[OH:1][C:2]1[CH:9]=[C:8]([N+:10]([O-:12])=[O:11])[CH:7]=[CH:6][C:3]=1[C:4]#[N:5].[CH2:13]1[CH2:23][CH2:22]N2C(=NCCC2)C[CH2:14]1.F[C:25](F)(F)C([O-])=O>CC#N>[CH3:25][C:13]([CH3:14])([O:1][C:2]1[CH:9]=[C:8]([N+:10]([O-:12])=[O:11])[CH:7]=[CH:6][C:3]=1[C:4]#[N:5])[C:23]#[CH:22]To a solution of 2-hydroxy-4-nitro-benzonitrile (413.6 mg, 2.52 mmol, prepared as described in Yasubiro Imakura et al, Chem. Pharm. Bull, 40 (7), 1691-1696, (1992)) in CH3CN (1.5 mL) cooled to −5° C. was added DBU (0.48 mL, 3.2 mmol) and CuCl2.2H2O (2 mg), followed by addition of a solution of trifluoroacetate prepared above over 30 min while maintaining the reaction temperature below 0° C. After addition, the reaction mixture was stirred at 0° C. for 2 h, then concentrated under reduced pressure. The residue was partitioned between EtOAc (100 mL) and water (30 mL), and the separated organic layer washed with 1 N aqueous HCl (2×20 mL), 1 N aqueous NaOH (20 mL), 1 N aqueous NaHCO3, brine, then dried (Na2SO4), and concentrated under reduced pressure. The crude product was chromatographed (silica gel) eluting with 0% to 50% EtOAc/hexane to furnish the title compound (280 mg, 48%).
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