S. Chimichi, Marco Boccalini, Alessandra Matteucci
Sep 22, 2008
Citations
0
Influential Citations
7
Citations
Journal
Tetrahedron
Abstract
Reaction of 3-acyl-4-methoxy-1-methylquinolinones 2 and 5 with hydrazines has been investigated under different experimental conditions. Compound 2 always gave rise selectively and exclusively to the regioisomeric 1,3-disubstituted- or 2,3-disubstituted-pyrazolo[4,3-c]quinolin-4(5H)one (compounds 3a,b or 4a,b, respectively), while reaction of 5 with N-methylhydrazine led to a mixture of pyrazoles 7a and 8a. With N-phenylhydrazine, compounds 7b or 8b were regioselectively obtained. Compound 8a could be selectively synthesized working in solventless conditions. Structural elucidation of all products was independently achieved by NMR spectroscopy.