synthesis of pyrano pyrimidines using by guanidine as a base catalyst in aqueous media

Multi-component reactions (MCRs) achieve significant task in combinatorial chemistry due to the ability to prepare target compounds with more efficiency and atomic economy by the reaction of three or more compounds together in a single step. Moreover, MCRs increase simplicity and synthetic efficiency on the conventional organic transformations.1-2Recently, pyran and substituted 4H-pyrans have attracted wide notices. They perform the major construction blocks of several natural products and form the core of noteworthy compounds are displaying broad biological activities such as; antimicrobial3, antiviral4 activities and antiprolife reation agents.In this research, a mixture of dimethylbarbituric asid(1mmol), malononitril (1mmol) and aldehyde (1mmol) in the presence of guanidine as a base catalyst in queues media at room temperature to afford 7-amino-1,3-dimethyl-2,4-dioxo-5-phenyl-2,3,4,5-tetrahydro-1H-pyrano[2,3-d] pyrmimidine-6-carbonitrile derivatives in high to excellent yields as target products.

Keywords:

Catalyst , Knoevenagel condensation , 1 , 3-dimethylbarbitoric acid , Three- component reaction