Acetic Acid → 7,8-Dihydro-1H-thiopyrano[3,2-d]pyrimidine-2,4(3H,6H)-dione

Participants

Reaction Steps

To a suspension of 2-(ethylthio)-7,8-dihydro-3H-thiopyrano[3,2-d]pyrimidin-4(6H)-one (4.5 g, 19.7 mmol) in water (20 mL) was added 3.0 mL of conc. HCl and 6.0 mL of AcOH. The mixture was heated to reflux and stirred overnight. The reaction was cooled and the solid that formed was collected by filtration, washed with water and methanol, evaporated and dried to obtain 7,8-dihydro-1H-thiopyrano[3,2-d]pyrimidine-2,4(3H,6H)-dione as a white solid (2.6 g, 72%). Without further purification, the crude product was used directly in the next step.

Provenance & Evidence