General procedure for the synthesis of 2-dimethylaminopyrimidine-5-carbaldehyde from 2-chloropyrimidine-5-carbaldehyde: 2-chloropyrimidine-5-carbaldehyde (412 mg, 2.89 mmol) and triethylamine (Et3N, 482 μL, 3.47 mmol) were dissolved in dioxane (20 mL), followed by the addition of a solution of dimethylamine (Me2NH) in tetrahydrofuran (THF) (1.59 mL, 2.0 M, 3.18 mmol). The reaction mixture was stirred at room temperature for 1 h. After completion of the reaction, the reaction solution was filtered and the solid was washed with dioxane (5 mL). The filtrate was concentrated under vacuum to give 2-dimethylaminopyrimidine-5-carbaldehyde (427 mg, 97.7% yield) as a yellow solid. The product was analyzed by LC-MS (ES+) and showed a molecular ion peak [MH]+ of 152.2. HPLC analysis showed a retention time (Rt) of 4.14 min and a purity of 97.9%.
