345227-01-2Relevant academic research and scientific papers
New Rearrangements of Arylhydrazones in Polyphosphoric Acid: Extension to the Thiophene and Indole Series. 5
Fusco, Raffaello,Sannicolo, Franco
, p. 1691 - 1696 (2007/10/02)
The behavior toward polyphosphoric acid of arylhydrazones of a few heterocyclic carbonyl compounds of the thiophene and indole series is described.The phenylhydrazone and 2,6-dimethylphenylhydrazone of ethyl α-thienylglyoxylate gave ethyl 4- and 5-(4-aminoaryl)-α-thienylglyoxylate, arising from two different sigmatropic rearrangements.The N,3,5-trimethylphenylhydrazone of 2-methylindole-3-carboxaldehyde afforded the 4--2-methylindole-3-carboxaldehyde resulting from a sigmatropic rearrangement, while the 2,6-dimethylphenylhydrazone of the same carbonyl compound unexpectedly gave the 3-(4-amino-3,5-dimethylphenyl)-2-methylindole-3-carboxaldehyde generated through a sigmatropic reaction.Chemical evidences are given for the assigned structures.
