Novel Stereoselective Oximes: Their Synthesis and Anti-leishmanials Evaluation

Background: Novel oximinoethers of indanones / aryloxy indanones were designed, synthesized and evaluated in vitro as antileishmanials against Leishmania donovani. Most of the synthesized compounds (5-12) exhibited 100% inhibition at 10 μg/mL against promastigotes and six compounds (5, 6, 7, 9, 11 and 12) exhibited 100% inhibition at 10 μg/mL with an IC50 in the range of 1.65-4.98 μg/mL against amastigotes. Among all, compounds (5-8 and 11) with monochloro, dichloro and fluoro group on aryloxy moiety exhibited excellent in vitro inhibition, thus providing new structural scaffold that can be further optimized to new antileishmanials agents. Methods: In this we were prepared stereo selective oximes. We explored green synthetic method that is replacing DMF as water. Results: The compounds used in the present study were prepared utilizing previously developed methodology for Mannich-aldol reaction. The synthetic route for the preparation of (E)-2-Imidazol-1- ylmethyl-indan-1-one O-benzyl-oximes 5-8 and aryloxy oximes alkyl azoles of indanone 13 and 14 and 9-12 is outlined in (Scheme 2-4). Earlier, the Mannich-aldol-type reaction is described between ketone, paraformaldehyde and azoles using L-proline as an organic catalyst to yield the 2-hydroxymethyl-2- imidazol-1-ylmethyl-indan-1-one (2). However, we modified the reaction conditions in a green manner by replacing organic toxic solvent DMF to water, reducing temperature and source of Imidazole to yield the same intermediate in excellent yields. We have utilized this intermediate (2) for the synthesis of designed molecules (Prototype I-II) for antileishmanial study. Conclusion: We have designed and synthesized the novel azoles with aryloxy and oximino functions making use of our developed methodology of the water mediated Mannich-aldol-type adducts. The preliminary investigations of biological results revealed that, these compounds have potential as antileishmanial agents and has opened a new avenue for further exploration.