Malonic acids amine-catalyzed condensation reactions

The carbon nucleophiles in amine-catalyzed reaction conditions are usually rather acidic compounds containing two electron-attracting substituents. Malonic esters, cyanoacetic esters, and cyanoacetamide are examples of compounds which undergo condensation reactions under Knoevenagel conditions.115 Nitroalkanes are also effective nucleophilic reactants. The single nitro group sufficiently activates the a hydrogens to permit deprotonation under the weakly basic conditions. Usually, the product that is isolated is... 

The active methylene group of malonic acid readily takes part in condensations with aldehydes. The reaction is catalyzed by ammonia and various amines. Decarboxylation occurs at room temperature or upon heating to 100° to give, in most cases, a mixture of a,/3- and, y-olefinic... 

Reactions of 1,3,5-triazine (1) with amidines, amidine salts or nitriles which have acidic a-methylcne groups are of great preparative value. The base-catalyzed reactions produce 5-substituted pyrimidin-4-amines 3 (R3 = NH2) in good yield. The corresponding imidate or thioamidate hydrochlorides yield 4-alkoxy- and 4-(alkylsulfanyl)pyrimidines, respectively.24 Some other malonic acid derivatives react in a similar manner as shown below. In these cases, a sodium alkoxide is needed as condensing agent.18,25... 

---