反応 #86459

反応方程式

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

triethyl amine

TFA

Diphenyl phosphoryl azide

→

title compound

収率 60.0%

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

収率 60.0%

溶媒

tert-BuOH

dichloromethane

反応条件

後処理

1. 1
   workup.ADDITIONwas added
2. 2
   workup.WAITkept at this temperature for overnight
3. 3
   濃縮The reaction mixture was then concentrated in vacuo
4. 4
   その他to obtain a crude residue
5. 5
   温度cooled to 0° C
6. 6
   その他the resultant reaction mixture
7. 7
   workup.STIRRINGwas then stirred at room temperature for 2 h
8. 8
   その他The solvents were removed under vacuum
9. 9
   workup.ADDITIONthe crude residue was diluted with ethyl acetate and saturated sodium carbonate solution
10. 10
    その他The aqueous layer was separated
11. 11
    抽出extracted with ethyl acetate (3×30 mL)
12. 12
    洗浄The organic phase was washed with brine
13. 13
    乾燥dried over Na2SO4
14. 14
    ろ過filtered
15. 15
    濃縮concentrated
16. 16
    その他The residue was purified by silica gel column chromatography

実験手順

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]+.

出典