8-Hydroxyquinoline → 3-(4-Methyl-1H-imidazol-1-yl)-5-(trifluoromethyl)aniline

Participants

Reaction Conditions

Reaction Steps

A suspension of 3-bromo-5-(trifluoromethyl)aniline (4.80 g, 20 mmol), 4-methylimidazole (1.97 g, 24 mmol), potassium carbonate (3.04 g, 22 mmol), CuI (0.57 g, 3 mmol), and 8-hydroxyquinoline (0.44 g, 3 mmol) in dry DMSO (20 mL) in a pressure tube was degassed by bubbling N2 into the suspension for 10 minutes while stirring. The tube was sealed tightly. The mixture was heated at 120° C. (oil bath temperature) for 15 h. The mixture was cooled down to 45-50° C. and 14% aq. NH4OH (20 mL) was added. The mixture was maintained at this temperature for 1 h. After cooling to rt, water and ethyl acetate were added. The aqueous layer was extracted with ethyl acetate and the combined organic layers were passed through a short silica gel column to remove most of green/blue Cu salt. The filtrate was dried over sodium sulfate and concentrated on a rotavap. The crude product was recrystallized from EtOAc/hexanes, giving pure pale yellow needles. The mother liquor was concentrated and the residue was purified on silica gel column (5% methanol/methylene chloride), yielding a second crop as pale yellow needles.

Provenance & Evidence