ethyl 1-(4-aminophenyl)-1H-imidazole-4-carboxylate → ethyl 1-(4-{[1-methyl-3-({[(1-methylethyl)oxy]carbonyl}amino)-3-oxopropyl]amino}phenyl)-1H-imidazole-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of ethyl 1-(4-aminophenyl)-1H-imidazole-4-carboxylate (for a preparation see intermediate 85) (9.4 g, 40.6 mmol), 1-methylethyl (2E)-2-butenoylcarbamate (for a preparation see intermediate 49) (6.96 g, 40.6 mmol), and yttrium nitrate hexahydrate (1.56 g, 4.06 mmol) in dry acetonitrile (200 mL) was stirred at 60° C. for 48 h then cooled to room temperature and concentrated in vacuo. The residue was suspended in AcOEt (250 mL) and the organic phase was washed with water (×2) then brine, dried over MgSO4 and concentrated in vacuo. Purification of the residue by flash chromatography on silica gel (gradient: 60-100% AcOEt in Hexanes followed by 0 to 5% methanol in AcOEt) gave ethyl 1-(4-{[1-methyl-3-({[(1-methylethyl)oxy]carbonyl}amino)-3-oxopropyl]amino}phenyl)-1H-imidazole-4-carboxylate (5 g, 12.42 mmol, 31%) as a colourless gum.

Provenance & Evidence