Under N2 atmosphere, 5-chloro-N-(3,4-dimethoxyphenyl)thiazolo[5,4-d]pyrimidin-7-amine (100 mg, 0.31 mmol), tert-butyl 4-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzylamino)benzoate (150 mg, crude), Pd(PPh3)4 (30 mg, 0.026 mmol) and Na2CO3 (150 mg, 1.41 mmol) in 5 mL of water was added in 30 mL of 1,4-dioxane. The mixture was stirred at reflux for 18 hours. The solvent was removed under reduce pressure and the residue was purified by silica gel chromatography, eluting with petroleum ether and ethyl acetate (5:1) to give tert-butyl 4-(3-(7-(3,4-dimethoxyphenylamino)thiazolo[5,4-d]pyrimidin-5-yl)benzylamino)benzoate (72 mg, 41%) as a yellow sold. 1H NMR (300 MHz, DMSO): δ 8.87 (s, 1H), 8.54-8.47 (m, 2H), 7.86-7.82 (m, 3H), 7.49-7.28 (m, 2H), 7.27-7.23 (m, 1H), 6.94 (d, 1H, J=8.7 Hz), 6.65-6.62 (m, 2H), 4.49 (s, 2H), 4.16 (s, 3H), 4.13 (s, 3H). LC-MS: 570 [M+H]+, tR=1.83 min. HPLC: 98.31% at 214 nm, 98.91% at 254 nm, tR=8.06 min.
