Type: Article
Regioselective multicomponent synthesis of fully substituted pyrazoles and bispyrazoles catalyzed by zinc triflate
Journal: Synlett (14372096)Year: 2011/01/01Volume: Issue: 15
DOI:10.1055/s-0030-1261202Language: English
Abstract
A variety of fully substituted pyrazoles were easily prepared through a three-component condensation of aldehydes, arylhydrazines, and ethyl acetoacetate in the presence of catalytic amounts of zinc triflate [Zn(OTf) under solvent-free conditions. Selective synthesis of symmetrical and unsymmetrical bispyrazoles from dialdehydes in high yields can be considered as a notable advantage of this method. © Georg Thieme Verlag Stuttgart · New York.
Author Keywords
aldehydesarylhydrazinespyrazolessolvent-freezinc triflateacetoacetic acid derivativealdehyde derivativearylhydrazine derivativebispyrazole derivativecarboxylic acid derivativedialdehyde derivativediethyl 3,3' (1,3 phenylene) bis(5 methyl 1 phenyl 1h pyrazole 4 carboxylate)diethyl 3,3' (1,4 phenylene) bis(5 methyl 1 phenyl 1h pyrazole 4 carboxylate)ethyl 1 (4 chlorophenyl) 3 [3 [4 (ethoxycarbonyl) 5 methyl 1 para tolyl 1h pyrazol 3 yl]phenyl] 5 methyl 1h pyrazole 4 carboxylateethyl 1 (4 chlorophenyl) 3 [4 [4 (ethoxycarbonyl) 5 methyl 1 phenyl 1h pyrazol 3 yl]phenyl] 5 methyl 1h pyrazole 4 carboxylateethyl 1 (4 chlorophenyl) 5 methyl 3 phenyl 1h pyrazole 4 carboxylateethyl 3 (3 chlorophenyl) 5 methyl 1 para tolyl 1h pyrazole 4 carboxylateethyl 3 (3 chlorophenyl) 5 methyl 1 phenyl 1h pyrazole 4 carboxylateethyl 3 (4 bromophenyl) 5 methyl 1 phenyl 1h pyrazole 4 carboxylateethyl 3 (4 cyanophenyl) 5 methyl 1 para tolyl 1h pyrazole 4 carboxylateethyl 3 (4 cyanophenyl) 5 methyl 1 phenyl 1h pyrazole 4 carboxylateethyl 3 (4 methoxyphenyl) 5 methyl 1 phenyl 1h pyrazole 4 carboxylateethyl 3 [4 [4 (ethoxycarbonyl) 5 methyl 1 para tolyl 1h pyrazol 3 yl]phenyl] 5 methyl 1 phenyl 1h pyrazole 4 carboxylateethyl 3 hexyl 5 methyl 1 phenyl 1h pyrazole 4 carboxylateethyl 5 methyl 1 phenyl 3 (thiophen 2 yl) 1h pyrazole 4 carboxylateethyl 5 methyl 1,3 diphenyl 1h pyrazole 4 carboxylatehydrazine derivativepyrazole derivativesolventtrifluoromethanesulfonic acidunclassified drugzinc triflate