Two simple and closely related methods for the preparation of 2-and 4-pyridineazo compounds are described, based upon the reactions of (a) the sodium derivative of 2- aminopyridine with p-nitrosodimethylaniline, and (b) the disodium derivative of nitrobenzene or $-substituted nitrobenzenes with 2-aminopyridine. By these methods, a variety of new azo compounds have been prepared in which the azo linkage is attached to the 2-position of ...