JOURNAL OF ASIAN NATURAL PRODUCTS RESEARCH
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was stirred at reflux for 12 h. e residue was filtered and concentrated in vacuo. Crude was
purified by flash chromatography using PE/EA (10:1) to yield 12 (1.63 g, 78%) as a white
solid. 1H NMR (500 MHz, CDCl3) δ 7.41 (br d, J = 7.7 Hz, 4H), 7.33 (br t, J = 7.3 Hz, 4H),
7.27 (dd, J = 2.3, 1.3 Hz, 1H), 7.26 (br t, J = 7.3 Hz, 2H), 7.13 (dd, J = 2.3, 1.3 Hz, 1H), 6.71
13
(t, J = 2.0 Hz, 1H), 6.25 (s, 1H), 3.86 (s, 3H), 3.76 (s, 3H); C NMR (125 MHz, CDCl3)
δ 166.8, 160.5, 159.0, 140.8 (2C), 131.9, 128.7 (4C), 126.9 (4C), 126.6 (2C), 109.9, 107.6,
107.2, 81.9, 55.5, 52.2. HRESIMS: m/z 347.1286 [M – H]− (calcd for C22H19O4, 347.1289).
3.2.11. Preparation of methyl 5-(benzhydryloxy)-2-bromo-3-methoxybenzoate (12a)
& methyl 3-(benzhydryloxy)-2-bromo-5-methoxybenzoate (12b)
To a 0 °C solution of 12 (1.045 g, 3 mmol) in 10 ml CH3CN, a solution of NBS (550 mg,
3.09 mmol) in 5 ml CH3CN was added via addition funnel. e solution was allowed to
come to room temperature and stirred for 24 h. e mixture was concentrated and quenched
with 10% Na2S2O3 (30 ml). e aqueous phase was extracted with EA (20 ml for 3 times).
e organic phase was washed with brine (50 ml) and dried over anhydrous Na2SO4, fil-
tered under reduced pressure, and the organic phase was concentrated under vacuum.
Crude was purified by flash chromatography using PE/EA (10:1) to yield 12a (270 mg,
21%) as a colorless oil and 12b (769 mg, 60%) as a white solid. 12a: 1H NMR (500 MHz,
CDCl3): δ 7.42 (br d, J = 7.1 Hz, 4H), 7.37 (br t, J = 7.3 Hz, 4H), 7.31 (br t, J = 7.2 Hz, 2H),
6.88 (d, J = 2.7 Hz, 1H), 6.68 (d, J = 2.7 Hz, 1H), 6.23 (s, 1H), 3.89 (s, 3H), 3.81 (s, 3H); 13C
NMR (150 MHz, CDCl3): δ 166.6, 157.4, 156.6, 139.9 (2C), 128.7 (2C), 128.5 (2C), 127.9
(2C), 127.6, 126.9 (2C), 126.5 (2C), 108.7, 103.4, 101.8, 81.9, 56.0, 52.1; NOESY (500 MHz,
CDCl3): H-4/H-9, H-4/H3-8, H-6/H-9. ESI-MS: m/z 425/427 [M − H]−, 427/429 [M + H]+.
12b: 1H NMR (500MHz, CDCl3): δ 7.48 (br d, J = 7.2 Hz, 4H), 7.33 (br t, J = 7.3 Hz, 4H) 7.25
(tt, J = 7.4, 1.9 Hz, 2H), 6.75 (d, J = 2.8 Hz, 1H), 6.52 (d, J = 2.8 Hz, 1H), 6.23 (s, 1H), 3.92
(s, 3H), 3.66 (s, 3H); 13C NMR (150 MHz, CDCl3): δ 167.2, 159.0, 155.2, 140.5 (2C), 134.7,
128.7 (4C), 127.9 (2C), 126.5 (4C), 106.9, 105.4, 103.3, 82.7, 55.5, 52.6; NOESY (500 MHz,
CDCl3): H-4/H-9, H-4/H3-8, H-6/H3-8. ESI-MS: m/z 425/427 [M − H]−, 427/429 [M + H]+.
3.2.12. Preparation of methyl 3-((9H-fluoren-9-yl)oxy)-5-methoxybenzoate (13)
To a solution of 7 (1.1 g, 6 mmol) and K2CO3 (1.66 g, 12 mmol) in anhydrous acetone
(20 ml), 9-bromo-9H-fluorene (2.94 g, 12 mmol) was added. e reaction mixture was
stirred at reflux for 16 h. e residue was filtered and concentrated in vacuo. Crude was
purified by flash chromatography using PE/EA (10:1) to yield 13 (1.35 g, 65%) as a white
solid. 1H NMR (500 MHz, CDCl3): δ 7.70 (br d, J = 7.6 Hz, 2H), 7.54 (br d, J = 7.5 Hz, 2H),
7.52 (br s, 1H), 7.42 (br t, J = 7.5 Hz, 2H), 7.27 (br t, J = 7.5 Hz, 2H), 7.26 (br s, 1H), 6.77
(t, J = 2.3 Hz, 1H), 6.36 (s, 1H), 3.91 (s, 3H), 3.79 (s, 3H); 13C NMR (150 MHz, CDCl3):
δ 166.8, 160.7, 159.6, 142.5 (2C), 140.6 (2C), 132.1, 129.5 (2C), 127.8 (2C), 125.5 (2C),
120.2 (2C), 109.5, 108.1 (2C), 79.7, 55.6, 52.3. HRESIMS: m/z 345.1130 [M – H]− (calcd
for C22H17O4, 345.1132).
3.2.13. Preparation of compounds 13a and 13b
To a 0 °C solution of 13 (1.039 g, 3 mmol) in 10 ml CH3CN, a solution of NBS (550 mg,
3.09 mmol) in 5 ml CH3CN was added via addition funnel. e solution was allowed to come
to room temperature and stirred for 24 h. e reaction was concentrated and quenched with
10% Na2S2O3 (30 ml). e aqueous phase was extracted with EA (20 ml for 3 times). e