SU667097A3 - Method of fighting weeds - Google Patents

Description

 : 1.. The invention relates to chemical methods of weed control, and specifically to a method based on the use of phenylurea derivatives. N- (4-chlorophenyl) -N-monochloroacetyl-N, N-dimethylurea is known, which is used as a plant growth regulator f1. There is a known method of weed control, in which N- (4-chlorophenyl-N, N-dimethylurea (monuron)) is used in the active ingredient Kachestba {2 However, it is not sufficiently effective. The purpose of the invention is to find a highly effective way to control weeds based on phenylurea. The above objective is achieved by using a compound with the formula of where X is chlorine, 7 5СЛОР, bromine, trifluoromethyl ;; R is methyl, methoxy; T methyl, or R and R together with the nitrogen atom form a pyrilidinyl morphalil; P - represented It is O or 1, in the amount of 8.89 kg / ha Formulations for the use of preparations usual ... Compounds of formula I are obtained by reaction between 1,3,3-trisubstituted urea and sodium hydride according to the following reaction between the obtained sodium urea salt and ethylchloric acid acid chloride to produce M- (carbamyl) ethyl / oxamylate (method A). The following are examples of the preparation of a compound of formula I according to method A. Example 1: Preparation of N- (dimethylcarbamyl) -ethyl-3- | trifluoromethyloxyanilate. Sodium hydride (21.6 g, 9 mol) is suspended (-in 300 ml of tetrahydrofuran (dried over a molecular sieve) and dropwise, in an atmosphere of argon, a solution of 1-g (metatrifluoromethylphenyl) -3.3- dimethyl urea (191 g, 0.823 mol). The mixture is stirred for 1 hour at room temperature and 1 hour at a temperature of 40-45 ° C. The solution is decanted under argon atmosphere and added dropwise to a solution of ethyl chloride (120 g, 0.88 mol) in 200 ml of tetrahydrofuran. At the same time, the reactor is cooled with water so that the temperature inside it is maintained Appeared at or below. A precipitate appears, the mixture is stirred for about 16 hours at room temperature and then for 1 hour at a temperature. Volatiles are removed from the reaction mixture in vacuo. The residue is dissolved in 600 mp of benzene and 200 ml. The organic sodium bicarbonate solution is treated with 200 ml of additional sodium bicarbonate solution and dried over magnesium sulphate. The solvent is removed in vacuo and the remaining crude product is crystallized from benzene / hexane. The yield of the product is 175.7 (65% of theoretical, mp. 67-69. The structure of the product is confirmed by absorption spectra in the infrared region and nuclear magnetic resonance spectra. Example 2. Preparation of fi- (dimethylcarbamyl) ethyl 3, 4-dichloroxanylate Sodium hydride (24.5 g, 1.02 mol) is suspended in 300 ml of anhydrous tetrahydrofuran. Dropwise to a suspension of sodium hydride, in an argon atmosphere, 217 g (0.93 mol) 1-0 are added at room temperature, 4-dichlorophenyl-3, 3-dimethylurea in 1600 m of tatra hydrofuran A. After this, the mixture is stirred from 1 h at room temperature for another 1 h The temperature is about 40-45 C. The solution is then transferred under argon into a dropping funnel and added dropwise to 136.5 g (1.0 mol) of ethyl 1-acid chloride dissolved in 180 ml of tetrahydrofuran. The temperature rises to. After This mixture is stirred for 2 hours at room temperature, and then 1 1/2 hours at a temperature of 40-45 ° C, after which the mixture is subjected to final stirring for approximately at room temperature. Volatile. ., the substances are removed in vacuo and the residue is treated with 800 ml of benzene and 400 ml of L% sodium bicarbonate solution. The insoluble material is filtered off, nicknamed benzene and dried. The initial benzene filtrate is washed with two more portions of 5% sodium bicarbonate solution in 200 ml each and dried over magnesium sulfate. This solution was concentrated in vacuo, filtered and the filter cake was washed with hexane and dried, combined with the original filter cake. 249.8 g (80% of the theoretical yield) of the product are obtained, melting at 123-124 ° C. The structure of the product is confirmed by infrared absorption spectra and nuclear magnetic resonance spectra. The preferred method (Method B) for the preparation of compounds of the formula D includes a one-step reaction of a urea product having the formula (X, W, L, and R have the above values with an ethyl oxalyl halide of the formula egHg-O-fi-dz II ff O, where Z is chlorine or a bromo substituent.The reaction is carried out in the presence of a solvent, however, in contrast to the process described earlier, a less expensive solvent, such as a chlorinated hydrocarbon, such as methylene chloride j chloroform, carbon tetrachloride or tetrachloride, can be used. ethyl, benzyl or toluene type hydrocarbons, or daethyl ether; this, if desired, is tetrahydrofuran used in this reaction, however, chlorine hydrocarbons with a molecular weight of 30% are preferred, such as methylene chloride and chloroform. Reactivity is carried out at a temperature At the boiling point at the boiling point, disintegrate in the general case. The reaction generally takes place in the temperature range from 40 to 120 ° C, preferably M & xjjy 40-80 0, depending on the solvent. The solvent and operating temperature are chosen so as to avoid possible thermal decomposition of the product. In the reactions, besides the required M-carbamylethyloxyanilate, hydrogen halide or hydrogen chloride or hydrogen bromide is also formed. To ensure the removal of hydrogen halide byproduct, maintain atmospheric pressure or slightly less pressure. The following examples illustrate the preparation of compounds of Formula I according to Method B. Example 3. Preparation of K- (dimethylcarbamyl) ethyl 3-trifluoromethyloxyanilate (compound 3 in Table 1). 116 g (0.5 mol) 1,1-dimethyl-3-13-trifluoromethylphenyl) urea, 250 MP of methylene chloride and 82 g (0.6 mol) of ethyl oxalyl chloride are placed in a glass reactor. The resulting solution is refluxed for 7 hours, during which time it will react. all urea After distillation of the solution and excess acid chloride by distillation, 161 g of a white solid with a mp. 67-69 C, according to analyzes, containing 96% of the pure product. Yield 97%, Example 4. Preparation of AND- (di methylcarbamyl) ethyl-3-4-dichloroxy nilate (compound 2 in Table 1.). 902 g (3.88 mol) of 1- (3,4-di chlorophenyl) -3, -dimethylurea and 2 l of anhydrous chloroform are loaded into a round-bottom four-neck flask with a capacity of 5 l. The mixture is cooled with ice-cold water at a slow introduction. (. Mol) of ethyl oxalyl chloride, read. The temperature is maintained below 20 s. At the end of the introduction of ethyl oxalyl chloride, the reaction mixture is left at slight reflux for 8-9 hours until the reaction is complete (the reaction is monitored by liquid phase chromatography). The solution is evaporated when pomanivanii approximately one-fourth of the original volume. A white solid is formed solidly. After drying, 1.182 g (yield 91%) of the desired compound q with a purity of 98% is obtained (t; pl. 123-124c). TABLE Compounds of Formula I

Below are examples of the application of the proposed weed control.

a) Processing the active principle before the appearance of shoots.

On an analytical balance, 20 mg of the test compound are weighed on a piece of glossy paper. The paper and compound are placed in a 30 ml wide-mouth flask and 3 ml of acetone containing 1% Tween 20 (monolaurinate) is added to dissolve the compound.

polyoxyethylene sorbitan). If the test compound does not dissolve in acetone, a different solvent is used, such as water, alcohol, or dib. Treatment with the next starting point after germination,

Seeds of six plant species: DigitoriQ .SonguinotiS, Echinochtoa cruS ofil, Avena aafiva, Brassica juncca, Rumejc crispuS, Pbaseofus vulgar

are sown on cages, as described by Bbsjie. Beds are placed in a greenhouse with a temperature of 70-85 R (21-29 s) and watered daily by spraying. Approximately 10–14 days after sowing, when the first leaves of the leguminous plants are almost fully developed and the first three-leafed sprouts begin to form, the plants are processed. The spray preparation is prepared by dissolving 20 mg of the test compound in 5 ml of acetone containing methyl formamide (DMF). When using DMF to dissolve the test compound, it is used in an amount of 0.5 MP or less, and then another solvent is added up to a volume of 3 ml, and 3 ml of the solution is sprayed evenly onto the soil with a small pile of npdaaecTBHH one day after sowing her seed weeds. A spraying spray is applied using a 15 psi (350 N / m) compressed air atomizer. The dosage of the test compound in weed treatment is 8 lb / acre (3.6 kg per 0.4005 ha), and the spray volume is 143 gallons / acre (530 l). The day before the treatment, the group has DU1INU. 7 inches (17.78 cm), 5 inches wide (12.7 cm) and 2.75 inches high (7 cm), filled to a height of 2 inches (5.08 cm) with loamy sandy soil. The seeds of various weeds are sown in separate rows across the width of the pile, and the seeds are covered with earth, so that they are at a depth of 0.5 inch (1.27 cm). Seeds are sown at a sufficient distance from each other, so that for one row, after the emergence of shoots, there are about 20-50 shoots, depending on the size of the plants. The following seeds are used in ogalts: etaria $ pp., F.chinocbloa, AvGna sat / va, Amaranth S reiroftexus, Bra3sicQ Jt / ncea, Rumex crtspus, Dlgitarra sangujno (S. After processing, after the treatment, once in the greenhouse: in a greenhouse with a temperature of 70 -5 G (21-29 0) and sprayed by spraying. Determine the degree of damage or weed control of each species by comparing with untreated control plants of the same age on a scale from 0 to 100%. At the same time, 0% means no damage, a 100% complete destruction;

i% tween 20 followed by the addition of 5 ml of water. The solution is applied by spraying onto the leaves, using an atomizer, under a pressure of 5 psi (BTO n / m). The concentration of the spray preparation is 2% and the dosage

Connection number

Available properties:

  one

., .-- ... .- ,. .. ...

3

- -. -

: B ---. ;

7

known compounds:. . „„, „.,

//

and ITH-C-jr /

corresponds to 8 lb / acre (3.6 kg per 0.4005 ha). The spray volume is 476 gallons / acre {1080l / 0.405 ha).

The results of the experiments are given in 5. table.2.

1 T a b. l and c a 2

Efficiency (%) of the active principle in the processing of plants

after

up to infibeni

no germination

,

seedling

98

99

99

100

99.6

100

99

100

94

100

26

92

55

96

100

99.8

87

99.6

§four

99.1

 Mean value for seven species of hell. Average value for neck of plant ead.

Thus, the proposed Weed Control System is effective.

Claims (2)

The invention The method of controlling weeds by treating weeds Acting on the basis of phenylurea derivatives, characterized in that, in order to increase the efficiency of the method, a compound of the general formula 00 Wdd-OCjHj L ... Lt, where X is chlorine; 09710 y - chlorine, bromine, trifluoromethyl; .R is methyl, methoxy; methyl, or L, and R together with the nitrogen atom form methylpiperidine, morpholyl; p-represents O or 1, in an amount of 8.89 kg / ha. Sources of information taken into consideration during the examination 1. French Patent No. 1250422, cl. And 01 N, I960. 2. N.N.Melnikov. Chemistry and pesticide technology. M., Chem., 15 19-74, p. 376.