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Synthesis of 5‐oxo‐5 H ‐chromeno[3,4‐ c ]pyridine‐1‐carbonitriles and features of their NMR spectra
Author(s) -
Shkoor Mohanad,
Su HawLih,
Ahmed Suzan,
Hegazy Sarah
Publication year - 2020
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.3826
Subject(s) - chemistry , pyridine , substituent , nitrile , moiety , proton nmr , proton , stereochemistry , medicinal chemistry , organic chemistry , physics , quantum mechanics
Two different methods leading to 5‐oxo‐5 H ‐chromeno[3,4‐ c ]pyridine‐1‐carbonitriles were investigated. Reactions of 3‐aminocrotonirile with substituted salicylaldehydes provided 5‐oxo‐5 H ‐chromeno[3,4‐ c ]pyridine‐1‐carbonitriles with the same substituent on positions 2 and 4 of the system. The reaction of 3‐aminocrotonirile with variety of substituted 3‐acetylcoumarins lead to 5‐oxo‐5 H ‐chromeno[3,4‐ c ]pyridine‐1‐carbonitriles with different substituents on positions 2 and 4. The structures of the products were confirmed by spectroscopic methods. The presence of nitrile moiety in the structures with fixed geometry caused the highly downfield shift of the aromatic proton at position 10 in 1 H NMR spectrum. The electronic factor of the substituents caused variation of this downfield shift.