Trifluoroacetic acid → 1-(3-methoxy-4-((6-methoxypyridin-3-yl)methoxy)benzyl)-5-(2,7-diazaspiro[3.5]nonan-2-yl)-1H-benzo[d]imidazole

Participants

Reaction Steps

To a stirred solution of tert-butyl 2-(1-(3-methoxy-4-((6-methoxypyridin-3-yl)methoxy)benzyl)-1H-benzo[d]imidazol-5-yl)-2,7-diazaspiro[3.5]nonane-7-carboxylate (0.53 g, 0.88 mmol) in dichloromethane (10 mL) was added trifluoroacetic acid (5.0 mL. 64.90 mmol). The reaction mixture was allowed to stir at room temperature. After 1 h, the mixture was concentrated, and the residue partitioned between 3 M ammonium hydroxide solution and dichloromethane. The phases were separated, and the aqueous phase was extracted with dichloromethane. The combined organic phases were washed with brine, dried over magnesium sulfate, filtered, and concentrated. Chromatographic purification (Combi-Flash, 40 g SiO2 gold column, 1-15% methanol/dichloromethane elute) afforded 0.28 g (64%) of the product as a solid: 1H NMR (400 MHz, CDCl3) δ 8.18 (d, J=2.1 Hz, 1H), 7.80 (s, 1H), 7.65 (dd, J=8.5, 2.4 Hz, 1H), 7.10 (d, J=8.6 Hz, 1H), 6.88-6.79 (m, 2H), 6.78-6.65 (m, 3H), 6.47 (dd, J=8.6, 2.1 Hz, 1H), 5.18 (s, 2H), 5.00 (s, 2H), 3.92 (s, 3H), 3.75 (s, 3H), 3.61 (s, 4H), 2.86-2.78 (m, 4H), 2.54 (b, 1H), 1.82-1.74 (m, 4H) ppm; (M+1)=500.

Provenance & Evidence