Synthesen von Aminolumazinen

Syntheses of Aminolumazines 6‐aminolumazien 2 (1‐(6‐amino‐2,4,7‐trioxo‐1,2,3,4,7,8‐hexahydropteridin‐8‐yl)‐1‐deoxy‐ D ‐ribitol), a degradation product of russupteridine‐yellow I ( 1 ) has been prepared from l‐deoxy‐l‐(2,4,7‐trioxo‐1,2,3,4,7,8‐hexahydeopteridin‐8‐yl)‐ D ‐ribitol ( 5 ) via the azo compound 6 and its reduction with Sn/HCOOH. Condensation of 5‐amono‐6‐(D‐ribitylamino)uracil ( 8 ) with parabanic acid ( 9 ) has led to ta synthesis of russupteridine‐yellow IV ( 4 ); l‐deoxy‐l‐(2,6,8‐trioxo‐2,4,5,6,7,8‐hexahydro‐l H ‐imidazolo[4,5‐g]pteridin‐4‐yl‐ D ‐ribitol), albeit in low yield.