Reaktion #215484

Reaktionsgleichung

diethyl 2-(6,7,8,9-tetrahydro-2-dibenzofuranyl)-4-hydroxy-4-methyl-1,3-cyclohexanedicarboxylate

sodium hydroxide

ethanol

→

3-(6,7,8,9-Tetrahydro-2-dibenzofuranyl)-glutaric acid

Lösungsmittel

dioxan

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction mixture is heated to 90° for 30 minutes
2. 2
   Einengenconcentrated to about 1/3rd of its volume
3. 3
   workup.DISTILLATIONby distilling off the solvents
4. 4
   workup.ADDITIONAfter diluting the mixture with 750 ml of water, 350 ml of concentrated hydrochloric acid
5. 5
   workup.ADDITIONare added, with ice-water cooling
6. 6
   SonstigeThe crude acid which has precipitated
7. 7
   Filtrationis filtered off
8. 8
   Waschenwashed thoroughly with water
9. 9
   Sonstigedried

Vorschrift

A solution of 44.2 g (0.1 mol) of diethyl 2-(6,7,8,9-tetrahydro-2-dibenzofuranyl)-4-hydroxy-4-methyl-1,3-cyclohexanedicarboxylate in 250 ml of dioxan is added dropwise to a solution of 120 g (3 mols) of sodium hydroxide in 125 ml of water with 250 ml of ethanol at 90° in the course of 30 minutes. The reaction mixture is heated to 90° for 30 minutes and then concentrated to about 1/3rd of its volume by distilling off the solvents. After diluting the mixture with 750 ml of water, 350 ml of concentrated hydrochloric acid are added, with ice-water cooling. The crude acid which has precipitated is filtered off, washed thoroughly with water and dried. 3-(6,7,8,9-Tetrahydro-2-dibenzofuranyl)-glutaric acid is thus obtained as light yellow-brown crystals of melting point 165°-170°. A sample crystallised from ethanol/water melts at 169°-174°.

Quelle