Reaktion #43447

Reaktionsgleichung

sodium hydride

ethylene glycol

3,4,6-trichloropyridazine

bromo-dichloropyridazine

→

solid

Ausbeute 83.0%

2-[(3,6-Dichloro-4-pyridazinyl)oxy]ethanol

Ausbeute 83.0%

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONAfter the addition
2. 2
   workup.ADDITIONwas added portionwise
3. 3
   Waschenwashed in with more dry THF (50 ml)
4. 4
   Sonstigeat room temperature
5. 5
   Sonstigeovernight
6. 6
   EinengenThe mixture was concentrated (to ⅓ volume)
7. 7
   workup.ADDITIONthen diluted with aqueous sodium bicarbonate solution
8. 8
   Extraktionextracted with chloroform (5×) and ethyl acetate (3×)
9. 9
   WaschenThe combined organic extracts were washed with water
10. 10
    Trocknendried over sodium sulphate
11. 11
    Sonstigeevaporated
12. 12
    Filtrationthe solids filtered off
13. 13
    Waschenwashed with CHCl3 (×3)
14. 14
    Sonstigedried in a vacuum oven overnight at 40° C.

Vorschrift

A solution of ethylene glycol (55 ml) in tetrahydrofuran (200 ml) was treated at around 0° C. (ice bath cooling) with sodium hydride (60% dispersion in oil, 5.9 g) over 40 minutes. After the addition was complete, 3,4,6-trichloropyridazine (27 g) containing isomers of bromo-dichloropyridazine as impurity was added portionwise and washed in with more dry THF (50 ml) and the mixture was stirred at 0° C. for 1 hour and then at room temperature overnight. The mixture was concentrated (to ⅓ volume) then diluted with aqueous sodium bicarbonate solution and extracted with chloroform (5×) and ethyl acetate (3×). The combined organic extracts were washed with water, dried over sodium sulphate and evaporated and the solids filtered off and washed with CHCl3 (×3) and dried in a vacuum oven overnight at 40° C. affording a white solid (25.5 g, 83%), containing some bromo-derivative (10-15%).

Quelle