Reaktion #1685717

Reaktionsgleichung

NaOH

MeOH H2O

L-allo-isoleucine

NaOH

toluene

→

solid

BOC-alloisoleucine

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigethe cooling bath was removed
2. 2
   Extraktionextracted with 3×500 mL of CH2Cl2
3. 3
   Trocknendried over MgSO4
4. 4
   Filtrationfiltered
5. 5
   Sonstigeevaporated
6. 6
   Sonstigeto give a gum
7. 7
   Sonstigethe reaction mixture was evaporated
8. 8
   Sonstigeto obtain a gum which
9. 9
   Sonstigewas dried under high vacuum for 2 days

Vorschrift

L-allo-isoleucine (20.0 gm, 0.152 mole) was suspended in 200 ml of 50% MeOH/H2O. The pH was adjusted to 9-9.5 with 4N NaOH. The reaction mixture was cooled to 10° C. and di-tert butoxydicarbonate (39.8 gm, 0.184 mole) was added. The pH was maintained at 9-9.5 with NaOH. After about 0.5 hour, the cooling bath was removed. The reaction mixture was stirred at room temperature for 3-4 hours. TLC in 5% MeOH/CH2 Cl2 was taken. When the reaction was complete, the reaction mixture was acidified to pH 3 with 20% citric acid, extracted with 3×500 mL of CH2Cl2, dried over MgSO4, filtered and evaporated to give a gum. 200 mL of toluene were added and the reaction mixture was evaporated. This last step was repeated two more times to obtain a gum which was dried under high vacuum for 2 days to give a solid (37.53 gm).

Quelle