Nitric Acid → 2-(2-Ethoxy-5-nitrophenyl)-5-methyl-7-cyclopentyl-3H-imidazo[5,1-f][1,2,4]-triazin-4-one

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Reaction Conditions

Reaction Steps

Using an ice-acetone bath, 48.6 ml of trifluoroacetic acid (TFA and 12.1 ml of 70% strength nitric acid are cooled to −10° C., 3.0 g (8.86 mmol) of the compound from example 25A, dissolved in 7 ml of TFA are added dropwise, and the mixture is stirred at 0° C. for 20 hours. The reaction solution is stirred into 400 ml of ice-water and 200 ml of dichloromethane and neutralized using about 200 ml of saturated sodium bicarbonate solution. The aqueous phase is separated off and extracted 3 times with dichloromethane, and the combined organic phases are dried and concentrated. The residue is chromatographed on silica gel using toluene with added ethyl acetate in a gradient from 11 to 60%.

Provenance & Evidence