ES) 167 (M + H). Anal. Calcd for C8H7ClN2: C, 57.67; H, 4.23;
Cl, 21.28; N, 16.81. Found: C, 57.41; H, 4.20; Cl, 21.01; N, 16.83.
6-Chloro-2-methyl-2H-indazole (2 g). Tan solid: mp 70 °C
2-Ethyl-2H-indazole (3e). Colorless oil (lit.10 colorless oil);
1H NMR (400 MHz, DMSO-d6) δ 8.34 (s, 1H), 7.66 (d, 1H, J )
8.4 Hz), 7.57 (d, 1H, J ) 8.7 Hz), 7.19 (m, 1H), 6.99 (m, 1H),
4.42 (q, 2H, J ) 7.3 Hz), 1.48 (t, 3H, J ) 7.3 Hz); 13C NMR (100
MHz, DMSO-d6) δ 148.59, 125.82, 123.59, 122.07, 121.45, 121.16,
117.57, 48.38, 16.44; MS (+ve ES) 147 (M + H). Anal. Calcd for
C9H10N2: C, 73.94; H, 6.89; N, 19.16. Found: C, 73.84; H, 6.93;
N, 19.24.
1
(EtOAc); H NMR (400 MHz, DMSO-d6) δ 8.30 (s, 1H), 7.76 (d,
1H, J ) 1.8 Hz), 7.60 (d, 1H, J ) 9.1 Hz), 7.17 (dd, 1H, J ) 9.1
and 1.9 Hz). 4.14 (s, 3H); 13C NMR (100 MHz, DMSO-d6) δ
147.05, 126.76, 125.98, 125.27, 122.69, 119.96, 119.47, 40.83. MS
(+ve ES) 167 (M + H). Anal. Calcd for C8H7ClN2: C, 57.67; H,
4.23; Cl, 21.28; N, 16.81. Found: C, 57.41; H, 4.26; Cl, 21.49; N,
16.65.
2-Ethyl-5-chloro-2H-indazole (3f). Yellow oil; 1H NMR (400
MHz, DMSO-d6) δ 8.36 (s, 1H), 7.77 (d, 1H, J ) 1.9 Hz), 7.62 (d,
1H, J ) 9.1 Hz), 7.18 (dd, 1H, J ) 9.1 and 1.9 Hz), 4.43 (q, 2H,
J ) 7.3 Hz), 1.47 (t, 3H, J ) 7.3 Hz); 13C NMR (100 MHz, DMSO-
d6) δ 146.89, 126.74, 125.95, 123.87, 122.45, 120.05, 119.67,
48.62, 16.33; MS (+ve ES) 181 (M + H). Anal. Calcd for C9H9N2-
Cl: C, 59.84; H, 5.02; N, 15.51; Cl, 19.63. Found: C, 59.87; H,
4.94; N, 15.61; Cl, 19.61.
2-Ethyl-6-chloro-2H-indazole (3g). Off-white solid: mp 59-
61 °C (EtOAc); 1H NMR (400 MHz, DMSO-d6) δ 8.42 (s, 1H),
7.72 (d, 1H, J ) 8.8 Hz), 7.66 (s, 1H), 6.99 (d, 1H, J ) 8.8 Hz),
4.52 (q, 2H, J ) 7.2 Hz), 1.47 (t, 3H, J ) 7.2 Hz); 13C NMR (100
MHz, DMSO-d6) δ 148.66, 130.75, 124.66, 123.26, 122.41, 120.57,
116.42, 48.60, 16.30; MS (+ve ES) 181 (M + H). Anal. Calcd for
C9H9N2Cl: C, 59.84; H, 5.02; N, 15.51; Cl, 19.63. Found: C,
59.96; H, 4.94; N, 15.69; Cl, 19.48.
2-Ethyl-5-methoxy-2H-indazole (3h). Off-white solid: mp
79-81 °C (EtOAc); 1H NMR (400 MHz, DMSO-d6) δ 8.15 (s, 1H),
7.48 (d, 1H, J ) 9.1 Hz), 6.96 (s, 1H), 6.87 (dd, 1H, J ) 9.1 and
1.6 Hz), 4.36 (q, 2H, J ) 7.3 Hz), 3.73 (s, 3H), 1.45 (t, 3H, J )
7.3 Hz); 13C NMR (100 MHz, DMSO-d6) δ 154.74, 145.21, 122.59,
121.97, 120.18, 118.96, 97.89, 55.72, 48.22, 16.46; MS (+ve ES)
177 (M + H). Anal. Calcd for C10H12N2O: C, 68.16; H, 6.86; N,
15.90; O, 9.08. Found: C, 68.23; H, 6.89; N, 15.89; O, 8.98.
2-Ethyl-6-methoxy-2H-indazole (3i). Yellow oil; 1H NMR
(400 MHz, DMSO-d6) δ 8.20 (s, 1H), 7.52 (d, 1H, J ) 9.1 Hz),
6.90 (s, 1H), 6.66 (dd, 1H, J ) 9.1 and 2.2 Hz), 4.34 (q, 2H, J )
7.3 Hz), 3.75 (s, 3H), 1.45 (t, 3H, J ) 7.3 Hz); 13C NMR (100
MHz, DMSO-d6) δ 158.44, 149.54, 123.64, 121.95, 117.44, 115.89,
95.31, 55.62, 48.05, 16.41; MS (+ve ES) 177 (M + H). Anal. Calcd
for C10H12N2O: C, 68.16; H, 6.86; N, 15.90; O, 9.08. Found: C,
68.21; H, 6.84; N, 15.90; O, 9.00.
5-Methoxy-2-methyl-2H-indazole (2h). Yellow oil: 1H NMR
(400 MHz, DMSO-d6) δ 8.16 (s, 1H), 7.52 (d, 1H, J ) 9.1), 6.88
(d, 1H, J ) 1.8 Hz), 6.66 (dd, 1H, J ) 9.1 and 1.8 Hz), 4.06 (s,
3H), 4.01 (s, 3H); 13C NMR (100 MHz, DMSO-d6) δ 158.47,
149.74, 125.10, 121.87, 117.67, 115.90, 95.10, 55.62, 40.33; MS
(+ve ES) 163 (M + H). Anal. Calcd for C9H10N2O‚0.3 H2O: C,
64.50; H, 6.38; N, 16.72. Found: C, 64.63; H, 6.33; N, 16.74.
6-Methoxy-2-methyl-2H-indazole (2i). White solid: mp 72-
74 °C (EtOAc); 1H NMR (400 MHz, DMSO-d6) δ 8.11 (s, 1H),
7.46 (d, 1H, J ) 9.3 Hz), 6.96 (d, 1H, J ) 2.3 Hz), 6.86 (dd, 1H,
J ) 9.3 and 2.3 Hz), 4.08 (s, 3H), 4.03 (s, 3H); 13C NMR (100
MHz, DMSO-d6) δ 154.73, 145.35, 124.06, 122.20, 120.19, 118.77,
97.80, 55.71, 40.49; MS (+ve ES) 163 (M + H). Anal. Calcd for
C9H10N2O‚0.4H2O: C, 63.81; H, 6.43; N, 16.54. Found: C, 63.95;
H, 6.37; N, 16.54.
2-Ethyl-4-nitro-2H-indazole (3b). Yellow solid: mp 75-77
1
°C (EtOAc); H NMR (400 MHz, DMSO-d6) δ 8.87 (s, 1H), 8.16
(m, 2H), 7.46 (t, 1H, J ) 8.0 Hz), 4.56 (q, 2H, J ) 7.3 Hz), 1.52
(t, 3H, J ) 7.3 Hz); 13C NMR (100 MHz, DMSO-d6) δ 149.81,
140.68, 126.86, 125.00, 124.87, 120.98, 114.55, 49.07, 16.36; MS
(+ve ES) 192 (M + H). Anal. Calcd for C9H9N3O2: C, 56.54; H,
4.74; N, 21.98; O, 16.74. Found: C, 56.68; H, 4.78; N, 21.98; O,
16.68.
2-Ethyl-5-nitro-2H-indazole (3c). Yellow solid: mp 62-64
1
°C (EtOAc); H NMR (400 MHz, DMSO-d6) δ 8.83 (s, 1H), 8.78
(s, 1H), 7.97 (d, 1H, J ) 9.4 Hz), 7.74 (d, 1H, J ) 9.4 Hz), 4.53
(q, 2H, J ) 7.3 Hz), 1.50 (t, 3H, J ) 7.3 Hz); 13C NMR (100 MHz,
DMSO-d6) δ 149.64, 142.46, 129.18, 121.03, 120.44, 120.05,
118.61, 49.14, 16.05; MS (+ve ES) 192 (M + H). Anal. Calcd for
C9H9N3O2: C, 56.54; H, 4.74; N, 21.98; O, 16.74. Found: C,
56.61; H, 4.75; N, 21.98; O, 16.62.
Acknowledgment. We thank Mr. Randy D. Rut-
kowske for providing NMR analysis of the products and
Drs. Philip A. Harris and Michael R. Peel for helpful
discussions.
2-Ethyl-7-nitro-2H-indazole (3d). Yellow solid: mp 74-76
°C (EtOAc) (lit.11 mp 73-74 °C); 1H NMR (400 MHz, DMSO-d6)
δ 8.78 (s, 1H), 8.28 (d, 1H, J ) 7.7 Hz), 8.24 (d, 1H, J ) 8.2 Hz),
7.22 (m, 1H), 4.55 (q, 2H, J ) 7.3 Hz), 1.52 (t, 3H, J ) 7.3 Hz);
13C NMR (100 MHz, DMSO-d6) δ 140.13, 137.22, 130.73, 127.02,
125.93, 125.32, 120.32, 49.12, 16.33; MS (+ve ES) 192 (M + H).
Anal. Calcd for C9H9N3O2: C, 56.54; H, 4.74; N, 21.98; O, 16.74.
Found: C, 56.67; H, 4.80; N, 21.98; O, 16.56.
Supporting Information Available: Data from 1H NMR
and ROESY experiments for 1-methyl-6-nitro-1H-indazole and
2-methyl-6-nitro-2H-indazole. This material is available free
(11) Balasubrahmanyam, S. N.; Radhakrishna, A. S. J. Org. Chem.
1977, 42, 897.
JO0265434
J. Org. Chem, Vol. 68, No. 10, 2003 4095