Step A: Synthesis of 4-(dimethoxymethyl)-2-(methylsulfonyl)pyrimidine
1. 4-(Dimethoxymethyl)-2-(methylsulfonyl)pyrimidine (9.24 g, 46.1 mmol) was dissolved in 150 mL of dichloromethane (DCM) at 0 °C and cooled with stirring.
2. 3-Chloroperoxybenzoic acid (23.87 g, 70% pure, 96.8 mmol) was added in a single addition.
3. The reaction mixture was allowed to warm slowly to room temperature and stirring was continued for 2 hours.
4. Quench the reaction by adding 150 mL of 10% sodium sulfite solution.
5. The mixture was transferred to a separatory funnel to separate the organic and aqueous layers.
6. The organic layer was washed sequentially with 150 mL of 10% sodium carbonate solution (twice) and saturated saline (once).
7. The organic layer was dried with anhydrous magnesium sulfate, filtered, and concentrated in vacuum to remove solvent.
8. The crude product was purified by fast chromatography to afford 10.25 g (96% yield) of the title compound 4-(dimethoxymethyl)-2-(methylsulfonyl)pyrimidine.
1H NMR (400 MHz, CDCl3) δ 8.96 (d, J = 4.9 Hz, 1H), 7.78 (d, J = 4.9 Hz, 1H), 5.34 (s, 1H), 3.46 (s, 6H), 3.38 (s, 3H).
