ON THE NITROSATION OF N-MONOSUBSTITUTED 1-NAPHTHYLAMINES - FORMATION OF N-MONOSUBSTITUTED 4-NITROSO-1-NAPHTHYLAMINE DERIVATIVES AND BENZOCONDENSED INDAMINIUM SALTS

By nitrosation of the mineralic acid salts of N-monosubstituted 1-naph thylamines (7) N-monosubstituted N'-hydroxy-naphthoquinone diiminium s alts (9) are formed. These compounds can condense with their naphthyla mine educts 7 to deeply colored N-(4-amino-naphthyl)-substituted napht hoquinone diiminium salts 11 which are available by the reaction of th e mineralic acid salts of N-monosubstituted 1-naphthylamines 7 with on e half equivalent of nitrous acid in acetic acid solution also. The ne w indaminium salts 11 absorb, in contrast to their deprotonated specie s 12 which exhibit intense absorption bands at about 550 nm, in the ne ar infrared region very intensively at about 820 nm.