Premium
Regioselective synthesis of some novel pyrazoles, isoxazoles, pyrazolo[3,4‐ d ]pyridazines and isoxazolo[3,4‐ d ]pyridazines pendant to benzimidazole
Author(s) -
Shaaban Mohamed R.,
Farag Ahmad M.,
Saleh Tamer S.,
Osman Fayez H.
Publication year - 2007
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.5570440127
Subject(s) - chemistry , pyridazine , isoxazole , regioselectivity , benzimidazole , hydrazine (antidepressant) , nitrile , pyrazole , hydrate , enone , cycloaddition , medicinal chemistry , organic chemistry , stereochemistry , catalysis , chromatography
2‐Acetyl‐1‐methyl‐1 H ‐benzimidazole reacts with dimethylformamide‐dimethyl‐acetal (DMF‐DMA) to afford the corresponding E ‐1‐(1‐methyl‐1 H ‐benzimidazol‐2‐yl)‐3‐ N,N ‐dimethylaminoprop‐2‐enone. The latter compound reacts regioselectively with some nitrilimines and nitrile oxides to afford the corresponding pyrazole and isoxazole derivatives, respectively. These reaction products react with hydrazine hydrate to give the novel pyrazolo[3,4‐ d ]pyridazine and isoxazolo[3,4‐ d ]pyridazine derivatives, respectively.