Reaction #47846

Reaction equation

2-Aminothiophene-3-carboxamide

potassium ethylxanthate

→

title compound

Yield 67.8%

2-Thioxo-2,3-dihydrothieno[2,3-d]pyrimidin-4(1H)-one

Yield 67.8%

Solvents

DMF

Conditions

Workup

1. 1
   Temperaturecooled to RT
2. 2
   Concentrationconcentrated on the rotovap under reduced pressure at 90° C
3. 3
   workup.ADDITIONThe residue was diluted with 300 mL of aqueous citric acid (5%)
4. 4
   Temperaturecooled to 0° C.
5. 5
   FiltrationThe tan powder was filtered
6. 6
   Otherdried overnight

Procedure

2-Aminothiophene-3-carboxamide (13 g, 92 mmol) and potassium ethylxanthate (48 g, 275 mmol) were mixed together and added to DMF (300 mL). The resulting mixture was heated to 150° C. for 6 hrs, then cooled to RT and concentrated on the rotovap under reduced pressure at 90° C. The residue was diluted with 300 mL of aqueous citric acid (5%) and cooled to 0° C. and stirred for 30 min. The tan powder was filtered and dried overnight to give (11.5 g) of the title compound MS (ES+): 185 (M+H)+.

Source