An efficient, one-pot synthetic protocol toward spirooxindole
derivatives containing 1,4-dihydropyridine-fused 1,3-diazaheterocycle
fragments, a class of biologically active compounds starting from
1,1-bis(methylthio)-2-nitroethylene, 1,n-diamine, isatin, or its
derivatives, and malononitrile is described. The reaction proceeds
in ethanol in the presence of 10 mol% of piperidine as a
basic catalyst under reflux conditions to produce the title compounds
in 74-85% yields.
spirooxindole - 1,4-dihydropyridine - malononitrile - 1,n-diamine - 1,1-bis(methylthio)-2-nitroethylene
- multicomponent reaction