Ammonium formate → Tert-butyl 3-[(2r)-2-(aminomethyl)-3.4-dihydro-2h-chromen-6-yl]propanoate

Participants

Reaction Conditions

Reaction Steps

A mixture of carbamate of Example 12 (10.8 g, 23.6 mmol), ammonium formate (29 g, 460 mmol) and palladium hydroxide on carbon (Pearlman's catalyst) (4.3 g) in absolute ethanol (250 mL) was heated at 50° C. for 4 hours under argon. Some white solid appeared in the condenser. The reaction mixture was vacuum filtered through a pad of Celite. The filtrate was concentrated in vacuo to obtain an off-white solid which was subsequently dissolved in 1 N sodium hydroxide solution (200 mL). The mixture was extracted with ethyl acetate (200, 200, 100 mL). The combined organic layer was washed with brine (100 mL) and dried over anhydrous sodium sulfate. Removal of solvent in vacuo afforded the desired product cleanly as an oil (6.0 g, 88%): 1H NMR (CDCl3) δ1.40 (s, 9H), 1.70-1.81 (m, 1H), 1.90-2.00 (m, 1H), 2.46-2.51 (t, J=6.9 Hz, 2H), 2.70-2.85 (m, 4H), 2.93 (d, J=5.4 Hz, 2H), 3.90-4.00 (m, 1H), 6.73 (d, J=8.4 Hz, 1H), 6.87 (s, 1H), 6.90 (d, J=8.1 Hz, 1H); CI-MS m/z 292 (M+H+).

Provenance & Evidence