反应详情

The polar diastereoisomer of 4-(1H-indol-3-yl)-3,6-dihydro-2H-pyridine-1-carboxylic acid-(4-dimethylamino-4-phenylcyclohexylmethyl)-amide (256 mg, 0.56 mmole) was dissolved in abs. ethanol (10 ml) and DCM (2 ml). Citric acid (108.8 mg, 0.57 mmole) was added in one portion at ca. 35° C. while stirring. After stirring for 4 hours at RT only brown droplets on the wall of the flask were visible. The supernatant solution was decanted and concentrated by evaporation in vacuo to ca. 5 ml. Diethyl ether (50 ml) was added in portions at RT. The precipitate formed was filtered off after 2 hours, washed with ether (2×3 ml) and dried in vacuo. The polar diastereoisomer of 4-(1H-indol-3-yl)-3,6-dihydro-2H-pyridine-1-carboxylic acid-(4-dimethylamino-4-phenylcyclohexylmethyl)-amide citrate (222 mg, m.p. 125°-130° C., 61%, Example 22) was a pale brown solid.

1. stirringAfter stirring for 4 hours at RT only brown droplets on the wall of the flask
2. customThe supernatant solution was decanted
3. concentrationconcentrated by evaporation in vacuo to ca. 5 ml
4. additionDiethyl ether (50 ml) was added in portions at RT
5. customThe precipitate formed
6. filtrationwas filtered off after 2 hours
7. washwashed with ether (2×3 ml)
8. customdried in vacuo