Urea → Thieno(3,2-d)pyrimidine-2,4(1H,3H)-dione

Participants

Reaction Conditions

Reaction Steps

A solid mixture of methyl-3-aminothiophene-2-carboxylate (76 g, 480 mmol) and urea (189 g, 3140 mmol) was heated, with stirring, to 180° C. for 5 h. The mixture was cooled to 90° C. and water (1000 ml) added. After stirring at room temperature for 16 h, a cream coloured solid was filtered and washed twice with further water. The solid was dried in vacuo at 40° C. to give the title compound in 94% yield, >95% purity. LC-MS m/z=169.0 [M+H]+; RT=1.29 min; LC-MS method 2. 1H NMR: δH (400 MHz, D6-DMSO) 6.90 (1H, d, J=5.5 Hz), 8.04 (1H, d, J=5.5 Hz), 11.10-11.80 (2H, b).

Provenance & Evidence