To a three-neck round bottom flask equipped with over-head mechanic stirrer were added 2-amino-6-ethylamino-4-iodopyrimidine hydrochloride (188.5 g, 0.60 mol), ethyl acrylate (221 mL, 2.0 mol), triethylamine (285 mL, 2.0 mol), DMF (1.3 L), and tetrakis(triphenylphosphine)palladium(0) (Pd(PPh3)4, 31.3 g, 0.027 mol). The reaction mixture was heated to 95° C. and stirred for 3 h (monitored by LC/MS). After reaction completion, the reaction mixture was evaporated about to 1/10 of original volume and partitioned with 500 mL of ethyl acetate and 1000 mL of water. The aqueous layer was extracted with ethyl acetate 5 times. (E)-Ethyl 3-(2-amino-4-(ethylamino)-6-methylpyrimidin-5-yl)acrylate (100 g, 67% yield) was obtained by recrystallization from acetone after evaporation of ethyl acetate. 1H NMR (400 MHz, CD3OD) δ 7.48 (dd, J1=16.0 Hz, J2=4.0 Hz, 1H), 6.20 (dd, J1=16 Hz, J2=4 Hz, 1H), 4.25 (q, J=7.2 Hz, 2H), 3.51 (q, J=7.6 Hz, 2H), 2.39 (s, 3H), 1.3 (t, J=7.2 Hz, 3H), 1.2 (t, J=7.6 Hz, 3H). MS (EI) for C12H18N4O2: 251.3 (MH+).
