Acetaldehyde → 4-Ethyl-1,3,4,5-tetrahydropyrrolo[4,3,2-de] isoquinoline

Participants

Reaction Steps

LiAlH4 (0.440 g, 11.6 mmol) was added in portions to a solution of 3,4-dihydropyrrolo[4,3,2-de]isoquinolin-5(1H)-one, Intermediate 1 (0.4 g, 2.32 mmol) in dry THF (20 ml). The mixture was brought to reflux for 3 hours, cooled, diluted with aqueous THF and filtered. The solid cake was washed with THF (2×) and the residue was evaporated to give a light brown solid. This brown solid was dissolved in MeOH (20 ml) and acetaldehyde (0.334 g, 7.6 mmol) and sodium triacetoxy borohydride (0.482 g, 2.3 mmol) were added. The mixture was stirred for 1 hour and evaporated to half its volume and partitioned between 1N Na2CO3 and dichloromethane. The organic phase was washed with brine, dried (MgSO4) and evaporated. The crude product was purified by flash chromatography using 10% MeOH to 50% MeOH in dichloromethane with 1% NEt3. Yield: 142 mg. Grey solid. MS m/z 187 [M+H]+.

Provenance & Evidence