[Br:1][C:2]1[CH:3]=[C:4]([N+:12]([O-:14])=[O:13])[C:5]([O:10][CH3:11])=[C:6]([CH:9]=1)[CH2:7]Br.P(OCC)(OCC)OCC.[H-].[Na+].O=[C:28]1[CH2:33][CH2:32][N:31]([C:34]([O:36][C:37]([CH3:40])([CH3:39])[CH3:38])=[O:35])[CH2:30][CH2:29]1.[Cl-].[NH4+]>O1CCCC1.CN(C)C=O>[Br:1][C:2]1[CH:3]=[C:4]([N+:12]([O-:14])=[O:13])[C:5]([O:10][CH3:11])=[C:6]([CH:9]=1)[CH:7]=[C:28]1[CH2:33][CH2:32][N:31]([C:34]([O:36][C:37]([CH3:40])([CH3:39])[CH3:38])=[O:35])[CH2:30][CH2:29]1A mixture of 5-bromo-2-methoxy-3-nitrobenzyl bromide (8.4 9, 26 mmol) and triethyl phosphite (4.5 g, 27 mmol) was heated to 160° C. for 2 h and then evaporated in vacuo to give a dark amber oil. This was dissolved in anhydrous tetrahydrofuran (20 mL) and added dropwise to a stirring suspension of sodium hydride (60%) (1.14 g) in anhydrous N,N-dimethylformamide (100 mL) at 0° C. The mixture was left to stir for 1 hour. tert-Butyl 4-oxopiperidine-1-carboxylate (5.17 g, 26 mmol) in anhydrous THF (30 mL) was added to the mixture. Stirring was continued for 4 h at room temperature before the mixture was poured into saturated ammonium chloride (100 mL) and extracted with diethyl ether (2×150 mL). The combined organic layer was evaporated in vacuo to give a crude oil. Silica gel chromatography eluting with diethyl ether in petroleum ether (5–30%) gave the title compound (3.9 g, 35%) as an oil.
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