SHEET SILICATE CATALYZED DEMETHYLATION AND FISCHER-HEPP REARRANGEMENTOF N-METHYL-N-NITROSOANILINE

N-methyl-N-nitrosoaniline (I) undergoes Fischer-Hepp rearrangement in clay microenvironment. Three different types of clays, K10-montmorillo nite, KSF and bentonite clays (we found that the first two are active for this reaction) as well as cation-exchanged K10-montmorillonites ar e employed. In addition to the rearranged product, N-methyl-4-nitrosoa niline (IT), the solid state reaction also yields the denitrosation pr oduct, N-methylaniline, and the denitrosated as well as demethylated p roduct, aniline. When the reaction is studied in various solvents with K10-montmorillonite clay, the rearranged product II is predominant in polar protic solvents. This may be due to the fact that there is a po ssibility of the formation of the corresponding alkyl nitrite in polar solvents which will favour nitrosation. When nitrite traps such as hy drazine, sulphamic acid or sodium nitrite are added in the clay-cataly zed reaction (both in the solid state and in the solvent), the rearran gement is completely stopped. Based on our experimental observations, an intermolecular rearrangement is proposed.