Reaction Steps
To a solution of 3-hydroxy-4-nitrobenzaldehyde (0.80 g, 4.78 mmol), in DMF (15 mls) was added ethyl 6-bromohexanoate (1.30 g, 5.82 mmol) and potassium carbonate (1.23 g, 8.91 mmol). The mixture was stirred at 70° C. for 12 hours, cooled, poured into water and extracted twice with ethyl acetate. The combined organic fractions were washed once with water and dried over anhydrous magnesium sulfate. After the solvents were removed under reduced pressure, a red oil remained which was purified by column chromatography (70% hexane/30% ethyl acetate) to give 6-(5-formyl-2-nitro-phenoxy)-hexanoic acid ethyl ester as a yellow oil (1.00 g, 67%). 1H NMR (400 MHz, CDCl3) δ: 10.06 (s, 1H), 7.92 (d, 1H, J=8.8 Hz), 7.58 (d, 1H, J=1.2 Hz), 7.54 (dd, 1H, J=8 Hz, J=1.6 Hz), 4.20 (q, 2H, J=6.8 Hz), 4.14 (t, 2H, J=7.2 Hz), 2.36 (t, 2H, J=8.0 Hz), 1.90 (m, 2H), 1.73 (m, 2H), 1.57 (m, 2H), 1.29 (t, 3H, J=6.8 Hz). 13C NMR (400 MHz, CDCl3) δ: 173.79, 169.46, 151.87, 143.23, 133.66, 125.32, 121.93, 115.88, 69.65, 60.42, 34.12, 28.54, 25.40, 24.52, 14.25. IR (neat): 3396, 3110, 3080, 3047, 2944, 2869, 2735, 1730, 1705, 1607, 1531, 1489, 1465, 1434, 1381, 1351, 1311, 1272, 1161, 1093, 1063, 1030, 961, 863 cm−1.
