A green protocol for the synthesis of 4,6-disubstituted-3-cyano-2-pyridones from cyanoacetamides and 1,3-dicarbonyl compounds or chalcones using guanidine based ionic liquid as catalyst has been developed. In solventfree conditions at 30°C, [TMG] [Lac] (1,1,3,3-tetramethylguanidine lactate) was found to have the highest catalytic activity among the ionic liquids including [TMG] [Ac] (1,1,3,3-tetramethylguanidine acetate), [TMG] [Pr] (1,1,3, 3-tetramethylguanidine propionate), [TMG][n-Bu] (1,1,3,3-tetramethylguanidine n-butyrate) and [TMG] [TFA] (1,1,3,3-tetramethylguanidine trifluoroacetate). The catalyst was recovered and recycled several times without significant loss of catalytic activity.

A novel, one-pot synthesis of 6-aminouracils via in situ generated ureas and cyanoacetylureas in the presence of an ionic liquid catalyst, 1,1,3,3-tetramethylguanidine acetate, is described. The catalyst can be recycled for five consecutive runs without loss of activity. The mechanism for the ring closure of cyanoacetylurea to 6-aminouracil is also discussed.

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A simple, efficient and environmentally friendly process for synthesis of 3,4-dihydropyrimidinones using a onepot three-component condensation of aromatic aldehydes, b-dicarbonyl compounds, and urea/thiourea is discussed. The cost-effective, new generation ionic liquid (IL), tri-(2-hydroxyethyl) ammonium acetate was used as both solvent and catalyst. The reactions were carried out using both conventional heating and microwave energy. Application of IL technology with microwave energy represents an attractive and rapid alternative to the conventional acidÁbase catalyzed thermal processes.

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