CS266985B1 - Substituted N- (2,6-dialkylphenyl) -N'-arenesulfonylureas - Google Patents

Abstract

The solution relates to substituted N- -/2,6-dialkylphenyl/-N'-arenesulfonylureas of the general formula I, which have herbicidal activity. The compounds mentioned can be prepared by reacting substituted N-2,6-dialkylanilines of the general formula II with arenesulfonylocyanate of the general formula III in an inert organic solvent from the group including benzene, toluene, xylene, acetonitrile, chloroform, dichloromethane, tetrahydrofuran at a temperature of up to 120 °C. In the formulas R1 is H, Cl, CH3 or methoxycarbonyl and R2 and R3 mean CH3 or ethyl and R4 is methoxy-C1-5alkyl.

Description

The invention relates to a process for substituted N- (2,6-dialkylphenyl) -N'-arenesulfonylureas and to a process for their preparation. Said compounds can be used as herbicides.

Sulfonylureas are widely described in both patent and literature. These are, for example, sulfonamide derivatives with heterocyclic amines, such as aminotriazines and aminopyrimidines (Houben-Weyl: Methoden der organischen Chemie, 4th edition, Volume E 4, Georg Thieme Verlag, Stuttgart 1983, pp. 400-402). A number of compounds of this group have herbicidal or pharmacological properties. Less known are sulfonamide compounds with sterically shielded anilines (Atanasova, I. A. et al .: Synthesis (8), 734-6 (1987)).

Substituted N- (2,6-dialkylphenyl) -N'-arenesulfonylureas of the formula I have now been found.

R ²

In which R is hydrogen, chlorine, methyl or methoxycarbonyl, R and R are methyl or 4-ethyl and R is 1-methoxy-2-propyl or 1- (methoxycarbonyl) ethyl.

Also disclosed is a process for the preparation of said compounds of formula I by reacting substituted N-2,6-dialkylanilines of formula II p2 (Q) -NH-R ⁴ '- (/ 11), wherein R ² , R ³ and R 3 ⁴ have the meanings already given with the arenesulfonyl isocyanate of the general formula III

(111), in which R ³ is as defined above, in the presence of an inert organic solvent from the group consisting of benzene, toluene, xylene, acetonitrile, chloroform, dichloromethane, tetrahydrofuran at a temperature of up to 120 ° C. The reaction can advantageously be carried out at the reflux of the solvent or in a pressure vessel.

The reaction can be catalyzed by triethylamine, pyridine and the like. The reaction products are insoluble in the reaction medium after cooling of the mixture and can be separated from the solvent or reactants, for example by suction.

Compounds of formula II - intermediates - can be prepared by methods known in the literature, such as the hydrogenation alkylation of 2,6-dialkylanilines with ketones (BE 810 763, CS 219 856, US 4 200 451) or by reacting 2,6-dialkylanilines with alkyl bromides, alkylbenzenesulfonates or alkyl tosylates, (DE 2 318 340) optionally by alkylation of 2,6-dialkylanilines with 2-halopropionic acid esters.

The starting compounds of formula III can also be prepared by known methods, e.g. by the reaction of sulfonamides with phosgene (U.S. Pat. No. 3,371,114, DOS 2,152,971, Ulrich, H. et al., Angew. Chem. 78, 761 (1966), Houben-Weyl: Methods of Organic Chemistry, 4th Edition, Vol. E 4, pp. 803-810, Hagemann, Stuttgard, 1983).

The substituted N- (2,6-dialkylphenyl) -N'-arenesulfonylureas of the invention can be used to control weeds. For this purpose, they can be formulated as solutions, emulsions, suspensions, powders and the like. These are prepared in a known manner, for example by mixing the active compound with excipients

CS 266 985 B1 substances such as liquid solvents or solid carriers, optionally using surfactants, are emulsifiers or dispersants.

The following examples illustrate but do not limit the scope of the invention.

Example 1

To 4.15 g (0.02 mol) of 2-methyl-6-ethyl-N- (1'-methoxy-2'-propyl) aniline in 30 ml of cyclohexane was gradually added 3.9 g (0.02 mol) of p-toluenesulfonyl isocyanate in 20 ml of cyclohexane. After 2 hours of reaction, a solid began to precipitate, which was filtered off with suction the next day and washed with cyclohexane. 6.75 g (84%) of N- (2-methyl-6-ethylphenyl) -N-1'-methoxy-2'-propyl] -N'-p-toluenesulfonylurea with m.p. t. 114.6 ° C.

For C 11 H 11 N 2 O 5 S (404.53) calculated: C: 62.37; H: 6.98; N: 6.92; Z X 6 O Za 4

S, 7.93%, found: C, 62.7%,

H, 7.0; N, 6.5; S, 7.8%.

The compounds listed in Table 1 were prepared in the same manner.

Table 1

Compound T. t. ° C Yield% Molar mass Analysis found / calculated % C % H % N % WITH N- (2-methyl-6-ethylphenyl) -N- 133.8 45 404.50 59.0 5.9 6.9 8.3 - 1- 1- (methoxycarbonyl-ethyl | -N'- -benzenesulfonylurea 59.38 5.98 6.93 7.92 N- (2-methyl-6-ethylphenyl) -N- 59.8 6.3 6.7 8.0 - [Ir (methoxycarbonyl) ethyl] -N'- -o-toluenesulfonylurea 160.6 55 418.52 60.26 6.20 6.69 7.66 N- (2,6-diethylphenyl) -N- [1- 147.1 48 432.55 61.4 6.6 6.4 7.3 - (methoxycarbonyl) -ethyl-N ^- -o-toluenesulfonylurea 61.08 6.52 6.48 7.41 N- (2-methyl-6-ethylphenyl) -N- [1- 138.3 40 418.52 60.2 6.1 6.6 7.9 - (methoxycarbonyl) -ethyl] N'- -p-toluenesulfonylurea 60.26 6.26 6.69 7.66 N- (2,6-diethylphenyl) -Ν-Γ1- 138.2 47 432.55 61.5 6.4 6.4 7.7 - (methoxycarbonyl) -ethyl] -N'- -p-toluenesulfonylurea 61.08 6.26 6.48 7.41 N- (2-methyl-6-ethylphenyl) -N- [1- 184.3 83.5 438.94 54.0 5.2 6.3 7.6 - (methoxycarbonyl) -ethyl) N'-p- -chlorobenzenesulfonylurea 54.72 5.28 6.38 7.31 N- (2,6-diethylphenyl) -N-Cl- 152.0 46 452.97 55.5 5.6 6.0 7.3 - (methoxycarbonyl) -ethyl] N'- -o-chlorobenzenesulfonylurea 55.68 5.56 6.18 7.08 N - (- 2-methyl-6-ethylphenyl) -N-Cl- • 147.6 38 462.54 57.5 5.6 6.4 7.2 - (methoxycarbonyl) -ethyl J-N'-o-methoxycarbonylbenzenesulfonylurea 57.12 5.7 6.06 6.93 N- (2,6-dimethylphenyl) -N-Cl- (methoxycarbonyl) -ethyl] -N'- 166.8 61 390.77 58.44 5.68 7.17 8.21 58.58 5.71 7.06 8.91 -benzenesulfonylurea N-2,6-dimethylphenyl-N-C1- 202.5 80 424.91 53.71 4.98 6.59 6.59 7.55 - (methoxycarbonyl) J-ethyl / N'-o- -chlorobenzenesulfonylurea 54.33 5.11 8.22 N-2,6-dimethylphenyl-N- (1- 151.8 67 404.49 59.39 5.98 6.93 7.93 - (methoxycarbonyl-ethyl) -N-p- -toluenesulfonylurea 59.22 6.05 6.87 7.50 N- (2-methyl-6-ethylphenyl) -N / 1'- 106.2 66 390.81 6.8 6.8 6.7 8.0 -methoxy-2'-propyl] -N'-benzene- -sulfonylurea 61.50 6.71 7.17 8.21

I

CS 266 985 Bl

Example 2

In the containers made of polyvinyl chloride (16.5x21x3 cm) filled with standard aluminous-sandy soil, the following rows were sown as test objects:

A - deaf oats (Avena fatua), F - buckwheat (Fagopyrum vulgare), S - mustard (Sinapis alba), P - millet (Panicům milliaceum), L - mustard (Lepidium sativum).

After leveling the soil surface, a light watering was performed and the soil surface was immediately sprayed with formulations containing as active ingredients the compounds of the formula I in a concentration of 0.5%. The formulations were used in a volume of 2 ml per container, corresponding to a dose of 2.5 kg.ha The herbicide metolachlor was used as a standard. The degree of damage to the test plants was determined on day 21 after treatment and was expressed by a rating scale of 0 to 5, in which grade 0 means plants normally developed, grade 5 means plants dead. The results are summarized in Table 2.

Table 2

Substituent Test object

R ¹ R ² R ³ R ⁴ A F with P L H methyl ethyl 1- (methoxycarbonyl) ethyl 2 3 2 3 3.5 2-methyl methyl ethyl 1- (methoxycarbonyl) -1-ethyl 2 3 2 4 2 2-methyl ethyl ethyl 1- (methoxycarbonyl) - -ethyl 2 2 1 3.5 2 4-methyl methyl ethyl 1- (methoxycarbonyl) ethyl 2 3 1 3.5 0 4-methyl ethyl ethyl 1- (methoxycarbonyl) ethyl ' 2 3 0 3.5 2 4-chlorine methyl ethyl 1- (methoxycarbonyl) ethyl 1 1 0 3.5 3.5 2-chlorine ethyl ethyl 1- (methoxycarbonyl) - -ethyl 3 3 2 4 4 2-methoxycarbonyl methyl ethyl 1- (methoxycarbonyl) ethyl 2.5 3 2 3 2 H methyl methyl 1- (methoxycarbonyl) - -ethyl 1 2 0 2 2 2-chlorine methyl methyl 1- (methoxycarbonyl) ethyl 3.5 3.5 1 2 3.5 4-methyl methyl methyl 1- (methoxycarbonyl) ethyl 2 0 0 3.5 2 H methyl ethyl 1-methoxy-2-propyl 3 2 2 4 1 Standard metolachlor 3 3 4 2.5 3.5

CS 266 985 Bl

Claims (2)

OBJECT OF THE INVENTION 1-2 in which R is hydrogen, chlorine, methyl or methoxycarbonyl, R and R are methyl or 4-ethyl and R is 1-methoxy-2-propyl or 1- (methoxycarbonyl) ethyl. 2. A process for the preparation of the compounds according to item 1, characterized in that the substituted N-2,6- -dialkylaniline of general formula II, 2 NH-R ⁴ / 1 /, Substituted N-2,6-dialkylphenyl / -N'-arenesulfonylureas of the general formula I R ² In which R 1, R 2 and R 3 are as defined above, are treated with an arenesulfonyl isocyanate of the general formula III with ₂ nco (111), in which R 1 is as defined above, in the presence of an inert organic solvent from the group consisting of benzene, toluene, xylene, acetonitrile, chloroform, dichloromethane, tetrahydrofuran at a temperature of up to 120 ° C.