Catalytic hydrogenation of 3‐benzyloxycarbonylaminoazino[1,2‐ x ]‐azin‐4‐ones. A facile access to 3‐amino‐6,7,8,9‐tetrahydro‐4 H ‐pyrido[1,2‐ a ]pyridin‐4‐ones and 3‐Amino‐6,7,8,9‐tetrahydro‐4 H ‐azino[1,2‐ x ]pyrimidin‐4‐ones

By catalytic hydrogenation of 3‐(benzyloxycarbonyl)amino‐4 H ‐pyrido[1,2‐ a ]pyridin‐4‐ones 28 and 29 , and azino[1,2‐ x ]pyrimidin‐4‐ones 32–35, 41 , and 42 , partial saturation of the heterocyclic systems and removal of the benzyloxycarbonyl moiety was observed to give 3‐amino‐6,7,8,9‐tetrahydro‐4 H ‐pyrido[1,2 a ]pyridin‐4‐ones 30 and 31 , and 3‐amino‐6,7,8,9‐tetrahydro‐4 H ‐azino[1,2‐ x ]pyrimidin‐4‐ones 36–39, 43 , and 44 in high yields. The methods represent a simple two step synthesis, starting from heterocyclic α‐amino compounds and methyl (Z)‐2‐(benzyloxycarbonyl)amino‐3‐dimethylaminopropenoate followed by catalytic hydrogenation.