Br[C:2]1[CH:7]=[C:6]([F:8])[C:5]([N+:9]([O-:11])=[O:10])=[CH:4][C:3]=1[F:12].[C:13]([Cu])#[N:14].[O-]S([O-])(=O)=O.[Na+].[Na+].CC(OC)(C)C>CN1C(=O)CCC1>[F:12][C:3]1[CH:4]=[C:5]([N+:9]([O-:11])=[O:10])[C:6]([F:8])=[CH:7][C:2]=1[C:13]#[N:14]A mixture of 1-bromo-2,5-difluoro-4-nitro-benzene (95 g, 399 mmol) and CuCN (71.8 g, 798 mmol) in NMP (700 mL) was set to a pre-heated 160° C. oil-base and stirred at 160° C. under N2 over 450 min. The mixture was cooled to RT, charged with Na2SO4 (300 g) and MTBE (1 L), and stirred for an additional 15 min. The resulting mixture was filtered and the filtrate was charged with 800 mL of water, then the separated aqueous layer was extracted with MTBE. The combined organic layers were washed with water and brine, dried over Na2SO4 and concentrated. The material was recrystallized from EtOH/water (2/1) to yield 2,5-Difluoro-4-nitro-benzonitrile (50 g, 68% yield) as a pale brown solid. 1H NMR (400 MHz, CDCl3) δ 7.96-7.95 (dd, 1H), 7.67-7.64 (dd, 1H).
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