Synthesis of N-{5-Oxo-2-thioxo(2,5-dithioxo)hexahydroimidazo-[4,5-d]imidazol-1(2H)-yl}formamides

A synthetic route to novel N -{5-oxo-2-thioxo(2,5-dithioxo)hexahydroimidazo[4,5- d ]imidazol-1(2 H )-yl}formamides, by a tandem N-formylation and ring-contraction reaction of 5,7-disubstituted 3-thioxoperhydroimidazo[4,5- e ]-1,2,4-triazine-6-ones(thiones) with formic acid, has been developed.