Reaktion #499141

Reaktionsgleichung

histidine

sodium hydroxide

hydrochloric acid

N-octyloxycarbonyl-β-alanine

2-(5-norbornene-2,3-dicarboximido)-1,1,3,3-tetramethyluronium tetrafluoroborate

→

white crystalline product

Ausbeute 63.0%

N-octyloxycarbonyl-β-alanyl-L-histidine

Ausbeute 63.0%

Lösungsmittel

water

triethylamine

water

acetone

dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwere added dropwise
2. 2
   Sonstigethe temperature below 30° C
3. 3
   workup.STIRRINGAfter stirring for 6 hours
4. 4
   workup.STIRRINGAfter stirring for 30 minutes
5. 5
   SonstigeThe white precipitate formed
6. 6
   Filtrationwas filtered off
7. 7
   Sonstigedried
8. 8
   workup.DISSOLUTIONThe crude product was dissolved in 10 ml/g
9. 9
   Temperaturof refluxing 96% ethanol
10. 10
    FiltrationThe solution was filtered while hot and the product
11. 11
    Sonstigethen crystallized at room temperature

Vorschrift

30 g of N-octyloxycarbonyl-β-alanine were dissolved in 300 ml of dimethylformamide and 1 molar equivalent of triethylamine. Next, 1 molar equivalent of 2-(5-norbornene-2,3-dicarboximido)-1,1,3,3-tetramethyluronium tetrafluoroborate was added. The mixture was then stirred for 1 hour at a temperature of 250° C. Next, a solution containing 1.2 molar equivalents of histidine and 1.2 molar equivalents of sodium hydroxide in 100 ml of water were added dropwise, while keeping the temperature below 30° C. After stirring for 6 hours, the mixture was neutralized with 1 molar equivalent of 5N hydrochloric acid, followed by 100 ml of water. After stirring for 30 minutes, the mixture was poured into 2 liters of acetone. The white precipitate formed was filtered off and dried. The crude product was dissolved in 10 ml/g of refluxing 96% ethanol. The solution was filtered while hot and the product then crystallized at room temperature. After processing the precipitate, 29.4 g of a white crystalline product were obtained (63% yield).

Quelle