[F:1][C:2]1[C:3]([N+:11]([O-:13])=[O:12])=[C:4]([OH:10])[CH:5]=[C:6]([F:9])[C:7]=1[F:8].C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.[CH3:33][O:34][CH2:35][CH2:36]O.N(C(OC(C)C)=O)=NC(OC(C)C)=O>C1COCC1>[F:9][C:6]1[CH:5]=[C:4]([O:10][CH2:36][CH2:35][O:34][CH3:33])[C:3]([N+:11]([O-:13])=[O:12])=[C:2]([F:1])[C:7]=1[F:8]To a mixture of 3,4,5-trifluoro-2-nitrophenol (1.93, 10 mmol), Ph3P (3.93 g, 15 mmol), and 2-methoxy-ethanol (1.18 ml, 15 mmol) in anhydrous THF (25 ml) a solution of diisopropyl azodicarboxylate (2.91 ml, 15 mmol) in THF (5 ml) was added at 0° C. and the reaction mixture was stirred at room temperature for 16 h. The volatiles were evaporated and the residue was dissolved in CH2Cl2 (100 ml) and the organic layer was washed with water (100 ml), brine (100 ml) dried (MgSO4) and evaporated. The residue obtained was purified over flash silica gel chromatography to obtain the titled product in 68% (1.70 g) yield. 1H NMR (300 MHz, CDCl3): δ 6.78 (ddd, J=2.4, 6.0, 11.7 Hz, 1H), 4.19 (t, J=4.5 Hz, 2H), 3.72 (t, J=4.5 Hz, 2H), 3.39 (s, 3H).
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