Reaktion #40711

Reaktionsgleichung

3-(2-thienyl)alanine

LiAlH4

NaOH

benzyl chloroformate

NaOH

→

title compound

Ausbeute 96.9%

Phenylmethyl [2-hydroxy-1-(2-thienylmethyl)ethyl]carbamate

Ausbeute 96.9%

Lösungsmittel

H2O

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturheated to reflux
2. 2
   TemperaturThe mixture was then heated
3. 3
   Temperaturunder reflux for 8 hours
4. 4
   workup.STIRRINGthe mixture was stirred for 5 minutes
5. 5
   workup.STIRRINGthe mixture was stirred at room temperature for 3 hours
6. 6
   ExtraktionFor workup, the mixture was extracted with dichloromethane
7. 7
   Sonstigethe organic phase was dried
8. 8
   Sonstigethe solvent was evaporated
9. 9
   Filtrationthe remaining residue was filtered through silica gel (eluent: CH2Cl2/methanol 2.5%)

Vorschrift

24.8 g of 3-(2-thienyl)alanine (144.8 mmol) were added in portions to 11.0 g of LiAlH4 in 550 ml of tetrahydrofuran, heated to reflux. The mixture was then heated under reflux for 8 hours and subsequently stirred at room temperature overnight. 17.6 ml of 10% NaOH solution were added and then 22 ml of H2O were slowly added dropwise, and the mixture was stirred for 5 minutes. Then, first 391 ml of 10% NaOH solution and subsequently, at −5° C., 22.2 g of benzyl chloroformate (130.32 mmol) were added, and the mixture was stirred at room temperature for 3 hours. For workup, the mixture was extracted with dichloromethane, the organic phase was dried, the solvent was evaporated and the remaining residue was filtered through silica gel (eluent: CH2Cl2/methanol 2.5%). 36.8 g of the title compound were obtained as a yellowish oil.

Quelle