Acetic Acid → N-{[7-(Methylsulfonyl)-4H-1,3-benzodioxin-2-YL]methyl}propan-1-amine

Participants

Reaction Steps

(−)-N-benzyl-N-{[7-(methylsulfonyl)-4H-1,3-benzodioxin-2-yl]methyl}propan-1-amine (0.25 g, 0.67 mmol), palladium on carbon (10%, 30 mg), concentrated AcOH (0.1 ml) and EtOH (15 ml) was hydrogenated at 40 psi for 1 h. The reaction mixture was filtered through a pad of celite and the filtrate was evaporated to dryness. The crude product was dissolved in EtOAc (100 ml) and basified with Na2CO3 (10%, 50 ml). The layers were separated and the aqueous layer was extracted with EtOAc (2×75 ml). The combined organic layers were collected, dried (Na2SO4), filtered and evaporated to dryness (0.32 g). Purification by flash chromatography (EtOAc/MeOH 10:1) afforded the pure title compound (0.13 g, 71%, >95% e.e.). The amine was converted into the hydrochloric acid salt and crystallized from EtOH/MeOH/DEE. M.p. 235° C. [α]DMeOH=−80°. 1H-NMR (400 MHz, MeOH): δ 7.49 (1H, dd, J1 8.0 Hz J2 2.0 Hz), δ 7.41 (1H, d, 2.0 Hz), δ 7.30 (1H, d, J 8 Hz), δ 5.25 (1H, t, J 5.2 Hz), δ 5.02 (2H, dd, J1 50 Hz, J2 16 Hz), δ 3.1 (3H, s), δ 2.97 (2H, m), δ 2.65 (2H, t, J 7.2 Hz), δ 1.56 (2H, m), δ 0.95 (3H, t, J 7.6 Hz).

Provenance & Evidence