Reaktion #86459

Reaktionsgleichung

2-chloro-6-fluoro-3,5-dimethoxybenzoic acid

triethyl amine

TFA

Diphenyl phosphoryl azide

→

title compound

Ausbeute 60.0%

2-chloro-6-fluoro-3,5-dimethoxyaniline

Ausbeute 60.0%

Lösungsmittel

tert-BuOH

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added
2. 2
   workup.WAITkept at this temperature for overnight
3. 3
   EinengenThe reaction mixture was then concentrated in vacuo
4. 4
   Sonstigeto obtain a crude residue
5. 5
   Temperaturcooled to 0° C
6. 6
   Sonstigethe resultant reaction mixture
7. 7
   workup.STIRRINGwas then stirred at room temperature for 2 h
8. 8
   SonstigeThe solvents were removed under vacuum
9. 9
   workup.ADDITIONthe crude residue was diluted with ethyl acetate and saturated sodium carbonate solution
10. 10
    SonstigeThe aqueous layer was separated
11. 11
    Extraktionextracted with ethyl acetate (3×30 mL)
12. 12
    WaschenThe organic phase was washed with brine
13. 13
    Trocknendried over Na2SO4
14. 14
    Filtrationfiltered
15. 15
    Einengenconcentrated
16. 16
    SonstigeThe residue was purified by silica gel column chromatography

Vorschrift

A suspension of 2-chloro-6-fluoro-3,5-dimethoxybenzoic acid (10.8 g, 0.0077 mol) and triethyl amine (0.934 g, 0.0092 mol) in tert-BuOH (50 mL) was stirred for 5 min. To the resulting reaction mixture, Diphenyl phosphoryl azide (2.53 g, 0.0092 mol) was added and heated up to 82° C. and kept at this temperature for overnight. The reaction mixture was then concentrated in vacuo to obtain a crude residue. The crude residue was dissolved in dichloromethane (20 mL) and cooled to 0° C. TFA (4 mL) was added to the reaction mixture and the resultant reaction mixture was then stirred at room temperature for 2 h. The solvents were removed under vacuum and the crude residue was diluted with ethyl acetate and saturated sodium carbonate solution. The aqueous layer was separated and extracted with ethyl acetate (3×30 mL). The organic phase was washed with brine, dried over Na2SO4, filtered, and concentrated. The residue was purified by silica gel column chromatography using the eluent (gradient hexane to hexane-ether (65:35)) to afford the title compound (0.95 g, yield: 60%) as solid. MS (ESI): 205.7 [M+H]+.

Quelle