Ethyl 3,3-diethoxypropionate → 1-(2-Methoxyethyl)-2-thioxo-2,3-dihydropyrimidin-4(1H)-one

Temperature

60 °C

To a stirring solution of 1-(2-methoxyethyl)thiourea (21.38 g, 159.3 mmol) and ethyl 3,3-diethoxypropanoate (46.5 mL, 239.0 mmol) in MeOH (300 mL) was added a freshly prepared solution of 0.96N sodium methoxide in MeOH (250 mL, 239.0 mmol) dropwise over 30 minutes at room temperature under argon. The reaction mixture was heated to 60° C. for 45 minutes and cooled to room temperature. Solvent was removed under reduced pressure and toluene (250 mL) was added to the residue. The mixture was stirred at reflux for an additional 3 hours and then cooled to room temperature. Water (200 mL) was added and the layers were separated. The aqueous layer was washed with CH2Cl2 (50 mL), neutralized with 2N aqueous HCl and extracted with CH2Cl2 (3×200 mL). The combined organic layers were dried over Na2SO4 and concentrated in vacuo. The residue was recrystallized from i-PrOH (200 mL) to give the title compound (13.3 g, 45%) as a light yellow crystalline solid.

1. temperaturecooled to room temperature
2. customSolvent was removed under reduced pressure and toluene (250 mL)
3. additionwas added to the residue
4. temperatureat reflux for an additional 3 hours
5. temperaturecooled to room temperature
6. additionWater (200 mL) was added
7. customthe layers were separated
8. washThe aqueous layer was washed with CH2Cl2 (50 mL)
9. extractionextracted with CH2Cl2 (3×200 mL)
10. dry with materialThe combined organic layers were dried over Na2SO4
11. concentrationconcentrated in vacuo
12. customThe residue was recrystallized from i-PrOH (200 mL)

ORD record

ord-0d2ae3e7cc554baca0b92e201a03ac42

Source dataset

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08835449B2