Eco-friendly synthesis of novel spiro dipyrazolo [3, 4-b: 4΄, 3΄-e] pyridine

Green synthesis of spiro dipyrazolo[3,4-b: 4΄,3΄-e]pyridine has been reported via one-pot three-component reaction in H2O in the presence of p-TSA as catalyst. Spirooxindoles display a wide range of biological and pharmaceutical activities such as anti-HIV, influenza virus, as inhibitors of the dengue virus and anti-cancer agents.1 Dipyrrazolopyridines are much attractive in the synthetic and medicine target for researchers, owing to their significant fluorescence, biological and pharmacological activities such as anti-cancer agent, hypotensive, cytotoxic and anti-bacterial activity.2,3 In additional, spiro[dipyrazolo[3,4-b΄:4΄,3΄-e]pyridines system although less investigated exhibit also very promising biological agents, due to the spiro rigid framework and the presence of specific functional groups.4As a part of our ongoing interest in this context, we reported a simple and facile synthesis of a new type of spiro dipyrazolo[3,4-b: 4΄,3΄-e]pyridine (4) in the presence of p-TSA as catalyst (Fig. 1) from starting materials pyrazol-3-one derivatives (2), pyrazol-5-amine derivatives (3), and 5,6-dihydro-1H-pyrrolo[3,2,1-ij]quinolone 1,2(4H)-dione (1) in environmentally friendly solvent H2O.

کلیدواژه ها:

eco-friendly ، spirooxindole ، medicinal ، dipyrrazolopyridine