Nitrogen → 3-(3,5-difluorophenyl)dihydro-2H-pyran-4(3H)-one

Temperature

10 °C

To a mixture of (1R,2R)-2-aminocyclohexanol hydrochloride (0.418 g, 2.76 mmol), nickel(II) chloride hexahydrate (0.328 g, 1.378 mmol) and 3,5-difluorophenylboronic acid (6.53 g, 41.3 mmol) was added NaHMDS in THF (55.1 mL, 55.1 mmol) at 10° C. dropwise under N2. After addition, the mixture was stirred at 10° C. for 20 min. 2-Propanol (113 mL) (previously bubbled by N2) was added at 0° C. and then the mixture was stirred at RT for 10 min. 3-iodo-4,4-dimethoxytetrahydro-2H-pyran (Preparation X1) (7.5 g, 27.6 mmol). in THF was added dropwise and the mixture was heated at 60° C. overnight. The reaction mixture was cooled in ice bath, added 1.0HCl until acidic and stirred for 10 min. Concentrated in vacuum. Extracted with EtOAc and the organic layer was washed with brine and concentrated. The residue was purified by column chromatography on silica gel to give 3-(3,5-difluorophenyl)dihydro-2H-pyran-4(3H)-one (1.6 g, 7.54 mmol, 27.4% yield). 1H NMR (500 MHz, CDCl3) δ ppm 6.78 (dd, J=8.24, 2.14 Hz, 2 H) 6.62-6.75 (m, 1 H) 4.21 (dd, J=11.44, 5.65 Hz, 2 H) 3.85-4.01 (m, 2 H) 3.76 (dd, J=8.55, 6.10 Hz, 1 H) 2.60-2.75 (m, 1 H) 2.48-2.60 (m, 1 H)

1. additionAfter addition
2. custom2-Propanol (113 mL) (previously bubbled by N2)
3. additionwas added at 0° C.
4. stirringthe mixture was stirred at RT for 10 min
5. temperaturethe mixture was heated at 60° C. overnight
6. temperatureThe reaction mixture was cooled in ice bath
7. additionadded 1.0HCl until acidic and
8. stirringstirred for 10 min
9. concentrationConcentrated in vacuum
10. extractionExtracted with EtOAc
11. washthe organic layer was washed with brine
12. concentrationconcentrated
13. customThe residue was purified by column chromatography on silica gel

ORD record

ord-2abe3415b97c41e2a5f507b3a2b3d3a0

Source dataset

uspto-grants-2014_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08710061B2