A mixture of 2-chloro-9-methyl-6-morpholin-4-yl-9H-purine-8-carbaldehyde (210 mg, 0.79 mmol), 2-cyclopropylbenzimidazole (150 mg, 0.95 mmol), tris(dibenzylideneacetone)dipalladium (44 mg, 0.05 mmol), Xphos (90 mg, 0.18 mmol) and Cs2CO3 (618 mg, 1.90 mmol) in dioxane (3 mL) and DMF (1 mL) was purged with argon then heated at 145° C. for 45 min in a microwave reactor. The reaction mixture was filtered through a pad of celite, washing with EtOAc. The filtrate was concentrated in vacuo and purified by column chromatography (Si—PCC, EtOAc:cyclohexane, 0-75%) affording 2-(2-Cyclopropylbenzoimidazol-1-yl)-9-methyl-6-morpholin-4-yl-9H-purine-8-carbaldehyde as an orange solid (282 mg, 89%). LCMS (Method H): RT 3.79 min, [M+H]+ 436.4
