1. 5-bromo-2-cyanopyrimidine (221 mg, 1.2 mmol) was dissolved in anhydrous THF (10 mL) under nitrogen protection and cooled to -78 °C. The reaction temperature was reduced to -78 °C by a slow dropwise addition of THF solution of methylmagnesium bromide (3.0 mL, 4.20 mmol, 1.4 M).
2. slowly add THF solution of methylmagnesium bromide (3.0 mL, 4.20 mmol, 1.4 M) dropwise and maintain the reaction temperature at -78 °C.
3. the reaction mixture was stirred continuously at -78 °C for 3.5 hours.
4. Upon completion of the reaction, the reaction was quenched with saturated aqueous NH4Cl solution.
5. The reaction mixture was extracted with EtOAc and the organic layers were combined.
6. The organic layer was dried with anhydrous Na2SO4, filtered and concentrated. 7.
7. Purify the crude product by silica gel column chromatography with an eluent ratio of petroleum ether:EtOAc (1:0 to 0:1).
8. The target fraction was collected and concentrated to give 1-(5-bromopyrimidin-2-yl)ethanone (1.55 mg, 61% yield). 9. The product was analyzed by 1H NMR.
9. The product was characterized by 1H NMR (CDCl3, 500 MHz): δ 9.00 (s, 2H), 2.80 (s, 3H).