fined above, and where required reacting the resulting 2-halogenopropionate compound with hydroquinone and subsequently, where required, with an alkali metal base.
Thus, the present invention further provides a process for the production of a compound of the general formula ~III), which comprises reacting a compound of the general formula C~l3 O
Zl-CH -.C-Zl ~VIII) in which each zl independently represents a halogen atom, with a compound of Nit 144 - 14 -~3~

the general formula Rl R2 i10 CH(C 2)n C ~ Xa (~X) in which Rl, R , X, a and n have the meanings given above.
Examples of the compounds of the formula (VIII) used as starting materials i71 the production of compounds of formula (III) are:
2-bromopropionyl bromide and 2-chloropropionyl chloride.
Examples of the other starting materials of the formula (IX) also used in the production o compounds of formula (III) are:
2-benzyloxyethanol, 3-benzyloxypropanol, l-methyl-2-benzyloxyethanol, 2-~-methyl benzyloxyethanol, 2-~2-chlorobenzyloxy)ethanol, 2-(3-chlorobenzyloxy) ethanol, 2-(4-chlorobenzyloxy)ethanol, 2-(2,4-dichIorobenzyloxy)-ethanol, 2-~2,6-dichlorobenzyloxy)ethanol, 2-(3,4-dichlorobenzyloxy)ethanol, 2-(2-methyl--benzyloxy)ethanol, 2-(4-methylbenzyloxy)ethanol, 2-(2-methoxybenzyloxy)-ethanol, 2-(4-methoxybenzyloxy)ethanol, 2-(2-bromobenzyloxy)ethanol, 2-(4-bromobenzyloxy) ethanol, l-methyl-2-~-methylbenzylethanol, 2-(2-fluorobenzyloxy)ethanol, 2-~3-fluorobenzyloxy)ethanol, 2-(~-fluorobenzyloxy)ethanol, 2-~2-nitrobenzyloxy) ethanol, 2-~3-nitrobenzyloxy)ethanol, 2-~4-nitrobenzyloxy)ethallol, l-methyl-2-~2-fluorobenzyloxy)-ethanol, 3-~2-fluorobenzyloxy)propanol, 3-(~-fluorobenzyl-oxy)propanol.
If 2-bromopropionyl bromide and 2-benzyloxyethanol are used as starting materi~ls, the course of the reaction for the production of compounds of formula ~III) is illustrated by the following equation:

Nit 144 - 15 -

3~

C113 o Br-CH~ C-Br ~ H0-CH2CH20CH
CH3 o -? Br-CH_ CO-CH2CH20CH2 ~ ~ H-Br In the process for the production of compounds of formula (III) any of the inert solvents or diluents as described hereinbefore is preferably used to obtain the end products with high purity in high yield. Likewise this reaction is preferably carried out in the presence of the acid-binding agent as described hereinbefore.
The reaction conditions of temperature and pressure are also chosen from those mentioned hereinbefore.
The present invention further provides a process for the production of a compound of the formula IVII), which comprises reacting a compound of the formula H0 ~ H

with a compound of the general formula Zl-CH- C0-CH(CH2) -0-CH- ~ Xa ~III) in which Rl, R2, X, a~ _ and zl have the meanings given above.
Examples of the compounds of the formula (III) used as starting materials have already been mentioned as preferred intermediates above, and can be prepared as described above.
If hydroquinone and 2-benzyloxyethyl-2-bromopropionate are used as starting materials~ the course of the reaction for the procluction of compounds of formula ~VII) is illustrated by the following equation:

~ Nit l~}~ - 16 -~2~

HO ~ OH ~ Br -IH CO -CH2CH20CH2 ~3 C~l3 O
HO~O-~II C-CH2CH2CH2~3 ~ H Br In the process for the production of compounds of formula (VII) any of the inert solvents or diluents as described hereinbefore is preferably used to obtain the end products with high purity in high yield. Likewise this reaction is preferably carried out in the presence of the acid-binding agent as described hereinbefore.
The reaction conditions of temperature and pressure are also chosen from those mentioned hereinbefore.
I`he active compounds of formula (I) show excellent selective herbici-dal effect when used as soil-treating agents to bé used pre- or post-emergence of gramineous weeds. Since these active compounds show li*tle or no toxicity towards warm-blooded animals and show good selecti~ity for agricultural plants, that is, cause no phytotoxicity for agricultural plants, they can be conveniently used as herbicides for controlling weeds.
The following examples serve to illustrate processes for the production of herbicidally active compounds of formula ~I) Example A CH3 1l F3C~O~O-CH C O-(C~l2)2-O-CH
~I) Nit 1~4 17 ~Z3~

2504 g of 4-(4-trifluorometh~Jlphenoxy)phenol were added to 150 ml o~ dry ace~onitrile, and 28.7 g of 2-benzyl-oxyethyl 2-bromopropionate and 14.5 g of anhydrous potass~m carbonate were added thereto. Then, the mixture W2S
refluxed for 4 hours, stirring well. After the complek~
ion of the reaction, acetonitrile was distilled off under reduced pressure.
Toluene was added to the residue, and the toluene layer was washed successively with 1~ strength by weight sodium hydroxide a~ueous solution and water. Upon distilling off toluene under reduced pressure, there were obkained 41 g of colourless, viscous end product, 2-benzyl-oxyethyl 2-(4-[4-trifluoromethylphenoxy)phenoxy] propionate.
~ 1-5300 ~xamole B

Cl CH~ 0 Cl~O~-O-CH--C-O-(CH2~ 2-0-CH2~F
~2) 30.6 g of 4-(3,5-dichloro-2-pyridyloxy)phenol sodium salt and 30.5 g of 2-(4-fluorobenzyloxy)ethyl 2-chloropropionate were added to 100 ml of dimethylformamide~
and the mixture was heated to 70 to 80C ~or 3 hours with stirring. After cooling to room temperature, the reaCtiGn solution was poured into 300 ml o~ water, then extracted with ether. The ether layer was washed successively with 1~ strength by weiæht sodiurn hydroxide aqueous solution and water, followed by dehydration Upon distilling off the ether, there were obtained 38 g of a pale yellow, viscous, oily end product, 2~ fluorobenzyloxy)ethyl 2-~4-(3,5-dichloro-2-pyridyloxy)phenoxy]propionate.
1.5643 Nit 144 - 18 -~, ~ , .

~34~ 2 '`Ex~m~le C
.
CH~ o F
3 ~ ~ OCH -C-0-CH2CH2-0-CX2 ~ '(29) 33.4 g of 2-(2-fluorobenzyloxy)ethyl-2-(4-hydroxy-phenoxy)propionate were dissolved in 120 ml o~ dimethyl-5. formamide, 15.2 g of potassium carbonate were added thereto,then the mixture was heated at 9$C for one hour with stirring. 27.1 g of 4-trifluoro~thyl chlarobenzer.e were added to the solution which was then heated to 95 to 100C for five hours. After cooling the reaction solution to room temperature, it was poured into ice-water, then extracted with toluene. The toluene layer was washed successively with 1% strength by weight sodium hydroxide solution and water,' and was dried and filtered. The toluene was distilled o~f.under reduced pressure, and further ~olatile 15 by-products were removed at l00C~O.l mmHg. The end product of 2-(2-fluorobenzyloxy)ethyl-2-~4-(4-trifluoro-methy1phenoxy)phenoxy]propionate was obtained in a yield of 20.7 g. (nD l.5235) ExamDle D .

2'0 F3C ~ 0 ~ OCH - C--CH2CH2--CH2 ~ (30) '31.6 g of 2-benzyloxyethyl-2-(4-h~droxyphenoxy)-propionate were dissolved in lO0 ml o~ dimethylsulfoxide, 15.2 g of potassium carbonate were added thereto, then the mixture was heated at 90C'for one hour with stirring.
20.0 g of 2-chloro-5-trifluoromethylpyridine were added dropwise to this solution which was then maintained at 90C for a ~urther two hours. After cooling the reaction.solut.ion.to.room .te~perat~re, it.was poure~ into.

~- Nit 144 - 19 -, ~. ~, ~....... . . .

~L23~

ice-water, then extracted with ether. The ether layer was dried and filtrated, and the ether was distilled off. The end product of 2-benzyloxy-ethyl-2-[4-(5-trifluoromethyl-2-pyridyloxy)-phenoxy]propionate was obtained in a yield of 41.0 g (m.p. 44-47C).
Processes for the preparation of the novel intermediate compounds of formulae (III) and (VII) according to the present invention are illustrated by the following Examples.
Example 1 CH3 0 Br-CH- C-0-CH2CH2-0-CH

(a compound of formula (III)).
15.2 g of 2-benzyloxyethanol and 10.6 g of triethylamine were dissolved in 150 ml of toluene, and the solution was cooled to -5C. A
solution of 21.6 g of 2-bromopropionylbromide in 30 ml of toluene was added dropwise thereto at -5 to 0C with stirring. The reaction mixture was further maintained a~ room temperature for two hours. The mixture was then washed successively with 1% strength by weight sodium hydroxide solution and water, and the toluene solution was then driad and filtered. The toluene was distilled off under reduced pressure, and the end product of 2-benzyloxyethyl-2-bromopropionate was obtained in a yield of 26.7 g (n20 5 1.5182).

The intermediate compounds of the general formula (III~ of th.is invention shown in Table 1 were produced in a manner similar to that described above:

Table 1 1 2 Zl-CH - C-O-CH(CH2)n-O-cH ~ (III) Nit 144 - 20 -~3~

Tablel zl Rl R2 n Xa Physical constant Br H H 1 H n20.5 1 5182 Br H ~ 1 2-F nDO 1.5038 Cl H H 1 4-F nD 1.5004 Br H H 1 4-F nD 1.5040 Br H H 1 2-C1~ 0 5 1.5302 Br H H 1 4-C1 ~ 1.52~9 Cl H H 1 4-Br~ '5 1.5321 Br H ~ 1 4-Br`nD'5 1.54~4 Br ~ X 1 2-CH3~ 1.5186 ~r H H 1 2 OCH~nD'5 1.5260 Br H X 1 3-Noz~ 1~5394 Br H H 1 2,4-C12~ 1.5395 ~r H H 1 3~4-C12nD 1.5409 C1 H H 1 2,6-C12n2o 1.5412 ~r CH3 H 1 H n20'5 1.5100 Br H CH3 1 Hn20~5 1.5116 Br H H 2 H nD 5 1.5130 H H 1 4-OCH3nD '5 1.5250 ~xamDle 2 HO ~ OCH - C~--CH2C~2--C;~2 (a compound o~ formula (~II)) 12.1 g of hydroquinone were dissolved in 60 ml of Nit 144 - 21 -` ' ' ' .

~.~3~

dry dimethylformamide, 31.7 g of potassi~n carbonate were added thereto in a slow stream df nitrogen, and then the mixture was heated to 90 to 95C ~or one hour with stirring.
The mixture was cooled to 60C, and to it were added dropwise 28.7 g of 2-benzyloxyethyl-2-bromoprOpiOnate.
The reaction mixture was heated at 90C for two hours.
After cool~ng the reaction solution to room temperature, it was poured into ice-water and adjusted to pH7, then e~tracted with 100 ml of toluene. The toluene layer was dried and filtered, and then toluene was remo~ed under reduced pressure. The colorless oily product of 2-benzyloxyethyl-2-(4-hydroxyphenoxy)propionate was obtained in a yield of 24.6 g (~ 1-5 1.5390) The intermediates compound of the general formula (VII) of this invention shown in Table were produced in a manner similar to that described abcve:
Table 2 1 2 M-O ~ OCH-C-O-CH(CH2)n-0-CH ~ ~ (VII) M Rl R2 n Xa Phys.ical.c.ons.t.ant .H H H 1 - ~ ~ 5 1.5390 H H H 1 2-F n21 5 1.5260 H H H 1 4-Cl n21.5 1 5473 . H H H 1 3,4-C12 n21 5 1.5570 H 3 1 H n20 5 1.5321 H CH~ 1 H nD 5 1.5336 H H H 2 H n21 5 1.5344 . H H H 1 4-oCH3 n20 5 1.5422 , ::
Nit 144 - 22 -.. . _ . .

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A substituted propionic acid ester compound of the formula (X) in which R1 and R2 each independently are a hydrogen atom or a C1 to C6 alkyl group, X is a hydrogen or halogen atom or a nitro, C1 to C6 alkyl or C1 to C6 alkoxy group, a and n each independently are 1 or 2, and W is a halogen atom, or a 4-hydroxyphenoxy group, or alkali metal salt thereof.

2. A substituted 2-halogenopropionate compound of the formula in which R1 and R2 each independently are a hydrogen atom or a C1 to C6 alkyl group, X is a hydrogen or halogen atom or a nitro, C1 to C6 alkyl or C1 to C6 alkoxy group, a and n each independently are 1 or 2, and Z1 is a halogen atom.

3. A substituted 2-(4-hydroxyphenoxy)-propionate compound of the formula in which R1 and R2 each independently are a hydrogen atom or a C1 to C6 alkyl group, X is a hydrogen or halogen atom, or a nitro, C1 to C6 alkyl and C1 to C6 alkoxy group, and a and n each independently are 1 or 2.

4. A compound according to claim 1, 2 or 3, wherein R1 is hydrogen.

5. A compound according to claim 1, 2 or 3, wherein R1 is C1 to C6 alkyl.

6. A compound according to claim 1, 2 or 3, wherein R2 is hydrogen.

7. A compound according to claim 1, 2 or 3, wherein R2 is C1 to C6 alkyl.

8. A compound according to claim 1, 2 or 3, wherein X is hydrogen, fluoro, chloro, bromo, iodo, nitro, methyl, methoxy, ethyl, ethoxy, n-propyl, n-propoxy, isopropyl, isoproxy,or n-, iso-, sec- or tert-butyl or -butoxy.

9. A compound according to claim 1, 2 or 3, wherein R1 and R2 each independently is hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl or tert-butyl, and X is hydrogen, fluoro, chloro, bromo, nitro, methyl or methoxy.

10. A compound according to claim 1, 2 or 3, wherein R1 and R2 are both hydrogen, Xa is p-chloro, and n is 1.

11. A compound according to claim 1, 2 or 3, wherein R1, R2 and X
are all hydrogen, and n is 1.

12. A compound according to claim 1, 2 or 3, wherein R1, R2 and X
are all hydrogen, and n is 2.

13. A compound according to claim 1, 2 or 3, wherein R1 and X are both hydrogen, R2 is methyl and n is 1.

14. A compound according to claim 1, 2 or 3, wherein R1 and R2 are both hydrogen, but Xa is o-fluoro.

15. A compound according to claim 1, 2 or 3, wherein R2 and X are both hydrogen, R1 is methyl and n is 1.

16. A process for preparing a compound according to claim 1 which comprises reacting a compound of the formula in which each Z independently represents a halogen atom, with a compound of the formula in which R1, R2, X, a and n are as defined in claim 1, and where required reacting the resulting 2-halogenopropionate compound with hydroquinone and subsequently, where required, with an alkali metal base.