CS266986B1 - Method of n-(2,6-dialkylphenyl)-n-arenesulphonyl ureas preparation - Google Patents

Abstract

The solution relates to the N- - / 2,6-dialkylphenyl / N * -arénsulfonylmočovín of Formula I by reacting the derivative 2,6-dialkylaniline of formula II with general arsenulfonyl isocyanate of formula III in an inert aprotic medium solvent at a temperature of up to 120 ° C. The solution can be used in the chemical industry.

Description

The invention relates to a process for the preparation of N- (2,6-dialkylphenyl) N -'-arenesulfonylureas. These compounds can be used as herbicides.

Sulfones Ureas derived from sulfonamides and heterocyclic amines such as aminotriazines and aminopyrimidines are known from the literature (Houben-Weyl: Methoden der organischen Chemie, 4th edition, Vol. E 4, Georg Thieme Verlag, Stuttgart 1983, pp. 400-402). Several of the compounds in this group have herbicidal or pharmacological properties. Some 2,6-dialkylaniline derivatives have been described by Atanasov A. I. et al. (Synthesis 8, 734-736, 1987) and prepared by decomposing trichloroacetanilides with caustic soda in the presence of sulfonamides. The disadvantage of this method is that it is a multi-step synthesis and that it allows only average yields to be obtained.

It has now been found that N- (2,6-dialkylphenyl) -N'-arenesulfonylureas of formula I wherein

R ^{3 is} hydrogen, chlorine or methyl, 2 3

R and R are methyl or ethyl, 4

R is hydrogen, acetyl or chloroacetyl

can be prepared by reacting a 2,6-dialkylaniline derivative of formula II R ²

NH-R ^4/11 /

3 4 wherein R, R and R are as defined in arénsulfonylizokyanátom of formula III ^'1/111 / of ₂ NCO wherein R ³ is as defined above in an inert aprotic organic solvent such as benzene, toluene, xylene, dichloromethane, chloroform, acetonitrile, tetrahydrofuran at temperatures up to 120 C.

It has also been found that said reaction can be catalyzed by tertiary amines such as triethylamine, pyridine and others.

The products obtained are generally insoluble in the reaction medium when cold and can be isolated therefrom, e.g. suction. Soluble end products can be isolated from the reaction mixture by concentration and crystallization.

The advantage of the process according to the invention in comparison with known processes lies mainly in its simplicity and high yields.

3 4 v _yz .

Intermediates of formula II, wherein R, R and R are as defined above, can be prepared by known methods (J. Am. Chem. Soc. 43, 282, 1943; Ber. 73, 1377, 1940; Ark. Kemi 22 A , No. 18, 4, 1946). Intermediates of formula III, wherein R ³ is as defined above, can be prepared e.g. by reacting arenesulfonamides with phosgene (U.S. Pat. No. 3,371,114, De 2 152 971, Ulbrich et al., Angew. Chemie 78, 761, 1966) or by reacting arenesulfonamides with chlorosulfonyl isocyanate (DE 1 289 526).

CS 266 986 Bl

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

Example 1

To 3.6 g (0.03 mol) of 2,6-dimethylaniline in 20 ml of anhydrous benzene with vigorous stirring was added 6.5 g (0.03 mol) of o-chlorobenzenesulfonyl isocyanate in 20 ml of benzene. As a result of the exothermic reaction, the temperature of the reaction mixture rose to 45 DEG C., and the product began to precipitate, which was filtered off with suction after washing for 1 hour, washed with benzene and dried. 9.0 g (89%) of N- (2,6-dimethylphenyl) -N'-o-chlorobenzenesulfonylurea with m.p. t. 177.7 ° C.

For C ₁₅ H ₁₅ Cl N ₂ O ₃ S (mh 338.91):

calculated:% C 53.16; % H 4.46; % N 8.27; % S 9.46 Found:% C 53.28; % H 4.50; % N 8.06; % S 9.90.

Example 2

To 5.64 g (0.025 mol) of 2-methyl-6-ethyl-alpha-chloroacetanilide in 20 ml of anhydrous benzene was added 4.58 g (0.025 mol) of benzenesulfonyl isocyanate, and the mixture was heated under reflux for 2 h. After cooling, 4.3 g (42%) of crystallized N- (2-methyl-6-ethylphenyl) -N-chloroacetyl-N'-benzenesulfonylurea were isolated from the reaction mixture, which, after crystallization from carbon tetrachloride, had a m.p. t. 117.3 ° C.

For C _1Q H ₁ O Cl N, O. S (mh 408.92); 1o iy Z 4 calculated:% C 55.80; % H 5.18; % N 6.85; % S 7.84 Found:% C 56.0; % H 5.3; % N 6.6; % S 7.3

The procedures of Examples 1 and 2 were, at different reaction temperatures, other compounds of formula I, which are described in the following table.

Table

Compound T. t. ° C Exhaust % Molar mass Analysis z i wall / calculated % C % H % N % WITH N- (2,6-diethylphenyl) -N'-p-toluenesulfonylurea 185.6 80 346.45 62.7 62.40 6.4 6.40 8.1 8.09 8.8 9.25 N- (2-methyl-6-ethylphenyl) ~ N'-p- -toluenesulfonylurea 188.6 84.6 332.42 61.42 61.3 6.06 6.1 8.43 8.4 9.64 9.3 N- (2,6-dimethylphenyl) -N * -p-toluenesulfonylurea 170.5 55 318.39 60.1 60.36 5.76 5.70 8.7 8.80 9.8 10.07 N-7 2,6-diethylphenyl / -N-o-toluenesulfonylurea 147.0 82 346.45 60.6 62.40 6.5 6.40 7.9 8.09 9.0 9.25 N- (2,6-dimethylphenyl) -N-o-toluenesulfonylurea 171.3 89 318.39 59.7 60.36 5.7 5.70 8.7 8.80 10, - 10.07 N- (2-methyl-6-ethylphenyl) -N-O "toluenesulfonylurea" 161.7 70 332.42 61.2 61.42 6.1 6.06 8.5 8.43 9.3 9.64 N- (2,6-diethylphenyl) -N'-o-chlorobenzenesulfonylurea 162.3 82 366.87 55.6 55.66 5.6 5.22 7.6 7.64 8.8 8.74 N- (2-methyl-6-ethylphenyl) -N '' - o-chlorobenzenesulfonylurea 166.7 77 352.84 55.6 55.47 5.1 4.86 7.9 7.94 9.5 9.07 N- [2-methyl 1-6-ethylphenyl] -N-benzenesulfonylurea 205.8 83 318.39 60.5 60.36 5.7 5.70 8.8 8.80 10.3 10.07

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Continuation table

Compound T. t. ° C Yield « Molar mass Analysis found / calculated % C % H % N " WITH N- (2,6-dimethylphenyl) -N'-benzene- 204.4 81 304.37 59.7 5.4 9.3 11.1 sulfonylurea 59.19 5.30 9.20 10.53 N- (2,6-diethylphenyl) -N-benzene- 199.7 95 332.42 61.8 6.1 8.4 10.0 sulfonylurea 61.42 6.06 8.43 9.64 N- (2,6-methyl-6-ethyl-phenyl) -N- 95.6 37 360.44 60.2 6.4 7.6 9.7 -acety 1-N * -benzenesulfonyls Urea 59.98 5.59 7.77 8.90 N- (2,6-dimethylphenyl) -N-chloroacetyl- 97.7 53.5 394.88 55.1 4.9 7.0 8.0 -N'-p-toluenesulfonylurea 54.77 4.85 7.09 8.12

OBJECT OF THE INVENTION

Claims (2)

OBJECT OF THE INVENTION Process for the preparation of N- (2,6-dialkylphenyl) -N-arenesulphonylureas of general formula I wherein / 1 / r! hydrogen, chlorine or methyl, 2 3 * R and R are methyl or ethyl, R ^{4 is} hydrogen, acetyl or chloroacetyl, characterized in that the 2,6-dialkylaniline derivative of the general formula II R ² NH-R ^4/11 / Wherein R 1, R 2 and R 3, as defined above, act as arenesulfonyl isocyanates of formula III (111) wherein R ¹ is as defined above in an inert aprotic organic solvent such as benzene, toluene, xylene, acetonitrile, dichloromethane, tetrahydrofuran at a temperature up to 120 ° C.