Sodium borohydride → HCID 59375056, compound

Participants

Reaction Steps

A suspension of 2-acetyl-5-(2,6-difluorophenyl)-2,3,4,9-tetrahydro-1H-carbazole-8-carboxamide (Example 27-1, 30 mg, 0.081 mmol) and sodium borohydride (6.2 mg, 0.163 mmol) in methanol (1 mL) was stirred at rt for 1 h. The mixture was diluted with DCM, washed with NaHCO3 (aq) and water, and dried and concentrated. The residue was purified by preparative HPLC to provide two diastereomers of 5-(2,6-difluorophenyl)-2-(1-hydroxyethyl)-2,3,4,9-tetrahydro-1H-carbazole-8-carboxamide. Each one was partitioned between 1 M aqueous sodium hydroxide and DCM, followed by drying and concentration, to provide the separated racemic diastereomers of 5-(2,6-difluorophenyl)-2-(1-hydroxyethyl)-2,3,4,9-tetrahydro-1H-carbazole-8-carboxamide. The more polar diastereomer (Example 28-1) was a white solid (10 mg, 33%). 1H NMR (400 MHz, chloroform-d) δ 1.26 (d, J=6.59 Hz, 3 H) 1.30-1.43 (m, 1 H) 1.78-1.89 (m, 1 H) 1.97-2.05 (m, J=12.74 Hz, 1 H) 2.14-2.22 (m, 1 H) 2.24-2.35 (m, 1 H) 2.57 (dd, J=16.04, 10.77 Hz, 1 H) 2.81 (dd, J=16.48, 5.05 Hz, 1 H) 3.70-3.79 (m, 1 H) 6.96-7.04 (m, 3 H) 7.32-7.41 (m, 2 H) 10.05 (s, 1 H). Mass spectrum m/z 371.1 (M+H)+. The less polar diastereomer (Example 28-2) was a white solid (8 mg, 27%). 1H NMR (400 MHz, chloroform-d) δ 1.26 (d, J=6.15 Hz, 3 H) 1.34-1.40 (m, 1 H) 1.42-1.53 (m, 1 H) 1.75-1.90 (m, 2 H) 2.24-2.35 (m, 1 H) 2.68 (dd, J=16.26, 10.11 Hz, 1 H) 2.94 (dd, J=16.26, 5.27 Hz, 1H) 3.80 (s, 1 H) 6.96-7.05 (m, 3 H) 7.34-7.40 (m, 2 H) 10.05 (s, 1 H). Mass spectrum m/z 371.1 (M+H)+.

Provenance & Evidence