The general procedure for the synthesis of 2,4-dimethoxypyrimidine from 6-chloro-2,4-dimethoxypyrimidine was as follows:
1. 6-Chloro-2,4-dimethoxypyrimidine (0.66 mmol) was dissolved in anhydrous THF (13.2 mL) under argon protection and degassed by drumming argon for a few minutes.
2. Catalyst PdCl2 (dppf) (27.0 mg, 0.033 mmol, 5.0 mol%), TMEDA (0.130 g, 1.12 mmol, 1.7 equiv), and reductant NaBH4 (42.4 mg, 1.12 mmol, 1.7 equiv) were added sequentially.
3. The reaction mixture was stirred at room temperature and under argon atmosphere for an appropriate time.
4. After completion of the reaction, post-treatment was carried out according to standard methods.