Synthesis of new spirooxindole derivatives through 1,3-dipolar cycloaddition of azomethine ylides and their antitubercular activity

Non-stabilized azomethine ylides, generated in situ from isatin derivatives and l-proline, have been reacted with (E,E)-1,3-bis(arylidene)indan-2-ones as dipolarophiles in a 1,3-dipolar cycloaddition reaction. Novel functionalized dispiroheterocyclic compounds were obtained with low diastereoselectivity and the regiochemical outcome of the cycloaddition reaction was confirmed by single crystal X-ray analysis. The compounds were investigated by in vitro screening against Mycobacterium tuberculosis (MIC) using the agar dilution method and displayed good activities.