Acetic acid (65 μl, 0.95 mmol) and sodium triacetoxyborohydride (200 mg, 0.95 mmol) were added to a solution of 2-(1-amino-propyl)-3-benzyl-3H-pyrrolo[2,1-f][1,2,4]triazin-4-one (Example 26, 180 mg, 0.64 mmol) and cyclohexanone (62 mg, 0.64 mmol) in 1,2-dichloroethane (5 mL). The mixture was stirred for 4 h at room temperature concentrated under reduced pressure and the residue partitioned between ethyl acetate and saturated sodium bicarbonate. The organic phase was separated, dried (MgSO4) and concentrated to give the title compound (211 mg, 91%) as a white solid: 1H NMR (DMSO-d6) δ 0.69–1.19 (m, 10H), 1.38–1.89 (m, 6H), 1.99 (m, 1H), 3.63 (m, 1H), 4.82 (m, 1H), 5.80 (m, 1H), 6.55 (s, 1H), 7.06 (s, 1), 7.15 (m, 2H), 7.22–7.35 (m, 4H).
