Electrocatalytic trimerization of N,N′-dialkylbarbituric acids: facile and efficient way to 2′H-5,5′:5′,5″-terpyrimidine-2,2′,2″,4,4′,4″,6,6′,6″-(1H,1′H,1″H,3H,3′H,3″H,5H,5″H)-nonone framework

Electrocatalytic oxidation of N,N′-dialkylbarbituric acids with alkali metal halides as mediators leads to the selective and efficient formation of 2′H-5,5′:5′,5″-terpyrimidine-2,2′,2″,4,4′,4″,6,6′,6″-(1H,1′H,1″H,3H,3′H,3″H,5H,5″H)-nonone frameworks in 50–90% yields as a result of the complex electrocatalytic cascade process. Barbiturates, among them condensed barbiturates such as 2′H-5,5′:5′,5″-terpyrimidine-2,2′,2″,4,4′,4″,6,6′,6″-1H,1′H,1″H,3H,3′H,3″H,5H,5″H)-nonone frameworks are a perspective class of compounds with interesting pharmacological and physiological activity. The application of the effective electrocatalytic cascade method to the formation of medicinally relevant 2′H-5,5′:5′,5″-terpyrimidine-2,2′,2″,4,4′,4″,6,6′,6″-(1H,1′H,1″H,3H,3′H,3″H,5H,5″H)-nonone frameworks is also beneficial from the viewpoint of diversity-oriented large-scale processes and represents novel, facile and environmentally benign synthetic concept for electrocatalytic cascade reaction strategy.

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► The electrocatalytic trimerization of barbituric acids has been found.
► Halides as mediators lead to the selective formation of barbiturate trimers.
► The mechanism of the complex electrocatalytic cascade process is proposed.
► Efficient way to condensed barbiturates was found.
► This catalytic procedure is beneficial from the viewpoint of ‘green chemistry’.