DD255729A5 - METHOD OF PREPARING NEW PHENOXY-BENZOYL MALONSAEUREESTER DERIVATIVES - Google Patents

Abstract

The invention relates to a process for the preparation of novel phenoxy-benzoyl-malonsaeureester derivatives of the general formula (I), wherein R 1 is halogen, cyano, nitro, methylthio, C 1-4 -alkyl or trifluoromethyl, R 2 and R 3 independently of one another hydrogen, halogen or Trifluoromethyl, R4 is hydrogen, halogen, cyano or nitro and R5 is C1-4 alkyl. For example, 5- (2-chloro-4-trifluoromethyl-phenoxy) -2-chloro-benzoyl malonic acid, di-ethyl ester is prepared. The novel compounds prepared according to the invention are distinguished by a high herbicidal activity. Formula I

Description

For this 1 page formulas

Field of application of the invention

The invention relates to a process for the preparation of novel phenoxy-benzoyl-malonic acid ester derivatives which are suitable as active ingredient for herbicidal compositions.

Characteristic of the known state of the art

It is known that certain phenoxy-benzoic acid derivatives have a herbicidal activity. Such compounds are described in U.S. Patent Nos. 3,979,437 and 3,652,645.

Object of the invention

The invention is intended to provide improved herbicides.

Explanation of the essence of the invention

The object of the invention is to provide a process for the preparation of novel phenoxy-benzoyl-malonic acid derivatives of the general formula I (wherein

R ^{1 is} halo, cyano, nitro, methylthio, C 1-4 alkyl or trifluoromethyl; ;

R ² and R ^{3 are} independently hydrogen, halogen or trifluoromethyl; R "is hydrogen, halogen, cyano or nitro and

R ⁵ C ₄ AIkYl means).

The new compounds of the general formula I differ from the known derivatives in the structure of the group bonded to the carbonyl group.

The novel compounds to be prepared according to the invention are substantially superior in their herbicidal activity-in particular in pre-emptive treatment-to the known derivatives of similar structure. The novel compounds of the general formula I can be successfully used in several crops, especially in maize, for the selective control of grassy and broadleaf weeds. In an advantageous representative of the compounds of the general formula I, R ^{1 is} trifluoromethyl, R ^{2 is} chlorine, R ^{3 is} hydrogen, R ^{4 is} nitro and R ^{6 is} ethyl.

In a further advantageous representative of the compounds of the general formula I, R ^{1 is} trifluoromethyl, R ² and R ^{3 are} chlorine, R "is nitro and R ^{5 is} ethyl.

In another advantageous representative of the compounds of general formula I, R ¹ and R ^{2 are} chlorine, R ^{3 is} hydrogen, R ^{4 is} nitro and R ^{5 is} ethyl.

By the term "C ₁ ^ alkyl" are meant straight-chain or branched alkyl groups having 1-4 carbon atoms (eg.

Methyl, ethyl, n-propyl, isopropyl, η-butyl, etc.).

The invention thus provides a process for the preparation of compounds of general formula I (wherein R ¹ , R ² , R ³ , R ⁴ and R ^{5 have} the above meaning), which is characterized in that

a) a phenoxybenzoic acid derivative of general formula (II) (wherein R ¹ , R ² , R ³ and R ^{4 have} the above meaning and Y is halogen, cyano or C ₁ ^ alkyl carbonyloxy) with a metal derivative of a malonic ester of the general formula (III) (in which R ^{5 has} the above meaning) or in the presence of a metal compound-preferably magnesium chloride-is reacted with a malonic ester of the general formula (III); or

b) a phenol of general formula (IV) (wherein R ¹ , R ² and R ^{3 have} the above meaning) or an alkali metal salt thereof with a benzoic acid derivative of general formula (V) (wherein R ⁴ and R ^{5 have} the above meaning and Z is halogen) is reacted.

According to the process variant a) of the process according to the invention, preference may be given to using the sodium, potassium or magnesium derivatives of the malonates of the general formula (III). If a free compound of the general formula (III) is used, the reaction is preferably carried out in the presence of magnesium compounds-in particular magnesium chloride-as the metal compound. The reaction may conveniently be carried out in an inert solvent. Suitable inert solvents are hydrocarbons (for example benzene, toluene, xylene), ethers (for example diethyl ether, 1,2-dimethoxyethane, tetrahydrofuran or dioxane), amides (for example dimethylformamide, hexamethylphosphoric triamide), ketones (for example acetone or diethyl ketone ), Nitriles (eg acetonitrile), etc. into consideration.

The malonic esters of the general formula (III) are reacted in the form of their metal salts with the compounds of the general formula (II). The malonate metal salts can be prepared beforehand from the compounds of general formula (III) by reaction with alkali metal or alkaline earth metal compounds (or organometallic compounds). However, it is also possible to proceed by reacting the compounds of the general formulas (II) and (III) in the presence of metal compounds, preferably magnesium chloride, with the metal salts of the compounds of the general formula (III) being formed in situ in the reaction mixture.

The reaction is carried out at a temperature between -10 and +180 ⁰ C, preferably at 30-100 ⁰ C, performed. The products obtained can, if appropriate after removal of the by-products formed, be isolated by known methods. The malonic esters of general formula (III), the metal salts thereof and the starting materials of general formula (II) are known in part. Such compounds are disclosed in U.S. Patent Nos. 3,979,437 and 3,656,645 and in Org. Synth. Coil. Vol. 285IV. and J. Org. Chem. 50, 2622 (1985). The novel compounds of general formula (II) can be prepared analogously to the processes disclosed in the cited references.

According to process variant b), the starting materials of the general formulas (IV) and (V) are expediently reacted in the presence of an inert solvent or diluent. The reaction medium may be the solvents listed in process variant a). The reaction is conveniently carried out in the presence of an acid binder. Suitable for this purpose are alkali metal hydroxides, carbonates, ethylates or tert. butylate, e.g. For example, sodium or potassium hydroxide, carbonate, ethylate or tert. Butylate, or organic bases such as triethylamine, etc.

embodiments

Further details of the invention can be found in the following examples, without limiting the scope of protection to these examples.

example 1

Preparation of diethyl 5- (2-chloro-4-trifluoromethyl-phenoxy) -2-nitro-benzoyl-malonate

a) To a solution of 38.0 g of 5- (2-chloro-4-trifluoromethyl-phenoxy) -2-nitro-benzoyl chloride in 50 ml of benzene at room temperature with stirring within 20 minutes, a solution of 17.6 g diethyl malonate produced Äthoxymagnesiummalonat in 50 ml of benzene added dropwise. After completion of the addition, the reaction mixture is refluxed for one hour and then cooled. To the viscous solution are added with stirring 50 ml of 20% sulfuric acid. The phases are separated and the aqueous layer is extracted twice with in each case 50 ml of benzene. The extracts are combined, washed with water and a sodium bicarbonate solution and concentrated. 47.8 g of the title compound are obtained in the form of a yellow oil. Mp .: 72-76 ° C.

a) A mixture of 19.7 g of 2-chloro-4-trifluoromethyl-phenol, 32.7 g of diethyl 2-nitro-4-fluoro-benzoyl-malonate, 13.8 g of potassium carbonate and 100 ml of anhydrous Dimethylsulfoxydwird at 5O ⁰ C is stirred. After a reaction time of 24 hours, the reaction mixture is diluted with 100 ml of water and extracted three times with 50 ml of benzene each time. The benzene phase is dried over anhydrous magnesium sulfate, whereupon the solvent is distilled off. The resulting yellow oil is recrystallized from a mixture of benzene and hexane. There are obtained 40.3 g of the title compound. Mp: 72-76 ⁰ C.

c) A mixture of 21,9g sodium ^ -chloro ^ -trifluoromethyl-phenolate, 32,7g 2-nitro-4-fluoro-benzoyl-malonic acid diethyl ester and 100 ml of anhydrous dimethyl sulfoxide is stirred at 50 ⁰ C. After a reaction time of 24 hours, the reaction mixture is diluted with 100 ml of water and extracted three times with 50 ml of benzene each time. The benzene phase is dried over anhydrous magnesium sulfate and evaporated. The resulting yellow oil is recrystallized from a mixture of benzene and hexane. There are obtained 39,8g of the title compound.

Fp.:72-76°C.

Example 2

Preparation of diethyl 5- (2,6-dichloro-4-trifluoromethyl-phenoxy) -2-nitro-benzoyl-malonate

A solution of 45.8 g of 5- (2,6-dichloro-4-trifluoromethyl-phenoxy) -2-nitro-benzoylbromide and 50 ml of ether with stirring at room temperature within 20 minutes, a solution of diethyl malonate prepared from 17.6g Potassium malonate and 50 ml of ether added dropwise. After completion of the addition, the reaction mixture is refluxed for one hour, then cooled, whereupon 50 ml of 20% sulfuric acid are added with stirring. The phases are separated, the aqueous layer is extracted twice with 50 ml of ether. The organic phases are combined, washed successively with water and a sodium bicarbonate solution and concentrated. The resulting yellow oil solidifies slowly. There are obtained 49.9 g of the title compound. Mp .: 84-88 ⁰ C.

Example 3

Preparation of diethyl 5- (2-chloro-4-trifluoromethyl-phenoxy) -2-chloro-benzoyl-malonate A mixture of 35.0 g of 5- (2-chloro-4-) cooled to ⁰ ° C. with a salt-ice mixture trifluoromethyl-phenoxy) -2-chlorobenzoic acid, 10.0 g of triethylamine and 100 ml of toluene, 12.1 g of pivaloyl chloride are added at such a rate that the temperature does not exceed 0 ° C.

During the addition and subsequent stirring (about 15-20 minutes) precipitates triethylamine hydrochloride. The feeding device for the pivaloyl chloride is replaced with a dropping funnel containing an ethereal ethoxymagnesium malonate solution prepared from 17.6 g of diethyl malonate. The ethereal solution is added dropwise maintaining the temperature between -5 and ⁰ ° C. The reaction mixture is allowed to stand overnight, after which 200 ml of a 5% sulfuric acid solution are added. The aqueous phase is extracted twice with 50 ml of ether. The combined organic phases are washed with dilute sulfuric acid and a sodium bicarbonate solution, dried over anhydrous sodium sulfate and concentrated. There are obtained in the form of pale yellow crystals 44.3 g of the title compound. Mp .: 59-65 ° C.

Example 4

Preparation of diethyl 5- (2,4,6-trichloro-phenoxy) -2-nitro-benzoyl-malonate To a 500 ml flask equipped with a stirrer and dropping funnel are weighed 9.52 g of anhydrous magnesium chloride and 100 ml of anhydrous acetonitrile. 16.0 g Diäthylmalonat be added to the heterogeneous mixture, whereupon the flask is placed in an ice bath and 28 ml of triethylamine are added. The solution is stirred at ⁰ ° C for 15 minutes whereupon 38.1 g of 5- (2,4,6-trichloro-phenoxy) -2-nitrobenzoyl chloride are added dropwise. The reaction mixture is stirred for one hour at ⁰ ° C. and for 12 hours at room temperature and finally cooled to ⁰ ° C. To the mixture is added 60 ml of a 5M hydrochloric acid solution. The resulting solution is extracted three times with 100 ml of ether, then the combined extracts are dried over magnesium sulfate. After removal of the solvent and traces of diethyl malonate, a pale yellow oil is obtained which slowly solidifies. There are obtained 45.0 g of the title compound. Mp .: 71-73 ° C.

Example 5

The following 19 compounds of the general formula are prepared analogously to the previous Examples 1-4. The definition of the substituents R ¹ -R ⁵ , the melting points and the characteristic features of the NMR spectra are summarized in Table I.

Table I

Connection

R ¹

R ³

¹ H-NMR (ppm)

1.10 (m, CH _3); 4.1 (m, CH ₂ ); 4.93 (s, CH); 7.6 (m, ar-H)

., 0 (m, CH ₃ ) I 4.3 (m, CH ₂ ); 5.0 (s, CH); 8.0 (m, ar-H)

1.1 (m, CH _3); 4.0 (m, CH ₂ ); 4.7 (s, CH); 7.6 (m, ar-H)

1.0 (m, CH _3); 4.0 (m, CH ₂ ); 4.95 (s, CH); 7.9 (m, ar-H) 1.15 (m, CH ₃ ); 4.1 (m, CH ₂ ); 4.90 (s, CH); 7.7 (m, ar-H)

1.1 (m, CH _3); 4.0 (m, CH ₂ ); 4.85 (s, CH); 7.7 (m, ar-H) 1.0 (m, CH ₃ ); 4.0 (m, CH ₂ ); 4.8 (s, CH); 7.8 (m, ar-H) 1.0 (m, CH ₃ ); 4.1 (m, CH ₂ ); 4.9 (s, CH); 7.8 (m, ar-H) 0.95 (m, CH ₃ ); 4.0 (m, CH ₂ ); 4.8 (s, CH); 7.7 (m, ar-H) 3.67 (s, CH ₃ ); 4.8 (s, CH); 7.8 (m, ar-H) '

1.05 (m, CH ₃ ); 4.1 (m, CH ₂ ); 4.87 (s, CH); 7.6 (m, ar-H) 1.10 (m, CH ₃ ); 4.0 (m, CH ₂ ); 4.7 (s, CH); 7.6 (m, ar-H) 3.7 (m, CH _3, CH ₃ S); 4.8 (s, CH); 7.8 (m, ar-H) 1.10 (m, CH _3, 4.0 (m, CH _2); 4.80 (s, CH); 7.65 (m, ar-H) 3, 71 (m, OCH ₃ ), 1.02 (m, CCH ₃ ), 3.95 (m, CH ₂ ), 4.81 (s, CH);

7.6 (m, Ar-H)

Example 6

Biological application example

Grass seeds and seeds of crops are sown in a plastic container (size 10 χ 10 χ 10cm) in sand from the Danube. Various amounts of dilute emulsifiable concentrate containing the test compounds are sprayed on the surface of the sand (pre-emergent treatment) and three weeks after sowing (post-emergent treatment), respectively. The

1 CF ₃ Cl H NO ₂ C ₂ H ₅ 72-76 2 CF ₃ Cl Cl NO ₂ C ₂ H ₅ 84-88 3 CF ₃ Cl H Cl C ₂ H ₅ 59-65 4 Cl Cl Cl NO ₂ C ₂ H ₅ 71-73 5 Cl Cl H NO ₂ C ₂ H ₅ 62-65 CJ) CF ₃ Cl H CN C ₂ H ₅ 87-93 7 CF ₃ F H H C ₂ H ₅ oil 8th CF ₃ H F NO ₂ C ₂ H ₅ 47-49 9 CH ₃ H Cl br C ₂ H ₅ oil 10 CF ₃ H Cl NO ₂ CH ₃ oil 11 NO ₂ Cl H NO ₂ C ₂ H ₅ oil 12 CN Cl H Cl C ₂ H ₅ oil 13 CH ₃ S Cl H Cl CH ₃ oil 14 Cl CF ₃ H NO ₂ C ₂ H ₅ 67-71 15 CF ₃ H Cl NO ₂ CH3C3H7 oil

Plastic pots are poured daily with the amount of water required for normal plant growth and kept in a greenhouse. The results of the experiments are evaluated after 4 weeks using a scale between 0 and 10: 0 = no symptoms; 10 = 100% infected, destroyed plants.

As reference compounds, two herbicidal commercial products are used:

Acifluorfen (according to chemical nomenclature: sodium 5- (2-chloro-4-trifluoromethyl-phenoxy) -2-nitro-benzoate) and oxyfluoride (according to chemical nomenclature: 2-chloro-1- (3-ethoxy-3-nitrobenzoate) phenoxy) -4-trifluoromethyl-benzene).

The results are summarized in Table II. These results indicate that the average potency of the new compounds against grassy and broadleaf weeds - especially in the case of pre-emergent treatment - is clearly superior to the efficacy of the control substances.

The tolerance of different crops to the compositions of the invention is determined by the methods described in this example. The test results show that dicotyledonous crops tolerate all the compositions according to the invention well. Within the usual herbicidal doses, no phytotoxic symptoms occur at all. It has also been found that premegenter treatment corn, sunflower and legumes, the agents of the invention very well tolerated. In contrast, the reference compounds oxifluorfen and acifluorfen are tolerated in the treatment mentioned only by soybean plants.

Table II

Herbicidal activity of the compounds of the general formula I on various weeds and crop plants with pre-eminent and post-emergent treatment

test dose Amaranth. Chenopod. Echinoch. Setaria soy green Corn post Office to sunbathe verb. kg / ha retrofle. album crus-gal. italica beans peas flowers No. Wirks. pre post pre post pre post pre post pre post pre post pre pre post

1 0.3 6 0.3 6 6 6 8th 6 5 6 5 0 0 0 0 0 4 0 6 1.0 9 8th 9 10 8th 9 10 10 0 2 1 6 1 8th 2 10 2 0.3 6 1.0 8th 6 6 8th 6 5 6 5 0 0 0 0 0 4 0 6 1.0 9 0.3 6 8th 9 10 8th 9 10 10 0 2 1 6 0 8th 2 10  3 0.3 5 4 5 5 4 4 4 4 0 0 0 0 0 4 0 6 1.0 8th 1.0 8th 5 8th 6 6 6 8th 6 0 2 1 3 0 6 0 8th 4 0.3 9 8th 8th 8th 6 5 6 5 0 0 0 2 0 4 0 6 1.0 10 10 10 10 10 10 10 10 1 2 1 6 1 8th 2 8th 5 0.3 9 8th 8th 9 7 5 6 5 0 0 0 2 0 4 0 6 1.0 10 10 10 10 10th 10 10 10 1 2 1 6 1 8th 2 8th 6 0.3 6 6 6 6 6 4 4 5 0 0 0 2 0 3 0 6 1.0 8th 7 8th 7 8th 6 8th 6 0 2 1 6 0 6 0 8th 7 0.3 6 4 6 4 6 4 5 5 0 0 0 2 0 3 0 6 1.0 8th 5 8th 5 8th 6 8th 6 0 2 1 6 0 6 0 8th 8th 0.3 4 4 6 4 6 4 5 5 0 0 0 2 0 3 0 6 1.0 6 6 8th 6 8th 6 8th 6 0 2 1 6 0 6 0 8th 9 0.3 4 4 4 4 7 4 5 5 0 0 0 2 0 3 0 6 1.0 6 5 6 5 8th 6 8th 6 1 2 1 6 0 6 0 8th 10 0.3 8th 10 6 10 8th 8th 8th 8th 0 0 0 2 0 4 0 6 1.0 10 10 9 10 10 10 10 10 1 2 1 7 2 8th 2 10 11 0.3 6 4 6 6 7 6 6 5 0 0 0 0 0 4 0 5 1.0 8th 5 7 8th 8th 7 10 8th 0 2 1 6 1 6 2 10 12 0.3 6 4 5 6 8th 6 7 5 0 0 0 0 0 3 1 6 1.0 7 5 7 8th 10 10 8th 6 0 1 1 5 1 6 2 8th 13 0.3 4 4 4 4 5 5 5 5 0   0 0 0 0 3 0 5 1.0 7 6 6 5 8th 6 8th 6 1 2 1 3 1 5 1 6 14 0.3 6 5 7 6 7 6 8th 7 0 0 0 0 0 4 0 6 1.0 8th 6 8th 7 9 8th 10 10 0 2 1 6 1 8th 0 8th 15 0.3 6 7 6 7 6 6 5 6 0 0 0 0 0 4 0 6 1.0 8th 9 10 9 9 9 10 10 0 2 1 6 1 8th 2 10 Reference compounds: Aci 7 5 7 8th 6 8th 7 3 0 4 2 6 4 6 6 fluorine fen 10 8th 10 8th 9 10 10 6 2 8th 7 8th 8th 10 10 Oxi 6 6 6 6 8th 6 7 3 0 4 3 6 4 6 6 fluorine fen 10 8th 10 8th 10 10 10 6 3 9 8th 8th 9 10 10

COR "

C-OR

(I)

(I)

CHp

O Il • C - OR '

C-OR = O [E]

(Y)

Claims (5)

claims: A process for the preparation of phenoxybenzoyl malonic acid derivatives of the general formula (I) in which R ^{1 is} halogen, cyano, nitro, methylthio, C ₁ alkyl or trifluoromethyl; R ² and R ^{3 are} independently hydrogen, halogen or trifluoromethyl; R ^{4 is} hydrogen, halogen, cyano or nitro and R ^{5 is} C ₁ ^ alkyl, characterized in that a) a phenoxy-benzoic acid derivative of general formula (II) wherein R ¹ , R ² , R ³ and R ^{4 have} the above meaning and Y is halogen, cyano, nitro or C ₁ ^ alkyl carbonyloxy, having a Metal derivative of a malonic ester of the general formula (III), wherein R ^{5 has} the above meaning, or in the presence of a metal compound, preferably magnesium chloride, with a malonic ester of the general formula (III); or b) a phenol of the general formula (IV) in which R ¹ , R ² and R ^{3 have} the above meaning, or an alkali metal salt thereof with a benzoic acid derivative of the general formula (V), wherein R ⁴ and R ^{5 have} the above meaning and Z is halogen, reacted. 2. The method according to claim 1, characterized in that a benzoic acid derivative of the general formula (II) wherein R ¹ , R ² , R ³ and R ^{4 have} the above meaning and Yfür halogen, cyano, Äthylcarbonyloxy or tert. Butylcarbonyloxy, with a metal derivative of a malonic ester of the general formula (III), wherein R ^{5 has} the above meaning, is reacted. 3. The method according to claim 1, characterized in that one produces compounds of formula (I) wherein R ^{1 is} trifluoromethyl, R ^{2 is} chlorine, R ^{3 is} hydrogen, R ^{4 is} nitro and R ^{5 is} ethyl. 4. The method according to claim 1, characterized in that one produces compounds of formula (I) wherein R ^{1 is} trifluoromethyl, R ² and R ^{3 is} chlorine, R ^{4 is} nitro and R ^{5 is} ethyl. 5. The method according to claim 1, characterized in that one produces compounds of formula (I) wherein R ¹ and R ^{2 is} chlorine, R ^{3 is} hydrogen, R ^{4 is} nitro and R ^{5 is} ethyl.