ORDER
REPRINTS
Synthesis of Nitrocarbazoles by Urea Nitrate
1263
3-Nitro-9-ethylcarbazole (3c). 0.583 g, (81%) of yellow crystalline
solid; m.p. 127–1288C (Lit.[12] 126–127); IR: 3048, 2930, 1591, 1510,
1
1471, 1313, 749 cm21; H NMR (300 MHz, CDCl3): d 8.96 (d, 1H, J ¼
1.9 Hz), 8.38 (dd, 1H, J1 ¼ 2.0 Hz, J2 ¼ 12.5 Hz), 8.13 (d, 1H, J ¼ 7.8 Hz),
7.60 (t, 1H, J ¼ 7.6 Hz), 7.48 (m, 3H), 4.43 (q, 2H, J ¼ 7.1 Hz), 1.47 (t, 3H,
J ¼ 7.2 Hz); 13C NMR (75 MHz, CDCl3): d 143.0, 141.1, 140.6, 127.4, 122.9,
122.6, 121.6, 121.0, 120.7, 117.3, 109.4, 107.9, 38.1, 13.8; Mass m/z 240
(Mþ); Anal. Calcd for C14H12N2O2; C, 69.99; H, 5.03, N, 11.66; Found, C,
70.24; H, 4.93; N, 11.53.
3-Methyl-6-nitro-9-ethylcarbazole (3d). 0.701 g (92%) of yellow solid;
m.p. 89–908C; IR: 3093, 2965, 1598, 1487, 1385, 1307, 800 cm21; 1H NMR
(300 MHz, CDCl3): d 8.88 (d, 1H, J ¼ 2.2 Hz), 8.32 (dd, 1H, J1 ¼ 2.2 Hz,
J2 ¼ 9.0 Hz), 8.06 (d, 1H, J ¼ 7.7 Hz), 7.57 (t, 1H, J ¼ 8.1 Hz), 7.44–7.24
(m, 2H), 4.36 (q, 2H, J ¼ 7.2 Hz), 2.56 (s, 3H), 1.43 (t, 3H, J ¼ 7.2 Hz);
13C NMR (75 MHz, CDCl3): d 142.7, 140.9, 140.2, 127.2, 122.6, 122.3,
121.3, 120.8, 120.5, 117.0, 109.3, 107.8, 37.9, 21.5, 13.7; Mass m/z 254
(Mþ); Anal. Calcd for C15H14N2O2; C, 70.85; H, 5.55; N, 11.02; Found, C,
70.66; H, 5.61; N, 10.86.
6-Nitro-9-ethylcarbazole-3-aldehyde (3e). 0.683 g (85%) of yellow
solid; m.p. 247–2488C (Lit.[13] 248) IR: 3076, 2964, 1687, 1627, 1593,
1509, 1483, 1383, 1311, 723 cm21 1H NMR (300 MHz, DMSO-d6): d
;
10.14 (s, 1H, CHO), 9.04 (s, 1H), 8.65 (s, 1H), 8.46 (d, 1H, J ¼ 8.5 Hz),
8.14 (d, 1H, J ¼ 8.0 Hz), 7.60–7.49 (m, 2H), 4.89 (q, 2H, J ¼ 7.1 Hz), 1.53
(t, 3H, J ¼ 7.1 Hz); 13C NMR (75 MHz, DMSO-d6): d 192.2, 144.7, 143.9,
141.1, 129.9, 128.1, 125.6, 122.7, 122.5, 122.4, 118.2, 111.1, 110.5, 38.4,
14.1; Mass m/z 268 (Mþ); Anal. Calcd for C15H12N2O3; C, 67.16; H, 4.51;
N, 10.44; Found, C, 66.89; H, 4.65; N, 10.23.
ACKNOWLEDGMENT
We thank the Council of Scientific and Industrial Research, New Delhi,
India for financial support.
REFERENCES
1. (a) Knolker, H.-J.; Reddy, K.R. Isolation and synthesis of biologically
active carbazole alkaloids. Chem. Rev. 2002, 102, 4303–4427;
(b) Knolker, H.-J. Transition metal complexes in organic synthesis. Part
47. Organic synthesis via tricarbonyl (h4-diene) iron complexes. Chem.
Soc. Rev. 1999, 28, 151–157.