Sulfuric Acid → 6-amino-1-(1H-benzimidazol-2-ylmethyl)-2-thioxo-2,3-dihydropyrimidin-4(1H)-one

Participants

Reaction Steps

To a solution of N-(1H-benzimidazol-2-ylmethyl)thiourea (0.85 g, 4.1 mmol, obtained from Example 8(a)) in EtOH (10 mL) was added, dropwise, in portions during 7 h, sodium ethoxide (1M, 16.6 mL, 16.6 mmol) and a solution of ethyl cyanoacetate (1.76 mL, 16.6 mmol) in EtOH (10 mL) while the reaction was stirred at 80° C. After cooling to r.t. water (200 mL) was added followed by 2M sulphuric acid, the mixture was concentrated until precipitation occurred. The formed solid was collected by filtration, washed with water and dried to give the title compound (0.34 g, 30%) as a solid.

Provenance & Evidence