反应详情

To 2-(2,2,6,6-tetramethylpiperidin-4-ylidene)-ethylamine (0.480 g, 2.63 mmol) in MeOH (5 mL) is added 10% Pd/C (48 mg) and 5 N HCl (2.63 mL, 13.2 mmol). At 50 psi hydrogen gas at 50° C. the reaction mixture is stirred for 18 hours. The reaction is filtered to remove the catalyst and resubjected to the reaction conditions using RhClPPh3 (0.26 mmol). Due to incomplete reaction the mixture is diluted with water, concentrated to remove any organic solvent, filtered to remove any solids, and then concentrated again. The residue is dissolved in acetic acid and resubjected to the hydrogenation conditions using 100 mg of palladium black and 50 psi hydrogen gas at 50° C. for 18 hours. The mixture of products is not easily purified, so the crude mixture is treated with di-tert-butyl dicarbonate in dichloromethane and then purified by silica gel chromatography using a high enough percentage of 2 M NH3 in MeOH in dichloromethane to isolate 240 mg of [2-(2,2,6,6-tetramethyl-piperidin-4-yl)-ethyl]-carbamic acid tert-butyl ester. [2-(2,2,6,6-Tetramethyl-piperidin-4-yl)-ethyl]-carbamic acid tert-butyl ester (240 mg, 0.844 mmol) is dissolved in 2:1 MeOH:dichloromethane (10.5 mL) and HCl (g) is bubbled for 5 minutes. After 1 hour, the reaction mixture is concentrated to give a foam (219 mg). The foam is dissolved in MeOH and loaded onto an SCX 5 g resin column. The column is washed with MeOH, then the product is released with 7 M NH3 in MeOH. After concentration the title compound is obtained and used without further purification (138 mg).

1. customdichloromethane (10.5 mL) and HCl (g) is bubbled for 5 minutes
2. concentrationthe reaction mixture is concentrated