[CH3:1][O:2][C:3](=[O:21])[C:4]1[CH:9]=[CH:8][C:7]([CH:10]([C:16]#[N:17])[C:11]([O:13][CH2:14][CH3:15])=[O:12])=[C:6]([N+:18]([O-])=O)[CH:5]=1.ClCCl>C(O)(=O)C.C(OCC)(=O)C.[Zn]>[CH3:1][O:2][C:3]([C:4]1[CH:5]=[C:6]2[C:7]([C:10]([C:11]([O:13][CH2:14][CH3:15])=[O:12])=[C:16]([NH2:17])[NH:18]2)=[CH:8][CH:9]=1)=[O:21]Zinc powder (4.9 g) was added portion-wise at 80° C. to a solution of 4-(cyano-ethoxycarbonyl-methyl)-3-nitro-benzoic acid methyl ester (4.40 g, 15 mmol) in acetic acid. The mixture was then heated for 3 hours at 95° C. and 3 hours at 100° C. before being allowed to cool to room temperature at which point the reaction mixture was filtered and the insoluble matter rinsed with acetic acid. The filtrate was concentrated to give a brown oil which was subjected to flash silica chromatography using ethyl acetate as eluent. The partially purified oil was taken up into dichloromethane and the product precipitated using hexane to give the title compound as a pale brown solid (1.71 g, 6.5 mmol). LC-MS (1) Rt 1.88 min; m/z 263.
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