94511-17-8Relevant articles and documents
Reaction of 2-acyl-3-aminobenzofurans with hydrazines
Gatta,Settimj
, p. 937 - 943 (2007/10/02)
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 C2-O 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 temperature either the hydrazones or the monomethylhydrazones gave the same related α-azines. Microanalyses, ir, uv, 1H-nmr and ms spectra are in agreement with the proposed structures.