Phosgene → 4,5-Bis-(4-chloro-phenyl)-2-(2-ethoxy-4-trifluoromethyl-phenyl)-4,5-dihydro-imidazole-1-carbonyl chloride

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Reaction Steps

To a solution of 4,5-bis-(4-chloro-phenyl)-2-(2-ethoxy-4-trifluoromethyl-phenyl)-4,5-dihydro-1H-imidazole (46 g, 95.97 mmol, example 1) and triethylamine (66.9 mL, 479.9 mmol) in methylene chloride (2 L) cooled to 0° C. was added phosgene (124.3 mL, 239.9 mmol, ˜20% solution in toluene) dropwise over a period of 30 min. The reaction mixture was stirred at room temperature for 1 h. Nitrogen gas was bubbled through the reaction mixture to remove excess phosgene. The reaction mixture was concentrated to dryness, and the residue was dried in vacuo for 1 h to give 4,5-bis-(4-chloro-phenyl)-2-(2-ethoxy-4-trifluoromethyl-phenyl)-4,5-dihydro-imidazole-1-carbonyl chloride (51 g, 98% yield) as off-white solids. The product was used without further purification.

Provenance & Evidence