Abstract The reaction between arylsulfonyl chlorides and hydrazine has been studied, and it has been found that in the presence of excess hydrazine, the bis-derivatives are produced in small amounts along with monoarylsulfonyl hydrazides. It has been revealed that the reaction of monosulfonyl hydrazides with alkyl bromides in the presence of a base results only in N-alkylation of the sulfamide nitrogen, although the reaction in the presence of HCl ...