[CH:1]1([NH2:7])[CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]1.[N+](=C1CCCCCCCCC(C2CCCCCCCCCC=2)=C1)=[N-].Br[CH2:33][C:34]([O:36][CH3:37])=[O:35]>O1CCCC1>[CH:1]1([NH:7][CH2:33][C:34]([O:36][CH3:37])=[O:35])[CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]1A solution of cyclohexylamine (34.3 ml) and diazobicycloundecene (DBU, 44.8 ml) in dry tetrahydrofuran (500 ml) under a nitrogen atmosphere was cooled to 0° C. and was treated dropwise with a solution of methyl bromoacetate (28.4 ml) in tetrahydrofuran (50 ml). After stirring at room temperature overnight, the mixture was filtered to remove precipitated DBU-hydrobromide and the solvent evaporated. The resulting residue was dissolved in ether (200 ml), washed with water (2×100 ml), and brine (2×100 ml). The organic extract was dried, filtered and evaporated. Fractional distillation provided 21.1 g., b.p. 160°-170° C. (0.2 mm).
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