Nitric Acid → HCID 178487855, compound

Participants

Reaction Steps

2-Isopropyl-5-methoxybenzimidazole (50 g) was dissolved in 150 mL TFA and to the mixture was added 5 mL 90% nitric acid. The reaction was stirred overnight, and the solvents removed in vacuo and the residue neutralized to pH 7 with saturated aqueous sodium bicarbonate. The residue was extracted with ethyl acetate (4×100 mL). The combined ethyl acetate fractions were dried over sodium sulfate and concentrated to give a dark residue. Chromatography (3% methanol/methylene chloride) gave 2-isopropyl-4-nitro-5-methoxybenzimidazole as a yellow solid, 24 g. Also obtained was 25 g of 2-isopropyl-5-nitro-6-methoxybenzimidazole.

Provenance & Evidence