C(O[CH:4]=[C:5]([CH:8]([CH3:10])[CH3:9])[CH:6]=O)C.[NH2:11][C:12]([NH2:14])=[O:13].Cl.[OH-].[Na+]>C(O)C>[CH:8]([C:5]1[CH:6]=[N:11][C:12](=[O:13])[NH:14][CH:4]=1)([CH3:9])[CH3:10]A mixture of 3-ethoxy-2-isopropylprop-2-enal (ref. Menicagli, R. et al. Tetrahedron 1987, 43, 171–177) (250 mg, 1.76 mmol) and urea (250 mg, 4.16 mmol) in ethanol (2.5 ml) was treated with concentrated HCl (0.5 ml) and heated to reflux for 1 hour. Upon cooling, the reaction mixture was neutralized with 1N NaOH (0.6 ml) and extracted with chloroform. The organic layer was dried over MgSO4 and concentrated to provide 5-isopropylpyrimidin-2(1H)-one as an off-white solid (0.20 g; 82% yield).
Wird geladen…