反应详情

Methyl 3-oxobutanoate (2 mL, 18.5 mmol) was added dropwise to a solution of sodium methoxide (25% wt in MeOH, 5 mL) and anhydrous MeOH (20 mL). N-methyl thiourea (1.67 g, 18.5 mmol) was added to the reaction mixture. The resulting solution was stirred at reflux for 5 hours. After cooling to room temperature, the solvent was evaporated. The residue was dissolved in water (25 mL), and the solution was acidified to pH 2-3 with concentrated HCl. The solid material was recovered by filtration, washed with water (2×20 mL) and diethyl ether (1×30 mL), and dried in vacuo, affording 3,6-dimethyl-2-sulfanyl-3,4-dihydropyrimidin-4-one (2.16 g, 73% yield). The product was used without further purification.

1. temperatureat reflux for 5 hours
2. customthe solvent was evaporated
3. dissolutionThe residue was dissolved in water (25 mL)
4. filtrationThe solid material was recovered by filtration
5. washwashed with water (2×20 mL) and diethyl ether (1×30 mL)
6. customdried in vacuo