The chemistry of indazole and its N-oxide derivatives is very well-known. Indazole derivatives were extensively studied as bioactive compounds, such as anti-aggregatory and vasorelaxant activity by NO release and increase of cGMP levels and anticancer effects, antimicrobial and antiparasitic properties, among others. Recently, the research and development in the medicinal chemistry of these systems have produced compounds with contraceptive activities for men, for the treatment of osteoporosis, inflammatory disorders and neurodegenerative diseases. On the other hand, indazole N-oxide derivatives were poorly studied as bioactive compounds, but recently compounds with antiparasitic properties were produced. In this presentation, recent developments in the chemistry and medicinal chemistry of indazole and its N-oxide derivatives will be reviewed.

The chemistry of furoxans (1, 2, 5-oxadiazole-2-oxides) and benzofuroxans (benzo[1, 2-c]1, 2, 5- oxadiazole-1-oxides) is very well known. These systems are widely used in organic chemistry as intermediate compounds for the synthesis of numerous heterocycles. In the other hand, furoxan and benzofuroxan derivatives were extensively studied as bioactive compounds. They possess remarkable biological activities, such as anti-microbial and anti-parasitic properties, mutagenic, immunosuppressive and anticancer effects, anti-aggregating and vasorelaxant activity, among others. In some cases, molecular mode of action was proposed. Recently, the research and development in the medicinal chemistry of these systems have produced hybrid compounds in which furoxan or benzofuroxan moieties together with a classical drug moieties are present in a single molecule. So, new anti-ulcer drugs, calcium channel modulators and vasodilator derivatives were described and they are currently in study. In this presentation recent developments in the medicinal chemistry of furoxans and benzofuroxans will be reviewed.