To a solution of 2-amino-4-ethoxy-6-chloropyrido[3,2-d]pyrimidine (50 mg) in 1,4-dioxane (7 ml) and water (2.5 ml) was added N-(cyclopropyl)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2-thiophenecarboxamide (72 mg), K2CO3 (77 mg) and tetrakis(triphenylphosphine)palladium(0) (13 mg). The reaction mixture was heated to 90° C. for 1 hour. The reaction mixture was extracted with dichloromethane after which the organic layer was concentrated under reduced pressure. The crude product was purified by silica gel flash chromatography, the mobile phase being a 3:97 MeOH/CH2Cl2 mixture, resulting in the pure title compound as a white powder (64 mg, yield: 81%) which was characterized by its mass spectrum as follows: MS (m/z): 356 ([M+H]+, 100).
