Oxidation of some 4-substituted N-aminopyridinium salts
Abstract
Oxidation of 4-substituted N-aminopyridinium salts with aqueous bromine yields either the corresponding 1,1′-azopyridinium salts or 1-pyridiniopyridinium salts depending upon the nature of the 4-substituent. Thus N-amination and subsequent oxidation of 4-dimethylamino-, 4-methylphenylamino-, 4-methoxy-, and 4-methyl thio-pyridine yields the corresponding tetrazenes, but similar treatment of 4-t-butyl- 4-methyl-pyridine yields the corresponding 1-pyridiniopyridinium salts.