Metal-ammonia reduction and reductive alkylation of naphthalene sulphonamides. A new route to substituted naphthalenes.

Conditions have been found for the successful Birch reduction and reductive alkylation of N-alkyl arylsulphonamides, specifically in the naphthalene series. The derived C-alkylation products smoothly fragment on heating with re-aromatisation, affording a new specific route to 1-substituted naphthalenes starting from the 1-sulphonamides, and to both 2-mono-substituted and 2,4- (or 1,3-) disubstituted naphthalenes from the corresponding 2-sulphonamide.