Reaktion #607447

Reaktionsgleichung

DIAD

3-bromo-6-methyl-5-nitro-pyridin-2-ol

2,2,2-trifluoro-1-[4-(trifluoromethyl)phenyl]ethanol

triphenylphosphine

→

title compound

Ausbeute 41.0%

5-Bromo-2-methyl-3-nitro-6-[2,2,2-trifluoro-1-[4-(trifluoromethyl)phenyl]ethoxy]pyridine

Ausbeute 41.0%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwere added at room temperature under inert atmosphere (Ar)
2. 2
   Sonstigethe temperature below 40° C
3. 3
   Sonstigewas consumed
4. 4
   Sonstigeto reach room temperature
5. 5
   Sonstigebefore quenching with water (10 mL)
6. 6
   ExtraktionThe water phase was extracted with ethyl acetate (2×50 mL)
7. 7
   WaschenThe organic layer was washed with brine (20 mL)
8. 8
   Trocknendried over anhydrous Na2SO4
9. 9
   Filtrationfiltered
10. 10
    SonstigeThe solvent was removed in vacuo
11. 11
    Sonstigeto give a brown residue, which
12. 12
    Sonstigewas purified by combiflash column chromatography (silica gel, heptane/ethyl acetate, v/v=95/5)
13. 13
    workup.ADDITIONFractions containing the pure compound
14. 14
    Sonstigewere collected
15. 15
    Einengenconcentrated in vacuo

Vorschrift

To a stirring suspension of 3-bromo-6-methyl-5-nitro-pyridin-2-ol (0.25 g, 1.07 mmol) in THF (7 mL), 2,2,2-trifluoro-1-[4-(trifluoromethyl)phenyl]ethanol (0.39 g, 1.61 mmol, 1.5 equiv) and triphenylphosphine (0.42 g, 1.61 mmol, 1.5 eq) were added at room temperature under inert atmosphere (Ar). To this mixture, DIAD (diisopropyl diazodicarboxylate) (0.33 mL, 1.61 mmol, 1.5 eq) was added dropwise over 10 minutes while keeping the temperature below 40° C. The reaction mixture was stirred for 6 h under heating at 60° C. After this time, TLC indicted that the starting material was consumed and the reaction mixture was allowed to reach room temperature before quenching with water (10 mL). The water phase was extracted with ethyl acetate (2×50 mL). The organic layer was washed with brine (20 mL), dried over anhydrous Na2SO4 and filtered. The solvent was removed in vacuo to give a brown residue, which was purified by combiflash column chromatography (silica gel, heptane/ethyl acetate, v/v=95/5). Fractions containing the pure compound were collected and concentrated in vacuo to give the title compound (0.18 g, 41% yield) as a yellow oil.

Quelle