Reaktion #1836

Reaktionsgleichung

Cyclohexene

bromine

2-[2-(1H-tetrazol-5-yl)phenyl]-5-methylbenzofuran

1,4-dioxane

→

product

Ausbeute 85.0%

3-Bromo-2-[2-(1H-tetrazol-5-yl)phenyl]-5-methylbenzofuran

Ausbeute 85.0%

Lösungsmittel

carbon tetrachloride

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeA 1 L 3-neck round bottom flask equipped with a magnetic stirrer
2. 2
   Einengenit was concentrated under vacuum to an oily residue that
3. 3
   Sonstigewas partitioned between 100 mL of 1N aqueous sodium hydroxide and 100 mL of ether
4. 4
   SonstigeThe aqueous layer was removed
5. 5
   Extraktionextracted several times with ethyl acetate
6. 6
   WaschenThe combined extracts were washed with saturated aqueous sodium chloride
7. 7
   Trocknendried over magnesium sulfate
8. 8
   Filtrationfiltered
9. 9
   Einengenconcentrated under vacuum
10. 10
    Sonstigeto give a white foam that
11. 11
    Sonstigewas triturated with 100 mL of hot toluene
12. 12
    TemperaturThe mixture was cooled in an ice bath
13. 13
    Sonstigethe solids removed by filtration
14. 14
    Waschenthen washed with cold toluene, air
15. 15
    Sonstigedried
16. 16
    Sonstigedried under vacuum

Vorschrift

A 1 L 3-neck round bottom flask equipped with a magnetic stirrer, thermometer, dropping funnel and nitrogen bubbler was charged with 12.97 g (46.9 mmol) of 2-[2-(1H-tetrazol-5-yl)phenyl]-5-methylbenzofuran and 500 mL of 1,4-dioxane. To the well-stirred solution at room temperature was added a solution of 4.8 mL (93.2 mmol) of bromine in 35 mL of carbon tetrachloride dropwise over 1 hour. Cyclohexene (16 mL) was added to the reaction mixture then it was concentrated under vacuum to an oily residue that was partitioned between 100 mL of 1N aqueous sodium hydroxide and 100 mL of ether. The aqueous layer was removed, acidified with 50 mL of 2N aqueous hydrochloric acid, and extracted several times with ethyl acetate. The combined extracts were washed with saturated aqueous sodium chloride, dried over magnesium sulfate, filtered and concentrated under vacuum to give a white foam that was triturated with 100 mL of hot toluene. The mixture was cooled in an ice bath and the solids removed by filtration then washed with cold toluene, air dried and dried under vacuum to give 14.11 g (39.7 mmol, 85%) of product. 1H NMR (200 MHz,CDCl3 +1 drop DMSO-d6): 2.44 (s,3H), 7.1-7.3 (m,4H), 7.6 (m,2H), 7.86 (m,1H), 7.95 (m,1H).

Quelle