Weakly basic anion exchange resins are excellent catalysts for promoting condensations between aliphatic aldehyde and cyanoacetic acid. Ketones, with the exception of cyclohexanone, do not react satisfactorily. Aromatic aldehydes condense with cyanoacetic acid at room temperature but aliphatic aldehydes require the use of moderate temperatures. Organic salts of weakly basic anion exchange resins are more effective catalysts for the Knoevenagel reactions than the free amine resin. Different organic acid salts of weakly basic anion exchange resins have varying degrees of effectiveness as catalysts for the low temperature reactions but these differences are minimized when higher reaction temperatures are used.Weakly basic anion exchange resins have been shown to be effective catalysts in promoting the Knoevenagel condensation of aldehydes with ethyl acetoacetate, ethyl cyanoacetate, or diethyl malonate.3 It was also shown that the resin, either as the free amine or as the acetate of the free amine formed

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