Molecules 2020, 25, 5595
10 of 16
1
Methyl 4-acetyl-1H-indole-3-carboxylate (6q; C-4 isomer) (539.8 mg, 62%). Off-white solid: H-NMR
(DMSO-d6, 400 MHz): δ = 2.45 (s, 3H), 3.72 (s, 3H), 7.18 (d, 1H, J = 7.2 Hz), 7.26 (t, 1H, J = 7.5 Hz), 7.60
13
(d, 1H, J = 7.9 Hz), 8.14 (s, 1H), 12.17 (bs, 1H). C-NMR (CDCl3, 100 MHz): δ = 31.1, 51.0, 108.2, 114.3,
+
+
119.8, 120.7, 122.5, 132.6, 135.3, 137.0, 165.2, 205.2 ppm. HRMS (ESI ) m/z [M + Na] calculated for
C12H11NO3Na 240.0637, found 240.0634.
1
Methyl 6-acetyl-1H-indole-3-carboxylate (6q; C-6 isomer) (237.7 mg, 27%). Off-white solid: H-NMR
(DMSO-d6, 400 MHz): δ = 2.66 (s, 3H), 3.86 (s, 3H), 7.84 (dd, 1H, J = 8.4 and 1.5 Hz), 8.10 (d, 1H, J = 8.4
13
Hz), 8.15 (d, 1H, J = 1.5 Hz), 8.33 (d, 1H, J = 3.0 Hz), 12.39 (bs, 1H). C-NMR (DMSO-d6, 100 MHz): δ =
+
26.7, 50.8, 106.7, 113.4, 120.1, 121.1, 129.9, 131.5, 135.7, 135.9, 164.4, 197.3 ppm. HRMS (ESI ) m/z
+
[M+Na] calculated for C12H11NO3Na 240.0637, found 240.0640.
1
Methyl 4-methoxy-1H-indole-3-carboxylate (6r; C-4 isomer) (111.8 mg, 27%). Off-white solid: H-
NMR (CDCl3, 400 MHz): δ = 3.86 (s, 3H), 3.93 (s, 3H), 6.66 (d, 1H, J = 7.8 Hz), 7.00 (d, 1H, J = 8.0 Hz),
13
7.16 (t, 1H, J = 7.0 Hz), 7.81 (d, 1H, J = 2.8 Hz), 9.11 (bs, 1H). C-NMR (CDCl3, 100 MHz): δ = 51.3, 55.9,
+
+
102.9, 105.0, 108.6, 115.4, 124.2, 131.3, 138.4, 154.2, 165.0 ppm. HRMS (ESI ) m/z [M + Na] calculated
for C11H11NO3Na 228.0637, found 228.0634.
1
Methyl 6-methoxy-1H-indole-3-carboxylate (6r; C-6 isomer) (189.5 mg, 46%). Off-white solid: H-
NMR (DMSO-d6, 400 MHz): δ = 3.78 (s, 6H), 6.83 (dd, 1H, J = 8.6 and 2.2 Hz), 6.96 (d, 1H, J = 2.2 Hz),
13
7.84 (d, 1H, J = 8.6 Hz), 7.94 (d, 1H, J = 3.0 Hz), 11.70 (bs, 1H). C-NMR (DMSO-d6, 100 MHz): δ = 50.5,
55.2, 95.2, 106.3, 111.3, 119.7, 121.0, 131.2, 137.1, 156.1, 164.7 ppm. The values are in accordance with
the literature [82].
1
Methyl 7-methyl-1H-indole-3-carboxylate (6s) (245.9.5 mg, 65%). Off-white solid: H-NMR (CDCl3,
400 MHz): δ = 2.50 (s, 3H), 3.92 (s, 3H), 7.06 (d, 1H, J = 7.1 Hz), 7.19 (t, 1H, J = 7.6 Hz), 7.90 (d, 1H, J =
13
2.8 Hz), 8.02 (d, 1H, J = 8.0 Hz), 8.71 (bs, 1H). C-NMR (CDCl3, 100 MHz): δ = 16.5, 51.1, 109.2, 119.2,
120.7, 122.2, 123.8, 125.4, 130.7, 135.7, 165.8 ppm. The values are in accordance with the literature [83].
1
Methyl 6,7-dimethyl-1H-indole-3-carboxylate (6t) (235.0 mg, 58%). Off-white solid: H-NMR
(DMSO-d6, 400 MHz): δ = 2.32 (s, 3H), 2.39 (s, 3H), 3.79 (s, 3H), 6.99 (d, 1H, J = 8.0 Hz), 7.71 (d, 1H, J =
13
8.0 Hz), 7.99 (d, 1H, J = 3.0 Hz), 11.78 (bs, 1H). C-NMR (DMSO-d6, 100 MHz): δ = 13.1, 18.9, 50.5,
+
+
106.6, 117.4, 119.4, 123.8, 123.9, 129.5, 131.6, 136.5, 164.8 ppm. HRMS (ESI ) m/z [M + Na] calculated
for C12H13NO2Na 226.0844, found 226.0845.
1
Methyl 6-chloro-7-methyl-1H-indole-3-carboxylate (6u) (299.8 mg, 67%). Off-white solid: H-NMR
(CDCl3, 400 MHz): δ = 2.52 (s, 3H), 3.91 (s, 3H), 7.26 (d, 1H, J = 8.6 Hz), 7.90 (d, 1H, J = 2.9 Hz), 7.93 (d,
13
1H, J = 8.6 Hz), 8.56 (bs, 1H). C-NMR (CDCl3, 100 MHz): δ = 13.8, 51.2, 109.6, 118.6, 119.8, 123.5, 124.1,
-
−
128.9, 131.0, 136.2, 165.3 ppm. HRMS (ESI ) m/z [M − H] calculated for C11H9ClNO2 222.0322, found
222.0314.
1
Methyl 4,6-dimethyl-1H-indole-3-carboxylate (6v) (607.7 mg, 75%). Off-white solid: H-NMR
(DMSO-d6, 400 MHz): δ = 2.33 (s, 3H), 2.70 (s, 3H), 3.73 (s, 3H), 6.74 (s, 1H), 7.07 (s, 1H), 7.96 (d, 1H, J
13
= 3.0 Hz), 11.71 (bs, 1H). C-NMR (DMSO-d6, 100 MHz): δ = 20.9, 21.9, 50.6, 107.2, 109.7, 122.1, 124.9,
-
−
130.3, 131.6, 132.7, 137.6, 164.6 ppm. HRMS (ESI ) m/z [M − H] calculated for C12H12NO2 202.0868,
found 202.0872.
Methyl 1,6,7,8-tetrahydrocyclopenta[g]indole-3-carboxylate (6w) (305.6 mg, 71%). Off-white solid:
1
H-NMR (DMSO-d6, 400 MHz): δ = 2.08–2.15 (m, 2H), 2.95 (t, 2H, J = 7.3 Hz), 3.04 (t, 2H, J = 7.3 Hz),
13
3.79 (s, 3H), 7.08 (d, 1H, J = 8.0 Hz), 7.79 (d, 1H, J = 8.0 Hz), 7.99 (d, 1H, J = 3.0 Hz), 11.88 (bs, 1H). C-
NMR (DMSO-d6, 100 MHz): δ = 25.0, 29.9, 32.6, 50.6, 106.9, 118.1, 118.5, 124.4, 126.5, 131.6, 133.5, 138.3,
+
+
164.9 ppm. HRMS (ESI ) m/z [M + Na] calculated for C13H13NO2Na 238.0844, found 238.0848.
1
Methyl 7-chloro-1H-indole-3-carboxylate (6x) (175.7 mg, 21%). Pale yellow solid: H-NMR (DMSO-
d6, 400 MHz): δ = 3.82 (s, 3H), 7.18 (t, 1H, J = 7.8 Hz), 7.29 (dd, 1H, J = 7.7 and 1.1 Hz), 7.98 (d, 1H, J =
13
7.9 Hz), 8.11 (d, 1H, J = 3.1 Hz), 12.36 (s, 1H). C-NMR (DMSO-d6, 100 MHz) δ = 51.7, 108.6, 117.6,
-
−
120.4, 122.9, 123.3, 128.4, 134.1, 134.2, 165.3. HRMS (ESI ) m/z [M − H] calculated for C10H7NO2Cl
208.0165, found 208.0158.
1
Methyl 7-fluoro-1H-indole-3-carboxylate (6y) (285.6 mg, 37%). Off-white solid: H-NMR (DMSO-d6,
400 MHz): δ = 3.81 (s, 3H), 7.05 (dd, 1H, J = 11.5 and 8.0 Hz), 7.13–7.18 (m, 1H), 7.81 (d, 1H, J = 8.0 Hz),
13
8.12 (s, 1H), 12.49 (bs, 1H). C-NMR (DMSO-d6, 100 MHz): δ = 50.8, 107.3 (d, J = 16 Hz), 107.4, 116.5