Acetic Acid → Propanal

Participants

Reaction Steps

1.60 g (5.6 mmol) of 2-(quinuclidin-3-yl)amino-8-methoxy-1,2,3,4-tetrahydronaphthalene (obtained from 8-methoxy-2-tetralone and 3-aminoquinuclidine by reductive amination in the conventional fashion), 3.20 g (56 mmol) of propionaldehyde and 1.70 g (28 mmol) of glacial acetic acid were stirred for 30 minutes at 0° C. 0.80 g (11 mmol) of sodium cyanoborohydride was then added, and the mixture was stirred for 15 hours at room temperature. The reaction mixture was concentrated, taken up in toluene and reconcentrated, taken up in tert.-butyl methyl ether, and stirred vigorously for 30 minutes with 20% strength sodium hydroxide solution. The aqueous phase was extracted carefully with tert.-butyl methyl ether. Washing the combined organic phases with water and saturated sodium chloride solution, drying over potassium carbonate, and concentrating in a rotary evaporator yielded the crude product as an oil (2.0 g). Chromatography on silica gel (toluene/ethanol 3:1) supplied the title compound as a syrup.

Provenance & Evidence