Synthesis of 2-amino-4,6-dimethoxypyrimidine with dimethyl carbonate as methylating agent

2-amino-4,6-dimethoxypyrimidine (ADM) was prepared from 2-amino-4,6-dihydroxypyrimidine (ADH) in the presence of potassium carbonate and phase transfer catalyst (PTC), with dimethyl carbonate (DMC) instead of conventional toxic reagents (such as haloalkane and dimethyl sulfate, etc.). The best conversion (87.7 %) of ADH and selectivity (40.5 %) toward ADM were achieved under optimized conditions: tetrabutyl ammonium bromide (TBAB) as PTC, n(ADH):n(DMC):n(TBAB):n(K₂CO₃) = 1:5:0.1:3, reaction time = 10 h and reaction temperature = 150 °C.