反应详情

1 g of platinum chloride was added to a solution of 15 g (65 mmol) of 3,6-dimethyl-5-(4-methoxyphenyl)-3,4-dihydro-2-pyridone (Synthesis 305, 1985) in 75 ml of glacial acetic acid and the mixture was hydrogenated at room temperature and a pressure of 52 psi for 8 hours. The catalyst was then removed by filtration and the glacial acetic acid was evaporated under reduced pressure. The residue was dissolved in ethyl acetate and washed successively with ammonia (5%), water and a saline solution. The organic layer was dried on sodium sulphate, filtered and evaporated under reduced pressure. The resulting crude product (15 g) was purified chromatographically over a dry column of 700 g of silcagel (Merck, grain size 0.063-0.200 mm) using a mixture of dichloromethane and acetone (95:5) as an eluent. After evaporating the correct fractions, 5.8 g (38%) of the desired 3,6-dimethyl-5-(4-methoxyphenyl)-3,4,5,6-tetrahydro-2-pyridone were obtained in addition to 3.5 g (23%) of the starting compound.

1. customwas hydrogenated at room temperature
2. customThe catalyst was then removed by filtration
3. customthe glacial acetic acid was evaporated under reduced pressure
4. dissolutionThe residue was dissolved in ethyl acetate
5. washwashed successively with ammonia (5%), water
6. customThe organic layer was dried on sodium sulphate
7. filtrationfiltered
8. customevaporated under reduced pressure
9. customThe resulting crude product (15 g) was purified chromatographically over a dry column of 700 g of silcagel (Merck, grain size 0.063-0.200 mm)
10. additiona mixture of dichloromethane and acetone (95:5) as an eluent
11. customAfter evaporating the correct fractions