Potassium Carbonate → 4-Chloro-2-(2,4-dichloro-6-methylphenoxy)-7-(1-ethylpropyl)-1-methyl-1H-benzimidazole

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Reaction Conditions

Reaction Steps

A solution of 2,4-dichloro-7-(1-ethylpropyl)-1-methyl-1H-benzimidazole (5.5 g, 20.2 mmol), 2,4-dichloro-6-methylphenol (10 g, 56.5 mmol) and potassium carbonate (8.4 g, 60.8 mmol) in N,N-dimethylformamide (55 mL) was heated at 100° C. for 9 h. To the mixture was added 2,4-dichloro-6-methylphenol (5 g, 28.3 mmol) and potassium carbonate (4.2 g, 30.4 mmol) and heated at 100° C. for 16 h. Additional 2,4-dichloro-6-methylphenol (5 g, 28.3 mmol) and potassium carbonate (4.2 g, 30.4 mmol) were added and heated at 100° C. for 9 h. After cooling, the mixture was diluted with water and extracted with ethyl acetate. The extract was washed with brine, dried over magnesium sulfate, filtered and concentrated in vacuo. The residue was purified by column chromatography on NH silica gel eluting with a 12.5% ethyl acetate/n-hexane. The resulting solids were recrystallized from a 10% ethyl acetate/n-hexane to give 5.3 g (64%) of the title compound as a colorless crystal.

Provenance & Evidence