Synthesis of some diazabicyclic compounds of expected non narcotic analgetic activity

The biologically active 4H-pyrido [1, 2-a] pyrimidin-4-ones [1] including some hexahydro derivatives [2] are non acidic non-steroidal anti-inflammatory agents. Other pyrido [1, 2-a] pyrimidines were reported as analgetic anti-inflammatory agents [3-8]. In a search of analgetic pharmacophore in condensed pyrimidines, the chemistry and analgetic activity of the bioisoster pyrimido-[1, 2-a] azepine [9] 1 was reported. This work found that ester, carbamate, thiosemicarbazide, semicarbazide, urea and acyl urea groups are of special value in the analgetic activity of 1. On the other h and, it was assumed that any changes in the structure of 1, that might add to its analgetic effect, would be beneficial