Methyl 3-amino-2-thiophenecarboxylate → Thieno(3,2-d)pyrimidine-2,4(1H,3H)-dione

To a solution in which sodium cyanate (5.0 g, 77.0 mmol) was dissolved in water (15.0 mL), methyl 3-aminothiophen-2-carboxylate (6.05 g, 38.4 mmol) dissolved in a mixture solution (90 mL) of 50% glacial acetic acid and water was slowly added dropwise. After stirring for 5 hours at room temperature, thus prepared white precipitate was filtered. The white solid was dissolved in 2.0 N sodium hydroxide solution (90.0 mL). The mixture solution was cooled to 0° C. and acidified using acetic acid. Filtration of thus prepared white solid followed by drying yielded the target compound thieno[3,2-d]pyrimidin-2,4(1H,3H)-dione (5.2 g, 81% yield).

1. additionwas slowly added dropwise
2. filtrationthus prepared white precipitate was filtered
3. dissolutionThe white solid was dissolved in 2.0 N sodium hydroxide solution (90.0 mL)
4. temperatureThe mixture solution was cooled to 0° C.
5. filtrationFiltration of thus prepared white solid
6. customby drying

ORD record

ord-6c1e94244355453bb77413d281dade92

Source dataset

uspto-grants-2013_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08586580B2