Neat chlorosulfonic acid reacts with silica gel to give silica
sulfuric acid in which sulfuric acid is immobilized on the surface of
silica gel via a covalent bond. A combination of silica sulfuric acid
and sodium nitrite in the presence of wet SiO2 was used
as an effective nitrosating agent for the nitrosation of secondary
amines to their corresponding nitroso derivatives under mild and
heterogeneous conditions in excellent yields.
silica sulfuric acid - nitrosation - secondary
amines -
N-nitrosoamines
