CH649541A5 - METHOD FOR PRODUCING N-CARBAMOYL-BENZOESIC ACID-SULFIMIDE DERIVATIVES. - Google Patents

Description

The invention relates to a process for the preparation of N-carbamoyl-benzoic acid sulfimide derivatives of the general formula (I),

HSp he so on)

(D

where the meaning of R1 is the same as above, puts -60.

According to the process of the invention, the N-substituted formamides of the general formula (II) with inorganic halogenating agents with an oxidative effect, for. B. with free halogens or advantageously with sulfuryl-65 chloride. The reaction can be carried out at temperatures between 0-60 ° C, preferably at room temperature, suitably in an organic solvent, for. B. in aliphatic or aromatic hydrocarbons [He

3rd

649 541

xane, benzene, toluene, etc.] or their halogenated derivatives [chloroform, dichloromethane, chlorobenzene, etc.].

After the oxidative halogenation has ended, the salt of benzoic acid sulfimide which is formed with alkali metal or alkaline earth metal hydroxides [NaOH or Ca (OH) 2] or with organic bases [triethylamine, pyridine] is advantageously added to the reaction mixture in the form of a solution.

Most of the compounds of general formula (I) separate out from the reaction mixture in crystalline form and can be separated by filtration. The crystalline product can be cleaned of the salt-like impurities in a manner known per se, by washing with aqueous or aqueous-organic solvents.

The unreacted benzoic acid sulfimide can be regenerated from the washing liquid or from the mother liquor by treatment with an acid.

An advantage of the process is that compounds of the general formula (I) can be prepared without the use of phosgene. Another advantage is that by avoiding the isolation of highly toxic intermediates with simple technological steps, a product of great purity is obtained with a good yield.

Further details of the process are given in the examples, without restricting the invention to the examples.

example 1

13.5 g of sufuryl chloride are added dropwise to the mixture of 5.9 g of N-methylformamide and 8 ml of chloforome with ice cooling in such a way that the temperature should not rise above 10 ° in the meantime. After the dropping has ended, the cooling is stopped and the reaction mixture is stirred for a further 8 hours. Due to intensive gas formation, the temperature does not rise above 14 ° C in the first two hours. Accordingly, a solution of 18.4 g of benzoic acid sulfimide in a mixture of 14 ml of triethylamine and 40 ml of chloroform is added dropwise to the mixture while stirring for 20 minutes with intensive ice cooling. The temperature of the mixture is kept between 15-20 ° C. After stirring for a further 2 hours at room temperature, the separated white crystals are filtered, washed with 2 × 10 ml of 50% aqueous acetone and dried. 12.0 g of N-methyl-carbamoyl-benzoic acid sulfimide are obtained. Mp 222-24 ° C.

Example 2

5 The procedure of Example 1 is followed, with the difference that 7.3 g of N-ethylformamide are used as the starting material instead of N-methylformamide. 14.0 g of N-ethyl-carbamoyl-benzoic acid sulfimide are thus obtained. Mp: 224 ° C.

After evaporation of the chloroform filtrate, the residue is washed with twice 5 ml of 50% aqueous acetone and a further 1.2 g of product are thereby obtained.

Example 3

15 The procedure is as in Example 1, but 12.7 g of N-cy-clohexyl-formamide are used as the starting material instead of N-methylformamide. After the reaction has ended, the product remains in the chloroform solution, which is evaporated and then washed with twice 10 ml of 50% strength aqueous acetone 20. 22.5 g of cyclohexyl-carbamoyl-benzoic acid sulfimide are obtained.

Example 4

The procedure is as in Example 1, but the starting material used is 7.7 g of N-butylformamide instead of N-methylformamide. 14.6 g of butyl-carbamoyl-benzoic acid sulfimide are obtained, mp. 134-136 ° C. The evaporation residue of the chloroform solution is washed twice with 5 ml of 50% aqueous acetone and thereby another 4.6 g of product are obtained.

Example 5

The procedure is as in Example 1, but instead of N-methylformamide 13.5 g of N-benzyl-35 formamide are used as the starting material. So you can win 15.6 g of benzyl-carbamoyl - benzoic acid sulfimide, mp. 163 ° C. The evaporation residue of the chloroform solution is washed with twice 5 ml of 50% aqueous acetone, and an additional 1.4 g of product can thereby be obtained.

40

Example 6

The procedure is as in Example 1, but instead of benzoic acid sulfimide, 21.8 g of 6-chloro-benzoic acid sulfimide are used. 14 g of N-methyl-carbamoyl-6-45-chloro-benzoic acid sulfimide are obtained.

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Claims (5)

649 541 2nd PATENT CLAIMS 11. Process for the preparation of N-carbamoylbenzoic acid sulfimide derivatives of the general formula (I) ■ CD N -C-KIH-'R O'-Nq in which R represents an alkyl, cycloalkyl or aralkyl group and also alkyl, cycloalkyl or aralkyl groups which are mono- or polysubstituted by alkyl, Rl signifies hydrogen or halogen, characterized in that N-substituted formamides of the general formula (II) R-NHCH O (II) wherein the meaning of R is given above, with a halogenating agent and subsequently with a salt of benzoic acid sulfimide of the general formula (III) formed with an organic or inorganic base, (III) where the meaning of R1 is the same as above. 2. The method according to claim 1, characterized in that oxidative halogenating agent, preferably sulfuryl chloride, is used as the halogenating agent. 3. Process according to claims 1 and 2, characterized in that the reaction is carried out at temperatures between 0 and 60 ° C. 4. Process according to Claims 1 to 3, characterized in that the reaction is carried out in organic solvents, preferably in halogenated aliphatic or aromatic solvents, such as chloroform, dichloromethane, chlorobenzene. 5. Process according to Claims 1 to 4, characterized in that the salts formed with alkali metal or alkaline earth metal hydroxides are used as salts of benzoic acid sulfimide formed with inorganic bases. wherein R represents an alkyl, cycloalkyl or aralkyl group and also alkyl, cycloalkyl or aralkyl groups which are mono- or polysubstituted by alkyl, and 5 R1 denotes hydrogen or halogen. Numerous representatives of the compounds of the general formula (I) are known to have important effects as crop protection agents. The fungicidal and bactericidal activity of the compounds of the general formula (I) which can be used in agriculture is described in U.S.-PS. 3,264,314 and in Japanese Patent No. 71 36, 613, with demonstration of the biological activity of the compounds of the general formula (I) on numerous compounds. In the generally known methods of preparation of the compounds of the general formula (I), phosgene is used. Thus, the compounds of the general formula (I) can be prepared by the direct reaction of the benzoic acid sulfimide with the isocyanate, in which case the isocyanate used can be the cheapest after reaction of the corresponding amine with phosgene can be isolated from the reaction mixture by distillation. The compounds of the formula (I) can furthermore be prepared by reacting the N-chlorocarbonylbenzoic acid sulfimide which can be obtained from phosgene and benzoic acid sulfimide with amines. A common disadvantage of the two methods is that the safety-related warning measures that are absolutely necessary because of the extraordinary toxicity of the phosgene used complicate the technological processes. The isocyanates are also dangerous, poisonous substances with an irritating effect, and their transport and consumption in industry are also desirable as special safety measures. It has now been found that the compounds of the general formula (I) can be prepared in good yield and purity if N-substituted form-40 amides of the general formula (II) R-NHCH O (II) wherein the meaning of R is the same as above, with a halogenating agent and subsequently with a salt of benzoic acid sulfimide of the general formula (III) formed with an organic or inorganic base 50 55