Synthesis of 5-Arylidene barbituric acid derivatives using a bis compound of imidazole as an organocatalyst in water

Organocatalysis term is referring to the promotion of the chemical reactions using catalytic amounts of an organic compound which only consist of hydrogen, carbon, nitrogen, oxygen, sulfur and phosphorus atoms without any metallic atoms or ions. The importance of these types of catalysts has been increasing due to their novelty, excellent selectivity and efficiency in the synthesis of more complicated compounds. Although it is not a long time of recognition of these compounds in the separated field in the catalysis, many advantages of their utilization in the organic reactions such as non-sensitive to moisture and oxidants, accessibility, low toxicity and price are unique and remarkable.1-3Imidazole is a five-membered heterocycle containing two non-adjacent nitrogen atoms. This cyclic structure is available in many natural and bio-active compounds such as histidine, histamine and purine. Besides, a few drugs have been reported to have an imidazole ring in their structures.4-5In continuation of our interest in the application of new catalysts in organic synthesis, we decided develop an efficient synthetic processes using green and eco-friendly methods for the synthesis of 5-arylidene barbituric acid derivatives in a Knoevenagel reaction of various types of aldehydes and barbituric acid in the presence a bis compound of imidazole as an organocatalyst (Scheme 1).

Keywords:

Organocatalyst , Bis-imidazole , 5-Arylidene barbituric acid , Water