Br[CH2:2][C:3]1[CH:15]=[CH:14][C:6]([C:7]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8])=[CH:5][C:4]=1[N+:16]([O-:18])=[O:17].O.[CH3:20][N:21](C=O)C>>[CH3:20][NH:21][CH2:2][C:3]1[CH:15]=[CH:14][C:6]([C:7]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8])=[CH:5][C:4]=1[N+:16]([O-:18])=[O:17]Anhydrous methylamine was bubbled into anhydrous DMF (200 mL) at 0° C. for 15 min. A solution of t-butyl 4-bromomethyl-3-nitrobenzoate (5.0 g, 15.8 mmol) (Int. J. Peptide. Res., 36, 31 (1990)) in DMF (10 mL) was added dropwise to the cold amine solution. The solution was stirred at 0° for 30 min and poured into water. The mixture was extracted with ethyl acetate and the combined organic layers were washed with water, dried (sodium sulfate) and concentrated to give a yellow-brown oil. The oil was purified by chromatography (silica gel, 3% isopropanol/CH2Cl2) to give the title compound (1.5 g, 36%). 1H NMR (400 MHz, CDCl3) δ8.5 (s, 1H), 8.2 (d, 1H), 7.7 (d, 1H), 4.05 (s, 2H), 2.5 (s, 3H), 1.6 (s, 9H).
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