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Reaction of 2‐acyl‐3‐aminobenzofurans with hydrazines
Author(s) -
Gatta Franco,
Settimj Guido
Publication year - 1984
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.5570210401
Subject(s) - chemistry , hydrazone , furan , hydrazine (antidepressant) , ring (chemistry) , medicinal chemistry , cleavage (geology) , bond cleavage , dimethylhydrazine , organic chemistry , stereochemistry , catalysis , engineering , medicine , colorectal cancer , cancer , geotechnical engineering , chromatography , fracture (geology)
While 2‐acetyl and 2‐benzoyl‐3‐aminobenzofurans did not react with hydrazine, monomethyl‐ and N,N ‐dimethylhydrazine to give the related hydrazones, their 3‐ N ‐( p ‐toluenesulfonyl) derivatives afforded them smoothly in good yields. Depending upon reaction conditions, products arising from hydrazone cyclization to benzofuropyrazoles and/or from furan ring cleavage at the C2O bond to give 5‐(2‐hydroxyphenyl)pyrazoles were also formed. The formation of these products depends upon hydrazones configuration and is discussed. Only ( E )‐isomers appear to undergo furan ring opening. In acidic media at room temprature either the hydrazones or the monomethylhydrazones gave the same related α‐azines. Microanalyses, ir, uv, 1 H‐nmr and ms spectra are in agreement with the proposed structures.