dihydroindole (11a). To a suspension of 6a (2.40 g, 0.01
mol) and 4-(dimethylamino)pyridine (2.69 g, 0.022 mole)
in DMF (20 mL) was added a solution of thiophen-2-
carbonyl chloride (1.17 mL, 1.61 g, 0.011 mol) in DMF (5
mL) at 4-8 °C over a period of 30 min. The mixture was
stirred at this temperature for further 30 min. Water (40 mL)
was added, and the mixture was stirred for an additional 2
h at 5 °C. The solid precipitate was filtered, and the crude
product (4.37 g, 93%) was recrystallized from acetonitrile
to give 11a (2.86 g, 60%) as orange crystals: mp 183-184
116.0, 99.6, 63.8, 14.2; IR (KBr, cm-1) 3433, 3092, 1743,
1669. Anal. Calcd for C16H12ClNO4S: C, 54.94; H, 3.46;
Cl, 10.14; N, 4.00; S, 9.17. Found: C, 55.13; H, 3.33; Cl,
10.02; N, 3.90; S, 9.07.
5-Chloro-3-[1-hydroxy-1-(2-thienyl)methylene]-1-meth-
oxycarbonyl-2-oxo-2,3-dihydroindole (12b). This com-
pound was prepared analogously to 12a, starting from 6b
(22.5 g, 0.10 mol). The resulting crystalline product (32.9
g, 98%) was recrystallized from acetonitrile to give 12b (24.0
1
g, 72%) as white crystals: mp 156-158 °C. H NMR
1
°C. H NMR (CDCl3, 400 MHz) δ 8.12 (1H, dd, J ) 3.3
(CDCl3, 200 MHz) δ 7.95 (1H, d, J ) 8.8 Hz), 7.88 (1H,
dd, J ) 1.1 Hz, J ) 3.7 Hz), 7.75 (1H, dd, J ) 1.1 Hz, J )
4.8 Hz), 7.61 (1H, d, J ) 2.2 Hz), 7.27 (1H, dd, J ) 4.8 Hz,
J ) 3.7 Hz), 7.21 (1H, dd, J ) 2.2 Hz, J ) 8.8 Hz), 4.08
(3H, s); 13C NMR (CDCl3, 50.3 MHz) δ 171.2, 167.3, 150.9,
135.1, 133.0, 132.4, 131.7, 129.8, 127.9, 126.3, 123.4, 119.0,
116.2, 99.8, 54.3; IR (KBr, cm-1) 3429, 1767, 1612. Anal.
Calcd for C15H10ClNO4S: C, 53.66; H, 3.00; Cl, 10.56; N,
4.17; S, 9.55. Found: C, 53.80; H, 2.97; Cl, 10.45; N, 4.10;
S, 9.64.
Hz, J ) 1.3 Hz), 8.00 (2H, d, J ) 7.4 Hz), 7.93 (1H, d, J )
2.0 Hz), 7.72 (1H, d, J ) 8.8 Hz) 7.51 (1H, dd, J ) 4.8 Hz,
J ) 1.3 Hz), 7.11 (1H, dd, J ) 3.7 Hz, J ) 5.1 Hz), 6.99
(1H, dd, J ) 2.2 Hz, J ) 8.8 Hz), 6.5 (2H, d, J ) 7.3 Hz),
4.45 (2H, q, J ) 7.1 Hz), 3.01 (6H, s), 1.45 (3H, t, J ) 7.1
Hz); IR (KBr, cm-1) 2929, 1735, 1635. Anal. Calcd for
C23H22ClN3O4S: C, 58.53; H, 4.70; Cl, 7.51; N, 8.90; S,
6.79. Found: C, 58.30; H, 4.58; Cl, 7.37; N, 8.76; S, 6.69.
4-Dimethylaminopyridinium Salt of 5-Chloro-3-[1-
hydroxy-1-(2-thienyl)methylene]-2-oxo-1-phenoxycarbo-
nyl-2,3-dihydroindole (11c). This compound was prepared
analogously to 11a, starting from 6c (2.88 g, 0.01 mol). The
resulting crystalline product (5.10 g, 98%) was recrystallized
from acetonitrile to give 11c (3.06 g, 58.8%) as yellow
crystals: mp 195-195.5 °C. 1H NMR (CDCl3, 400 MHz) δ
8.06 (3H, m), 7.86 (1H, d, J ) 8.6 Hz), 7.82 (1H, bs), 7.58
(1H, bd, J ) 4.8 Hz), 7.42 (2H, m), 7.30 (3H, m), 7.18 (1H,
m), 7.06 (1H, bd, J ) 8.6 Hz), 6.60 (2H, d, J ) 7.3 Hz),
5-Chloro-3-[1-hydroxy-1-(2-thienyl)methylene]-2-oxo-
1-phenoxycarbonyl-2,3-dihydroindole (12c). Method A.
This compound was prepared analogously to 12a, starting
from 6c (28.8 g, 0.1 mol). The resulting crystalline product
(39.7 g, 99.8%) was recrystallized from acetonitrile to give
12c (33.0 g, 83%) as yellow crystals: mp 140-142 °C. 1H
NMR (CDCl3, 200 MHz) δ 7.95 (1H, d, J ) 8.8 Hz), 7.87
(1H, dd, J ) 3.8 Hz, J ) 1.0 Hz), 7.78 (1H, dd, J ) 5.0 Hz,
J ) 1.0 Hz), 7.63 (1H, d, J ) 2.1 Hz), 7.45 (2H, m), 7.33
(3H, m), 7.28 (1H, dd, J ) 5.0 Hz, J ) 3.8 Hz), 7.18 (1H,
dd, J ) 8.8 Hz, J ) 2.1 Hz); 13C NMR (CDCl3, 50.3 MHz)
δ 171.1, 167.4, 150.0, 149.0, 135.0, 132.9, 132.5, 131.8,
130.1, 129.7, 127.9, 126.6, 126.5, 123.7, 121.4, 119.1, 116.4,
99.8; IR (KBr, cm-1) 3097, 1750, 1691, 1634. Anal. Calcd
for C20H12ClNO4S: C, 60.38; H, 3.04; Cl, 8.91; N, 3.52; S,
8.06. Found: C, 60.59; H, 3.10; Cl, 8.81; N, 3.50; S, 7.85.
Method B. A mixture of 10c (1.0 g, 0.0025 mol) and
DMAP (0.33 g, 0.00275 mol) was disolved in DMF (5 mL)
at 0 °C. After 1-2 min stirring a yellow precipitate formed.
A mixture of water (12.5 mL) and concentrated HCl (0.7
mL) was added, and the mixture was stirred for an additional
30 min at 5 °C. The solid precipitate was filtered, and the
crude product (1.0 g, 100%) was recrystallized from aceto-
nitrile to give 12c (0.62 g, 62%) as yellow crystals: mp 136-
1
3.16 (6 H, s); H NMR (DMSO-d6, 200 MHz) δ 8.62 (1H,
dd, J ) 3.6 Hz, J ) 1.1 Hz), 8.22 (1H, d, J ) 2.5 Hz), 8.20
(2H, d, J ) 7.7 Hz), 7.65 (1H, d, J ) 8.6 Hz), 7.58 (1H, dd,
J ) 1.1 Hz, J ) 5.0 Hz), 7.48 (2H, m), 7.32 (3H, m), 7.07
(1H, dd, J ) 3.6 Hz, J ) 5.0 Hz), 6.97 (2H, d, J ) 7.7 Hz),
6.84 (1H, dd, J ) 2.4 Hz, J ) 8.6 Hz), 3.17 (6H, s); IR
(KBr, cm-1) 3219, 3062, 2930, 1754, 1715, 1688, 1645.
Anal. Calcd for C27H22ClN3O4S: C, 62.36; H, 4.26; Cl, 6.82;
N, 8.08; S, 6.17. Found: C, 62.01; H, 4.23; Cl, 6.67; N,
8.17; S, 5.92.
5-Chloro-1-ethoxycarbonyl-3-[1-hydroxy-1-(2-thienyl)-
methylene]-2-oxo-2,3-dihydroindole (12a). To a suspension
of 6a (24.0 g, 0.1 mol) and 4-(dimethylamino)pyridine (26.9
g, 0.22 mole) in DMF (200 mL) was added a solution of
thiophen-2-carbonyl chloride (11.7 mL, 16.1 g, 0.11 mol)
in DMF (50 mL) at 4-8 °C over a period of 30 min. The
mixture was stirred at this temperature for further 30 min.
A mixture of water (400 mL) and concentrated HCl (17 mL)
was added, and the mixture was stirred for an additional 2
h at 5 °C. The solid precipitate was filtered, and the crude
product (33.1 g, 95%) was recrystallized from aqueous
ethanol to give 12a (31.4 g, 90%) as yellow crystals: mp
118-120 °C. 1H NMR (CDCl3, 400 MHz) δ 7.95 (1H, d, J
) 8.6 Hz), 7.88 (1H, dd, J ) 3.8 Hz, J ) 1.2 Hz), 7.75 (1H,
dd, J ) 1.2 Hz, J ) 5.0 Hz), 7.62 (1H, d, J ) 2.2 Hz), 7.27
(1H, dd, J ) 5.0 Hz, J ) 3.8 Hz), 7.22 (1H, dd, J ) 8.6 Hz,
J ) 2.2 Hz), 4.54 (2H, q, J ) 7.4 Hz), 1.49 (3H, t, J ) 7.4
Hz); 13C NMR (CDCl3, 101 MHz) δ 171.1, 167.0, 150.2,
135.1, 132.9, 132.3, 131.6, 129.5, 127.8, 126.1, 123.2, 118.8,
1
137 °C, having IR and H NMR spectra identical to those
of the sample obtained in Method A.
Ammonium Salt of 5-Chloro-1-ethoxycarbonyl-3-[1-
hydroxy-1-(2-thienyl)methylene]-2-oxo-2,3-dihydroin-
dole (13a). To a solution of 12a (0.7 g, 0.002 mol) in DMF
(4 mL) was added ammonium carbonate (0.16 g, NH3 content
22%, 0.002 mol), and the mixture was stirred for 2 h at 25
°C. Water (10 mL) was added. The solid precipitate was
filtered to give 13a (0.61 g, 83%) as yellow crystals: mp
1
193-197 °C. H NMR (DMSO-d6, 200 MHz) δ 8.61 (1H,
bd, J ) 3.5 Hz), 8.18 (1H, d, J ) 2.1 Hz), 7.58 (1H, d, J )
8.5 Hz), 7.55 (1H, m), 7.1 (5H, m), 6.78 (1H, dd, J ) 8.4
Hz, J ) 2.2 Hz), 4.35 (2H, q, J ) 7.1 Hz), 1.32 (3H, t, J )
7.1 Hz); IR (KBr, cm-1) 2982, 1737, 1621. Anal. Calcd for
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