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An unusual arylation of 4‐oxo‐3,4‐dihydropyrimido[4,5‐ b ]quinoline
Author(s) -
Campaigne E.,
Randau 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.5570080120
Subject(s) - chemistry , quinoline , chlorine , pyridine , ring (chemistry) , chlorine atom , medicinal chemistry , stereochemistry , combinatorial chemistry , organic chemistry
Treatment of 4‐oxo‐3,4‐dihydropyrimido[4,5‐6 ]quinoline (II) with phosphorus oxychloride and a dialkylaniline resulted in the introduction of a p ‐dialkylaminophenyl group at position‐5, and reduction of the central (pyridine) ring, as well as substitution of oxygen by chlorine at po‐sition‐4, forming compounds considered to be 4‐chloro‐5‐( p ‐dialkylaminophenyl)‐5, 10‐dihydro‐pyrimido[4,5‐6 ]quinolines (XV). Several 4‐oxo‐3,4‐dihydropyrimido[4,5‐ b ]quinolines having phenyl substituents at position‐5 were synthesized unequivocally, and could be readily reduced to the corresponding 4‐oxo‐5‐phenyl‐3,4,5,10‐tetrahydropyrimido[4,5‐6]quinolines, and the 4‐oxo group replaced by chlorine, in the usual manner, leading to compounds related structurally to XV. Comparison of the chemical and physical properties of these compounds established the structure of XV, and a mechanism which rationalizes the formation of XV from II is presented.