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Reactions of 4‐(Dicyanomethylene)‐3‐methyl‐1‐phenyl‐2‐pyrazolin‐5‐one Towards Amines and Phenols
Author(s) -
Metwally Saoud A. M.,
El Naggar Galal M.,
Younis Mansour I.,
ElEmary Talaat I.,
Elnagdi Mohamed Hilmy
Publication year - 1989
Publication title -
liebigs annalen der chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0170-2041
DOI - 10.1002/jlac.198919890262
Subject(s) - pyrazolones , chemistry , malononitrile , yield (engineering) , phenols , cyanide , medicinal chemistry , organic chemistry , catalysis , materials science , metallurgy
3‐Methyl‐1‐phenyl‐2‐pyrazoline‐4,5‐dione ( 3 ) condenses readily with malononitrile in refluxing ethanol to yield 4‐(dicyanomethylene)‐3‐methyl‐1‐phenyl‐2‐pyrazolin‐5‐one ( 4 ). Compound 4 readily reacts with aliphatic, aromatic, and heterocyclic amines to yield 4‐substituted (aminocyanomethylene)‐3‐methyl‐1‐phenyl‐2‐pyrazolin‐5‐ones ( 8 ). o ‐Substituted arylamines afford also 4‐substituted (arylcyanomethylene)pyrazolones, which readily cyclize to give the 4‐azolylidene pyrazolones 9a–c . Secondary and tertiary amines and activated phenols condense with 4 by hydrogen cyanide elimination to yield compounds 10a–c and 10a, b , respectively.