New heterocyclic ring systems--V synthesis and pharmacological activity of 6H-1,3,4-thiadiazolo [3',2':1,2]-5-oxopyrimido [5,4-b] indole derivatives and of 1-phenyl-6H-1,2,4-triazolo [1',5':1,2]-5-oxopyrimido[5,4-b] indole.

As a part of a study on analgesic and antiinflammatory active condensed heterocyclic compounds containing the pyrimidinic ring, a number of 6H-1,3,4-thiadiazolo [3',2':1,2]-5-oxopyrimido [5,4-b]indole and 1-phenyl-6H-1,2,4-triazolo [1',5':1,2]-5-oxopyrimido [5,4-b] indole were synthesized and tested. The results of pharmacological assays are reported and discussed.