Chemical behaviour of 3‐aminopyridine and of 3,5‐diaminopyridine. Syntheses of (3‐pyridyl)‐pyrazolones

Through conversion of 3‐nitraminopyridine, two x‐nitro‐3‐aminopyridines are obtained in a very small yield. By bromination of 3,5‐bis‐(acetylamino) pyridine, a small yield of a dibromo derivative is obtained. From 3‐amino‐5‐bromopyridine the following compounds are prepared via the diazonium compound: 3‐bromo‐5‐fluoro‐pyridine, 3‐bromo‐5‐iodopyridine, 3‐bromo‐5‐cyanopyridine, and some azo dyestuffs. From (3‐pyridyl)hydrazine and ethyl acetoacetate 1‐(3′‐pyridyl)‐3‐methyl‐pyrazolone‐5 is obtained; from 3‐amino‐5‐bromopyridine, a (bromopyridyl)‐methylpyrazolone is obtained in an analogous manner.