2.3- Diaminopyridines, diazotization

N02 diazotate p-choroaniline with subsequent combination of the product with 2,6-diaminopyridine and action of ammine complexes of Cu(II). This results in the formation... 

Tables IX-52 to IX-61 list the physical properties of the diaminopyridines. Miscellaneous reactions, including the oxidation and diazotizations of diaminopyridines, have been reported. 2,6-Diaminopyridine reacts with 2-bromopyridine to give 2-amino-6-(2-pyridylainino)pyridine (IX-194). ...

Amino-2,4,6-triiodobenzoic acid is diazotized and allowed to react with 2,6-diaminopyridine to give 3-(2,6-diamino-3-pyridylazo)-2,4,6-tiiiodobenzoic acid. Diazotization of 6-amino-l,2,3.4-tetrahydrocarbazole followed by treatment with 2,6-diaminopyridine yields IX-198. ... 

A few 3-cyanopyridines have been prepared, in 40-50 per cent yield, by reaction of a 3-pyridyl diazonium salt with potassium cuprocyanide or cuprous cyanide2i8, 755-7 Though 2- and 4-aminopyridines have been converted into 2- and 4-halogenopyridines via the diazonium reaction, the ready reaction of the 2- and 4-pyridyldiazonium ions with nucleophiles present in the solutions in which they are formed makes their use in cyana-tion difficult if not impossible. The difference in ease of diazotization between a 2- and a 3-aminopyridine permits the conversion of 2,5-diaminopyridine into 2-amino-5-cyanopyridine by diazotization in dilute acid is. The easier diazotization (p. 359) of 4-aminopyridine 1-oxides and the greater stability... 

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