Regioselective synthesis of 1,3,5- and 1,3,4,5-substituted pyrazoles via acylation of N-Boc-N-substituted hydrazones
作者:Alessandro Tinarelli、Paolo Righi、Goffredo Rosini、Daniele Andreotti、Roberto Profeta、Simone Spada
DOI:10.1016/j.tet.2010.11.057
日期:2011.1
Acylation of N-Boc-N-methylhydrazones followed by TFA treatment affords regioselective access to substituted pyrazoles. Both regioisomers of 1-methyl-3,5-disubstituted-1H-pyrazoles can be selectively obtained. This procedure can also be employed for the regioselective preparation of fully substituted 1H-pyrazoles.