The present invention relates to a process for preparing sulfuric diamides of the general formula I R1R2N&mdashS(O)2&mdashNH2&emsp&emsp(I) in which R1 and R2 are each independently a primary alkyl radical having from 1 to 8 carbon atoms, a secondary alkyl radical having from 3 to 8 carbon atoms or a cycloalkyl radical having from 5 to 8 carbon atoms, or, together with the nitrogen atom, form a 5- to 8-membered, saturated nitrogen heterocycle which, as well as the nitrogen atom, may have a further heteroatom selected from O and S as a ring member, where the nitrogen heterocycle is unsubstituted or may have 1, 2, 3 or 4 alkyl groups having in each case from 1 to 4 carbon atoms as substituents. The process comprises the following steps: i) the reaction of a secondary amine of the formula II R1R2NH&emsp&emsp(II) &emspin which R1 and R2 are each as defined above with sulfuryl chloride in an inert solvent, especially an aromatic solvent, in the presence of a tertiary amine to give a sulfamoyl chloride of the formula III R1R2N&mdashS(O)2&mdashCl&emsp&emsp(III) &emspin which R1 and R2 are each as defined above, and ii) reaction of the sulfamoyl chloride of the formula III obtained in step i) with ammonia, the sulfamoyl chloride of the formula III being used in step ii) in the form of the solution obtained in step i) in the inert solvent, especially the aromatic solvent.
