Methanol → lithium (S)-1-(2-(quinuclidin-3-ylamino)ethyl)-1H-indazole-7-carboxylate

Participants

Reaction Steps

To a stirred solution of (S)-methyl 1-(2-(quinuclidin-3-ylamino)ethyl)-1H-indazole-7-carboxylate (370 mg, 1.12 mmol) from Step F above in tetrahydrofuran (5 mL) was added lithium hydroxide monohydrate (142 mg, 3.4 mmol), water (5 mL) and methanol (5 mL). The mixture was stirred at room temperature for 17 h and then concentrated under reduced pressure. The residue was co-evaporated with toluene (2×10 mL) and dried overnight under vacuum to afford crude lithium (S)-1-(2-(quinuclidin-3-ylamino)ethyl)-1H-indazole-7-carboxylate (360 mg, quantitative yield) which was used in the next step without further purification: 1H NMR (500 MHz, DMSO-d6) δ 7.97 (s, 1H), 7.53 (dd, J=8.0, 1.0 Hz, 1H), 7.32 (dd, J=6.5, 1.0 Hz, 1H), 6.96 (t, J=7.0 Hz, 1H), 4.85-4.75 (m, 2H), 4.50-3.50 (br s 2H), 2.90-2.70 (m, 3H), 2.65-2.45 (m, 4H), 2.11-2.07 (m, 1H), 1.68-1.65 (m, 2H), 1.51-1.46 (m, 1H), 1.31-1.26 (m, 1H), 1.10-1.06 (m, 1H); MS (ESI+) m/z 315 (M+H).

Provenance & Evidence