Reaktion #487421

Reaktionsgleichung

triethylborate

p-bromoanisole

sulfuric acid

water

→

expected product

(4-methoxyphenyl)-boronic acid

Lösungsmittel

ether

diethyl ether

diethyl ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe mixture was refluxed for 2 hours
2. 2
   workup.WAITfor one hour at ambient temperature
3. 3
   workup.STIRRINGstirring
4. 4
   workup.WAITwas carried out for one hour
5. 5
   ExtraktionThe organic phase was extracted with 100 ml of a saturated aqueous solution of sodium bicarbonate
6. 6
   Extraktionfollowed by extraction with ether
7. 7
   Sonstigedrying
8. 8
   Sonstigeevaporating under reduced pressure

Vorschrift

100 ml of a solution of 10 g of p-bromoanisole in anhydrous diethyl ether were added dropwise at reflux under an inert gas atmosphere to a suspension of 1.3 g of Mg turnings in 5 ml of anhydrous diethyl ether, and the mixture was refluxed for 2 hours. The mixture was then poured into a solution of 9.02 ml of triethylborate in 60 ml of anhydrous ether cooled to -70° C. After stirring for one hour at -70° C., then for one hour at ambient temperature, the solution was poured into a mixture of 11 ml of sulfuric acid and 50 g of ice and water and stirring was carried out for one hour. The organic phase was extracted with 100 ml of a saturated aqueous solution of sodium bicarbonate and the aqueous phases were combined and reacidified with 6N hydrochloric acid, followed by extraction with ether, drying and evaporating under reduced pressure to obtain 3.9 g of the expected product.

Quelle