Hydrochloric Acid → HCID 1284950, compound

Participants

Reaction Steps

Urea (1.20 g, 0.0200 mol) and 3,4-diaminobenzoic acid (3) (3.04 g, 0.0200 mol) in pentan-1-ol (10 mL) was vigorously stirred and heated to reflux under a nitrogen atmosphere. The heating was discontinued after 4 hours and on cooling to room temperature, water (30 mL) was added. The pH was adjusted to 1 with conc. HCl. The resultant dark solid was filtered off, washed with further water (2×20 mL) and dried to give 3.00 g (84% yield) of benzimidazol-2-one-5-carboxylic acid (4) as a black powder,

Provenance & Evidence