反应详情

The polar diastereoisomer of 4-(5-chloro-1H-indol-3-yl)piperidine-1-carboxylic acid-(4-dimethylamino-4-phenylcyclohexylmethyl)-amide (267 mg, 0.54 mmole) was dissolved in abs. ethanol (7 ml). Citric acid (105.1 mg, 0.55 mmole) was added in one portion at ca. 35° C. while stirring. After stirring for several hours at RT no precipitate was visible. The reaction mixture was reduced to ca. 1 ml of solution and diethyl ether (25 ml) was added in portions. The precipitate formed was filtered off after 18 hours, washed with Et2O (3×2 ml) and dried in vacuo. The polar citrate of 4-(5-chloro-1H-indol-3-yl)piperidine-1-carboxylic acid-(4-dimethylamino-4-phenylcyclohexylmethyl)-amide (324 mg, m.p. 125°-130° C., 88%, Example 19) was a colourless solid.

1. stirringAfter stirring for several hours at RT no precipitate
2. additionwas added in portions
3. customThe precipitate formed
4. filtrationwas filtered off after 18 hours
5. washwashed with Et2O (3×2 ml)
6. customdried in vacuo