Reaktion #518364

Reaktionsgleichung

cyanocobalamin

trimethylsulfoxonium iodide

sodium borohydride

sodium hydroxide

→

title compound

Mecobalamin

Lösungsmittel

water

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe mixture was heated in a water bath
2. 2
   workup.STIRRINGAfter stirring for 1 hour as it
3. 3
   Temperaturthe mixture was cooled to room temperature
4. 4
   workup.STIRRINGstirred overnight
5. 5
   FiltrationThe precipitates were collected by filtration
6. 6
   Sonstigedried

Vorschrift

To 1.3 l of ion-exchanged water were added 100 g of cyanocobalamin and 32.46 g of trimethylsulfoxonium iodide. After replacing the atmosphere of the system by nitrogen, the mixture was heated in a water bath and a solution of sodium borohydride (40 g)/2N sodium hydroxide (2 ml)/water (200 ml) was added dropwise thereto under stirring at an inner temperature of 40° C. over 30 minutes. After stirring for 1 hour as it was, the mixture was cooled to room temperature and then stirred overnight. The precipitates were collected by filtration and dried, to give a crude product of the title compound. Thereto was added 1 l of a 50% acetone aqueous solution, and the mixture was heated, adjusted to pH 6.5 with concentrated hydrochloric acid and then filtered. After washing with 400 ml of a 50% acetone aqueous solution, 2.8 l of acetone was added dropwise thereto and the mixture was stirred at 17° C. overnight. Precipitated crystals were collected by filtration and dried, to give 90 g of the title compound (yield 91%).

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