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Reaction of 4‐hydrazinoquinolines with β‐diketones. Synthesis and spectroscopy ( 1 h, 13 c nmr, ms) of some pyrazolylquinolines
Author(s) -
Singh S. P.,
Tarar L. S.,
Vaid R. K.,
Elguero J.,
Martínez A.
Publication year - 1989
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.5570260340
Subject(s) - chemistry , intramolecular force , pyridine , nuclear magnetic resonance spectroscopy , carbon 13 nmr satellite , carbon 13 nmr , proton nmr , medicinal chemistry , stereochemistry , fluorine 19 nmr
A series of 4‐pyrazolylquinolines have been prepared from 4‐hydrazinoquinolines and β‐dicarbonyl compounds and the previously proposed diazepine structure for the reaction products has been ruled out. A 13 C nmr study established the 3‐position of the methyl group when two isomers were possible. Finally, a careful 1 H nmr study of 2‐ and 4‐pyrazolylquinolines led to the conclusion that intramolecular hydrogen bonds between aromatic (or heteroaromatic) C‐H and pyridine like nitrogens is the factor that determines the conformation of these compounds.