反应详情

The product (15 g) from Step 3 in n-butanol (300 ml) was hydrogenated at room temperature and atmospheric pressure using a 10% palladium on carbon catalyst. When the uptake of hydrogen ceased, the catalyst was filtered off and the filtrate evaporated under reduced pressure. The residue was purified by short-path distillation (at 140°-150°/0.2 mmHg) to afford a main fraction (11.6 g) containing 57% w/w of the desired propionate which was recrystallised from cold hexane to give n-butyl 2-[4-(5-trifluoromethylpyrid-2-yloxy)-phenoxy]propionate. The propionate may then be obtained substantially pure by recrystallisation from cold hexane.

1. customwas hydrogenated at room temperature
2. filtrationthe catalyst was filtered off
3. customthe filtrate evaporated under reduced pressure
4. distillationThe residue was purified by short-path distillation (at 140°-150°/0.2 mmHg)
5. customto afford a main fraction (11.6 g)
6. customwas recrystallised from cold hexane