4-(7-bromo-2-chlorothieno[3,2-d]pyrimidin-4-yl)morpholine (3.55 g, 10.6 mmol), (2-Ethenyl)tri-n-butyltin (3.41 mL, 11.7 mmol), Pd(PPh3)4 (613 mg, 0.53 mmol), and 1,4-Dioxane (30 mL, 400 mmol) were combined in a sealed tube and heated at 100° C. 19.5 h. Complete reaction was confirmed by LCMS. Concentrated in vacuo and purified by silica gel chromatography (0 to 50% ethyl acetate/heptanes) on the CombiFlash® Rf system and concentrated in vacuo to give 4-(2-chloro-7-vinylthieno[3,2-d]pyrimidin-4-yl)morpholine (1.18 g, 39.5% yield)
