7-Nitroindazole is a non-selective inhibitor of NOS isoforms in vitro. However, it shows good anti-nociceptive effects in vivo without affecting blood pressure via inhibition of eNOS. The IC50 values for inhibition of rat nNOS, bovine eNOS, and rat iNOS are 0.71, 0.78, and 5.8 μM, respectively.
yellow powder or Yellow orange solid soluble in DMSO.
7-nitroindazole is a specific inhibitor of neural nitric oxide synthase (nNOS), an enzyme that converts arginine to citrulline and nitric oxide (NO) in neuronal tissue. NO is a key player in the hippocampal long-term potentiation (LTP) and in general cell signaling.
7-Nitroindazole is a heterocyclic small molecule containing an indazole ring that has been nitrated at the 7 position. It is a potent, selective brain inhibitor of mouse cerebellar Nitric Oxide Synthase, a hemoprotein enzyme that, in neuronal tissue, converts arginine to citrulline and nitric oxide (NO).
Sodium salt of the non-selective NOS inhibitor 7-nitroindazole (7-Nitroindazole).
General procedure for the synthesis of 7-nitroindazole from 2-methyl-6-nitroaniline: To a stirred solution of 2-methyl-6-nitroaniline (10 g, 0.065 mol) in acetic acid (470 ml, 47 times the volume) was slowly added an aqueous solution (9 ml) of sodium nitrite (1.54 g, 0.06 mol, 1.1 equiv). The reaction mixture was stirred at room temperature for 30-45 min. The progress of the reaction was monitored by thin layer chromatography (TLC, unfolding agent 30% ethyl acetate/hexane, Rf=0.7). After completion of the reaction, acetic acid was removed by distillation under reduced pressure. The obtained residue was dissolved in ice water (200 ml), the precipitated solid was filtered, washed with cold water and dried under vacuum to afford the target product 7-nitroindazole as a yellow solid (10 g, 98% yield).
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