反应详情

A mixture of the pyrimidine 18-2 (3.76 g, 21.8 mmol), pivaloyl chloride (10.7 mL, 87 mmol), Et3N (15.2 mL, 109 mmol) and THF (80 mL) were stirred at room temperature for 24 hours. A further 3 mL of pivaloyl chloride and 4 mL of Et3N was added and the mixture stirred for another 24 hours. The solution was poured into saturated Na2CO3, extracted with EtOAc (2×), washed with brine, dried (MgSO4) and filtered through a pad of silica gel. Removal of the solvent afforded an orange solid. Trituration with ether/hexane ˜20:1 and filtration provided the title compound 18-4 as a white solid.

1. stirringthe mixture stirred for another 24 hours
2. extractionextracted with EtOAc (2×)
3. washwashed with brine
4. dry with materialdried (MgSO4)
5. filtrationfiltered through a pad of silica gel
6. customRemoval of the solvent
7. customafforded an orange solid
8. filtrationTrituration with ether/hexane ˜20:1 and filtration