Cyclic- and differential pulse voltammetric measurements were performed on a PC-controlled CH instruments model CHI 620C electrochemical analyzer. Cyclic voltammetric experiments were performed on 1 mM porphyrin dyads solution in dichloromethane at scan rate of 100 mV/s using 0.1 M tetrabutyl ammoniumperchlorate (TBAP) as supporting electrolyte. The working electrode is glassy carbon, standard calomel electrode (SCE) is reference electrode and plantinum wire is an auxillary electrode. After a cyclic voltammogram (CV) had been recorded, ferrocene was added, and a second voltammogram was measured. UV-visible spectra were recorded with a Shimadzu spectrophotometer (Model UV-3600). Concentration of the samples used for these measurements ranged from about 5 x 10− 4 M. Steady state fluorescence spectra were recorded using a Spex model Fluoromax-3 spectrofluorometer for solutions having optical density at the wavelength of excitation (λex) ≈ 0.11. Fluorescence lifetime measurements were carried on a picosecond time-correlated single photon counting (TCSPC) setup (FluoroLog3-Triple Illuminator, IBH Horiba JobinYvon) employing a picosecond light emitting diode laser (NanoLED, λex = 345 nm) as the excitation source.
All the calculations have been carried out using a Gaussian 09 package on a personal computer. The Ground state geometry of compounds 5a-x were optimized using density functional theory (DFT), while time-dependent DFT (TDDFT) was employed for the estimation of ground to excited-state transitions. The obtained geometries were to be genuine global minimum structures, using B3LYP hybrid functional and 6-31G (d, p) basis set, and were used as the input for further calculations. The geometries were then used to obtain frontier molecular orbital’s (FMOs)
3-(4-Methylbenzyl)pyrano[3,2-c]chromene-2,5-dione (3e):
Yield: (0.171 g) 87%, colorless solid; M.P: 164–166°C; 1H NMR (500 MHz, CDCl3): δ 8.06 (d, J = 7.8 Hz, 1H, aromatic), 7.69–7.62 (m, 2H, aromatic, CH), 7.46–7.37 (m, 2H, aromatic), 7.20–7.12 (m, 4H, aromatic), 3.84 (s, 2H, CH2), 2.34 (s, 3H, CH3) ppm. 13C NMR (126 MHz, CDCl3): δ 159.91, 159.48, 159.03, 153.14, 136.79, 136.18, 133.98, 133.52, 129.66, 129.60, 129.10, 125.16, 123.27, 117.28, 113.13, 103.69, 36.31, 21.05 ppm. FT-IR (KBr): 3018, 2360, 1722, 1640, 1603, 1575, 1502, 1451, 1391, 1112, 1075 cm− 1. MS-ESI: m/z 319 [M + H]+; HRMS-ESI: calcd for C20H15O4 [M + H]+ 319.0970; found 319.0971.
3-(4-Ethylbenzyl)pyrano[3,2- c ]chromene-2,5-dione (3f):
Yield: (0.172 g) 84%, colorless solid; M.P: 166–168°C; 1H NMR (500 MHz, CDCl3): δ 8.06 (dd, J = 7.9, 1.1 Hz, 1H, aromatic), 7.72–7.60 (m, 2H, aromatic, CH), 7.44–7.36 (m, 2H, aromatic), 7.19 (q, J = 8.2 Hz, 4H, aromatic), 3.85 (s, 2H, CH2), 2.64 (q, J = 7.6 Hz, 2H, OCH2), 1.24 (t, J = 7.6 Hz, 3H, CH3) ppm. 13C NMR (126 MHz, CDCl3): δ 159.92, 159.49, 159.04, 153.13, 143.12, 136.19, 133.97, 133.77, 129.63, 129.16, 128.39, 125.16, 123.27, 117.28, 113.13, 103.70, 36.33, 28.45, 15.48 ppm. FT-IR (KBr): 3609, 3019, 2894, 2824, 2403, 1724, 1599, 1485, 1421, 1216, 1041 cm− 1. MS-ESI: m/z 333 [M + H]+; HRMS-ESI: calcd for C21H17O4 [M + H]+ 333.1127; found 333.1131.
3-(3-Fluorobenzyl)pyrano[3,2- c ]chromene-2,5-dione (3g):
Yield: (0.143 g) 72%, colorless solid; M.P: 190–192°C; 1H NMR (400 MHz, CDCl3): δ 8.06 (dd, J = 7.9, 1.4 Hz, 1H, aromatic), 7.72–7.63 (m, 2H, aromatic, CH), 7.44–7.39 (m, 2H, aromatic), 7.34–7.29 (m, 1H, aromatic), 7.08 (d, J = 7.7 Hz, 1H, aromatic), 7.05–6.92 (m, 2H, aromatic), 3.88 (s, 2H, CH2) ppm. 13C NMR (101 MHz, CDCl3): δ 164.17, 161.73, 160.20, 159.26, 158.89, 153.18, 139.15 (d, J = 7.62 Hz), 135.41 (d, J = 252.85 Hz), 130.33 (d, J = 7.62 Hz), 128.48, 125.19, 124.80 (d, J = 2.18 Hz), 123.29, 117.29, 116.08 (d, J = 21.79 Hz), 114.12 (d, J = 20.70 Hz), 113.00, 103.56, 36.44 ppm. FT-IR (KBr): 3455, 3130, 3060, 2826, 2747, 2629, 2192, 1724, 1642, 1604, 1454, 1119 cm− 1. MS-ESI: m/z 323 [M + H]+; HRMS-ESI: calcd for C19H12O4F [M + H]+ 323.0720; found 323.0712.
3-(4-Fluorobenzyl)pyrano[3,2- c ]chromene-2,5-dione (3h):
Yield: (0.157 g) 79%, colorless solid; M.P: 183–185°C; 1H NMR (400 MHz, CDCl3): δ 8.06 (dd, J = 7.9, 1.3 Hz, 1H, aromatic), 7.72–7.63 (m, 2H, aromatic, CH), 7.40 (dd, J = 12.4, 5.0 Hz, 2H, aromatic), 7.29–7.27 (m, 1H, aromatic), 7.25 (d, J = 2.2 Hz, 1H, aromatic), 7.03 (dd, J = 16.2, 7.5 Hz, 2H, aromatic), 3.86 (s, 2H, CH2) ppm. 13C NMR (101 MHz, CDCl3): δ 163.19, 160.76, 160.15, 159.35, 158.99, 153.19, 135.26 (d, J = 227.78 Hz), 132.38, 130.72 (d, J = 7.62 Hz), 129.10, 125.22, 123.31, 117.33, 115.76 (d, J = 21.79 Hz), 113.06, 103.61, 36.04 ppm. FT-IR (KBr): 3502, 3461, 3024, 2954, 1728, 1615, 1511, 1443, 1282, 1228, 1047 cm− 1. MS-ESI: m/z 323 [M + H]+; HRMS-ESI: calcd for C19H12O4F [M + H]+ 323.0720; found 323.0717.
3-(2-Chlorobenzyl)pyrano[3,2- c ]chromene-2,5-dione (3i):
Yield: (0.161 g) 77%, colorless solid; M.P: 140–142°C; 1H NMR (300 MHz, CDCl3): δ 8.07 (d, J = 7.6 Hz, 1H, aromatic), 7.66 (t, J = 7.4 Hz, 1H, aromatic), 7.54 (s, 1H, CH), 7.46–7.35 (m, 4H, aromatic), 7.34–7.27 (m, 2H, aromatic), 4.01 (s, 2H, CH2) ppm. 13C NMR (76 MHz, CDCl3): δ 159.92, 159.32, 158.89, 153.12, 136.41, 134.44, 134.14, 134.05, 131.77, 129.95, 128.91, 127.31, 127.26, 125.15, 123.26, 117.25, 113.04, 103.62, 34.31 ppm. FT-IR (KBr): 3229, 3023, 2404, 1725, 1640, 1603, 1575, 1394, 1217, 1115 cm− 1. MS-ESI: m/z 339 [M + H]+; HRMS-ESI: calcd for C19H12O4Cl [M + H]+ 339.0424; found 339.0424.
3-(2-Bromobenzyl)pyrano[3,2- c ]chromene-2,5-dione (3j):
Yield: (0.179 g) 76%, colorless solid; M.P: 221–223°C; 1H NMR (400 MHz, CDCl3): δ 8.05 (dd, J = 7.9, 1.4 Hz, 1H, aromatic), 7.71 (s, 1H, CH), 7.70–7.64 (m, 1H, aromatic), 7.46–7.38 (m, 4H, aromatic), 7.26–7.19 (m, 2H, aromatic), 3.85 (s, 2H, CH2) ppm. 13C NMR (101 MHz, CDCl3): δ 160.28, 15923, 158.91, 153.22, 139.05, 136.79, 134.20, 132.05, 130.37, 130.32, 128.37, 127.82, 125.23, 123.32, 122.85, 117.33, 113.03, 103.58, 36.40 ppm. FT-IR (KBr): 3061, 2954, 2920, 1725, 1642, 1601, 1578, 1461, 1393, 1185 cm− 1. MS-ESI: m/z 383 [M + H]+; HRMS-ESI: calcd for C19H12O4Br [M + H]+ 382.9919; found 382.9920.
3 3-(3-Bromobenzyl)pyrano[3,2- c ]chromene-2,5-dione (3k):
Yield: (0.78 g) 33%, colorless solid; M.P: 188–190°C; 1H NMR (400 MHz, CDCl3): δ 8.06 (dd, J = 7.9, 1.2 Hz, 1H, aromatic), 7.73–7.64 (m, 2H, aromatic, CH), 7.47–7.37 (m, 4H, aromatic), 7.25–7.19 (m, 2H, aromatic), 3.85 (s, 2H, CH2) ppm. 13C NMR (101 MHz, CDCl3): δ 160.32, 159.27, 158.96, 153.25, 139.06, 136.82, 134.22, 132.08, 130.40, 130.36, 128.41, 127.84, 125.26, 123.36, 122.88, 117.36, 113.06, 103.61, 36.42 ppm. FT-IR (KBr): 3021, 2407, 2362, 1726, 1640, 1600, 1395, 1216, 1033 cm− 1. MS-ESI: m/z 383 [M + H]+; HRMS-ESI: calcd for C19H12O4Br [M + H]+ 382.9919; found 382.9923.
3-(4-Bromobenzyl)pyrano[3,2- c ]chromene-2,5-dione (3l):
Yield: (0.198 g) 84%, colorless solid; M.P: 206–208°C; 1H NMR (500 MHz, CDCl3): δ 8.06 (d, J = 7.9 Hz, 1H, aromatic), 7.69 (s, 1H, CH), 7.68–7.65 (m, 1H, aromatic), 7.47 (d, J = 8.3 Hz, 2H, aromatic), 7.43–7.38 (m, 2H, aromatic), 7.18 (d, J = 8.3 Hz, 2H, aromatic), 3.83 (s, 2H, CH2) ppm. 13C NMR (126 MHz, CDCl3): δ 160.20, 159.26, 158.91, 153.19, 136.55, 135.70, 134.17, 131.96, 130.87, 128.59, 125.22, 123.30, 121.14, 117.32, 113.02, 103.56, 36.26 ppm. FT-IR (KBr): 3023, 2891, 2399, 2363, 1728, 1599, 1485, 1409, 1216, 1020 cm− 1. MS-ESI: m/z 383 [M + H]+; HRMS-ESI: calcd for C19H12O4Br [M + H]+ 382.9919; found 382.9918.
3-(2,4-Dichlorobenzyl)pyrano[3,2- c ]chromene-2,5-dione (3m):
Yield: (0.150 g) 64%, colorless solid; M.P: 216–218°C; 1H NMR (400 MHz, CDCl3): δ 8.07 (dd, J = 7.9, 1.1 Hz, 1H, aromatic), 7.71–7.63 (m, 1H, aromatic), 7.59 (s, 1H, CH), 7.46–7.38 (m, 3H, aromatic), 7.34 (d, J = 8.2 Hz, 1H, aromatic), 7.28–7.25 (m, 1H, aromatic), 3.97 (s, 2H, CH2) ppm. 13C NMR (101 MHz, CDCl3): δ 160.17, 159.23, 158.88, 153.23, 136.74, 135.15, 134.21, 134.21, 132.79, 132.55, 129.79, 127.57, 126.69, 125.23, 123.33, 117.34, 113.03, 103.58, 33.91 ppm. FT-IR (KBr): 3249, 3112, 3023, 2923, 2847, 2362, 1724, 1641, 1605, 1498, 1457, 1215, 1115 cm− 1. MS-ESI: m/z 373 [M + H]+; HRMS-ESI: calcd for C19H11O4Cl2 [M + H]+ 373.0034; found 373.0034.
3-(3,4-Dichlorobenzyl)pyrano[3,2- c ]chromene-2,5-dione (3n):
Yield: (0.168 g) 73%, colorless solid; M.P: 238–240°C; 1H NMR (400 MHz, CDCl3): δ 8.09–8.03 (m, 1H, aromatic), 7.74 (s, 1H, CH), 7.71–7.66 (m, 1H, aromatic), 7.44–7.39 (m, 4H, aromatic), 7.17–7.14 (m, 1H, aromatic), 3.84 (s, 2H, CH2) ppm. 13C NMR (101 MHz, CDCl3): δ 160.46, 159.18, 158.93, 153.25, 136.95, 134.34, 132.83, 132.70, 131.37, 130.98, 130.76, 128.54, 127.92, 125.30, 123.37, 117.39, 112.97, 103.52, 36.02 ppm. FT-IR (KBr): 3056, 2740, 2402, 1729, 1642, 1603, 1494, 1450, 1396, 1215 cm− 1. MS-ESI: m/z 373 [M + H]+; HRMS-ESI: calcd for C19H11O4Cl2 [M + H]+ 373.0034; found 373.0031.
3-(3-(Trifluoromethyl)benzyl)pyrano[3,2- c ]chromene-2,5-dione (3o):
Yield: (0.184 g) 80%, colorless solid; M.P: 232–234°C; 1H NMR (300 MHz, CDCl3): δ 8.06 (d, J = 7.8 Hz, 1H, aromatic), 7.74 (s, 1H, CH), 7.68 (t, J = 7.8 Hz, 1H, aromatic), 7.52 (dd, J = 19.3, 7.7 Hz, 4H, aromatic), 7.42 (t, J = 8.0 Hz, 2H, aromatic), 3.95 (s, 2H, CH2) ppm. 13C NMR (76 MHz, CDCl3): δ 160.40, 159.22, 158.92, 153.27, 137.76, 136.90, 134.27, 132.57, 131.21 (q, J = 258.30 Hz), 129.32, 128.19, 125.83, 125.83, 125.26, 124.12, 123.36, 117.36, 113.02, 103.57, 36.69 ppm. FT-IR (KBr): 3062, 2826, 2748, 2641, 2550, 1722, 1642, 1576, 1457, 1333, 1171 cm− 1. MS-ESI: m/z 373 [M + H]+; HRMS-ESI: calcd for C20H12O4F3 [M + H]+ 373.0688; found 373.0688.
3-(4-(Trifluoromethyl)benzyl)pyrano[3,2- c ]chromene-2,5-dione (3p):
Yield: (0.188 g) 82%, colorless solid; M.P: 218–220°C; 1H NMR (500 MHz, CDCl3): δ 8.06 (d, J = 7.9 Hz, 1H, aromatic), 7.74 (s, 1H, CH), 7.70–7.65 (m, 1H, aromatic), 7.60 (d, J = 8.1 Hz, 2H, aromatic), 7.48–7.36 (m, 4H, aromatic), 3.94 (s, 2H, CH2) ppm. 13C NMR (126 MHz, CDCl3): δ 160.38, 159.21, 158.90, 153.25, 140.86, 136.88, 134.28, 129.48, 128.14, 125.39, 125.27, 123.34, 122.69, 117.36, 112.99, 103.53, 36.68 ppm. FT-IR (KBr): 3022, 2406, 1727, 1608, 1496, 1429, 1324, 1216, 1120 cm− 1. MS-ESI: m/z 373 [M + H]+; HRMS-ESI: calcd for C20H12O4F3 [M + H]+ 373.0688; found 373.0692.
4-((2,5-Dioxo-2,5-dihydropyrano[3,2- c ]chromen-3-yl)methyl)benzonitrile (3q):
Yield: (0.118 g) 58%, colorless solid; M.P: 183–185°C; 1H NMR (500 MHz, CDCl3): δ 8.06 (dd, J = 7.9, 1.2 Hz, 1H, aromatic), 7.77 (s, 1H, CH), 7.71–7.66 (m, 1H, aromatic), 7.64 (d, J = 8.2 Hz, 2H, aromatic), 7.48–7.37 (m, 4H, aromatic), 3.94 (s, 2H, CH2) ppm. 13C NMR (126 MHz, CDCl3): δ 160.59, 159.14, 158.88, 153.28, 142.36, 137.22, 134.43, 132.63, 129.89, 127.50, 125.33, 123.38, 118.61, 117.41, 112.94, 111.19, 103.48, 37.01 ppm. FT-IR (KBr): 3060, 2697, 2626, 2499, 2350, 2259, 2028, 1723, 1641, 1604, 1332 cm-1. MS-ESI: m/z 330 [M + H]+; HRMS-ESI: calcd for C20H12NO4 [M + H]+ 330.0766; found 330.0766.
9-Methyl-3-(2-methylbenzyl)pyrano[3,2- c ]chromene-2,5-dione (3r):
Yield: (0.104 g) 51%, colorless solid; M.P: 200–202°C; 1H NMR (500 MHz, CDCl3): δ 7.85 (d, J = 1.0 Hz, 1H, aromatic), 7.66 (t, J = 1.1 Hz, 1H, aromatic), 7.47–7.42 (m, 1H, aromatic), 7.29–7.26 (m, 1H, aromatic), 7.26–7.21 (m, 1H, aromatic), 7.09 (d, J = 6.7 Hz, 3H, aromatic, CH), 3.84 (s, 2H, CH2), 2.45 (s, 3H, CH3), 2.35 (s, 3H, CH3) ppm. 13C NMR (126 MHz, CDCl3): δ 160.00, 159.62, 159.24, 151.37, 138.56, 136.67, 136.5, 135.22, 135.13, 129.90, 129.19, 128.77, 127.90, 126.22, 122.84, 117.02, 112.74, 103.61, 36.61, 21.38, 20.88 ppm. FT-IR (KBr): 3127, 3060, 2924, 2858, 2743, 1737, 1639, 1582, 1452, 1039 cm− 1. MS-ESI: m/z 333 [M + H]+; HRMS-ESI: calcd for C21H17O4 [M + H]+ 333.1127; found 333.1128.
3-Ethylpyrano[3,2- c ]chromene-2,5-dione (3s):
Yield: (0.117 g) 78%, colorless solid; M.P: 178–180°C; 1H NMR (300 MHz, CDCl3): δ 8.07 (d, J = 7.1 Hz, 1H, aromatic), 7.79 (s, 1H, CH), 7.66 (dd, J = 11.6, 4.1 Hz, 1H, aromatic), 7.42 (t, J = 7.3 Hz, 2H, aromatic), 2.62 (q, J = 7.4 Hz, 2H, CH2), 1.28 (t, J = 7.4 Hz, 3H, CH3) ppm. 13C NMR (76 MHz, CDCl3): δ 159.57, 159.50, 159.11, 152.98, 134.51, 133.78, 131.26, 125.07, 123.10, 117.20, 113.12, 103.58, 23.89, 11.86 ppm. FT-IR (KBr): 3526, 3024, 2403, 2355, 1729, 1626, 1397, 1216, 1032 cm− 1. MS-ESI: m/z 243 [M + H]+; HRMS-ESI: calcd for C14H11O4 [M + H]+ 243.0657; found 243.0654.
3-Propylpyrano[3,2- c ]chromene-2,5-dione (3t):
Yield: (0.123 g) 78%, colorless solid; M.P: 156–158°C; 1H NMR (400 MHz, CDCl3): δ 8.10–8.05 (m, 1H, aromatic), 7.78 s, 1H, CH), 7.70–7.62 (m, 1H, aromatic), 7.42 (dd, J = 11.5, 4.4 Hz, 2H, aromatic), 2.56 (td, J = 7.7, 1.0 Hz, 2H, CH2), 1.75–1.64 (m, 2H, CH2), 1.02 (t, J = 7.4 Hz, 3H, CH3) ppm. 13C NMR (101 MHz, CDCl3): δ 159.79, 159.61, 159.17, 153.08, 135.55, 133.83, 129.86, 125.12, 123.19, 117.27, 113.22, 103.62, 32.79, 20.94, 13.66 ppm. FT-IR (KBr): 3675, 3609, 3023, 2954, 2828, 2304, 1723, 1641, 1395, 1290, 1217, 1025 cm− 1. MS-ESI: m/z 257 [M + H]+; HRMS-ESI: calcd for C15H13O4 [M + H]+ 257.0814; found 257.0811.
3-Isobutylpyrano[3,2- c ]chromene-2,5-dione (3u):
Yield: (0.140 g) 84%, colorless solid; M.P: 160–162°C; 1H NMR (500 MHz, CDCl3): δ 8.07 (dd, J = 8.3, 1.3 Hz, 1H, aromatic), 7.75 (s, 1H, CH), 7.70–7.62 (m, 1H, aromatic), 7.42 (dd, J = 11.9, 4.4 Hz, 2H, aromatic), 2.45 (dd, J = 7.2, 0.8 Hz, 2H, CH2), 2.10–1.99 (m, 1H, CH), 0.98 (s, 3H, CH3), 0.97 (s, 3H, CH3) ppm. 13C NMR (126 MHz, CDCl3): δ 159.98, 159.73, 159.21, 153.13, 136.60, 133.89, 128.98, 125.14, 123.25, 117.30, 113.26, 103.59, 40.14, 27.09, 22.33 ppm. FT-IR (KBr): 3021, 2967, 2741, 2597, 1728, 1654, 1616, 1567, 1309, 1216 cm− 1. MS-ESI: m/z 271 [M + H]+; HRMS-ESI: calcd for C16H15O4 [M + H]+ 271.0970; found 271.0969.
3-Isopentylpyrano[3,2- c ]chromene-2,5-dione (3v):
Yield: (0.145 g) 83%, colorless solid; M.P: 148–150°C; 1H NMR (400 MHz, CDCl3): δ 8.10–8.05 (m, 1H, aromatic), 7.78 (s, 1H, CH), 7.66 (ddd, J = 9.0, 7.7, 1.6 Hz, 1H, aromatic), 7.42 (dd, J = 11.7, 4.4 Hz, 2H, aromatic), 2.62–2.54 (m, 2H, CH2), 1.67 (m, 1H, CH), 1.57–1.50 (m, 2H, CH2), 0.98 (s, 3H, CH3), 0.96 (s, 3H, CH3) ppm. 13C NMR (101 MHz, CDCl3): δ 159.61, 159.56, 159.11, 153.00, 135.14, 133.76, 130.37, 125.06, 123.12, 117.20, 113.16, 103.60, 36.65, 28.63, 27.73, 22.34 ppm. FT-IR (KBr): 3024, 2400, 2362, 1729, 1603, 1400, 1216, 1043 cm− 1. MS-ESI: m/z 285 [M + H]+; HRMS-ESI: calcd for C17H17O4 [M + H]+ 285.1127; found 285.1127.
3-Hexylpyrano[3,2- c ]chromene-2,5-dione (3w):
Yield: (0.132 g) 72%, colorless solid; M.P: 152–154°C; 1H NMR (400 MHz, CDCl3): δ 8.07 (dd, J = 8.2, 1.2 Hz, 1H, aromatic), 7.77 (s, 1H, CH), 7.66 (td, J = 8.2, 1.5 Hz, 1H, aromatic), 7.41 (t, J = 7.6 Hz, 2H, aromatic), 2.62–2.53 (m, 2H, CH2), 1.68–1.61 (m, 2H, CH2), 1.41–1.31 (m, 6H, 3CH2), 0.90 (t, J = 7.0 Hz, 3H, CH3) ppm. 13C NMR (101 MHz, CDCl3): δ 159.62, 159.51, 159.06, 152.99, 135.28, 133.74, 130.10, 125.03, 123.10, 117.18, 113.15, 103.57, 31.44, 30.75, 28.79, 27.57, 22.45, 13.97 ppm. FT-IR (KBr): 3020, 2403, 1731, 1631, 1484, 1408, 1215, 1029 cm− 1. MS-ESI: m/z 299 [M + H]+; HRMS-ESI: calcd for C18H19O4 [M + H]+ 299.1283; found 299.1284.
3-Octylpyrano[3,2- c ]chromene-2,5-dione (3x):
Yield: (0.147 g) 73%, colorless solid; M.P: 136–138°C; 1H NMR (400 MHz, CDCl3): δ 8.07 (d, J = 7.5 Hz, 1H, aromatic), 7.77 (s, 1H, CH), 7.71–7.62 (m, 1H, aromatic), 7.41 (t, J = 7.7 Hz, 2H, aromatic), 2.57 (t, J = 7.6 Hz, 2H, CH2), 1.65 (m, 2H, CH2), 1.41–1.24 (m, 10H, 5CH2), 0.89 (t, J = 6.7 Hz, 3H, CH3) ppm. 13C NMR (101 MHz, CDCl3): δ 159.59, 159.48, 159.03, 152.97, 135.25, 133.72, 130.09, 125.01, 123.07, 117.16, 113.13, 103.55, 31.72, 30.74, 29.21, 29.11, 29.08, 27.59, 22.54, 13.99 ppm. FT-IR (KBr): 3670, 3429, 2851, 1722, 1643, 1602, 1578, 1458, 1396, 1212, 1029 cm− 1. MS-ESI: m/z 327 [M + H]+; HRMS-ESI: calcd for C20H23O4 [M + H]+ 327.1596; found 327.1594.