Formamide → 3H,4H-thieno[3,2-d]pyrimidin-4-one

Participants

Reaction Conditions

Reaction Steps

A mixture of methyl 3-aminothiophene-2-carboxylate (1 g, 6.3 mmol) and formamide (2 g) is heated at 240° C. for 10 min. Upon cooling a precipitate appeared. It is dissolved in EtOH and filtered. The filtrate is concentrated under reduced pressure and the residue is purified by silica gel chromatography eluting with 10% MeOH in CH2Cl2 to yield 3H-thieno[3,2-d]pyrimid-4-one (249 mg, 26%) as a solid. 1H NMR (DMSO) δ 12.61 (1H, brs), 8.20 (1H, s), 8.17 (1H, d, J=5 Hz), 7.42 (1H, d, J=5 Hz).

Provenance & Evidence