Acetic Acid → 8-(1-(cyclopropylmethyl)piperidin-4-yloxy)-3,4-dihydropyrazino[1,2-a]indol-1(2H)-one

Participants

Reaction Conditions

Reaction Steps

To the solution of 0.27 g (0.95 mmol) 8-(piperidin-4-yloxy)-3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one in 6 mL tetrahydrofuran, 20 μL water, 11 μL (99 μg, 1.42 mmol) cyclopropanecarboxaldehyde, 0.16 mL (0.17 g, 2.8 mmol) acetic acid and 1.42 mL (1.42 mmol, 1M solution in tetrahydrofuran) sodium cyanoborohydride were added and the reaction mixture was stirred for 18 hours at 55° C. The mixture was poured on 10% aqueous sodium bicarbonate and was extracted three times with ethyl acetate. The combined organic layers were washed with brine, dried over magnesium sulfate, filtered and evaporated. The residue was flash-chromatographed on silica gel with dichloromethane: methanol:ammonia (9:1:0.1 v/v) as eluant to give 96 μg (30%) of the desired compound as a white solid.

Provenance & Evidence