p-Toluenesulfonic acid → 1-(2-Nitro-4-trifluoromethylphenyl)-butan-1,3-dione
Reaktionsgleichung
[N+:1]([C:4]1[CH:22]=[C:21]([C:23]([F:26])([F:25])[F:24])[CH:20]=[CH:19][C:5]=1[C:6]([CH:8]([C:16](=[O:18])[CH3:17])C(OC(C)(C)C)=O)=[O:7])([O-:3])=[O:2].C1(C)C=CC(S(O)(=O)=O)=CC=1>>[N+:1]([C:4]1[CH:22]=[C:21]([C:23]([F:24])([F:25])[F:26])[CH:20]=[CH:19][C:5]=1[C:6](=[O:7])[CH2:8][C:16](=[O:18])[CH3:17])([O-:3])=[O:2]Komponenten
3
Versuchsvorschrift
A mixture of crude t-butyl 2-(2-nitro-4-trifluoromethylbenzoyl)-3-oxobutanoate (9.1 g) and 4-toluenesulphonic acid (0.1 g) in dry, toluene (100 ml) was stirred and heated at reflux for 3 hours. The cooled mixture was extracted with aqueous sodium hydroxide solution (2M, 2×50 ml) and water (2×50 ml). The combined aqueous extracts were acidified to pH 1 and extracted with ether (3×100 ml). The combined organic layers were washed with water (50 ml), dried (anhydrous sodium sulphate) and filtered. The filtrate was evaporated to dryness and the residue was recrystallized from petroleum spirit (bp 60°-80° C.) to give 1-(2-nitro-4-trifluoromethylphenyl)-butan-1,3-dione (4.6 g) as an off white solid mp 80°-81° C.