Réaction #8253

Équation de réaction

sodium bicarbonate

Pyridine

5-Amino-2-(4-methylimidazol-1-yl)fluorobenzene

benzyl chloroformate

→

title product

Rendement 92.9%

5-Benzyloxycarbonylamino-2-(4-methylimidazol-1-yl)fluorobenzene

Rendement 92.9%

Solvants

dichloromethane

Conditions de réaction

Traitement

1. 1
   Températurecooled to −5°
2. 2
   Autrethe organic layer separated
3. 3
   Extractionthe aqueous layer re-extracted with dichloromethane (2×200 ml)
4. 4
   Séchagecombined organics dried (magnesium sulfate)
5. 5
   FiltrationAfter filtration and evaporation
6. 6
   Autrethe residue was recrystallised from toluene (300 ml)

Mode opératoire

5-Amino-2-(4-methylimidazol-1-yl)fluorobenzene (50.6 g, 0.265 M) was dissolved in dry dichloromethane (800 ml) under nitrogen, and cooled to −5°. Pyridine (26.1 g, 0.33 M) was added, followed by benzyl chloroformate (49.9 g, 0.292 M) over 30 minutes. The mixture was stirred and the temperature allowed to rise to ambient over 16 hours. Aqueous sodium bicarbonate (5%, 350 ml) was added, the organic layer separated, and the aqueous layer re-extracted with dichloromethane (2×200 ml), and combined organics dried (magnesium sulfate). After filtration and evaporation, the residue was recrystallised from toluene (300 ml) to give title product (80 g).

Source