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Helvetica Chimica Acta – Vol. 92 (2009)
Methyl 6-(4-Methoxyphenyl)-1,8-naphthyridine-3-carboxylate (4c). Yield 72%1). M.p. 296 – 2988.
1H-NMR (200 MHz, CDCl3): 9.57 (s, 1 H); 9.00 (s, 1 H); 8.61 (s, 1 H); 8.34 (s, 1 H); 7.60 (br. s, 4 H); 4.02
(s, 3 H); 3.86 (s, 3 H). 13C-NMR (75 MHz, CDCl3): 166.7; 160.1; 150.3; 137.2; 134.2; 133.9; 129.0; 128.7;
128.4; 128.2; 128.1; 127.4; 114.8; 55.3; 52.3. EI-MS: 294 (Mþ). Anal. calc. for C17H14N2O3: C 69.38, H 4.79,
N 9.52; found: C 69.32, H 4.74, N 9.32.
Methyl 6-Methyl-7-phenyl-1,8-naphthyridine-3-carboxylate (4d). Yield 74%1). M.p. 285 – 2878. IR
(KBr): 3060, 2924, 1721, 1611, 1429, 1254, 1103, 699. 1H-NMR (200 MHz, CDCl3): 9.55 (s, 1 H); 8.78 (s,
1 H); 8.10 (s, 1 H); 7.48 – 7.67 (m, 5 H); 3.98 (s, 3 H); 2.53 (s, 3 H). EI-MS: 278 (23, Mþ), 277 (100), 247
(8), 218 (10), 190 (7). Anal. calc. for C17H14N2O2: C 73.37, H 5.07, N 10.07; found: C 73.22, H 5.12, N
10.19.
Dimethyl 1,8-Naphthyridine-2,6-dicarboxylate (4e). Yield 88%1). M.p. 312 – 3158. IR (KBr): 2958,
1720, 1441, 1341, 1228, 1141, 1099, 775. 1H-NMR (200 MHz, CDCl3): 9.69 (s, 1 H); 9.0 (s, 1 H); 8.8 (d, J ¼
7.95, 1 H); 8.34 (d, J ¼ 7.95, 1 H); 4.08 (s, 3 H); 4.05 (s, 3 H). 13C-NMR (75 MHz, CDCl3): 166.4; 165.8;
148.8; 148.4; 139.3; 138.6; 129.3; 128.3; 123.0; 121.3; 52.9; 52.3. EI-MS: 246 (100, Mþ). Anal. calc. for
C12H10N2O4: C 58.54, H 4.09, N 11.38; found: C 58.23, H 4.46, N 10.98.
Ethyl 6-Methyl-1,8-naphthyridine-3-carboxylate (4f). Yield 82%1). M.p. 282 – 2858. IR (KBr): 3396,
1
2922, 1663, 1426, 1375, 1028, 762, 697. H-NMR (200 MHz, CDCl3): 9.52 (s, 1 H); 9.0 (s, 1 H); 8.78 (s,
1 H); 8.0 (s, 1 H); 4.42 (q, J ¼ 7.17, 2 H); 2.51 (s, 3 H); 1.39 (t, J ¼ 7.17, 3 H). EI-MS: 216 (100, Mþ), 199
(33), 183 (33), 152 (8), 77 (10). Anal. calc. for C12H12N2O2: C 66.65, H 5.59, N 12.95; found: C 66.62, H
5.68, N 12.81.
Ethyl 6-Ethyl-1,8-naphthyridine-3-carboxylate (4g). Yield 80%1). M.p. 286 – 2898. IR (KBr): 3390,
1
2982, 1690, 1490, 1390, 1028, 762, 697. H-NMR (200 MHz, CDCl3): 9.52 (s, 1 H); 8.83 (s, 1 H); 8.36 (s,
1 H); 8.13 (s, 1 H); 4.42 (q, J ¼ 7.21, 2 H); 2.92 (q, J ¼ 7.21, 2 H); 1.41 (t, J ¼ 7.21, 3 H); 1.31 (t, J ¼ 7.21,
3 H). EI-MS: 230 (100, Mþ). Anal. calc. for C13H14N2O2: C 67.81, H 6.13, N 12.17; found: C 67.78, H 6.08,
N 12.14.
Ethyl 6-Phenyl-1,8-naphthyridine-3-carboxylate (4h). Yield 84%1). M.p. 240 – 2428. IR (KBr): 3060,
2924, 1721, 1611, 1426, 1254, 1103, 699. 1H-NMR (200 MHz, CDCl3): 9.55 (s, 1 H); 8.78 (s, 1 H); 8.46 (s,
1 H); 8.10 (s, 1 H); 7.42 – 7.67 (m, 5 H); 4.38 (q, J ¼ 7.17, 2 H); 1.43 (t, J ¼ 7.17, 3 H). 13C-NMR (75 MHz,
CDCl3): 166.2; 150.5; 137.4; 137.3; 134.4; 134.0; 129.1; 128.9; 128.7; 128.4; 128.2; 127.2; 127.1; 61.1; 14.3.
EI-MS: 278 (100, Mþ), 249 (64), 183 (65), 137 (10), 128 (10). Anal. calc. for C17H14N2O2: C 73.36, H 5.07,
N 10.07; found: C 73.42, H 5.09, N 10.45.
Ethyl 6-Methyl-7-phenyl-1,8-naphthyridine-3-carboxylate (4i). Yield 82%1). M.p. 282 – 2858. IR
(KBr): 2927, 1706, 1613, 1407, 1257, 1106, 783. 1H-NMR (200 MHz, CDCl3): 9.6 (s, 1 H); 8.8 (s, 1 H); 8.12
(s, 1 H); 7.75 – 7.45 (m, 5 H); 4.51 (q, J ¼ 7.21, 2 H); 2.60 (s, 3 H); 1.50 (t, J ¼ 7.21, 3 H). 13C-NMR
(50 MHz, CDCl3): 165.6; 156.0; 152.7; 139.6; 138.7; 133.2; 131.7; 129.4; 129.2; 129.0; 128.2; 124.1; 120.5;
61.7; 20.6; 14.3. EI-MS: 292 (40, Mþ), 291 (100), 263 (75), 247 (10), 218 (11). Anal. calc. for C18H16N2O2:
C 73.95, H 5.51, N 9.58; found: C 73.99, H 5.66, N 9.64.
6-Ethyl 2-Methyl-1,8-naphthyridine-2,6-dicarboxylate (4j). Yield 88%1). M.p. 314 – 3168. IR (KBr):
3023, 2954, 1742, 1712, 1324, 1280, 1173, 1093, 783. 1H-NMR (200 MHz, CDCl3): 9.78 (d, J ¼ 2.93, 1 H);
8.91 (d, J ¼ 2.93, 1 H); 8.48 (d, J ¼ 8.08, 1 H); 8.38 (d, J ¼ 8.08, 1 H); 4.50 (q, J ¼ 7.34, 2 H); 4.09 (s, 3 H);
1.50 (t, J ¼ 7.34, 3 H). 13C-NMR (50 MHz, CDCl3): 165.3; 164.2; 156.4; 154.4; 152.7; 139.8; 139.4; 125.7;
122.9; 122.7; 62.1; 53.2; 14.3. EI-MS: 260 (3, Mþ), 230 (17), 215 (10), 202 (100), 174 (42), 160 (10), 128
(8), 101 (6). Anal. calc. for C13H12N2O4: C 60.40, H 4.65, N 10.76; found: C 60.35, H 4.68, N 10.68.
Methyl (2E)-2-(Azidomethyl)-3-(2-chloro-5-methylpyridin-3-yl)prop-2-enoate (6a). Yield 92%. M.p.
82 – 848. 1H-NMR (200 MHz, CDCl3): 8.22 (s, 1 H); 7.90 (s, 1 H); 7.58 (s, 1 H); 4.02 (s, 2 H); 3.92 (s, 3 H);
2.39 (s, 3 H). EI-MS: 266 (100, Mþ), 224 (76), 210 (23).
Methyl (2E)-2-(Azidomethyl)-3-(2-chloro-5-methyl-6-phenylpyridin-3-yl)prop-2-enoate (6d). Yield
91%. M.p. 110 – 1128. 1H-NMR (200 MHz, CDCl3): 7.95 (s, 1 H); 7.68 (s, 1 H); 7.60 – 7.42 (m, 5 H); 4.08 (s,
2 H); 3.93 (s, 3 H); 2.43 (s, 3 H). EI-MS: 342 (100, Mþ), 300 (66), 286 (45), 258 (12).
Methyl 5-[(1E)-2-(Azidomethyl)-3-methoxy-3-oxoprop-1-en-1-yl]-6-chloropyridine-2-carboxylate
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(6e). Yield 92%. M.p. 119 – 1218. H-NMR (200 MHz, CDCl3): 8.09 (d, J ¼ 8.08, 1 H); 7.91 (d, J ¼ 8.08,
1 H); 7.90 (s, 1 H); 3.99 (s, 3 H); 3.97 (s, 2 H). EI-MS: 310 (100, Mþ), 295 (76), 253 (65), 225 (36).