A mixture of (S)-1-[1-(cis-3-benzyloxycyclobutyl)-6-fluoro-1H-benzoimidazol-2-yl]ethylamine (310 mg, 0.91 mmol), 6-chloro-9-(tetrahydropyran-2-yl)-9H-purine (219 mg, 0.91 mmol) and DIPEA (0.81 mL, 4.57 mmol) in IPA (5 mL) was heated at 90° C. in a sealed vial for 16 h. After cooling to RT, the reaction mixture was concentrated in vacuo, dissolved in DCM and loaded onto an Isolute® SCX-2 cartridge which was washed with DCM, MeOH followed by 2M NH3/MeOH. The product containing fractions were combined and concentrated in vacuo. The resulting residue was purified by column chromatography (Si—PCC, gradient 0-10% 2M NH3/MeOH in DCM) to afford the title compound as a glassy white solid (320 mg, 76%). LCMS (Method B): RT 2.76 min [M+H]+ 458. 1H NMR (CDCl3, 400 MHz): δ 8.48 (1H, s), 7.95 (1H, s), 7.71-7.58 (2H, m), 7.42-7.35 (5H, m), 7.07-6.90 (2H, m), 5.95 (1H, s, br), 4.97-4.80 (m, 1H), 4.52 (2H, s), 4.05-3.92 (1H, m), 3.01-2.86 (2H, m), 2.81-2.64 (1H, m), 1.75 (3H, d, J=6.85 Hz).
