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Preparation of NH‐ pyrazoleacetic acid anilides from trilithiated acetoacetanilide, select aromatic esters, and hydrazine
Author(s) -
Smith Ellyn A.,
Potter Chandra,
Kennedy Zachary C.,
Puciaty Andrew J.,
AcevedoJake Amanda M.,
Hersey Stephen D.,
Metz Clyde R.,
Pennington William T.,
VanDerveer Donald G.,
Beam Charles F.
Publication year - 2010
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.285
Subject(s) - chemistry , regioselectivity , lithium diisopropylamide , hydrazine (antidepressant) , organic chemistry , aryl , medicinal chemistry , catalysis , deprotonation , ion , alkyl , chromatography
Acetoacetanilide was trilithiated with excess lithium diisopropylamide to form a reactive trianion‐type intermediate. This was followed by a regioselective Claisen‐type condensation of the trilithiated intermediate with a variety of aromatic esters to afford new C‐ acylated intermediates, 3,5‐diketopentane‐carboxanilides, that were not isolated but immediately condensed‐cyclized with hydrazine to afford the NH ‐pyrazoleacetanilides, 5‐aryl‐1 H ‐pyrazole‐3‐acetanilides, before these C ‐acylated intermediates had an opportunity to rearrange to anilino‐pyranones, 4‐anilino‐6‐aryl‐2 H ‐pyran‐2‐ones. J. Heterocyclic Chem., 2010.