Yield:312751-53-4 97%

Reaction Conditions:

in 1,4-dioxane; for 48 h;Heating / reflux;

Steps:

1.2.a

(a) Preparation of [2-(1H-Indol-3-yl)-ethyl]-thiourea: Tryptamine hydrochloride (1.00 g, 5.08 mmol) and potassium thiocyanate (0.741 g, 7.63 mmol) were added to dioxane (20 ml). The suspension was heated to reflux for 48 hours under an atmosphere of argon. The reaction was cooled to room temperature and was filtered over a plug of silica and washed with ethyl acetate. The filtrate was concentrated under reduced pressure to give the product as a beige solid (1.09 g, 4.95 mmol, 97%). δ_H (300 MHz) (DMSO d₆ 2.89 (2 H, t, J = 7), 3.66 (2 H, s, br), 6.94-7.00 (2 H, m), 7.07 (1 H, dt, J = 8, J = 1.3), 7.16 (1 H, s), 7.34 (1 H, d, J = 8.0), 7.60 (2 H, m), 10.81 (1 H, s).

References:

EP1555264,2005,A1 Location in patent:Page/Page column 14