Patent GB-1041012-A (GB)
Title: New sulphonyl carbamic esters and herbicidal compositions containing them
Inventor: CARPENTER KEITH
IPC: A01N47/24
Filed: 1961-09-08
Abstract: The invention comprises benzene sulphonyl carbamates of the general formula. <FORM:1041012/C2/1> wherein X is a methylamino or an N-methylformylamino group, and alkali metal, ammonium and amine salts thereof.  Specified compounds are methyl p-methylaminobenzenesulphonylcarbamate and methyl p-N-methylformylaminobenzenesulphonylcarbamate.  The compounds may be prepared by (a) reacting a sulphonamide of the general formula <FORM:1041012/C2/2> with methylchloroformate in an aqueous or organic medium in the presence of a basic condensing agent; (b) reacting an isocyanate of general formula <FORM:1041012/C2/3> with methanol, preferably at a temperature between 50 DEG  and 100 DEG  C. in a solvent such as chlorinated aromatic hydrocarbon of high boiling point, for example trichlorobenzene, in the presence of a slight excess of methanol; (c) reacting a sulphonyl halide of general formula <FORM:1041012/C2/4> wherein Hal is a halogen atom, preferably a chlorine atom, with methyl carbamate in the presence of a basic condensing agent such as tertiary amine, preferably pyridine, or an alkali metal derivative, for example potassium carbonate, or alternatively and preferably the carbamate starting material of Formula VII is in the form of an alkali metal, especially sodium, derivative; (d) reacting a urea derivative of general formula <FORM:1041012/C2/5> wherein R1 and R2 are the same or different and are hydrogen atoms or lower alkyl groups, with methanol, by heating the reactants, preferably in an excess of the alcohol as solvent, if desired under pressure and in the presence of an acid catalyst such as sulphuric acid; (e) oxidizing a sulphenyl or sulphinyl compound of general formula <FORM:1041012/C2/6> wherein A is -S- or -SO-, preferably with hydrogen peroxide in a solvent such as acetone, acetic acid, or a mixture of acetic acid and acetic anhydride, if desired at an elevated temperature, e.g. at about 100 DEG  C.; (f) where X in the general Formula I represents a methyl amino group, hydrolysing the corresponding N-lower acyl derivatives of general formula <FORM:1041012/C2/7> wherein Y is an N-methyl-lower acrylamino group, preferably an N-methylacetamido group preferably by aqueous sodium hydroxide; (g) where X in the general Formula I represents an N-methyl formylamino group, formylate the corresponding compound in which X is methylamino, preferably with formic acid or formyl fluoride; (h) when the sulphonyl carbamic ester of Formula I is in the form of an alkali metal derivative, treat the compound of Formula I with a stoichiometric quantity of the alkali metal or alkali metal alkoxide or hydroxide in a suitable solvent; (i) when the sulphonyl carbamic ester of Formula I is in the form of an amine salt, treat the compound of Formula I with a stoichiometric quantity of the amine, which may, for example, be diethanolamine, triethanolamine, octylamine or morpholine; (j) when the sulphonyl carbamic ester of Formula I is in the form of an ammonium salt, treat a solution of the compound of Formula I in a solvent such as methanol with gaseous ammonia. In an example, N-methylformanilide is reacted with chlorosulphonic acid to give p-N-methylformylaminobenzenesulphonylchloride which reacted with ammonia gives p-N-methylformylaminobenzenesulphonamide. To a mixture of the latter with anhydrous potassium carbonate and acetone is added methylchloroformate to give methyl p-N-methylformylaminobenzenesulphonylcarbamate. Other examples are given.ALSO:Herbicidal compositions comprise as active ingredients at least one benzenesulphonylcarbamate of the general formula <FORM:1041012/A5-A6/1> wherein X represents a mono-loweralkylamino group, a di-loweralkylamino group or an N-loweralkylformylamino group, and R represents a methyl, ethyl, allyl or 2-methoxyethyl group, and alkali metal, ammonium and amine salts thereof together with one or more compatible diluents suitable for use in herbicidal compositions.  Specified active ingredients are methyl p-methylaminobenzenesulphonylcarbamate, methyl p-N-methylformylaminobenzenesulphonylcarbamate.  The compositions preferably contain a wetting, dispersing or emulsifying agent, and Examples are given.  Examples of solid and liquid diluents are also given.  The compositions may also be in the form of aerosols. There may also be included in the composition adhesives and other herbicidally active compounds such as MCPB [g -(4-chlor-2-methylphenoxy)butyric acid], 2, 4-DB [g -(2, 4-dichlorophenoxy)butyric acid], MCPA (4-chloro-2-methyl-phenoxyacetic acid), 2, 4-D(2, 4-dichlorophenoacetic acid), 2, 4, 5-T(2, 4, 5-tri-chlorophenoxyacetic acid), phenylcarbamates and ureas, for example propham (iso-propyl-N-phenylcarbamate) and chloropropham [iso-propyl-N-(3-chlorophenyl)carbamate], and dalapon (sodium) (sodium a , a -dichloropropionate).