Sodium hydride → methyl 1-methyl-3-((8-methyl-8-azabicyclo[3.2.1]octan-3-ylamino)methyl)-1H-indazole-4-carboxylate

Participants

Reaction Steps

Sodium hydride (60%) (0.19 g) was added in portions to a solution of 8-methyl-8-azabicyclo[3.2.1]octan-3-amine dihydrochloride and stirred at ambient temperature for 1 h. To the reaction mixture, methyl 3-formyl-1-methyl-1H-indazole-4-carboxylate (0.41 g, 1.9 mmol) from Step A of Example 6 in 1% acetic acid in dichloromethane (50 mL) was added and stirred at ambient temperature for 3 h. Sodium triacetoxyborohydride (1.2 g, 5.6 mmol) was added, and the resulting suspension was stirred for 16 h at ambient temperature. The solvent was removed under reduced pressure, and the crude material purified by column chromatography (silica gel, 10:1:0.1 dichloromethane/methanol/concentrated ammonium hydroxide) to afford methyl 1-methyl-3-((8-methyl-8-azabicyclo[3.2.1]octan-3-ylamino)methyl)-1H-indazole-4-carboxylate (0.54 g, 100%) as a yellow oil: 1H NMR (300 MHz, CDCl3) δ 7.75 (d, J=7.5 Hz, 1H), 7.53 (d, J=8.5 Hz, 1H), 7.38 (t, J=6.0 Hz, 1H), 5.49 (s, 1H), 4.26 (s, 2H), 4.04 (s, 3H), 3.96 (s, 3H), 2.99-2.89 (m, 1H), 2.45 (s, 3H), 2.10-1.85 (m, 6H), 1.74-1.62 (m, 4H); LC/MS (ESI+) m/z 343 (M+H).

Provenance & Evidence