Phthalimide potassium salt → HCID 68854787, compound

Participants

Reaction Conditions

Reaction Steps

Potassium phthalimide (7.79 g, 42.1 mmol) is added to a stirred solution of racemic 3-(3-methanesulfonyloxypropyl)-piperidine-1-carboxylic acid tert-butyl ester (9.00 g, 28.0 mmol) in DMF (60 mL). The mixture is allowed to stir at 55° C. for 16 hours. At room temperature, the mixture is concentrated, the oil is diluted in ethyl acetate (50 mL), and the solution is washed with water (50 mL). The organic layer is concentrated and the crude product is chromatographed on silica gel, eluting with ethyl acetate in hexane 0-25%, to give 3-[3-(1,3-dioxo-1,3-dihydroisoindol-2-yl)-propyl]-piperidine-1-carboxylic acid tert-butyl ester (9.84 g, 94% yield). A stirred solution of this intermediate (9.00 g, 24.2 mmol) in ethanol (400 mL) is treated with hydrazine (4.65 g, 145 mmol). The mixture is heated at 50° C. for 16 hours to form a white suspension. At room temperature the suspension is quickly filtered and the filtrate is concentrated to give the oil containing a small amount of white solid. This mixture is diluted in ethanol (10 mL and diethyl ether (50 mL), filtered, and concentrated to provide the title compound as an oil (5.0 g, 85% yield).

Provenance & Evidence