Sodium Azide → 1-Amino-2-(3,4-difluorophenyl)propan-2-ol

Temperature

0 °C

To a solution of 2-(3,4-difluorophenyl)-2-methyl-oxirane (1.2 g, 7.06 mmol) in 10 mL of acetonitrile was added sodium azide (0.69g, 10.6 mmol) followed by lithium perchlorate (1.13 g, 10.6 mmol) and the suspension was heated to reflux overnight. After cooling, it was extracted with EtOAc, washed with saturated NaHCO3, dried over Na2SO4, filtered and the solvent was removed in vacuo. The light bron oil that was obtained was a 10:1 mixture of 1-azido-2-(3,4-difluorophenyl)-propan-2-ol and 2-azido-2-(3,4-difluorophenyl)-propan-1-ol (crude wt 2.0 g). It was dissolved in 40 mL of diethyl ether, cooled to 0° C. and then treated with a solution of lithium aluminum hydride (20.0 mL, 20 mmol). The resulting yellow suspension was then stirred at room temperature for 2 h. The reaction mixture was cooled to 0° C. and then carefully quenched sequentially with 0.8 mL of water, 0.8 mL of 3N NaOH followed by 2.5 mL of water. The resulting suspension was filtered through a fritted glass funnel. To the residue was added 100 mL Et2O and the suspension was heated to reflux for 20 min. The suspension was filtered and was combined with the previous filtrate, dried over MgSO4, filtered and the solvent was removed in vacuo. 1-Amino-2-(3,4-difluorophenyl)-propan-2-ol and 2-amino-2-(3,4-difluorophenyl)-propan-1-ol was obtained as a yellow glassy syrup (1.16 g, 87%) which was used in the next step immediately without further purification.

1. temperaturethe suspension was heated
2. temperatureto reflux overnight
3. temperatureAfter cooling
4. extractionit was extracted with EtOAc
5. washwashed with saturated NaHCO3
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. customthe solvent was removed in vacuo
9. customThe light bron oil that was obtained
10. temperatureThe reaction mixture was cooled to 0° C.
11. customcarefully quenched sequentially with 0.8 mL of water, 0.8 mL of 3N NaOH
12. filtrationThe resulting suspension was filtered through a fritted glass funnel
13. additionTo the residue was added 100 mL Et2O
14. temperaturethe suspension was heated
15. temperatureto reflux for 20 min
16. filtrationThe suspension was filtered
17. dry with materialdried over MgSO4
18. filtrationfiltered
19. customthe solvent was removed in vacuo

ORD record

ord-011136e7bbff4692a3965f0d4a78812b

Source dataset

uspto-grants-2003_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06620815B1