A mixture of 3-(2-chloro-4-morpholin-4-ylthieno[3,2-d]pyrimidin-6-ylmethylene)azetidine-1-carboxylic acid tert-butyl ester (1.1 g, 2.51 mmol), 2-ethylbenzimidazole (400 mg, 2.74 mmol), tris(dibenzylideneacetone)dipalladium (115 mg, 0.13 mmol), XPhos (240 mg, 0.50 mmol) and Cs2CO3 (1.25 g, 3.84 mmol) in dioxane (25 mL) was purged with argon then heated at 110° C. for 16 h. The reaction mixture was filtered through Celite®, washing with DCM, and the filtrate concentrated in vacuo. The resulting residue was purified by column chromatography (Si—PCC, MeOH:DCM, 0-10%) affording the title compound as an orange solid (1.5 g, quant.). LCMS (method A): RT 3.40 min [M+H]+ 533.4
