Acetic Acid → Ethyl (4-oxo-2-sulfanylidene-1,2,3,4-tetrahydropyrimidin-5-yl)acetate

Participants

Reaction Steps

Sodium ethoxide (6.105 g, 89.71 mmol) was added to absolute ethanol (150 mL) under an atmosphere of nitrogen followed by diethyl-2-formylsuccinate (1105) (crude, 16.5 g) in absolute ethanol (30 mL) and thiourea (6.829 g, 89.71 mmol). The reaction mixture was heated at reflux for 1 hour then cooled to room temperature at which stirring was continued for 16 hours. The volatiles were evaporated under reduced pressure to give a brown oily solid. Cold aqueous acetic acid solution (15%; 120 mL) was added and the resulting mixture was sonicated and then stirred at 0° C. until all the residue was in suspension. The resulting precipitate was collected by filtration. The filter cake was washed with water (100 mL) and dried to give the title compound (I106) (6.31 g, 19% yield over 2 steps) as an off-white solid; 1H NMR (400 MHz, d6-DMSO) δ 7.44 (s, 1H), 4.05 (q, J=7.1 Hz, 2H), 3.28 (s, 2H), 1.17 (t, J=7.1 Hz, 3H). LCMS Method C: rt 2.92 min; m/z 213.0 [M−H]−.

Provenance & Evidence