Sodium triacetoxyborohydride → HCID 15983189, compound

Participants

Reaction Conditions

Reaction Steps

A solution of methyl 1-[2-(4-aminopiperidin-1-yl)ethyl]-6-methoxy-1H-indole-2-carboxylate (Intermediate 12, 200 mg, 0.60 mmol) and 2,3-dihydro[1,4]dioxino[2,3-c]pyridine-7-carbaldehyde (WO 2004/058144) (100 mg, 0.60 mmol) in dry chloroform/methanol (10 mL, 1:1) was heated over 3 Å molecular sieves at 70° C. for 3 hours. The reaction mixture was cooled to 0° C., sodium triacetoxy borohydride (384 mg, 1.8 mmol) was added and the resulting mixture was stirred at room temperature for 30 minutes. The reaction mixture was filtered through a 0.45 μm membrane and concentrated to dryness under reduced pressure. The residue was taken up in dichloromethane (150 mL) and saturated aqueous sodium hydrogen carbonate solution (30 mL), the aqueous phase back extracted once with dichloromethane (70 mL) and the combined organic phases were dried over sodium sulfate. Chromatography on silica gel with dichloromethane/methanol (5:1), containing 0.125% ammonium hydroxide, gave the free base of the title compound, 239 mg (82% yield), as a colorless solid, mp 130° C.

Provenance & Evidence