反应详情

To a mixture of the amidine of step 1 (10 mmol and sodium bicarbonate (20 mmol) in isopropanol (150 ml), 3-bromo-1,1,1-trifluoroacetone (15 mmol) is added. After heating at 80°-85° C. for 24 hours, the reaction mixture is cooled and filtered. The residue is washed with methylene chloride and the combined organic fractions are dried over sodium sulfate, filtered and concentrated. The crude mixture is chromatographed on silica gel using mixtures of ethyl acetate, isopropanol and ammonium hydroxide as eluants to give the desired 4,5-dihydro-imidazole

1. additionis added
2. temperatureAfter heating at 80°-85° C. for 24 hours
3. temperaturethe reaction mixture is cooled
4. filtrationfiltered
5. washThe residue is washed with methylene chloride
6. dry with materialthe combined organic fractions are dried over sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated
9. customThe crude mixture is chromatographed on silica gel using mixtures of ethyl acetate, isopropanol and ammonium hydroxide as eluants