Alternative Synthesis of 1,8-Difluoroanthracene via the Balz-Schiemann Reaction

Figure 2

GC-MS chromatogram of sublimed 4 (top) giving single peak with retention time of 13.96 min and an M⁺ = 244 with a fragmentation pattern (bottom) corresponding to loss of CO from the anthraquinone (216 and 188). GC conditions: general-purpose column (15 m long) with a linear velocity flow rate set at 1.2 mL/min.