反应详情

50 ml of trimethyl orthoformate were added to 40.0 g of montmorillonite K-10 in 250 ml of anhydrous dichloromethane, after which a solution of 20.0 g of 3-chloro-2-(4-chloro-3-formylphenyl)-5-trifluoromethylpyridine in 50 ml of dichloromethane was added dropwise while stirring and cooling in ice. After stirring at 23° C. for 20 hours, the clay was removed and thoroughly washed with dichloromethane. The dichloromethane phase was concentrated. The residue was purified by chromatography on silica gel with cyclohexane/ethyl acetate (10:1). Yield: 22.1 g (96%) of a colorless oil.

1. temperaturecooling in ice
2. stirringAfter stirring at 23° C. for 20 hours
3. customthe clay was removed
4. washthoroughly washed with dichloromethane
5. concentrationThe dichloromethane phase was concentrated
6. customThe residue was purified by chromatography on silica gel with cyclohexane/ethyl acetate (10:1)