iso-Propoxypyridin-3-amine (1.30 g, 8.60 mmol) was added into a solution of methyl 4-chloro-5-methylthieno[2,3-d]pyrimidine-6-carboxylate (2.295 g, 9.46 mmol), XANTPHOS (0.995 g, 1.72 mmol) and cesium carbonate (3.922 g, 12.04 mmol) in degassed 1,4-dioxane (40 mL). The mixture was degassed under sonnication, tris(dibenzylideneacetone)dipalladium (0.394 g, 0.430 mmol) added and the mixture sonnicated further. The reaction was sealed, heated at 90° C. for 3.0 hours, cooled, filtered and the solid washed with cold 1,4-dioxane. The filtrate was poured into ammonium hydroxide solution and the precipitate collected to yield the title compound as dark yellow solid (2.05 g, 66%).
