5-Bromotryptophol

Synthesis

117235-22-0

32774-29-1

General procedure for the synthesis of 2-(5-bromo-1H-indol-3-yl)ethanol from methyl (5-bromo-1H-indol-3-yl)-acetate: to a solution of methyl ester (5-bromo-1H-indol-3-yl)-acetate (4 mmol, 1 eq.) in anhydrous THF (50 mL) was added lithium aluminum hydride (LiAlH4; 16 mmol, 4 eq.) in batches and the reaction The temperature was maintained at 0 °C. The reaction mixture was gradually brought to room temperature with continuous stirring for 30 min. The excess LiAlH4 was quenched by slow addition of saturated aqueous Na2SO4 while maintaining the temperature at about 0 °C. The reaction mixture was filtered. The reaction mixture was filtered and the filtrate was washed with THF. After combining the filtrates, the solvent was removed by concentration under reduced pressure and the residue was adjusted to pH 6 with 10% HCl solution and subsequently extracted with CHCl3. The organic layers were combined, dried with anhydrous Na2SO4, filtered and evaporated to dryness. The crude product was purified by fast column chromatography using EtOAc/hexane as eluent to afford the target product 2-(5-bromo-1H-indol-3-yl)ethanol. Yield: 83%; 1H NMR (300 MHz, CDCl3): δ 2.97 (t, J = 18 Hz, 2H), 3.86-3.93 (m, 2H), 4.09 (t, J = 21 Hz, 1H), 7.09 (d, J = 3 Hz, 1H), 7.22 (d, J = 9 Hz, 1H), 7.75 (s, 1H), 8.10 ( s, 1H); MS (APCI): m/z 241.2 [M + H]+.

References