N-Benzyl-7-bromo-2-chlorothieno[3,2-d]pyrimidin-4-amine (200 mg, 0.56 mmol) was dissolved in dioxane (2.5 mL) and nitrogen was flown for 20 minutes. After adding Pd(PPh3)4 (41 mg, 0.036 mmol) and tributyl(vinyl)tin (0.18 mL, 0.62 mmol), the mixture was stirred at 120° C. for 7 hours. The reaction mixture was cooled to room temperature and stirred for 2 hours after adding 10% potassium fluoride aqueous solution (5 mL). The reaction solution was filtered with celite and washed with ethyl acetate. The aqueous layer was separated from the organic layer and extracted once more with ethyl acetate. The combined organic layer was concentrated by drying with MgSO4. Purification of the mixture by silica gel chromatography (DCM/MeOH=97/3) yielded the target compound (95 mg, 55% yield).
