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Azinotriazines. II Cyclizations leading to pyrido[3,4‐ e ] ‐ and [4,3‐ e ]‐ as ‐triazines. Ring interconversion of a pyrido‐as‐triazine 1‐oxide to a pyridotriazole
Author(s) -
Lewis Arthur,
Shepherd Robert G.
Publication year - 1971
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570080110
Subject(s) - chemistry , dehydrogenation , hydrate , ring (chemistry) , hydrazine (antidepressant) , catalysis , medicinal chemistry , oxide , guanidine , triazine , pyridine , derivative (finance) , stereochemistry , organic chemistry , chromatography , financial economics , economics
Treatment of 4‐chloro‐3‐nitropyridine (I) with hydrazine hydrate followed by catalytic reduction gave 3‐amino‐4‐hydrazinopyridine (III). Acid‐catalyzed cyclizations of III and subsequent dehydrogenation gave pyrido[3,4‐ e ]‐ as ‐triazines (V). Treatment of I with guanidine followed by base‐catalyzed cyclization gave 3‐aminopyrido[4,3‐ e ]‐ as ‐triazine 1‐oxide (VII). The 1‐oxide function was removed by reduction and subsequent dehydrogenation gave the 3‐amino derivative (IX). On treatment with hot alkali VII rearranged to a triazolo[4,5‐ c ]pyridine (X). The ultraviolet and nmr spectra of derivatives of the title ring systems are reported.