An efficient and regiospecific preparation of trifluoromethyl substituted 4-( 1<i>H</i>-pyrazol-1 -yl)-7-chloroquinolines

Abstract

A new series of 4-[3-alkyl(aryl)(heteroaryl)-5-hydroxy-5-trifluoromethyl-4,5-dihydro-1H-pyrazol-1-yl]-7-chloroquinolines, where [alkyl = CH3; aryl = C6H5, 4-CH3C6H4, 4-FC6H4, 4-ClC6H4, 4-BrC6H4, 4-CH3OCgH4, 4-NO2CgH4, 4-biphenyl, 1-naphthyl; heteroaryl = 2-furyl and 2-thienyl] has been regiospecifi-caly obtained from the reaction of 7-chloro-4-hydrazinoquinoline with 4-substituted-l,1,1-trifluoro-4-methoxybut-3-en-2-ones in 61 - 96 % yield. Subsequently, dehydration reaction of 4,5-dihydropyra-zolylquinolines under acid conditions furnished a new series of 4-(3-substituted-5-trifluoromethyl-1H-pyra-zol-1-yl)-7-chloroquinolines in 73 - 96 % yield.