Reaktionsschritte
KOH (3.78 g, 67.6 mmol) was added to a solution of 1 (12.0 g, 41.0 mmol) dissolved in 250 mL of hot EtOH, and the mixture was refluxed for 24 hours. The solvent was filtered off, and following drying over P2O5 the white solid was suspended in 300 mL of toluene, and refluxed with oxalyl chloride (13.4 mL, 158.54) for 6 hours. Volatile components were removed, the yellow solid was taken in CH2Cl2 (100 mL), and added to a stirred solution containing p-hydroxybenzaldehyde (5.26 g, 43.1), triethylamine (36 mL, 0.261 mol), and DMAP (0.28 g, 2.3 mmol) in CH2Cl2 (100 mL). The mixture was let to stir at room temperature for three hours, and then heated to reflux for twelve hours. Following cooling to room temperature, the organic layer was washed with 1 M HCl (2×100 mL), and then distilled water (100 mL). The solvent was removed, and the product was obtained as an off-white solid following recrystallization from ethanol. Yield (8.5 g, 54%). 1H NMR: δH (CDCl3; 300 MHz): 0.91 (3 H, t, 3J=6.8 Hz, CH3), 1.21-1.58 (14 H, m, CH2), 1.85 (2 H, m, O—CH2—CH2), 4.07 (2 H, t, 3J=6.5 Hz, O—CH2), 7.00 (2 H, d, 3J=9.0 Hz, Ar—H), 7.42 (2 H, d, 3J=8.5 Hz, Ar—H), 7.98 (2 H, d, 3J=8.6 Hz, Ar—H), 8.16 (2 H, d, 3J=9.0 Hz, Ar—H), 10.03 (1 H, s, COH). 13C NMR: δC (CDCl3; 75 MHz): 14.5, 23.1, 26.4, 29.5, 29.7, 29.8, 30.0, 32.3, 68.8, 114.8, 121.2, 123.0, 131.6, 132.8, 134.3, 156.3, 164.3, 164.6, 191.4.
