Synthesis and pharmacological properties of 2-nitro-3-substituted-amino benzo[b]thiophenes and 1-substituted benzothieno[2,3-d]imidazoles.

The synthesis of 1-substituted benzothieno[2,3-d]imidazoles and their most suitable synthesis precursor 2-nitro-3-substituted-amino benzo[b]thiophenes is reported. Most of these latter compounds show analgesic and antiinflammatory activities sometimes comparable to those of phenylbutazone with less toxicity and gastric lesivity.