GB2135301A

GB2135301A - Herbicidal chloroacetanilide derivatives

Info

Publication number: GB2135301A
Application number: GB08304794A
Authority: GB
Inventors: Isao Shimazaki; Kunihiko Fujimori; Fumitaka Yoshida; Hideo Sadohara; Yasunori Ogawa
Original assignee: Kumiai Chemical Industry Co Ltd
Current assignee: Kumiai Chemical Industry Co Ltd
Priority date: 1983-02-21
Filing date: 1983-02-21
Publication date: 1984-08-30
Also published as: GB2135301B; GB8304794D0

Abstract

An N-methylchloroacetanilide derivative represented by the formula <IMAGE> where R is an alkyl group, an allyl group, a propargyl group, an alkoxyalkyl group, a tetrahydrofurylmethyl group, an alkyl group substituted by a halogen atom or a cycloalkyl group which may be substituted by an alkyl group has herbicidal properties.

Description

SPECIFICATION Chloroacetanilide derivative, process for its production and herbicidal composition containing it The present invention relates to an N-methylchloroacetanilide derivative represented by the formula

where R is an alkyl group, an allyl group, a propargyl group, an alkoxyalkyl group, a tetrahydrofurylmethyl group, an alkyl group substituted by a halogen atom or a cycloalkyl group which may be substituted by an alkyl group, a process for its production and a herbicidal composition containing it as an active ingredient.

Heretofore, various N-substituted acetanilide herbicides have been proposed and some of them have been actually in use. N-alkyl-substituted oe-haloacetanilides are known to be effective against plants mainly during the germination period and to exhibit strong herbicidal activities especially against narrow leaf plants (see Japanese Examined Patent Publication Nos.

10146/1964 and 17189/1964). Accordingly, they have a drawback that they tend to give phytotoxicity against narrow leaf plants such as paddy field rice, upland rice, corn, barley or wheat especially when such N-alkyl-substituted a-haloacetanilides are applied during the initial stage when such plants are still susceptible to the influence of the herbicides. Thus, they are not suitable for application to such plants during the germination, pre-germination or postgermination when the plants are still young and weak. Further, their herbicidal activities against broad leaf weeds are not so strong.

The present inventors have conducted extensive researches to overcome the above-mentioned drawback of N-alkyl-substituted a-haloacetanilides, and have found that the N-methylchloroacetanilide derivatives represented by the above Formula I are effective against paddy fields weeds such as monochoria (Monochoria vaginalis), barnyardgrass (Echinochloa crus-galli), smallflower unbrella plant (Cyperus difformis), Cyperus serotinus, three-square grass (Scirpus hotarui), common water plantain (Alisma canaliculatum) slender spikerush (Eleocharis acicularis), toothcup (Rotala indica) and false pimpernel (Lindernia procumbe). They exhibit excellent herbicidal activities against such weeds over the period ranging from germination to the initial growing stage of the weeds.They exhibit particularly high herbicidal effects against such paddy field weeds as three-square grass and Cyperus serotinus which have been regarded to be hardly controlable. They show selective herbicidal activities in the paddy fields and do not show phytotoxicity against rice plants. Among the compounds represented by the formula I, those having an alkyl group or an allyl group as R exhibit particularly good herbicidal activities. The most effective compounds are those wherein R is a lower alkyl group.

In French Patent No. 1,339,001, the compounds represented by the formula

where R is an alkyl group and R1 is a normal- or secondary alkyl group or an alkoxy group, are described to have herbicidal activities. Particularly, ortho-substituted compounds are described to have special herbicidal activities. However, as an example of the compound where R, is an alkoxy group, only the following compound is disclosed.

Further, the following compounds which resemble the compounds of the present invention are described to have herbicidal activities.

In French Patent No. 1,339,002, compounds represented by the following formulas are described to have herbicidal activities;

where R1 is an alkyl group and each of R, and R3 is a hydrogen atom or an alkyl group As specified examples, the following compounds are disclosed;

Further, Chemical Abstracts, Vol. 50, 14709i(1956) and Vol. 51, 1287f(1957) disclose the following compounds;

These two compounds are intermediates useful for the preparation of final products, and no biological activities thereof are described.

In Japanese Unexamined Patent Publication Nos. 145255/1981 and 145256/1981, compounds represented by the following formulas are described to have herbicidal activities.

(Publication No. 145255/1981) where R is methyl or ethyl, R, is C,6 alkyl, R2 is methyl, ethyl or tert-butyl and R3 is hydrogen or methyl at meta-position.

(Publication No. 145256/1981) where R is C1-5 alkyl.

Further, Japanese Examined Patent Publication No. 24067/1968 discloses a herbicide composed of a mixture of a compound represented by the formula

where each of R, and R2 is C'-4 alkyl, and a urea compound. The compound of formula Ill exhibits excellent herbicidal effects against gramineous weeds but it has poor herbicidal activities against broad leaf weeds. As stated in this reference, it is difficult to use the compound of the formula Ill by itself as a herbicide.

Whereas, the compounds of the present invention represented by the formula I have the following advantages over the compounds disclosed in the above-mentioned prior art references; (1) They exhibit superior herbicidal effects in a relatively low dosage against three-square grass and Cyperus serotinus which grow in a paddy field and which have been hardly controlable by the conventional herbicides.

(2) They are effective against these weeds not only during the germination or the initial stage of the growth but also during the later stage of the growth.

(3) They do not give phytotoxicity against crop plants especially paddy field rice even when they were applied in a high concentration, thus exhibiting superior selectivity.

The compounds of the present invention show high herbicidal effects against three-square grass during the period ranging from the pre-germination of the 3-leaf stage. In the case of the pre-germination, they exhibit high herbicidal activities against the weeds developing deep in the soil.

The conventional herbicides are effective only during the germination and no herbicidal effectiveness can thereby be expected against the weed developing deep in the soil. Although some of the conventional herbicides are more or less effective even during the growing stage of the three-square grass, the period during which they are effective is rather limited.

Namely, the compounds of the present invention are far superior to butachlor in the herbicidal effect against three-square grass and Cyperus serotinus during the initial stage (i.e. 1-3 leaf stage) of the growth (1-31). Butachlor is effective only during the germination.

Further, the compounds of the present invention are highly safe for application to transplanted paddy field rice and their superiority is more distinct in the case of direct sowing.

In the actual transplanted paddy field; the development of three-square grass tends to increase year after year and it is difficult to control the development by the conventional herbicides. The reason is that the conventional herbicide has a limited period for the application and the development of three-square grass takes place not only in the surface layer of the soil but also in a layer deeper than 3 cm and besides the period from the initiation of the germination to the completion of the germination is long. Thus, three-square grass is a weed which is hardly controlable. The yield of paddy field rice will be reduced by the weed and the damage created by the weed amounts to a reduction of the yield of the rice as high as from 27 to 59% reduction.This three-square grass can be completely controlled by a single application of the compound of the present invention at an optional time during the period ranging from the pre-germination to the 3 leaf stage. Thus, the contribution of the present invention to the cultivation of the paddy field rice is substantial.

Further, compounds of the present invention exhibit high herbicidal effects against Cyperus serotinus over the period ranging from the germination to the 2.5-3 leaf stage. The conventional herbicides are effective only during the germination of Cyperus serotinus and no effectiveness is thereby expected in the case where the weed is in its growing stage. Some of the conventional herbicides are effective when they are applied to the foliage during the growing stage. However, they are not so effective under irrigated conditions. Therefore, irrigation must be stopped when they are to be applied. Practically, however, this operation is very cumbersome and yet water drainage is frequently inadequate. Further, in the actual rice fields, the development of Cyperus serotinus is rather quick and lasts for a long period of time since the weeds develops one after another. Accordingly, it is very difficult to control this weed by the conventional herbicides. The development of the weed leads to the reduction of the yield of the rice and the reduction in the yield has been reported as high as from 10 to 48%. Under the circumstances, a herbicides capable of effectively controlling this weed is very much desired.

The compounds of the present invention are very effective in controlling the weed and yet they are quite safe to the paddy field rice. Namely, the compounds of the present invention have a feature that in the case of the transplanted rice, they are quite safe even during the period from immediately after the transplantation to 20 days thereafter.

The compounds of the present invention are new compounds which have never been described in literatures. Their herbicidal activities against three-square grass and Cyperus serotinus are far superior to the herbicidal activities of the known compounds having a structure similar to the structure of the compounds of the present invention or to the herbicidal activities of butachlor which is presently commercially available as a chloroacetamide type compound.

Particularly, the compounds of the present invention have a feature that they exhibit superior herbicidal activities against three-square grass and Cyperus serotinus even when the weeds are in a advanced leaf stage and that they have no phytotoxicity against rice plants.

The compounds of the present invention can readily be produced, for instance, by the following reaction;

where R is as defined above.

The above reaction may be conducted in a solvent such as acetone, methyl ethyl ketone, acetonitrile, tetrahydrofuran, dioxane, benzene, chlorobenzene, toluene, xylene, chloroform, dichloromethane or carbon tetrachloride.

As a dehydrochlorinating agent, there may be used an organic or inorganic base, for instance, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, an alkali metal carbonate such as sodium carbonate, potassium carbonate or sodium bicarbonate, or a tertiary amine such as triethylamine, dimethylaniline or pyridine.

The reaction may be conducted at a temperature from - 10 to 200"C for from 1 to 30 hours, whereby the desired compound can be obtained in good yield.

Now, the present invention will be described in further detail with reference to Production Examples.

Production Example 1:

In an acetone solution containing 6.5 g (0.043 mol) of 2-methoxy-5-methyl-N-methylaniline, 5.1 g (0.05 mol) of triethylamine was suspended. While stirring the suspension at room temperature, 20 ml of an acetone solution containing 5.3 g (0.047 mol) was dropwise added and the stirring was continued for 3 hours. Thereafter, the reaction products was poured into water and the oily substance was extracted with ethyl acetate, washed with a 5% aqueous hydrochloric acid solution and water and then dried over sodium sulfate. The ethylacetate solution was concentrated for crystallization, and the crystals thereby obtained were recrystallized from ethanol to obtain 7.9 g (yield; 80.6%) of a desired product having a melting point of from 75 to 76"C white prismatic crystals.

Production Example 2:

1.8 g (0.01 mol) of 2-isopropoxy-5-methyl-N-methylaniline and 1.1 g (0.011 mol) of triethylamine were dissolved in 50 ml of benzene. While stirring and cooling the solution at a temperature of from 5 to 10"C, 1.3 g (0.011 mol) of chloroacetylchloride was dropwise added.

After the dropwise addition, the mixture was reacted at room temperature for 30 minutes. Then, the reaction solution was successively washed with water, 5% hydrochloric acid and water, and then dried over sodium sulfate. Benzene was distilled off and the remaining oil was refined by silica gel column chromatography (developer: n-hexane/ethyl acetate = 3/7) to obtain 2.1 g of a brown liquid of n2,01.536 as the desired product. The yield was 82.3%.

Compounds Nos. 1 to 28 having physical properties as identified in Table 1 were obtained in the same or similar manner as the above Examples.

Table 1

Comp.

No. R Physical properties CH3 White prismatic crystals mp. 75-76"C 2 C2H5 Brown liquid nD2' 1.5310 3 n-C3H7 Brown liquid nod2' 1.5320 4 iso-C3H7 Brown liquid nB' 1.5316 5 n-C4Hg Brown liquid nD2' 1.5268 6 iso-C4Hg Orange liquid nD20 1.5221 7 sec-C4Hg Yellowish liquid nD20 1.5221 8 n-CsH" Gray powder mp. 43-44 C 9 n-C3H7-CH Yellowish liquid nD20 1.5199 CH3 10 n-C6H13- Yellowish liquid nD20 1.5165 11 CH3 Reddish brown liquid 1.5178 n-C3H7CH-CH2 1 2 iso-C3H7-CH2CH- Reddish brown liquid nD20 1.5130 CH3 1 3 iso-C3H7-(CH2)2CH- Reddish brown liquid nD20 1.5128 CH3 14 t-C4Hg-CH- Brown liquid I nO 1.5190 CH3 1 5 C2H5 Dark red liquid \ nod20 1.5144 CH-CH2 C2H5 1 6 CH2 = CHCH2- Brown liquid nod2' 1.5468 1 7 CH=-CCH2- Brown liquid n,21 1.5511 18 a Reddish brown prismatic crystals mp. 43-46 C 19 (3 Reddish brown liquid n,20 1.5370 20 J H3 Reddish brown liquid n,20 1.5268 21 CH34} Reddish brown liquid CH3R n,20 1.5222 22 n Reddish brown liquid c2R5t nD 1.5230 Table 1 (continued)

Comp.

No. R Physical properties 23 ClCH2Cll2CH2- Colourless liquid nD20 1.5390 24 CICH2CH2CH2CH2- Light brown liquid nD20 1.5393 25 CH3 Reddish brown liquid nD 1.5142 iso-CH7-CH 26 > Brown liquid CH2- 20 nD 1.5360 27 CH3OCH2CH2- Light brown liquid nD20 1.5311 28 C2H5OCH2CH2- Colorless liquid nod20 1.5238 Also prepared in a manner similar to the above Examples are the following compounds.

Table 2

R Physical properties (CH3)2-cH(cH2):r Reddish brown liquid nod20 1.5189 C2H5 Yellowish liquid nD20 1.5130 n-C,H,-CH-CHT i-C3H7 Light brown liquid nD2o 1.5008 CH n-C3H7 i-C3H7 Reddish brown liquid n201.5212 CH QH5 C2H5 Colorless liquid f nD 1.5325 The novel compounds of the present invention produced have significant herbicidal effects and no-phytotoxicity to rice and can be applied paddy fields, cultivated fields by soil treatmer.

or foliage treatment under selecting suitable method of application and suitable dose of the active ingredient.

The dose of the active ingredient of the compound of the present invnetion is depending upon a weather condition, a soil condition, a form of the composition, a season of the application and a method of the application and kinds of crop plants and kinds of weeds. It is usually in a range of 0.1 to 10 kg preferably 0.5 to 4 kg per 1 hectare in the treatment and it is usually applied to foliage in a concentration of 500 to 5000 ppm preferably 1000 to 400G ppm as the active ingredient.

When the compound of the present invention is used as the herbicide, the compound can be used in the original form and also in the form of compositions such as granules, wettable powder, dusts, emulsifiable concentrates, flowables, suspensions, etc. to provide superior effects.

In the preparation of the herbicidal compositions, the compound of the present invention can be uniformly mixed with or dissolved in suitable adjuvants such as solid carriers such as talc, bentonite, clay, kaolin, diatomaceous earth, silica gel, vermiculite, lime, siliceous sand, ammonium sulfate or urea; liquid carriers such as alcohols, dioxane, acetone, cyclohexanone, methyl naphthalene or dimethylformamide; surfactants as emulsifiers, dispersing agents or wetting agents such as alkyl sulfate, alkylsulfonate, polyoxyethylene fatty cid ethers, polyoxye thylenealkylaryl ethers such as polyoxyethylene nonylphenol ether or polyoxyethylene sorbitane monoalkylate; and carboxymethyl cellulose, gum arabic and other adjuvants.

The amounts of the active ingredients, adjuvants and additives in the herbicidal compositions of the present invention will be further illustrated.

Wettable powder: Active ingredient: 5 to 95 wt.% preferably 20 to 50 wt.% Surfactant: 1 to 20 wt.% preferably 5 to 10 wt.% Solid carrier: 5 to 85 wt.% preferably 40 to 70 wt.% The active ingredient is admixed 'with the solid carrier and the surfactant and the mixture is pulverized.

Emulsifiable concentrate: Active ingredient: 5 to 95 wt.% preferably 20 to 70 wt.% Surfactant: 1 to 40 wt.% preferably 5 to 20 wt.% Liquid carrier: 5 to 90 wt.% preferably 30 to 60 wt.% The active ingredient is dissolved in the liquid carrier and the surfactant is admixed.

Dust: Active ingredient: 0.5 to 10 wt.% preferably 1 to 5 wt.% Solid carrier: 99.5 to 90 wt.% preferably 99 to 95 wt.% The active ingredient is mixed with fine solid carrier and the mixture is pulverized.

Granule: Active ingredient: 0.5 to 40 wt.% preferably 2 to 10 wt.% Solid carrier: 99.5 to 60 wt.% preferably 98 to 90 wt.% The active ingredient is sprayed on the solid carrier or further coated with the solid carrier to form the granule.

Now, specific formulations will be given in the following Formulation Examples. However, it should be understood that the types of the additives and the proportions of various ingredients are not restricted to these Examples and may optionally be modified in a wide range. In these Examples, the percentage represents percent by weight.

Formulation Example 1: Wettable powder Active ingredient 50% Sodium dinaphthylmethane sulfonate 2% Sodium lignin sulfonate 3% Diatomaceous earth 45% The above ingredients were uniformly mixed and pulverized to obtain a wettable powder.

Formulation Example 2: Wettable powder Active ingredient 30% Sodium high or alcohol sulfate 5% White carbon 3% Clay 62% The above ingredients were uniformly mixed and pulverized to obtain a wettable powder.

Formulation Example 3: Emulsifiable concentrate Active ingredient 30% Polyoxy ethylene alkylaryl ether 11 % Calcium alkylbenzene sulfonate 4% Cyclohexanone 20% Methyl naphthalene 35% The above ingredients were uniformly dissolved to obtain an emulsifiable concentrate.

Formulation Example 4: Emulsifiable concentrate Active ingredient 50% Polyoxyethylene nonylphenol 5% Alkyl aryl sulfonate 5% Xylene 40% The above ingredients were uniformly dissolved to obtain an emulsifiable concentrate.

Formulation Example 5: Granule Active ingredient 5% Sodium lauryl alcohol sulfate 2% Sodium lignin sulfonate 5% Carboxy methyl cellulose 2% Clay 86% The above ingredients were uniformly mixed and pulverized. After adding water, the mixture was kneaded, then granulated by an extrusion granulating machine, and dried to obtain granules.

Formulation Example 6: Granule Active ingredient 3% Sodium lignin sulfonate 2% White carbon 2% Siliceous sand 93% The above ingredients were uniformly mixed and pulverized. After adding water, the mixture was kneaded, then granulated by an extrusion granulating machine, and dried to obtain granules.

Formulation Example 7: Dust Active ingredient 4% Diatomaceous earth 5% Clay 91% The above ingredients were uniformly mixed and pulverized to obtain a dust.

Formulation Example 8: Dust Active ingredient 2% White carbon 2% Kaoline 96% The above ingredients were uniformly mixed and pulverized to obtain a dust.

Now, the present invention will be described with reference to Test Examples.

Test Example 1: Into a 100 cm2 porcelain pot, paddy field soil was filled and puddled, and barnyardgrass, three-square grass, small flower umbrella plant and Monochoria were seeded and germinated tubers of Cyperus serotinus were planted. Paddy field rice seedlings (species: KINMAZE) of 2leaf stage were transplanted (each plant comprising two seedlings) and water was filled in a depth of 3 cm. Two days later, a predetermined amount of the wettable powder prepared in Formulation Example 1 and diluted with water was dropwise applied to the surface of the water Thereafter, the pot was left in a green house. Twenty one days after the application, the herbicidal effects and the phytotoxicity against the rice plants were evaluated. The evaluation was conducted in accordance with the following standards and the results thereby obtained are shown in Table 3.

The concentration of the active ingredients applied for the test of herbicidal activities was 50 g/10 a, and the concentration of the active ingredient for the phytotoxicity test was 100 g/10 a.

Evaluation standards for herbicidal effects and phytotoxicity 5 Withered 4.5 Herbicidal effect (or phytotoxicity) in a range of 90 to 99% 4 Herbicidal effect (or phytotoxicity) in a range of 80 to 89% 3.5 Herbicidal effect (or phytotoxicity) in a range of 70 to 79% 3 Herbicidal effect (or phytotoxicity) in a range of 60 to 69% 2.5 Herbicidal effect (or phytotoxicity) in a range of 50 to 59% 2 Herbicidal effect (or phytotoxicity) in a range of 40 to 49% 1.5 Herbicidal effect (or phytotoxicity) in a range of 30 to 39% 1 Herbicidal effect (or phytotoxicity) in a range of 20 to 29% 0.5 Herbicidal effect (or phytotoxicity) in a range of 1 to 19% O No herbicidal effect (or no phytotoxicity) Table 3 Herbicidal effects Phytotoxicity Smallflower Three- against Tested Barnyard- unbrella Mono- square Cyperus paddy field Compound grass plant choria grass serotinus rice Comp. 1 5 5 5 5 5 0 Comp. 2 5 5 5 5 5 0 Comp. 3 5 5 5 5 4 0 Comp. 4 5 5 5 5 5 0 Comp. 5 5 5 5 5 5 0 Comp. 6 5 5 5 5 5 0 Comp. 7 5 5 5 5 5 0 Comp. 8 5 5 5 5 4 0 Comp. 9 5 5 5 5 5 0 Comp. 10 5 5 5 4.5 4 0 Comp. 11 5 5 5 5 4.5 0 Comp. 12 5 5 5 5 5 0 Comp. 13 5 5 5 5 5 0 Comp. 14 5 5 5 5 5 0 Comp. 15 5 5 5 5 5 0 Comp. 16 5 5 5 5 4 0 Comp. 17 5 5 4 5 3.5 0 Comp. 18 5 5 5 5 5 0 Comp. 19 5 5 5 5 5 0 Comp. 20 5 5 5 5 5 0 Comp. 21 5 5 5 5 5 0 Comp. 22 5 5 5 4 4 0 Comp. 23 5 5 5 5 5 0 Comp. 24 5 5 5 5 5 0 Comp. 25 5 5 5 5 5 0 Comp. 26 5 5 4 5 5 0 Comp. 27 5 5 4.5 5 5 0 Comp. 28 5 5 5 5 5 0 Comparative 5 3 1 0 0 0 Comp. 1 Comparative 5 5 4.5 5 5 1 Comp. 2 Comparative 5 5 0 3 1 1 Comp. 3 Comparative 5 5 4 2 0 0 Comp. 4 Comparative 5 5 4 4 2 0 Comp. 5 Comparative 5 5 5 5 5 3 Comp. 6 Comparative Compound No. 1 Comparative Compound No. 2 Comparative Compound No. 3 Comparative Compound No. 4 Comparative Compound No. 5 Comparative Compound No. 6

Test Example 2: Into a 100 cm2 porcelain pot, paddy field soil was filled and puddled, and barnyardgrass and three-square grass were seeded and paddy field rice seedings (species: KINMAZE) of 2-leaf stage were transplanted (each plant comprising two seedlings). Water was filled in a depth of 3 cm. The weeds and rice were cultivated in a green house under irrigation until barnyardgrass and three-square grass reached the predetermined leaf stages (2.0 leaf stage for barnyardgrass and 1.5-2.0 leaf stage for three-square grass). Then, while maintaining the water in a depth of 3 cm, a predetermined amount of the wettable powder prepared in Formulation Example 1 and diluted with water was dropwise applied to the surface of the water.Thereafter, the pot was left in the green house and 30 days after the application, the herbicidal effects were evaluated. The results thereby obtained are shown in Table 4. The evaluation standards were the same as those presented in Test Example 1.

The concentration of the active ingredient for the test for the herbicidal effects was 50 g/ 10 a, and the concentration of the active ingredient for the test for the phytotoxicity against the paddy field rice plant was 100 g/10 a.

Table 4

Herbicidal effects Phytotoxicity Tested Barnyard- Three-square Cyperus against paddy Compound grass grass serotinus field rice Comp. 1 5 4.5 5 0 Comp. 2 5 4.5 5 0 Comp. 3 5 4.5 4 0 Comp. 4 4 4.5 5 0 Comp. 5 4 3.5 5 0 Comp. 16 5 4.5 4 0 Comparative Comp. 1 2 2 0 0 Comparative Comp. 2 4.5 4.5 2 1 Comparative Comp. 3 4 4 0 0.5 Comparative Comp. 4 4 4 0 0 Comparative Comp. 5 1 4.5 2 0 Comparative Comp. 6 0 2 0 0 Comparative Comp. 7 2 4 2 0.5 Comparative Comp. 8 1 4 0 0 Comparative Comp. 9 5 5 4 3 Commercially avail able herbicide u m 0 1 1 0 Chloromethoxy nil Comparative Compound No. 1 Comparative Compound No. 2 Comparative Compound No. 3 Comparative Compound No. 4 Comparative Compound No. 5 Comparative Compound No. 6 Comparative Compound No. 7 Comparative Compound No. 8 Comparative Compound No. 9

Test Example 3: Into a 1/5000 are Wagner pot, paddy field sand soil was filled and puddled, and 4 rice plant seedlings of 2-leaf stage were transplanted to each pot.Water was filled in a depth of 3 cm.

Two days later, a predetermined amount of the wettable powder prepared in Formulation Example 1 and diluted with water was dropwise applied to the surface of the water. Water was drained for three days at such rate that the water level was reduced by 2 cm per day. Each test was repeated three times. Each pot was left in a green house and 21 days after the application, the phytotoxicity against the rice plants was evaluated. The results obtained by the evaluation in accordance with the evaluation standards as mentioned in Test Example 1 are shown in Table 5. Table 5 Dosage Phyto- Dosage Phyto- Dosage Phyto No. g ai/10 a toxicity No. g ai/10a toxicity No. g ai/10a toxicity Comp. 200 0 Com- 200 3 Com- 200 3 para- para 1 100 0 tive 100 2 tive 100 1 Comp. Comp.

50 0 1 50 0 7 50 1 Comp 200 0 Com- 200 4 Com- 200 1 para- para 2 100 0 tive 100 3 tive 100 0 Comp. 50 1 Comp.

50 0 2 8 50 0 Comp. 200 0 Com- 200 2 Com- 200 5 para- para 3 100 0 tive 100 1 tive 100 4 Comp. Comp.

50 0 3 50 0 9 50 4 Comp 200 0 Com- 200 4 *1 200 2 para 4 100 0 tive 100 4 100 1 50 0 Comp. 50 2 50 0 4 Comp 200 0 Com- 200 2 *2 200 1 para 5 100 0 tive 100 1 100 0 Comp.

50 0 5 50 0 50 0 Comp. 200 0 Com- 200 1 para 16 100 0 tive 100 0 Comp.

50 0 6 50 0 Note: * 1 commercially available butochlor * 2 chloromethoxynil Test Example 4: Into a 100 cm2 plastic pot, paddy field soil was filled and puddled, seeds of three-square grass were seeded continuously in a depth of from 0 to 2 cm. Water was filled in a depth of 3 cm. One day later, a predetermined amount of the wettable powder prepared in Formulation Example 1 and diluted with water was dropwise applied to the surface of the water. Thereafter, the pot was left in a green house and 30 days after the application, the herbicidal effects for each depth were evaluated. The results obtained by the evaluation in accordance with the evaluation standard as specified in Test Example 1 are shown in Table 6.

Table 6 Herbicidal effects (50 g ai/10a) No. O cm 1 cm 2 cm Comp. 1 5 5 4.5 Comp. 2 5 5 4 Comp. 3 5 5 4 Comp. 4 5 5 3 Comp. 5 5 5 4 Comp. 16 5 5 3 Comparative Comp. 1 0 0 0 Comparative Comp. 2 5 5 2 Comparative Comp. 3 5 2 0 Comparative Comp. 4 3 0 0 Comparative Comp. 5 5 2 0 Comparative Comp. 6 2 0 0 Comparative Comp. 7 5 5 2 Comparative Comp. 8 4 0 0 Comparative Comp. 9 ~ 5 5 4 Butachlor 5 4 1 Chloromethoxynil 5 0 0

Claims

CLAIMS An N-methylchloroacetanilide derivative represented by the formula where R is an alkyl group, an allyl group, a propargyl group, an alkoxyalkyl group, a tetrahydrofurylmethyl group, an alkyl group substituted by a halogen atom or a cycloalkyl group which may be substituted by an alkyl group. 2. The N-methylchloroacetanilide derivative according to Claim 1 wherein R is an alkyl group or an allyl group. 3. The N-methylchloroacetanilide derivative according to Claim 2 wherein the alkyl group as R is a lower alkyl group. 4. The N-methylchloroacetanilide derivative according to Claim 1 wherein R is a methyl group or an ethyl group. 5. A process for producing an N-methylchloroacetanilide derivative represented by the formula where R is an alkyl group, an allyl group, a propargyl group, an alloxyalkyl group, a tetrahydrofurylmethyl group, an alkyl group substituted by a halogen atom or a cycloalkyl group which may be substituted by an alkyl group, which comprises reacting an N-methylaniline represented by the formula where R is as defined above, with chloroacetylchloride. 6. The process according to Claim 5 wherein a dehydrochlorinating agent is usd for the reaction. 7. A herbicidal composition containing an N-methylchloroacetanilide derivative represented by the formula where R is an alkyl group, an allyl group, a propargyl group, an alkoxyalkyl group, a tetrahydrofurylmethyl group, an alkyl group substituted by a halogen atom or a cycloalkyl group which may be substituted by an alkyl group, as an active ingredient. 8. The herbicidal composition according to Claim 7 wherein R is an alkyl group or an allyl group. 9. The herbicidal composition according to Claim 7 wherein R is a lower alkyl group. 10. The herbicidal composition according to Claim 7 wherein R is a methyl group or an ethyl group. 11. A herbicidal method which comprises applying an effective amount of the herbicidal composition as defined in Claim 7, to soil or plant foliages. 1 2. A herbicidal method which comprises applying the herbicidal composition as defined in Claim 7 to soil in an amount of 0.1-10 kg/HA as the active ingredient. 1 3. A herbicidal method which comprises applying the herbicidal composition as defined in Claim 7 to plant foliages in an active ingredient concentration of from 500 to 5000 ppm. CLAIMS (8 Jun 1983)

1. An N-methylchloroacetanilide derivative represented by the formula

wherein R is an alkyl group, an allyl group, a propargyl group, an alkoxyalkyl group, a tetrahydrofurylmethyl group, an alkyl-group substituted by a halogen atom, a cycloalkyl group, or an alkylcycloalkyl group.

2. An N-methylchloroacetanilide derivative according to claim 1, wherein R is an alkyl group or an allyl group.

3. An N-methylchloroacetanilide derivative according to claim 1 or claim 2, wherein R is a lower alkyl group.

4. An N-methylchloroacetanilide derivative according to any one of claims 1 to 3, wherein R is a methyl group or an ethyl group.

5. A process for producing an N-methylchloroacetanilide derivative according to claim 1, which comprises reacting an N-methylaniline represented by the formula

wherein R is as defined in claim 1, with chloroacetylchloride.

6. A process according to claim 5, wherein a dehydrochlorinating agent is used for the reaction.

7. The use of an N-methylchloroacetanilide derivative according to any one of claims 1 to 4 as a herbicide.

8. A herbicidal composition containing an N-methylchloroacetanilide derivative according to any one of claims 1 to 4 as an active ingredient.

9. A herbicidal method which comprises applying an effective amount of a composition according to claim 8 to soil or plant foliage.

10. A herbicidal method according to claim 9, which comprises applying 0.1 to 10 kg/HA of the active ingredient to soil.

11. A herbicidal method according to claim 9, which comprises applying the active ingredient at a concentration of from 500 to 5000 ppm to plant foliage.

12. An N-methylchloroacetanilide derivative according to claim 1, substantially as hereinbefore described with reference to Tables 1 and 2.

1 3. A process for producing an N-methylchloroacetanilide derivative according to claim 1, substantially as herein before described with reference to the Production Examples.

14. The use of an N-methylchloroacetanilide derivative according to claim 1 as a herbicide substantially as hereinbefore described.

1 5. A herbicidal composition containing an N-methyichloroacetanilide derivative according to claim 1, substantially as hereinbefore described with reference to the Formulation Examples.

1 6. A herbicidal method which comprises applying an effective amount of a composition according to claim 1 5 to soil or plant foliage, substantially as herein before described with reference to the Test Examples.