反应详情

The polar diastereoisomer of 3-(1H-indol-3-yl)piperidine-1-carboxylic acid-(4-dimethylamino-4-phenylcyclohexylmethyl)-amide (214 mg, 0.467 mmole) was dissolved in abs. ethanol (3 ml). Citric acid (90.6 mg, 0.471 mmole) was added in one portion at ca. 40° C. while stirring. The reaction mixture was stirred for 2 hours at RT. During this time no precipitate formed. Ethanol was distilled off down to a volume of 1 ml. Diethyl ether (10 ml) was added to the residue. The suspension was stirred for 20 hours at RT. The precipitate was filtered off, washed with diethyl ether (3×1.5 ml) and dried in vacuo. The polar diastereoisomer of 3-(1H-indol-3-yl)piperidine-1-carboxylic acid-(4-dimethylamino-4-phenylcyclohexylmethyl)-amide citrate (297 mg, m.p. 116°-120° C., 98%, Example 48) was a cream-coloured solid.

1. stirringThe reaction mixture was stirred for 2 hours at RT
2. customDuring this time no precipitate formed
3. distillationEthanol was distilled off down to a volume of 1 ml
4. additionDiethyl ether (10 ml) was added to the residue
5. stirringThe suspension was stirred for 20 hours at RT
6. filtrationThe precipitate was filtered off
7. washwashed with diethyl ether (3×1.5 ml)
8. customdried in vacuo