F[C:2]1[C:9]([F:10])=[C:8]([C:11]#[N:12])[C:7]([F:13])=[C:6]([F:14])[C:3]=1[C:4]#[N:5].[N:15]1([C:21]([O:23][C:24]([CH3:27])([CH3:26])[CH3:25])=[O:22])[CH2:20][CH2:19][NH:18][CH2:17][CH2:16]1.C(N(CC)CC)C>CC(C)=O.O>[C:4]([C:3]1[C:6]([F:14])=[C:7]([F:13])[C:8]([C:11]#[N:12])=[C:9]([F:10])[C:2]=1[N:18]1[CH2:17][CH2:16][N:15]([C:21]([O:23][C:24]([CH3:27])([CH3:26])[CH3:25])=[O:22])[CH2:20][CH2:19]1)#[N:5]2,3,5,6-tetrafluoroterephthalonitrile (1 g, 5 mmol) was dissolved in acetone (15 mL) in a 2-necked flask under Nitrogen. A solution of tert-butyl piperazine-1-carboxylate (1.39 g, 7.5 mmol) in water (3 mL) was then added followed by triethylamine (1.01 g, 10 mmol). The solution was heated to 55° C. for 8 h then cooled to rt. The resulting solid was filtered then washed with acetone. The filtrate was concentrated under vacuum and the residue was dissolved again in DCM (30 mL) and washed once with 1M HCl (30 mL) and once with brine (30 mL). The organics were dried over Na2SO4, filtered and the solvent removed in vacuo to give tert-butyl 4-(2,5-dicyano-3,4,6-trifluorophenyl)piperazine-1-carboxylate as a bright yellow solid (0.938 g, 51% yield).
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