Phosphorus oxychloride → 1,1-Dimethylethyl 4-(4-chlorophenyl)-3,6-dihydro-1(2H)-pyridinecarboxylate

Into a 250-mL round-bottom flask, was placed a solution of tert-butyl 4-(4-chlorophenyl)-4-hydroxypiperidine-1-carboxylate (compound 42.1, 9.00 g, 28.9 mmol) in pyridine (50 mL). With stirring, phosphoroyl trichloride (7.93 mL, 84.8 mmol) was added drop-wise. The resulting mixture was stirred overnight at room temperature and then concentrated under reduced pressure. The residue was diluted with ethyl acetate (20 mL) and carefully quenched by slow addition of aqueous sodium bicarbonate. The layers were separated and the organic layer was washed with aqueous sodium bicarbonate (2×30 mL), dried (Na2SO4), filtered, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography with ethyl acetate/petroleum ether (1:100 to 1:10) to yield the title compound as a colorless oil (6.1 g, 72%).

1. customInto a 250-mL round-bottom flask, was placed
2. stirringThe resulting mixture was stirred overnight at room temperature
3. concentrationconcentrated under reduced pressure
4. additionThe residue was diluted with ethyl acetate (20 mL)
5. customcarefully quenched by slow addition of aqueous sodium bicarbonate
6. customThe layers were separated
7. washthe organic layer was washed with aqueous sodium bicarbonate (2×30 mL)
8. dry with materialdried (Na2SO4)
9. filtrationfiltered
10. concentrationconcentrated under reduced pressure
11. customThe residue was purified by silica gel column chromatography with ethyl acetate/petroleum ether (1:100 to 1:10)

ORD record

ord-3b9bf6e857f24f4cad8c7aec75c31754

Source dataset

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09428502B2