反应详情

A room temperature solution of 2.53 gms. (4-Nitro-phenyl)-acetic acid in tetrahydrofuran (10 mL) is treated with 2.44 gms. 1′,1′-carbonyl-diimidizole and immediately immersed in an ice bath. The reaction mixture is stirred in the ice bath for 30 minutes then it is allowed to warm to room temperature. Once at room temperature the reaction mixture is treated with 1.21 mL piperidine, and then is stirred overnight at room temperature. The reaction is then made basic with the addition of saturated aqueous sodium bicarbonate, and the resulting mixture is extracted with ethyl acetate. The organics are separated, dried over anhydrous sodium sulfate, filtered, and subsequently evaporated to dryness in vacuo. The crude product residue is then chromatographed by flash silica gel chromatography using 50% ethyl acetate in hexanes as the eluant. Following evaporation of solvent, 2-(4-nitro-phenyl)-1-piperidin-1-yl-ethanone is isolated as a white solid in the amount of 3.18 gms. 2-(4-Nitro-phenyl)-1-piperidin-1-yl-ethanone (1.24 gms.) is then dissolved in tetrahydrofuran (5 mL), and slowly added dropwise to a 0° C., 1.0M solution (35 mL) of Borane in tetrahydrofuran. The reaction mixture is maintained at 0° C. for 20 minutes following the completion of the addition to the Borane/tetrahydrofuran solution. The reaction mixture is then allowed to warm to room temperature, and is subsequently refluxed using an oil bath. The reaction mixture is maintained at refluxing temperature overnight, then cooled to 0° C. and quenched with the addition of concentrated HCl (added until fizzing stops). The quenched reaction mixture is then extracted with ethyl acetate and water. The organic layer is then separated, dried over sodium sulfate and concentrated in vacuo. The solid isolated is then triturated with hexanes and a little ethyl acetate to yield 0.7563 gms. of 1-[2-(4-nitro-phenyl)-ethyl]-piperidine as a white solid following filtration.

1. customA room temperature solution of 2.53 gms
2. custom1′,1′-carbonyl-diimidizole and immediately immersed in an ice bath
3. extractionthe resulting mixture is extracted with ethyl acetate
4. customThe organics are separated
5. dry with materialdried over anhydrous sodium sulfate
6. filtrationfiltered
7. customsubsequently evaporated to dryness in vacuo
8. customThe crude product residue is then chromatographed by flash silica gel chromatography
9. customevaporation of solvent