| Abstract |
A comparative study of the Knoevenagel condensation of an aromatic aldehyde with an active methylene compound (e.g., malononitrile or ethyl cyanoacetate), using solvent free grindstone conditions and microwave irradiation is reported. Our solvent free approaches led these reactions to proceed faster, more cleanly and in higher yields. Moreover, they also allowed the use of nitrobenzaldehydes, which failed to yield the desired products under traditional and water based approaches. Thus, an efficient procedure for the Knoevenagel condensation of aryl and heteroaromatic aldehydes with malononitrile. using the complex [CdNa2(mu-L-2)](n)center dot 6.34H(2)O or commercial CdO as catalyst under solvent-free and very mild conditions has been developed. (C) 2017 Elsevier B.V. All rights reserved. |
