Reaktion #81549

Reaktionsgleichung

sodium bicarbonate

4-hydroxybenzoic acid

isobutylene

sulfuric acid

→

title product

4-Hydroxybenzoic acid tert-butyl ester

Lösungsmittel

1,4-dioxane

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe bomb was sealed
2. 2
   Temperaturthe reaction mixture was cooled to -78° C.
3. 3
   Extraktionextracted with diethyl ether (2×50.0 mL)
4. 4
   EinengenThe combined organic phases were concentrated
5. 5
   Sonstigethe residue chromatographed on silica gel (
6. 6
   Wascheneluted with 5% methanol in methylene chloride

Vorschrift

To a solution of 4-hydroxybenzoic acid (2.00 g, 14.5 mmol) in 1,4-dioxane (10.0 mL) saturated with isobutylene at -78° C. in a metal bomb was added concentrated sulfuric acid (0.150 mL). The bomb was sealed and warmed to room temperature. After 72 hours at room temperature, the reaction mixture was cooled to -78° C., poured into saturated sodium bicarbonate (30.0 mL) and extracted with diethyl ether (2×50.0 mL). The combined organic phases were concentrated and the residue chromatographed on silica gel (eluted with 5% methanol in methylene chloride to give 290 mg (Y: 10%) of the title product; 1H-NMR (CDCl3): δ7.89 (d, J=8.8 Hz, 2H), 6.83 (d, J=8.8 Hz, 2H), 1.57 (s, 9H).

Quelle