ChemInform Abstract: New Heterocyclic Ring Systems. Part 5. Synthesis and Pharmacological Activity of 6H-1,3,4-Thiadiazolo(3′,2′:1,2)pyrimido(5,4-b)indol-5-one Derivatives and of 1-Phenyl-6H-1,2,4-triazolo(1′,5′:1,2)pyrimido-(5,4-b)indol-5-one.

ChemInform Abstract

Cyclocondensation of the thiadiazole (II) with the indole derivative (I) leads to the formation of the fused oxopyrimidine (III). Sulfuration of (IIIa) with Lawesson's reagent gives the corresponding thioxopyrimidine (IV). The indole derivative (VI), obtained from (I) and phenyl isothiocyanate (V), reacts with hydrazine hydrate (VII) to yield the pyrimidoindolone (VIII) which gives the fused triazole (X) upon treatment with ethyl orthoformate (IX). The compounds (III), (IV), and (X) have antiinflammatory and analgetic properties.