Abstract

DESIGN, SYNTHESIS, CHARACTERIZATION AND EVALUATION OF THE ANTICANCER PROPERTIES OF OXA-TRIAZACYCLOPENTA [B] PHENANTHRENE DICARBOXYLIC ESTER DERIVATIVES

Sindhu Jose*, Arumugam Sankar, Ajeesh Kumar and Milesh Joseph

Abstract

The wide range of biologic activities of pyrazole makes it one of the most active classes of heterocyclic compounds. Pyrazole derivatives are used extensively to synthesize fused heterocyclic systems. Of these, pyrazalo pyrimidines have high chemical and pharmacologic importance as they structurally mimic biogenic purines. Here we describe the synthesis of quadracyclic regioisomers obtained from the cyclocondensation of ethyl 5-amino-1H-pyrazole-4-carboxylate and (7-chloro-4-oxo-chroman-3-yl)-oxo-acetic acid ethyl ester. Further studies demonstrated the requirement of orthogonal esters such that one of the ethyl groups must be replaced with a methyl group. We synthesized the corresponding quadracyclic regioisomers from methyl 5-amino-1H-pyrazole-4-carboxylate and (7-chloro-4-oxo-chroman-3- yl)-oxo-acetic acid ethyl ester. The present study aimed to characterize the diethyl and two positional ester isomers using HPLC, LCMS, NMR and XRD (crystallization) techniques. The compounds were also screened for their in vitro antiproliferative activity by MTT assay. The anti-proliferative activities of two of the derivative compounds, 6 and 9a, were superior to the currently used anticancer agent paclitaxel.

Keywords: Synthesis, Pyrazole, Dicarboxylic ester, Cyclopenta[b]phenanthrene, Anticancer activity.