Reaction #161643

Reaction equation

2-[(E)-4-Imidazol-1-yl-phenylimino]-propionic acid ethyl ester

Eaton's reagent

→

5-imidazol-1-yl-1H-indole-2-carboxylic acid ethyl ester

Solvents

potassium phosphate

Conditions

Workup

1. 1
   Extractionthe mixture was extracted with ethyl acetate (30 ml)
2. 2
   WashThe organic layer was washed with an aqueous solution saturated with sodium chloride (20 ml)
3. 3
   Concentrationthe organic layer was concentrated under reduced pressure
4. 4
   OtherThe resulting residue was purified by silica gel column chromatography (dichloromethane/methanol)

Procedure

2-[(E)-4-Imidazol-1-yl-phenylimino]-propionic acid ethyl ester (842 mg) was added to an Eaton's reagent (4 ml), and this was stirred at 100° C. for one hour. After adjusting the pH of the reaction mixture to 11 using an aqueous solution (about 10 ml) of 20% potassium phosphate, the mixture was extracted with ethyl acetate (30 ml). The organic layer was washed with an aqueous solution saturated with sodium chloride (20 ml), and the organic layer was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (dichloromethane/methanol). Thus, 5-imidazol-1-yl-1H-indole-2-carboxylic acid ethyl ester was obtained as a yellow amorphous material (370 mg, 47%).

Source