Phthalic Anhydride → 2-(2,5-Dimethylbenzoyl)benzoic acid
Reaktionsgleichung
[C:1]1(=[O:11])[O:6][C:4](=[O:5])[C:3]2=[CH:7][CH:8]=[CH:9][CH:10]=[C:2]12.[Al+3].[Cl-].[Cl-].[Cl-].[CH3:16][C:17]1[CH:18]=[CH:19][C:20]([CH3:23])=[CH:21][CH:22]=1>>[CH3:16][C:17]1[CH:18]=[CH:19][C:20]([CH3:23])=[CH:21][C:22]=1[C:4]([C:3]1[CH:7]=[CH:8][CH:9]=[CH:10][C:2]=1[C:1]([OH:6])=[O:11])=[O:5]Komponenten
4
Versuchsvorschrift
Monomers. The spirobislactone endcapping group, 4-carboxy-7,7'-dioxa-2,2'-spirobi (benzo[c]tetrahydrofuran) 5,was synthesized using a three-step procedure. Phthalic anhydride (PA) 1 was reacted with p-xylene 2 in the presence of AlCl3 to produce ##STR6## 2,5-dimethyl-2'-carboxybenzophenone 3. Oxidation by potassium permanganate yielded the triacid 4 which was cyclized to 5 by refluxing with Dowex 50X8-100 resin (H+) in 2-methoxyethyl ether and removing the water of reaction.