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Facile one‐pot syntheses of new polyfunctional pyrazolyl substituted and pyrazolofused pyridines
Author(s) -
El Latif Fawi M. Abd,
El Rady Eman A.,
Döupp Dietrich
Publication year - 2003
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.5570400107
Subject(s) - chemistry , benzothiazole , piperidine , methylene , benzimidazole , carbon atom , catalysis , acrylate , conjugate , ethyl acrylate , medicinal chemistry , pyridine , organic chemistry , ring (chemistry) , polymer , mathematical analysis , mathematics , monomer
Ethyl 2‐cyano‐3‐(5‐chloro‐1,3‐diphenylpyrazol‐4‐yl)acrylate ( 1 ) undergoes both conjugate addition of a number of methylene‐active ethanenitriles and direct addition of other active methylene donors to the cyano carbon atom. These additions are the starting events of cascades of subsequent reactions eventually forming (i) novel polyfunctional pyrazolyl‐substituted monocyclic pyridines ( 4a , b and 6 ), (ii) 1,3‐benzothiazole and benzimidazole‐fused pyridines ( 11, 13 ) and (iii) pyrazolo[5,4‐ b ]pyridines ( 19b, 20 ) in one‐pot reactions in ethanolic solution containing catalytic amounts of piperidine.