Reaktion #65221

Reaktionsgleichung

HCl

ethyl 4-(3,5-di-tert-butyl-4-hydroxy -phenyl)-2-oxo-2,6,7,8-tetrahydrocyclopenta [g] [1]benzopyran-3-carboxylate

potassium hydroxide

ethanol

→

2-oxo-2,6,7,8-tetrahydrocyclopenta[g] [1]benzopyran-3-carboxylic acid

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionextracted with ethyl acetate
2. 2
   WaschenThe extract was washed with water
3. 3
   Trocknendried (MgSO4)
4. 4
   workup.DISTILLATIONthe solvent was distilled off

Vorschrift

A mixture of ethyl 4-(3,5-di-tert-butyl-4-hydroxy -phenyl)-2-oxo-2,6,7,8-tetrahydrocyclopenta [g] [1]benzopyran-3-carboxylate (1.85 g), potassium hydroxide (1.12 g) and 80% ethanol (12 ml) was stirred at room temperature for 3 hours. The reaction mixture was then diluted with water, adjusted to pH4 with 6N HCl and extracted with ethyl acetate. The extract was washed with water and dried (MgSO4) and the solvent was distilled off to give crystals of 4-3,5-di-tert-butyl-4-hydroxyphenyl)-2-oxo-2,6,7,8-tetrahydrocyclopenta[g] [1]benzopyran-3-carboxylic acid. The crystals were collected by filtration and washed with isopropyl ether (1.13 g, 64.9%). mp. 256°-260° C.

Quelle