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A Convenient Synthesis of Some Pyrazolinone and Pyrazole Derivatives
Author(s) -
Aly ElSaied A.,
Abdo Mohamed A.,
ElGharably Atif A.
Publication year - 2004
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.200400146
Subject(s) - chemistry , pyrazole , sodium azide , reagent , aryl , dimethylformamide , medicinal chemistry , hippuric acid , phenyl isothiocyanate , organic chemistry , urine , biochemistry , alkyl , solvent
A convenient synthesis of some novel 6‐amino‐4‐aryl‐1‐phenyl‐3‐pyridin‐4‐yl‐1,4‐dihydropyrano[2,3‐ c ]pyrazole‐5‐carbonitriles ( 3a,b ) and 5‐chloro‐1‐phenyl‐3‐pyridin‐4‐yl‐1 H ‐pyrazole‐4‐carbaldehyde ( 4 ) is described. Compound 4 was obtained by the reaction of 2‐phenyl‐5‐pyridin‐4‐yl‐2,4‐dihydropyrazol‐3‐one ( 1 ) with dimethylformamide and phosphorus oxychloride under Vilsmeier‐Haack reaction conditions. Compound 4 was subjected to react with different reagents such as hippuric acid, sodium azide and aromatic ketones to afford 4‐(5‐chloro‐1‐phenyl‐3‐pyridin‐4‐yl‐1 H ‐pyrazolo‐4‐ylmethylene)‐2‐phenyl‐4 H ‐oxazol‐5‐one ( 5 ), 5‐azido‐1‐phenyl‐3‐pyridin‐4‐yl‐1 H ‐pyrazol‐4‐carbaldehyde ( 8 ) and 1‐aryl‐3‐(5‐chloro‐1‐phenyl‐3‐pyridin‐4‐yl‐1 H ‐pyrazol‐4‐yl)propenones ( 12a,b ), respectively. The latter compounds were also prepared via Michael reaction by treatment of compound 1 with some different chalcones.