Synthesis of 7-chloro-and 7-nitro-pyrazoloquinolone derivatives

Abstract

To study the synthesis routeof 7- chloro- and 7-nitro-pyrazoloquinolone derivativeswhich were expected to possess antianxiety activity. The synthesis of 7-chloro- and7-nitro-pyrazoloquinolone derivatives proceeded through 3steps. First, quinoline ring was produced from the reactionof diethyl ethoxymethylenemalonate and aniline or anilinederivatives, followed by thermal cyclization. Then,4-hydroxyquinoline derivatives were chlorinated with thionylchloride to yield 4-chloroquinoline intermediates. Finally,the desired products were achieved by the reaction of 4-chloroquinoline intermediates with phenylhydrazine.Cyclization of the amino group of phenylhydrazine with theester group of quinoline ring occurred at high temperature. Structures of the synthesized compounds were confirmedby IR, ('1)H-NMR,('13)C-NMR and MS data.