Hydrochloric Acid → 3-[2-(4-Dimethylamino-4-phenyl-cyclohexylamino)-ethyl]-1H-indol-5-ol dihydrochloride

Beteiligte Stoffe

Reaktionsschritte

Serotonin (405 mg) was dissolved in 1,2-dichloroethane/THF (5 ml/20 ml), and 4-dimethylamino-4-phenylcyclohexanone (500 mg), glacial acetic acid (131 μl) and red-hot sodium sulfate (2 g) were added thereto. After one hour's stirring at RT, sodium triacetoxyborohydride (759 mg) was added and stirring was carried out for a further two days. For working up, the mixture was concentrated, the residue was suspended in diethyl ether (15 ml), water (10 ml) and 2M HCl (1 ml), further diethyl ether (20 ml) was added, and the organic phase was coarsely separated off. The aqueous phase was first brought to pH 9 with 1M NaOH and extracted with ethyl acetate (3×5 ml), then adjusted to pH 11 and again extracted with ethyl acetate (5×10 ml). The organic extracts were dried and concentrated and the residue was purified by flash chromatography (eluant: MeOH/NEt3 99.5:0.5). 267 mg of the nonpolar diastereomer (m.p. 90-100° C.) were isolated and, dissolved in ethanol/2-butanone (3 ml/15 ml), were converted with 3.3M ethanolic HCl (642 μl) into the corresponding dihydrochloride (white solid; 304 mg; m.p. 215-217° C.).

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