Reaktion #312490

Reaktionsgleichung

hydrochloric acid

lithium diisopropylamide

4-hydroxybenzeneacetic acid

ethyl chloroformate

→

α-carboxy-4-hydroxybenzeneacetic acid

Lösungsmittel

water

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe temperature is raised from about -40° C. to about 20° C.
2. 2
   Sonstigethe monoester of α-carboxy-4-hydroxybenzeneacetic acid is recovered from the aqueous solution
3. 3
   SonstigeHydrolysis of the half-ester with sodium hydroxide

Vorschrift

About 0.5 mole of 4-hydroxybenzeneacetic acid is dissolved in about 50 ml of anhydrous tetrahydrofuran at -40° C. To this solution is added 3 equivalents of lithium diisopropylamide. The temperature is maintained at about -40° C. for about 15 minutes. Then 1 equivalent of ethyl chloroformate is added and the temperature is raised from about -40° C. to about 20° C. and the reaction mixture stirred for about 60 minutes. The reaction mixture is poured into water and the monoester of α-carboxy-4-hydroxybenzeneacetic acid is recovered from the aqueous solution. Hydrolysis of the half-ester with sodium hydroxide followed by acidification with hydrochloric acid gives α-carboxy-4-hydroxybenzeneacetic acid.

Quelle