Triethylamine → 5,7-dimethyl-8-methoxy-9-(2-dimethylaminoethyl)-1,2,3,4-tetrahydro-9H-fluorene

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Reaction Steps

A methanol solution containing 1.0 g of 5,7-dimethyl-8-methoxy-9-formylmethyl-1,2,3,4-tetrahydro-9H-fluorene in 10 ml of methanol was added dropwise to a methanol solution containing 3.0 g of dimethylamine hydrochloride and 5.2 ml of triethylamine in 30 ml of methanol at 0° C. After stirring at the same temperature for 3 hours, 100 mg of sodium borohydride was added, followed by further stirring at the same temperature for 2 hours. The reaction mixture was diluted with chloroform, washed successively with water and saturated aqueous sodium chloride solution and then dried with magnesium sulfate. The solvent was distilled off under reduced pressure and the residue was purified by a silica gel column chromatography (eluent: methanol:chloroform=1:1) to obtain 700 mg of 5,7-dimethyl-8-methoxy-9-(2-dimethylaminoethyl)-1,2,3,4-tetrahydro-9H-fluorene. This was dissolved in ethanol and to the solution were added ethanol.hydrochloric acid. The solvent was distilled off and the residue was recrystallized from diethyl ether-diisopropyl ether to obtain 220 mg of 5,7-dimethyl- 8-methoxy-9-(2-dimethylaminoethyl)-1,2,3,4-tetrahydro-9H-fluorene hydrochloride.

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