General procedure for the synthesis of 2-amino-5-methoxypyrimidine using 2-chloro-5-methoxypyrimidine as starting material: 2-chloro-5-methoxypyrimidine (0.817 g, 5.65 mmol) and 25% aqueous ammonia solution were added to a microwave reaction vessel. The reaction vessel was sealed and the reaction was heated at 150 °C for 3 hours. After completion of the reaction, the mixture was evaporated to dryness. The resulting crude product was dissolved in dichloromethane/methanol (1:1, v/v) solvent mixture and loaded on silica gel. Purification by fast column chromatography (eluent: 50-100% ethyl acetate in heptane solution with gradient elution) afforded 2-amino-5-methoxypyrimidine as colorless crystals (386 mg, 55% yield).1H NMR (400 MHz, DMSO-d6) δ 8.02 (s, 1H), 6.06 (br s, 1H), 3.71 (s, 3H).
