A novel class of antiinflammatory drugs, which are substituted derivatives of the fused tricyclic system 6-hydroxypyrimido [2, 1-flpurine-2, 4, 8 (lH, 3H, 9H)-trione (see, for instance, Table 111), is described. Synthetic procedures and structure determination with the assistance of X-ray crystallography are discussed. Semiempirical molecular orbital calculations are used to investigate the relative stability of the possible isomers and ...
![9-benzyl-1,3-dimethyl-7-[2-(ethylsulfoxy)ethyl]-6-hydroxypyrimido[2,1-f]purine-2,4,8(1H,3H,9H)-trione Structure](https://image.chemsrc.com/caspic/002/102212-67-9.png)
![Pyrimido[2,1-f]purine-2,4,8(1H,3H,9H)-trione,7-[2-(ethylthio)ethyl]-6-hydroxy-1,3-dimethyl-9-(phenylmethyl)- Structure](https://image.chemsrc.com/caspic/040/102212-66-8.png)