Cyclohexanone → HCID 59859849, compound

Participants

Reaction Steps

A solution of 5-bromo-2,3-dihydro-1H-indole (94.0 g, 20.2 mmol), cyclohexanone (4.6 mL, 44.4 mmol) and sodium cyanoborohydride (1.6 g, 25.5 mmol) in methanol (100 mL) was heated at reflux for 16 hours. More cyclohexanone (2.3 mL, 22.2 mmol) and sodium cyanoborohydride (1.6 g, 25.5 mmol) were added. Heating was continued for 1 day. The solvent was evaporated in vacuo, and the residue was treated with ammonium hydroxide in water. The product was extracted into dichloromethane, and dried over sodium sulfate. The solvent was evaporated in vacuo, and the product was purified by flash silica gel chromatography, eluted with ethyl acetate (1% to 2%) in hexane to give an oil, 7.49 g (37%). MS: m/z 280 (MH+). 1H NMR (CDCl3): 1.08-1.20 (m, 1 H), 1.25-1.42 (m, 4 H), 1.64-1.74 (m, 1 H), 1.76-1.88 (m, 4 H), 2.91 (t, 2 H), 3.24-3.32 (m, 1 H), 3.36 (t, 2 H), 6.23 (d, 1 H) and 7.08-7.11 (m, 2 H).

Provenance & Evidence