Arkivoc 2018, v, 0-0
McGowan, M. A. et al.
syringe. The reaction was stirred for 24 h, after which the solvent and unreacted oxalyl chloride were distilled
off under reduced pressure. The resulting yellow liquid was concentrated via azeotrope with benzene (3 x 50
mL) in vacuo, following which it was redissolved in CH2Cl2 and filtered to remove unreacted 7. The solvent was
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removed in vacuo and the product dried under a vacuum to yield (9) (2.21 g, 92%) as a yellow liquid; H NMR
(CDCl3): δ 2.89 (t, 4H), 1.78–1.68 (m, 4H), 1.31–1.25 (b, 8H). This was used directly in the next step with 11.
1,14-Tetradecanedioyl dichloride (10). To a stirred solution of 1,14-tetradecanedioic acid (8) (2.6 g, 10 mmol,
1 eq.) in anhydrous CH2Cl2 (165 mL) under nitrogen was added oxalyl chloride (16.5 mL, 190 mmol, 10 eq.)
rapidly via syringe. The reaction was stirred for 24 h, after which the solvent and unreacted oxalyl chloride
were removed by distillation under reduced pressure. The resulting yellow liquid was concentrated via
azeotrope with benzene (3 x 50 mL) in vacuo, following which it was redissolved in CH2Cl2 and filtered to
remove unreacted 8. The solvent was removed in vacuo and the product was dried under a vacuum to yield
(10) (2.68 g, 91%) as a yellow liquid, which was used directly in the next step with 11.
1,10-Bis(1-(phenylsulfonyl)-1H-indol-3-yl)decane-1,10-dione) (12). To a stirred solution of AlCl3 (2.24 g, 16.8
mmol, 4 eq.) in CH2Cl2 (90 mL) at 0 °C was added after 15 min a solution of 1,10-decanedioyl dichloride (9)
(1.01 g, 4.2 mmol, 1 eq.) in CH2Cl2 (3 mL) dropwise via an addition funnel. The solution was stirred 30 min,
after which a solution of 1-(phenylsulfonyl)indole (11) (2.15 g, 8.41 mmol, 2 eq.) in CH2Cl2 (20 mL) was added
over 30 min via addition funnel. During this time the solution turned from light yellow to dark orange. The
solution was allowed to come to rt and stirred for 2.5 h, during which the solution appeared dark red. The
reaction was quenched with ice (150 g) in a 400 mL beaker and covered with a watch glass until the ice
melted. The aqueous layer was then extracted with CH2Cl2 (4 x 75 mL) and the combined organic extracts were
washed with brine (2 x 50 mL), aqueous sodium carbonate (50 mL), and brine (2 x 50 mL). The organic layer
was then dried (MgSO4), filtered, and concentrated in vacuo to yield (12) as a white solid (2.54 g, 89%). The
solid was washed with 4:1 hexane:EtOAc and recrystallized in CH2Cl2/hexane to yield white solid product (12):
mp 194–197 °C; 1H NMR (CDCl3): δ 8.37–8.34 (m, 2H), 8.23 (s, 2H), 7.98–7.93 (m, 6H), 7.64–7.58 (m, 2H), 7.54–
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7.40 (m, 4H), 7.39–7.35 (m, 4H), 2.91 (t, 4H), 1.82–1.75 (m, 4H), 1.61–1.48 (b, 2H), 1.39 (m, 10H). C NMR
(CDCl3): 196.6, 134.8, 131.7, 129.9, 127.9, 127.3, 126.0, 125.1, 123.4, 113.2, 40.3, 29.5, 29.5, 24.7; IR (KBr):
3089, 3067, 2920, 2850, 1661 (C=O), 1540, 1444, 1381, 1287, 1180, 1134, 980, 934, 754, 683, 594. MS (EI):
680.4 (M+), 539.2, 446.2, 399.2, 327.1, 299.1, 257.1, 144.0, 116.1, 77.0 (100%). Anal. Calcd for C38H36N2O6S2: C,
67.04; H, 5.33; N, 4.11; S, 9.42. Found: C, 66.18; H, 5.33; N, 4.03; S, 8.97.
1,14-Bis(1-(phenylsulfonyl)-1H-indol-3-yl)tetradecane-1,14-dione) (13). To a stirred solution of AlCl3 (4.85 g,
36.4 mmol, 4 eq.) in CH2Cl2 (180 mL) at 0 °C was added after 15 min a solution of 1,14-tetradecanedioyl
dichloride (10) (2.67 g, 9.1 mmol, 1 eq.) in CH2Cl2 (6 mL) dropwise via an addition funnel. [note: some of the
acid was spilt during addition] The solution was stirred for 30 min, after which a solution of 1-
(phenylsulfonyl)indole (11) (4.65 g, 18.2 mmol, 2 eq.) in CH2Cl2 (40 mL) was added over 30 min via addition
funnel. During this time the solution turned from light yellow to dark orange-red. The solution was allowed to
come to rt and stirred for 2.5 h, during which the solution appeared dark red. The reaction was quenched with
ice (300 g) in a 600 mL beaker and allowed to stand overnight covered with a watch glass. The aqueous layer
was extracted with CH2Cl2 (4 x 125 mL) and the combined organic extracts were washed with brine (2 x 100
mL), aqueous sodium carbonate (100 mL), and brine (2 x 100 mL). The organic layer was then dried (MgSO4),
filtered, and concentrated in vacuo to yield (13) as a beige solid (4.81 g, 72%). The solid was washed with 4:1
1
hexane:EtOAc and recrystallized from EtOAc/hexane to yield the 13 as a light beige solid: mp 155–156 °C. H
NMR (CDCl3): 8.40–8.36 (m, 2H), 8.25 (s, 2H), 8.02–7.92 (m, 6H), 7.64–7.60 (t, 2H), 7.57–7.45 (m, 4H), 7.42–
7.32 (m, 4H), 2.95 (t, 4H), 1.82–1.75 (m, 4H), 1.63–1.55 (b, 2H), 1.45–1.24 (m, 12H). 13C NMR (CDCl3): 196.7,
141.7, 134.8, 131.7, 129.8, 127.3, 126.0, 125.1, 123.4, 113.2, 40.4, 29.8, 29.7, 29.6, 24.8. IR (KBr): 3111, 3066,
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