Hydrochloric Acid → 1-Oxo-2,3,4,5-tetrahydro-1H-[1,4]diazepino[1,2-a]benzimidazole-8-carboxylic acid

Participants

Reaction Steps

Triethylamine (14.3 g, 141.7 mmol) is added to a solution of the crude 1-(3-aminopropyl)-2-(methoxycarbonyl)-1H-benzimidazole-6-carboxylic acid hydrochloride (20 g, 47.2 mmol) in methanol (100 mL) and reaction mixture is refluxed for 1 h. The reaction mixture is cooled and acidified with 1M HCl. The solvent is evaporated and water is added. The resultant solid is collected by filtration and purified by acid-base neutralization using sodium bicarbonate and conc. HCl to afford the title compound (3.4 g, 30%) as a solid.

Provenance & Evidence