Synthesis of 2,2′‐bipyrimidine derivatives

A new total synthesis of 2,2′ ‐bipyrimidine derivatives by the direct condensation of 2‐amidinopyrimidinebenzenesulfonate with dicarbonyl compounds is described. The following 2,2′‐bipyrimidines have been prepared: 5‐ethyl‐4,6‐dihydroxy‐2,2′‐bipyrimidine; 5‐ethyl‐4,6‐dichloro‐2,2 ‐bipyrimidine; 4,6‐dihydroxy‐2,2′ ‐bipyrimidine; 5‐ethyl‐4,6‐dimethoxy‐2,2′ ‐bipyrimidine.