Cl[CH2:2][CH2:3][C:4]1[CH:5]=[C:6]([C:14]([O:16][CH3:17])=[O:15])[C:7]([C:10]([O:12][CH3:13])=[O:11])=[N:8][CH:9]=1.[N+](=C1CCCCCCCCCC1C1CCCCCCCCCC1)=[N-]>C1(C)C=CC=CC=1>[CH:3]([C:4]1[CH:5]=[C:6]([C:14]([O:16][CH3:17])=[O:15])[C:7]([C:10]([O:12][CH3:13])=[O:11])=[N:8][CH:9]=1)=[CH2:2]A solution of 2 g of 5-(2-chloroethyl)-pyridine-2,3-dicarboxylic acid, dimethyl ester and 0.13 mL diazobicycloundecane (DBU) in 40 mL of toluene is heated at reflux for 11/2 hours, cooled, and filtered. The filtrate is concentrated in vacuo, and the residue is chromatographed on silica gel using hexane-ethyl acetate mixtures to afford the desired product as a colorless oil.
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