Talik, Tadeusz published the artcileOn the reactions with nitrous acid of certain derivatives of 4-aminopyridine, substituted in position 2 or 2 and 6. III, Computed Properties of 18437-58-6, the publication is Roczniki Chemii (1959), 387-96, database is CAplus.
cf. C.A. 52, 5407b. It was established that 2-methyl-, 2,6-dimethyl-, and 2,6-dichloro-4-aminopyridine can be diazotized like aromatic compounds, in spite of the fact that the NH2 group is bound in the position 4. The following products of reactions of the diazonium salts were prepared: 4-iodo-(m. 43°, yield 29.6%); 4-chloro-, (25.5%; picrate m. 203°); 4-bromo-, (37.7%, b. 180-1°; picrate m. 184°), and 4-cyano-2-methylpyridine (8.2%, b. 201° m. 45°; picrate m. 161°). 2-Methyl-4-pyridinocarboxylic acid (64.6%, m. 292°), 4-iodo-(19.6%, m. 99°; picrate m. 192°), 4-chloro-(21.5%; picrate m. 167°), 4-bromo-(42.6%, b. 194°; picrate m. 178°), 4-thiocyano-(17.85%, m. 63°; picrate m. 182°), and 4-cyano-2,6-dimethylpyridine (13.9%, m. 81°; picrate m. 174°). 2,6-Dimethyl-4-pyridinocarboxylic acid (m. 281°), 4-hydroxy-(65.4%, m. 196°), 4-iodo-(39.56%, m. 160°), 4-bromo-(35.84%, m. 95°), 4-cyano-2,6-dichloropyridine (m. 95°), and 2,4,6-trichloropyridine (30.1%, m. 32°). The substitution of diazonium by the CNS group was possible only in the case of diazonium salt of 2,6-dimethyl-4-aminopyridine.
Roczniki Chemii published new progress about 18437-58-6. 18437-58-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 4-Amino-2-picoline, and the molecular formula is C17H20ClN3, Computed Properties of 18437-58-6.
Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem