To a stirred mixture of 9H-purin-6-ylamine (130 mg, 0.98 mmol) in DMF (5 mL) under an argon atmosphere was added NaH (60% in mineral oil, 40 mg, 0.98 mmol). After stirring for 10 min at RT, 2-bromomethyl-3-phenyl-1-(toluene-4-sulfonyl)-1H-indole (430 mg, 0.98 mmol) in DMF (10 mL) was added and stirring continued for 15 min. The crude reaction mixture was loaded onto an Isolute® SCX-2 cartridge then washed with MeOH and the product eluted with 2M NH3/MeOH. The product containing fractions were combined and concentrated under reduced pressure. The resulting residue was purified by column chromatography (Si—PCC, gradient 0-10% MeOH in DCM) affording the title compound as a white solid (370 mg, 77%). LCMS (Method C): RT 3.16 min [M+H]+ 495.1.
