Reaktion #52934

Reaktionsgleichung

2,6-Dichlorobenzyl chloride

N-(tert-butoxycarbonyl)-3,4-dihydroxy-L-phenylalanine methyl ester

K2CO3

→

N-(tert-butoxycarbonyl)-3,4-bis(2,6-dichlorobenzyloxy)-L-phenylalanine methyl ester

Ausbeute 71.8%

Lösungsmittel

water

DMF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionextracted with ether
2. 2
   TrocknenThe extract was dried (MgSO4)
3. 3
   Sonstigeevaporated
4. 4
   SonstigeThe residue was purified by column chromatography (silica gel; eluent: hexanes/CH2Cl2/EtOAc, 5:5:1)

Vorschrift

2,6-Dichlorobenzyl chloride (1.73 g) was added to a suspension of N-(tert-butoxycarbonyl)-3,4-dihydroxy-L-phenylalanine methyl ester (2.5 g), K2CO3 (2.22 g), and n-Bu4NI (0.297 g) in DMF (15 mL) at room temperature. The mixture was stirred overnight at room temperature, diluted with water and extracted with ether. The extract was dried (MgSO4) and evaporated. The residue was purified by column chromatography (silica gel; eluent: hexanes/CH2Cl2/EtOAc, 5:5:1) to yield N-(tert-butoxycarbonyl)-3,4-bis(2,6-dichlorobenzyloxy)-L-phenylalanine methyl ester (2.0 g), ESMS: m/z 630 (MH+), N-(tert-butoxycarbonyl)-3-(2,6-dichlorobenzyloxy)-4-hydroxy-L-phenylalanine methyl ester (0.39 g), ESMS: m/z 470(MH+), and N-(tert-butoxycarbonyl)-4-(2,6-dichlorobenzyloxy)-3-hydroxy-L-phenylalanine methyl ester (0.45 g), ESMS: m/z 470 (MH+), respectively.

Quelle