The present invention relates to a method for preparing an aqueous sulfonimide compound of the formula (Rf
1
—SO
2
) (Rf
2
—SO
2
)NH, wherein Rf
1
et Rf
2
are independently selected from the group comprising: a fluorine atom and groups having 1 to 10 carbon atoms selected from the perfluoroalkyl, fluoroalkyl, fluoroalkenyl and fluoroallyl groups, from a mixture M1 including (Rf
1
—SO
2
)(Rf
2
—SO
2
)NH, Rf
1
SO
2
H and/or Rf
2
SO
2
H, Rf
1
SO
2
NH
2
and/or Rf
2
SO
2
NH
2
, characterized in that said method includes an oxidation step of said mixture M1 using an oxidizing agent in order to obtain a mixture M2 including (Rf
1
—SO
2
)(Rf
2
—SO
2
)NH, Rf
1
SO
3
H and/or Rf
2
SO
3
H, and Rf
1
SO
2
NH
2
and/or Rf
2
SO
2
NH
2
.
本发明涉及一种制备以下公式的含
硫酰亚胺化合物
水溶液的方法: (Rf1—SO2)(Rf2—SO2)NH,其中Rf1和Rf2独立地选自包括
氟原子和1至10个碳原子的
全氟烷基、氟烷基、
氟烯基和
氟烯基的组中,从一个包括 (Rf1—SO2)(Rf2—SO2)NH,Rf1SO2H和/或Rf2SO2H,Rf1SO2NH2和/或Rf2SO2NH2的混合物M1中,其特征在于,所述方法包括使用氧化剂对所述混合物M1进行氧化步骤,以获得包括 (Rf1—SO2)(Rf2—SO2)NH,Rf1SO3H和/或Rf2SO3H,以及Rf1SO2NH2和/或Rf2SO2NH2的混合物M2。