反应详情

温度

0 °C

1-Hydroxybenzotriazole (456 mg, 3.38 mmol), DL-α-methyltryptamine (0.142 ml, 1.69 mmol) and N-methylmorpholine (0.375 ml, 3.38 mmol) were added to a solution of (4-dimethylamino-4-phenylcyclohexylidene)acetic acid hydrochloride (500 mg, 1.69 mmol) in dry dimethylformamide (10 ml) under argon. The solution was cooled to 0° C. and dicyclohexylcarbodiimide (687 mg, 3.38 mmol) was added. The reaction mixture was stirred at RT for 6 d. Working up of the mixture was carried out by separating off the urea which had precipitated out and introducing the filtrate into a mixture of saturated NaCl solution (40 ml) and saturated NaHCO3 solution (10 ml). Still further urea thereby precipitated out and was separated off. 5 M sodium hydroxide solution (2 ml, 10 mmol) was added to the filtrate and the mixture was diluted with water (200 ml). The product thereby precipitated out as a beige-coloured solid and was to be obtained in a yield of 83% (581 mg). Separation by chromatography on silica gel was carried out with EA/methanol (15:1), (10:1) and (5:1). The less polar diastereoisomer of 2-(4-dimethylamino-4-phenylcyclohexylidene)-N-[2-(1H-indol-3-yl)-1-methylethyl]acetamide were thereby obtained as a colourless solid with an m.p. of 184-187° C. in a yield of 24% (165 mg). It was possible to isolate the more polar diastereoisomer of 2-(4-dimethylamino-4-phenylcyclohexylidene)-N-[2-(1H-indol-3-yl)-1-methylethyl]acetamide as a colourless oil in a yield of 18% (126 mg).—Both amides were diastereoisomerically pure.

1. customby separating off the urea which
2. customhad precipitated out
3. additionintroducing the filtrate
4. additioninto a mixture of saturated NaCl solution (40 ml) and saturated NaHCO3 solution (10 ml)
5. customStill further urea thereby precipitated out and
6. customwas separated off
7. customThe product thereby precipitated out as a beige-coloured solid
8. customto be obtained in a yield of 83% (581 mg)
9. customSeparation by chromatography on silica gel