1,4-Dichlorobenzene → 2,5-Dichlorobenzophenone
Reaktionsgleichung
[CH:1]1[C:6]([Cl:7])=[CH:5][CH:4]=[C:3]([Cl:8])[CH:2]=1.[C:9](Cl)(=[O:16])[C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1.[Cl-].[Al+3].[Cl-].[Cl-]>>[Cl:7][C:6]1[CH:5]=[CH:4][C:3]([Cl:8])=[CH:2][C:1]=1[C:9]([C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1)=[O:16]Komponenten
4
Versuchsvorschrift
In one example of the prior methods just described, after heating dichlorobenzene and benzoyl chloride with aluminum chloride for 49 hours at 150° to 170° C., 2,5-dichlorobenzophenone was obtained in only 20% yield. (Th. de Crauw, Rec. Trav. Chim. Pay Bas 50, 767, (1931)). In another case, 2,5-dichlorobenzophenone was obtained in 0.8% yield, together with appreciable amounts of other isomers, after running the reaction in nitrobenzene for 10 hours at 100° C. (P. A. Goodman et al., J. Chem. Soc. (C) 2452, (1968)). Other unsuccessful examples can be found in the literature. See, e.g., J. Ganzmuller, J. Prakt. Chem. 138, 311, (1933); p. H. Gore et al., Zh. Org. Khim., 1145, (1967) 10% yield; M. Godfrey et al., Tetrahedron, 32, 843, (1976) (0.8% yield).