Reaktion #58027

Reaktionsgleichung

HCl

4-carboxymethyl-piperidine-1-carboxylic acid tert-butyl ester

diborane

hydrogen

NaOH

HCl

hydrogen

Hydrogen

→

4-(2-hydroxy-ethyl)-piperidine-1-carboxylic acid tert-butyl ester

Ausbeute 97.0%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction mixture was again cooled to 0° C.
2. 2
   workup.STIRRINGThe mixture was then stirred for 10 min
3. 3
   ExtraktionThe aqueous solution was extracted with ethyl acetate
4. 4
   Waschenthe organic phase washed with brine
5. 5
   Sonstigedried
6. 6
   Einengenconcentrated under reduced pressure

Vorschrift

To a solution of 4-carboxymethyl-piperidine-1-carboxylic acid tert-butyl ester (16.7 g, 69.0 mmol) in THF (100 mL) was added diborane (151 mL, 1.0 M solution in THF) over a period of 10 min at 0° C. Hydrogen gas was rapidly evolved and after gas evolution had ceased the reaction was stirred at room temperature for 1 h. The reaction mixture was again cooled to 0° C., and 1 M aqueous HCl was added dropwise to the reaction mixture with further evolution of hydrogen. Addition of HCl was continued until the evolution of hydrogen had almost ceased. The mixture was then stirred for 10 min and made basic (pH 13-14) by the addition of 1 M NaOH solution. The aqueous solution was extracted with ethyl acetate, the organic phase washed with brine, dried and concentrated under reduced pressure to yield 4-(2-hydroxy-ethyl)-piperidine-1-carboxylic acid tert-butyl ester (15.2 g, 97%).

Quelle