Synthesis and pharmacological evaluation of 4a-methyl-4,4a,5,6-tetrahydrothieno[2,3-h]cinnolin-3(2H)-ones.

A number of 4a-methyl-4,4a,5,6-tetrahydrothieno[2,3-h]cinnolin-3(2H)-one s (3-5) have been synthesized and tested for their pharmacological profile. These were compared with the 8-acetylamino-4, 4a,5,6-tetrahydrobenzo[h]cinnolin-3(2H)one 1 which we reported to be a potent antihypertensive agent. In vivo tests indicated that 3 displayed lower even if still significant levels of antihypertensive activity in respect to the lead compound, while all the new derivatives exhibited lower hypotensive activity. Tricyclic thienocinnolinones 3-5 demonstrated fairly potent plateled antiaggregatory activity.