Butanedione → N-(2,2-dimethoxyethyl)-2-(2-pyrrolidin-1-ylethyl)-2H-indazol-5-amine

Participants

Reaction Steps

To a solution of 2-(2-pyrrolidin-1-ylethyl)-2H-indazol-5-amine (1.14 g, 0.497 mmol) in 62 mL of dry THF was added 2.04 mL of dimethyl glyoxal in ether (45% glyoxal by weight). A slurry of NaBH(OAc)3 (1.66 g, 7.83 mmol) in THF (10 mL) was slowly added via addition funnel over 60 minutes, and the mixture stirred at room temperature for 12 hours, after which an additional equivalent of NaBH(OAc)3 was added. After an additional 12 hours, the mixture was quenched with saturated NaHCO3, filtered, and the solvents removed under reduced pressure. The residue was purified via column chromatography eluting with 5–15% Et3N in EtOAc to provide 650 mg (2.04 mmol) of the title compound. 1H NMR (300 MHz, DMSO-D6) δ ppm 1.55–1.73 (m, 4 H) 2.39–2.49 (m, 4 H) 2.85–2.96 (m, 2 H) 3.05–3.20 (m, 2 H) 3.28–3.33 (m, 6 H) 4.31–4.45 (m, 2 H) 4.48–4.61 (m, 1 H) 5.14–5.32 (m, 1 H) 6.37–6.50 (m, 1 H) 6.74–6.91 (m, 1 H) 7.21–7.42 (m, 1 H) 7.83–8.02 (m, 1 H); MS (ESI) m/z 319 [M+H]+.

Provenance & Evidence