反应详情

1-(2,2-Diethoxyethyl)-3-(4-trifluoromethylphenyl)urea (9.2 g, 28.7 mmol) was dissolved in a mixture of 113 ml of methanol and 57 ml of water. To the reaction solution was added 67.5 ml of 0.48N hydrochloric acid and the mixture was stirred for 48 hours at room temperature. To the reaction solution was added 1N sodium hydroxide to adjust pH to 7, followed by being concentrated under reduced pressure. The residue was extracted with ethyl acetate (100 ml×4). The extracts were combined, washed with water and saturated aqueous solution of sodium chloride successively, dried over magnesium sulfate and distilled off. The crystals thus separated out were recystallized from ethyl acetate-isopropylether to give 4.87 g of 1-(4-trifluoromethylphenyl)-2(1H,3H)-imidazolone (74%) as colorless prisms.

1. concentrationby being concentrated under reduced pressure
2. extractionThe residue was extracted with ethyl acetate (100 ml×4)
3. washwashed with water and saturated aqueous solution of sodium chloride successively
4. dry with materialdried over magnesium sulfate
5. distillationdistilled off
6. customThe crystals thus separated out