The present invention relates to a compound of the formula (I) wherein R1 is an unsubstituted or substituted hydrocarbon radical having a total of 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, R2 is an unsubstituted or substituted hydrocarbon radical having a total of 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, or the group NR1R2 is a heterocyclic ring having 3 to 8 ring atoms which is unsubstituted or substituted and contains the nitrogen atom of the group NR1R2 as ring heteroatom and may also contain one or two further ring heteroatoms from the group consisting of N, O and S, and Q is H or a cation. The compounds of the present invention can advantageously be used for the preparation of sulfonylureas and their precursors such as sulfochlorides or sulfonamides.