New Indazole Compounds Derived from Ethyl-4-Hydroxy-4'-Substituted-Cyclohexen- 6- One- Carboxylate: Synthesis and Biological Activity

Abstract

The work involves synthesis of new compounds: Schiff bases [VIII] _a-c, pyrazoles[V]_a-c, starting with chalcones [I]_a-c. 4- Hydroxyacetophenone was reacted with benzaldehyde , anysaldehyde and  tolyaldehyde  in basic medium to give three chalcones[I]_a-c compounds by Claisen-Schemidt reaction, the chalcones[I]_a-c were reacted with ethylacetoacetate in basic medium to get new compounds[II]_a-c, which were reacted with ethylchloroacetate in basic medium to obtained ester compounds  [III]_a-c.  The condensation of esters[III]_a-c with hydrazine hydrate led to produce accurse pounding  acid hydrazides [IV]_a-c , the reaction of acid hydrazides [IV]_a-c with ethyl aceto acetate led to formation  pyrazoles[V]_a-c , which were reacted with acetyl chloride in basic medium  to get compounds [VI]_a-c the later compound  reacted  with phenyl hydrazine or 2,4 di nitrophenyl hydrazine to led compounds [VII] _a-f .  On the other hand, acid hydrazides [IV] _a-c reacted with 4- substituted benzaldehyde to form Schiff bases [VIII] _a-I. The synthesized compounds were characterized by FTIR, ¹HNMR and Mass spectroscopy (of some of them).

Keywords: Chalcones, Acid hydrazide, Pyrazole, Indazoles, Schiff bases.