5-(4,5-dimethyl-1,3-thiazol-2-yl)-3-(phenylcarbonyl)-2,4(1H,3H)-pyrimidinedione (Prep 16, 80 mg, 0.244 mmol), K2CO3 (33.8 mg, 0.244 mmol), TBAI (9.03 mg, 0.024 mmol) and 3-bromo-1,1-bis(methyloxy)propane (0.033 mL, 0.244 mmol) in dry N,N-Dimethylformamide (DMF) (1.5 mL) were stirred in a closed vial at rt for 2 days then it was left standing at rt over the weekend. The mixture was diluted with EtOAc (20 mL) and washed with small portion of ice-water (3×1 mL). The organic was dried (Na2SO4, rotaevaporator) to afford a crude (95 mg) that was purified by silica chromatography, eluting with Cyclohexane:EtOAc 100:0 to 50:50 to afford the title compound as a white solid (42 mg).
