Sodium Dithionite → 5,6-Diamino-1-[2-(1H-benzimidazol-2-yl)ethyl]-2-thioxo-2,3-dihydropyrimidin-4(1H)-one

Participants

Reaction Steps

To 6-amino-1-[2-(1H-benzimidazol-2-yl)ethyl]-2-thioxo-2,3-dihydropyrimidin-4(1H)-one (0.55 g, 1.9 mmol, obtained from Example 12(b)) in acetic acid (5 mL) was added, dropwise, a solution of sodium nitrite (0.15 g, 2.1 mmol) in water (1.3 mL). After 50 min, sodium dithionite (0.67 g, 3.8 mmol) was added and the reaction stirred for 20 min, followed by evaporation of acetic acid in vacuo and addition of water (50 mL). The precipitated solid was collected by filtration, washed with water and dried in vacuo, providing the title compound (0.29 g, 50% yield). This material was used in the next step without further purification. MS (ESI)-m/z 303 (M+1).

Provenance & Evidence