Tryptamine → 1-(2,3-dihydro-5-benzofuranyl)-2,3,4,9-tetrahydro-1H-beta-carboline

Participants

Reaction Steps

Intermediate 3 was prepared using a two-step procedure. A solution of tryptamine (32.4 g, 0.2 mol) and 2,3-dihydrobenzofuran-5-carboxaldehyde (30.0 g, 1 eq.) in toluene (1 L) was heated under reflux for 4 hours. After removal of 4 mL of water and evaporation of toluene, the residue was dissolved in CH2Cl2 (1 L) in the presence of TFA (31 mL, 2 eq.). The resulting mixture was stirred at rt for 16 hours. Then, 1 L of a saturated aqueous solution of NaHCO3 was added. After extraction with CH2Cl2 and drying over MgSO4, the organic solution was evaporated in vacuo. Recrystallization from CH2Cl2/iPr2O (2:30) gave the title compound as white crystals in an 80% yield. 1H NMR (CDCl3), δ 7.6 (s, 1H), 7.5–7.6 (m, 1H), 7–7.3 (m, 5H), 6.7–6.75 (d, 1H), 5.1 (s, 1H), 4.5–4.6 (t, 2H), 3.3–3.45 (m, 1H), 3.05–3.2 (t, 3H), 2.7–3 (m, 2H).

Provenance & Evidence