Diisopropylethylamine → Methyl 2-oxo-7-(trifluoromethyl)-2,3-dihydro-1H-benzimidazole-4-carboxylate

Participants

Reaction Steps

To a stirring solution of methyl 2,3-diamino-4-(trifluoromethyl)benzoate (5.10 g, 0.022 mol) and diisopropylethylamine (6.26 g, 0.048 mol) in toluene (50 ml) was added a solution of triphosgene (2.58 g, 0.0087 mol) in toluene (20 ml) dropwise and stirred at room temperature for 16 h. The reaction mixture was concentrated in vacuo. The residue was diluted with 1N hydrochloric acid and extracted with ethyl acetate and tetrahydrofuran. The extracts were washed with water, dried over magnesium sulfate and concentrated in vacuo. A solution of 50% diisopropylether/n-hexane was added to the residue and white precipitates were filtered, washed with same solvent to give 5.00 g (0.019 mol 87%) of the title as a white powder

Provenance & Evidence