Phosphorus oxide (P4O10) → HCID 178462937, compound

Participants

Reaction Conditions

Reaction Steps

5,6-Diamino-1-ethyl-3,3-dimethyl-1,3-dihydro-indol-2-one (5.00 g, 22.80 mmol), and 4-nitro-pyrazole carboxylic acid (3.58 g, 22.80 mmol) were mixed with polyphosphoric acid (22.34 g, 228.0 mmol) and phosphorus pentoxide (1.63 g, 11.4 mmol) and stirred under nitrogen at 150° C. for 6 h. It was quenched with ice water (250 ml) and the resulting suspension was adjusted to pH 5 by adding aqueous ammonia. The crude microcrystalline solid was dissolved in ethyl acetate (400 mL). The organic layer was separated and the aqueous layer was further extracted with ethyl acetate (4×400 mL). After evaporation of the solvent, the crude product was purified by HPLC (High Performance Liquid Chromatography). 5-Ethyl-7,7-dimethyl-2-(4-nitro-1H-pyrazol-3-yl)-5,7-dihydro-1H-imidazo[4,5-f]indol-6-one was obtained as an orange solid (2.47 g, 32%).

Provenance & Evidence