A strategic approach to the synthesis of novel class of dispiroheterocyclic derivatives through 1,3 dipolar cycloaddition of azomethine ylide with (E)-3-arylidene-2,3-dihydro-8-nitro-4-quinolone

A series of novel dispiroheterocyclic system containing 4-quinolone nucleus are prepared by 1,3 dipolar cycloaddition of azomethine ylides with a newly prepared (E)-3-arylidene-2,3-dihydro-8-nitro-4-quinolone as dipolarophile. The ylide was generated in situ from isatin and sarcosine/1,3-thiazolane-4-carboxylic acid. The regio and stereochemistry of the synthesized product was established by 1H, 13C, 2D NMR techniques and single crystal X-ray analysis. The molecular mechanism of this cycloaddition has been investigated by means of the density functional theory (DFT) method. The experimental results of regioselectivity product of 1,3 dipolar cycloaddition have shown good agreement with the computed Frontier molecular orbital calculation (FMO) and fukui function analysis.