A three-component and one-pot reaction for synthesis of 1-(aroyl)3-{6-[3- (aroyl)selenoureido]pyridine-2-yl}selenourea

A three-component and one-pot reaction between pyridine-2,6-diamine and potassium selenocyanate in the presence of aroyl chlorides to afford the 1-(aroyl)3-{6-[3-(aroyl)selenoureido]pyridine-2-yl}selenourea in excellent yields. It is important to make the selenocyanate derivatives first and then to use this to prepare the selenourea derivatives. The present method carries the advantage that not only is the reaction performed under neutral conditions but also that the substances can be mixed without any activation or modification. Alsothis new protocol offers advantages such as mild reaction conditions, easy work-up, and use of an inexpensive and non-toxic catalyst, high yields of biological active products. To a solution of potassium selenocyanate in acetone was added aroyl chloride in acetone. The reaction mixture was stirred at r.t. for 10 min. Pyridine-2,6- diamine in acetone was added to the mixture. The reaction mixture was then stirred for 12h. The progress of the reaction was monitored by TLC. After completion of the reaction, the resulting precipitate was collected by filtration on a Buchner funnel and washed with cold water and recrystallized from EtOH to afford the pure title compounds.