Water → HCID 12151521, compound

Participants

Reaction Steps

Tetrahydroisoquinoline (Aldrich Chemical, 18.0 g, 135.1 mmol), 1-indanone (10.0 g, 75.1 mmol) and P2O5 (2.30 g, 16.1 mmol) in 150 mL of toluene were stirred under nitrogen and refluxed for 10 h with water removal via a Dean Stark apparatus. Upon cooling a large amount of fine white powder precipitated (as amine phosphate salts). The dark green solution was filtered under N2 through a medium porosity frit and assayed by NMR after tolune removal (about 85:15 mole ratio of product to ketone). Solvent was evaporated and indanone/amine (about 3.0 g) was removed in vacuo (90-160° C. at 0.5 mm Hg, 76 Pa). The process was stopped and the crude enamine residue recovered under inert atmosphere, giving 18.0 g of dark red-green oil, 95 percent yield. The crude product was analyzed by 1H and 13C NMR and showed less than 2 percent mole ketone.

Provenance & Evidence