LETTER
Novel Total Synthesis of Indolo[2,3-b]naphthalene-6,11-diones
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(CH), 128.5 (CH), 129.6 (CH), 133.6 (CH), 135.0 (C), 135.6
93 ºC (MeOH). 1H NMR (CDCl3): d = 3.37–3.43 (m, 1 H,
CHH), 3.64 (s, 3 H, CO2Me), 3.68 (s, 3 H, CO2Me), 3.84
(s, 3 H, OMe), 3.96–4.01 (m, 1 H, CHH), 4.72 (t, J = 7.5 Hz,
1 H, CH), 6.41 (d, J = 3.0 Hz, 1 H, ArH), 6.72 (m, 1 H, ArH),
7.35–7.43 (m, 2 H, 2 × ArH), 7.49–7.51 (m, 1 H, ArH), 7.82
(C), 136.4 (CH), 148.8 (C), 153.7 (C), 168.1 (C=O), 201.2
(C=O). MS (CI): m/z (%) = 326(1) [M+ + 1], 47(100).
Compound 4a: Oil. 1H NMR (CDCl3): 3.42–3.49 (m, 1 H,
CHH), 3.64 (s, 3 H, CO2Me), 3.93–4.00 (m, 1 H, CHH), 4.72
(t, J = 8.0 Hz, 1 H, CH), 6.96 (d, J = 9.0 Hz, 1 H, ArH), 7.21–
7.30 (m, 2 H, 2 × ArH), 7.34–7.53 (m, 3 H, 3 × ArH), 7.81–
7.91 (m, 2 H, 2 × ArH). 13C NMR (CDCl3): d = 37.4 (CH2),
47.8 (CH), 52.1 (OMe), 52.3 (OMe), 124.6 (CH), 126.7
(CH), 127.9 (CH), 129.5 (C), 130.8 (CH), 130.9 (CH), 131.6
(CH), 131.7 (CH), 132.7 (CH), 133.2 (C), 139.8 (C), 149.1
(C), 167.4 (C=O), 172.4 (C=O). MS (FAB): m/z (%) =
344(22) [M+ + 1], 149(100). Compound 5a: Mp 110–112 ºC
(MeOH). 1H NMR (CDCl3): d = 3.22–3.32 (m, 1 H, CHH),
3.83–3.91 (m, 5 H, CHH, CH, CO2Me), 6.66 (d, J = 7.5 Hz,
1 H, ArH), 6.84–6.89 (m, 2 H, 2 × ArH), 7.13–7.19 (m, 1 H,
ArH), 7.29–7.49 (m, 3 H, 3 × ArH), 7.99 (m, 1 H, ArH), 8.81
(br s, 1 H, NH). 13C NMR (CDCl3): d = 35.6 (CH2), 46.8
(CH), 52.1 (OMe), 109.6 (CH), 121.7 (CH), 124.9 (CH),
126.8 (CH), 127.7 (CH), 129.1 (C), 129.8 (C), 131.0 (CH),
131.7 (CH), 132.5 (CH), 139.9 (C), 141.3 (C), 167.6 (C=O),
179.6 (C=O). MS: m/z (%) = 281(13) [M+], 220(100).
Compound 6a: Mp 111–113 ºC (MeOH). 1H NMR (CDCl3):
d = 3.95 (s, 3 H, CO2Me), 4.49 (d, J = 10 Hz, 2 H, CH2),
6.99–7.42 (m, 6 H, 6 × ArH), 7.92 (d, J = 7.5 Hz, 1 H, ArH),
8.16 (s, 1 H, ArH). 13C NMR (CDCl3): d = 28.7 (CH2), 52.2
(OMe), 109.4 (C), 110.3 (CH), 113.2 (C), 113.7 (C), 118.7
(CH), 120.0 (CH), 122.2 (CH), 125.8 (CH), 127.8 (C), 129.5
(CH), 130.3 (CH), 131.8 (CH), 136.1 (C), 141.1 (C), 168.3
(C=O). MS (CI): m/z (%) = 345(18) [M+ + 2], 343(22) [M+],
264(100). Compound 6b: Mp 56–58 ºC (MeOH). 1H NMR
(CDCl3): d = 3.87 (s, 3 H, CO2Me), 4.54 (s, 2 H, CH2), 6.82
(s, 1 H, CH), 7.10–7.41 (m, 5 H, 5 × ArH), 7.58 (d, J = 8.0
Hz, 1 H, ArH), 7.91–7.99 (m, 2 H, 2 × ArH). 13C NMR
(CDCl3): d = 29.5 (CH2), 51.9 (OMe), 110.9 (CH), 115.2
(C), 118.9 (CH), 119.1 (CH), 121.8 (CH), 122.5 (CH), 125.8
(CH), 127.4 (C), 129.8 (C), 130.2 (CH), 130.7 (CH), 131.7
(CH), 136.2 (C), 142.3 (C), 168.4 (C=O). MS: m/z (%) =
265(66) [M+], 204(100). Compound 7a: Mp 206–208 ºC
(MeOH). 1H NMR (CDCl3–acetone–DMSO): d = 3.77 (s, 3
H, OMe), 6.61 (d, J = 5.0 Hz, 1 H, CH), 6.84 (m, 2 H, 2 ×
ArH), 7.04 (d, J = 5.0 Hz, 1 H, ArH), 7.47–7.59 (m, 3 H, 3 ×
ArH), 8.05 (s, 2 H, 2 × ArH), 9.35 (br s, 1 H, NH). 13C NMR
(CDCl3–acetone–DMSO): d = 51.4 (OMe), 109.3 (CH),
120.4 (CH), 120.9 (C), 122.0 (CH), 126.7 (C), 128.3 (C),
128.4 (CH), 128.8 (CH), 129.1 (CH), 130.3 (CH), 131.7
(CH), 136.2 (CH), 136.2 (C), 141.8 (C), 165.5 (C=O), 168.3
(C=O). MS: m/z (%) = 279(1) [M+], 58(100). Compound 8b:
Mp 378–380 °C (MeOH). 1H NMR (DMSO): d = 7.25–7.35
(m, 2 H, 2 × Ar-H), 7.55–7.57 (m, 2 H, 2 × Ar-H), 7.78–7.84
(m, 1 H, Ar-H), 7.95–8.07 (m, 3 H, 3 × Ar-H), 12.94 (br s, 1
H, NH). 13C NMR (TFAA): d = 113.3 (CH), 121.0 (C), 123.5
(C), 125.1 (CH), 128.9 (CH), 130.2 (CH), 130.3 (CH), 130.4
(CH), 134.5 (CH), 135.1 (C), 136.2 (CH), 139.7 (C), 140.6
(C), 148.4 (C), 154.3 (C), 179.2 (2 × C=O). MS: m/z (%) =
247(44), 219(100). Compound 3b: Mp 151–153 ºC
(d, J = 8.0 Hz, 1 H, ArH), 7.90 (d, J = 9.0 Hz, 1 H, ArH). 13
C
NMR (CDCl3): d = 37.7 (CH2), 47.6 (CH3), 51.8 (CH3), 52.3
(CH3), 55.2 (CH), 112.2 (CH), 116.8 (CH), 121.5 (C), 124.7
(CH), 128.0 (CH), 131.0 (CH), 132.8 (CH), 133.3 (CH),
133.3 (C), 142.7 (C), 149.3 (C), 162.0 (C), 167.0 (C=O),
172.6 (C=O). MS (FAB): m/z (%) = 374(41) [M+ + 1],
154(100). Compound 5b: Mp 147–149 ºC (MeOH). 1H
NMR (CDCl3): d = 3.23–3.29 (m, 1 H, CHH), 3.79 (s, 3 H,
OMe), 3.83 (s, 3 H, OMe), 3.85–3.89 (m, 2 H, CH, CHH),
6.70–6.90 (m, 5 H, 5 × ArH), 7.15 (t, J = 7.5 Hz, 1 H, ArH),
8.00 (d, J = 9.0 Hz, 1 H, ArH), 9.25 (s, 1 H, NH). 13C NMR
(CDCl3): d = 35.9 (CH2), 46.6 (CH), 51.7 (CH3), 55.3 (CH3),
109.7 (CH), 112.4 (CH), 117.6 (CH), 121.7 (CH), 121.8 (C),
124.9 (CH), 127.7 (CH), 129.2 (C), 133.4 (CH), 141.5 (C),
142.9 (C), 162.0 (C), 167.2 (C=O), 180.1 (C=O). MS: m/z
(%) = 311(8) [M+], 279(100). Compound 6c: Mp 139–141
ºC (MeOH). 1H NMR (CDCl3): d = 3.65 (s, 3 H, OMe), 3.93
(s, 3 H, OMe), 4.52 (d, J = 10.0 Hz, 2 H, CH2), 6.50–6.57 (m,
1 H, ArH), 6.71–6.75 (m, 1 H, ArH), 6.99–7.04 (m, 1 H,
ArH), 7.12–7.16 (m, 1 H, ArH), 7.25–7.41 (m, 1 H, ArH),
7.99 (d, J = 9.0 Hz, 1 H, ArH), 8.21 (d, 1 H, ArH). 13C NMR
(CDCl3): d = 28.8 (CH2), 51.8 (CH3), 55.1 (CH3), 110.3
(CH), 110.4 (CH), 113.2 (C), 113.6 (C), 115.6 (CH), 118.7
(CH), 120.0 (CH), 121.5 (C), 122.2 (CH), 127.8 (C), 132.9
(CH), 136.1 (C), 144.3 (C), 162.3 (C), 167.7 (C=O). MS
(FAB): m/z (%) = 376(3) [(M+ + 1) + 2], 374(5) [M+ + 1],
137(100). Compound 6d: Oil. 1H NMR (CDCl3): 3.73 (s, 3
H, OMe), 3.84 (s, 3 H, OMe), 4.54 (s, 2 H, CH2), 6.76–6.87
(m, 3 H, CH, 2 × ArH), 7.10 (t, J = 7.5 Hz, 1 H, ArH), 7.19
(t, J = 7.5 Hz, 1 H, ArH), 7.33 (d, J = 8.0 Hz, 1 H, ArH), 7.57
(d, J = 8.0 Hz, 1 H, ArH), 7.96–8.01 (m, 2 H, ArH, NH). 13
NMR (CDCl3): d = 29.8 (CH2), 51.6 (OMe), 55.1 (OMe),
C
110.8 (CH), 111.0 (C), 115.2 (C), 116.4 (CH), 119.0 (CH),
119.2 (CH), 121.8 (C), 121.8 (CH), 122.6 (CH), 127.5 (C),
133.0 (CH), 136.3 (C), 145.6 (CH), 162.3 (C), 167.8 (C=O).
MS: m/z (%) = 295(58) [M+], 220(100). Compound 7c: 206–
208 ºC (MeOH). 1H NMR (CDCl3–acetone–DMSO): d =
3.61 (s, 3 H, OMe), 3.64 (s, 3 H, OMe), 6.50–6.54 (m, 1 H,
CH), 6.68–6.70 (m, 1 H, ArH), 6.79–6.84 (m, 2 H, ArH),
6.90–6.93 (m, 2 H, ArH), 7.89–7.95 (m, 2 H, ArH), 8.98 (br
s, 1 H, NH). 13C NMR (CDCl3–acetone–DMSO): d = 51.5
(CH3), 55.2 (CH3), 109.8 (CH), 114.1 (CH), 114.3 (CH),
121.0 (CH), 121.3 (C), 122.6 (CH), 126.8 (C), 129.2 (CH),
132.9 (CH), 137.2 (CH), 138.8 (C), 141.9 (C), 162.2 (C),
165.8 (C=O), 169.0 (C=O). MS: m/z (%) = 309 (12) [M+],
250(100). Compound 8d: Mp 386–388 °C (MeOH). 1H
NMR (DMSO): d = 3.87 (s, 3 H, OMe), 7.23–7.34 (m, 3 H,
3 × ArH), 7.43–7.54 (m, 1 H, ArH), 7.93–7.99 (m, 1 H,
ArH), 8.53 (d, J = 8.6 Hz, 1 H, ArH), 12.8 (br s, 1 H, NH).
13C NMR (TFAA): d = 54.8 (CH3), 111.3 (C), 112.7 (CH),
115.0 (C), 117.5 (CH), 119.6 (CH), 120.5 (C), 125.3 (CH),
129.9 (CH), 130.4 (CH), 130.6 (C), 132.2 (CH), 140.5 (C),
150.0 (C), 153.8 (C), 165.5 (C), 179.3 (2 × C=O). MS: m/z
(%) = 277(42) [M+], 29(100).
(MeOH). 1H NMR (CDCl3): d = 1.18 (t, J = 7.0 Hz, 3 H,
CH3), 3.30 (d, J = 18.5 Hz, 1 H, CHH), 3.91 (s, 3 H, OMe),
4.14 (q, J = 7.0 Hz, 2 H, CH2O), 4.51 (d, J = 18.0 Hz, 1 H,
CHH), 6.91–6.99 (m, 2 H, 2 × ArH), 7.25 (s, 1 H, 2 × ArH),
7.41–7.54 (m, 2 H, 2 × ArH), 7.82 (d, J = 9.0 Hz, 1 H, ArH),
8.07 (d, J = 8.5 Hz, 1 H, ArH). 13C NMR (CDCl3): d = 13.9
(CH3), 42.6 (CH2), 55.9 (CH3), 62.5 (CH2), 65.8 (C), 109.2
(CH), 116.5 (CH), 125.6 (CH), 126.7 (CH), 128.1 (C), 128.3
(CH), 129.6 (CH), 133.5 (CH), 135.7 (C), 148.7 (C), 156.8
(C), 166.5 (C), 168.2 (C=0), 198.6 (C=O). MS (CI): m/z
(%) = 356(1) [M+ + 1]; 266(100). Compound 4c: Mp 91–
(12) (a) Saxton, J. E. In The Chemistry of Heterocyclic
Compounds; John Wiley and Sons: New York, 1994.
(b) Gribble, G. W. J. Chem. Soc., Perkin Trans. 1 2000, 7,
1045. (c) Gribble, G. W. In Second Supplement to the 2nd
Edition of Rodd’s Chemistry of Carbon Compounds,
Heterocyclic Compounds; Sainsbury, M., Ed.; Elsevier
Science Publications: Amsterdam, 1997. (d) Bosch, J.;
Bonjoch, J.; Amat, M. The Alkaloids 1996, 48, 75–189.
Synlett 2004, No. 2, 267–270 © Thieme Stuttgart · New York