Sodium hydride → HCID 178497599, compound

Participants

Reaction Steps

To a stirred suspension of (R)-(+)-3-aminoquinuclidine dihydrochloride (916.0 mg, 4.6 mmol) in dichloromethane (60 mL) was added sodium hydride (368 mg, 9.2 mmol) in portions and the mixture was stirred for 1 h. Acetic acid (0.15 mL) was added dropwise. Then methyl 3-formyl-1H-indazole-4-carboxylate (B1) (776 mg, 3.8 mmol) was added and the mixture continued to stir at room temperature for an additional 2 h. Sodium triacetoxyborohydride (4.2 g, 19.6 mmol) was added in one portion and stirring was continued overnight at room temperature. The solvent was removed under reduced pressure, and the crude material was purified by column chromatography (silica gel, 90:10:1 dichloromethane/methanol/concentrated ammonium hydroxide) to afford (R)-methyl 3-((quinuclidin-3-ylamino)methyl)-1H-indazole-4-carboxylate as a brown solid (2.15 g, quant. yield): 1H NMR (500 MHz, CDCl3) δ 7.80 (dd, J=7.2, 0.7 Hz, 1H), 7.68 (dd, J=8.4, 0.7 Hz 1H), 7.36 (dd, J=8.3, 7.3 Hz, 1H), 4.30 (d, J=14.2 Hz, 1H), 4.25 (d, J=14.2 Hz, 1H), 3.96 (s, 3H), 3.28-3.25 (m, 1H), 3.12-3.07 (m, 1H), 2.99-2.91 (m, 4H), 2.73-2.69 (m, 1H), 2.19-2.12 (m, 1H), 2.04-2.00 (m, 1H), 1.80-1.74 (m, 1H), 1.65-1.57 (m, 1H), 1.52-1.46 (m, 1H). MS (ESI+) m/z 315 (M+H)

Provenance & Evidence