ꢂꢁꢁꢁ
M.V.S.R.K. Chaitanya and P.K. Dubey: Naphthyridine-1-H -pyrazole-4-carboxylic acid esters/carbaldehydesꢀ ꢀ5
1H, -NH), 11.12 (sharp, s, 1H, -NH, D2O exchangeable); MS: m/z 341 1H, -NH), 12.55 (sharp, s, 1H, -NH, D2O exchangeable); MS: m/z 337
[M+H]+. Anal. Calcd for C17H13ClN4O2: C, 59.92; H, 3.85; N, 16.44. Found: [M+H]+. Anal. Calcd for C18H16N4O3: C, 64.28; H, 4.79; N, 16.66. Found:
C, 59.90; H, 3.80; N, 16.40.
C, 64.24; H, 4.73; N, 16.64.
6-Bromo-4-oxo-1,4-dihydro-[1,8]naphthyridine-3-carboxylic
acid [1-(4-methoxy-phenyl)-ethylidene]-hydrazide (9j)ꢀYield
2.98 g (72%); mp 158–160°C; IR: 3400–3150 (broad, medium, -NH-
stretching), 1710 (strong, sharp, -CO- stretching), 1676 cm-1 (strong,
sharp, -CO- stretching); 1H NMR: δ 1.20 (s, 3H, -CH3), 2.31 (s, 3H, -CH3),
7.27–8.40 (m, 6H, Ar-H), 8.90 (s, 1H, -CH, α-proton to the enamine
nitrogen), 10.50 (s, 1H, -NH), 12.99 (sharp, s, 1H, -NH, D2O exchange-
able); MS: m/z 416 [M+H]+. Anal. Calcd for C18H15BrN4O3: C, 52.06; H,
3.64; N, 13.49. Found: C, 52.02; H, 3.62; N, 13.46.
6-Bromo-4-oxo-1,4-dihydro-[1,8]naphthyridine-3-carboxylic
acid [1-(4-chloro-phenyl)-ethylidene]-hydrazide (9d)ꢀYield
2.98 g (71%); mp 148–150°C; IR: 3400–3000 (broad, medium, -NH-
stretching), 1684 (strong, sharp, -CO- stretching), 1670 cm-1 (strong,
1
sharp, -CO- stretching); H NMR: δ 1.26 (s, 3H, -CH3), 7.48–8.30 (m,
6H, Ar-H), 8.88 (s, 1H, -CH, α-proton to the enamine nitrogen), 10.26
(s, 1H, -NH), 11.79 (sharp, s, 1H, -NH, D2O exchangeable); MS: m/z
420 [M+H]+. Anal. Calcd for C17H12BrClN4O2: C, 48.65; H, 2.88; N, 13.35.
Found: C, 48.64; H, 2.86; N, 13.30.
4-Oxo-1,4-dihydro-[1,8]naphthyridine-3-carboxylic acid [1-(4-ni-
tro-phenyl)-ethylidene]-hydrazide (9e)ꢀYield 2.94
g (84%);
mp162–164°C; IR: 3400–2900 (broad, medium, -NH- stretching),
General procedure for the preparation of 10
Products 10 were obtained from 9 by using the procedure described
above for the preparation of 7.
(strong, sharp, -CO- stretching), 1668 cm-1 (strong, sharp, -CO- stretch-
1
ing); H NMR: δ 1.26 (s, 3H, -CH3), 7.28–8.40 (m, 7H, Ar-H), 8.90 (s,
1H, -CH, α-proton to the enamine nitrogen), 10.25 (s, 1H, -NH), 12.10
(sharp, s, 1H, -NH, D2O exchangeable); MS: m/z 352 [M+H]+. Anal.
Calcd for C17H13N5O4: C, 58.12; H, 3.73; N, 19.93. Found: C, 58.10; H, 3.71;
N, 19.90.
1-(4-Oxo-1,4-dihydro-[1,8]naphthyridine-3-carbonyl)-3-phe-
nyl-1H-pyrazole-4-carbaldehyde (10a)ꢀYield 2.33 g (68%); mp
182–184°C; IR: 3400–3100 (broad, medium, -NH- stretching), 1695
(strong, sharp, -CO- stretching), 1684 cm-1 (strong, sharp, -CO- stretch-
ing); 1H NMR: δ 7.10–8.32 (m, 8H, Ar-H), 8.60 (s, 1H, -CH, α-proton to
the enamino nitrogen), 9.10 (s, 1H, -CHO), 9.30 (s, 1H, pyrazole-CH),
10.20 (sharp, s, 1H, -NH, D2O exchangeable); MS: m/z 345 [M+H]+.
Anal. Calcd for C19H12N4O3: C, 66.28; H, 3.50; N, 16.27. Found: C, 66.26;
H, 3.46; N, 16.24.
6-Bromo-4-oxo-1,4-dihydro-[1,8]naphthyridine-3-carboxylic
acid [1-(4-nitro-phenyl)-ethylidene]-hydrazide (9f)ꢀYield 3.50 g
(81%); mp 177–179°C; IR: 3300–3000 (broad, medium, -NH- stretch-
ing), 1694 (strong, sharp, -CO- stretching), 1678 cm-1 (strong, sharp,
-CO- stretching); 1H NMR: δ 1.30 (s, 3H, -CH3), 7.18–8.35 (m, 6H, Ar-H),
8.11 (s, 1H, -CH, α-proton to the enamine nitrogen), 9.98 (s, 1H, -NH),
11.45 (sharp, s, 1H, -NH, D2O exchangeable); MS: m/z 431 [5+H]+. Anal.
Calcd for C17H12BrN5O4: C, 47.46; H, 2.81; N, 16.28. Found: C, 47.43; H,
2.80; N, 16.26.
1-(6-Bromo-4-oxo-1,4-dihydro-[1,8]naphthyridine-3-carbonyl)-
3-phenyl-1H-pyrazole-4-carbaldehyde (10b)ꢀYield 3.00 g (71%);
mp 190–192°C; IR: 3400–3100 (broad, medium, -NH- stretching), 1693
(strong, sharp, -CO- stretching), 1659 cm-1 (strong, sharp, -CO- stretch-
ing); 1H NMR: δ 7.11–8.32 (m, 7H, Ar-H), 8.62 (s, 1H, -CH, α-proton to
the enamine nitrogen), 9.12 (s, 1H, -CHO), 9.30 (s, 1H, pyrazole -CH),
11.10 (sharp, s, 1H, -NH, D2O exchangeable); MS: m/z 424 [M+H]+.
Anal. Calcd for C19H11BrN4O3: C, 53.92; H, 2.62; N, 13.24. Found: C,
53.90; H, 2.60; N, 13.22.
4-Oxo-1,4-dihydro-[1,8]naphthyridine-3-carboxylic acid [1-(4-
methyl-phenyl)-ethylidene]-hydrazide (9g)ꢀYield 2.30 g (72%);
mp 134–136°C; IR: 3400–3200 (broad, medium, -NH- stretching), 1692
(strong, sharp, -CO- stretching), 1665 cm-1 (strong, sharp, -CO- stretch-
ing); 1H NMR: δ 1.25 (s, 3H, -CH3), 2.30 (s, 3H, -CH3), 7.28–8.19 (m, 7H,
Ar-H), 8.90 (s, 1H, -CH, α-proton to the enamine nitrogen), 10.16 (s,
1H, -NH), 12.55 (sharp, s, 1H, -NH, D2O exchangeable); MS: m/z 321
[M+H]+. Anal. Calcd for C18H16N4O2: C, 67.49; H, 5.03; N, 17.49. Found:
C, 67.46; H, 5.00; N, 17.46.
3-(Chloro-phenyl)-1-(4-oxo-1,4-dihydro-[1,8]naphthyridine-
3-carbonyl)-3-phenyl-1H-pyrazole-4-carbaldehyde (10c)ꢀYield
2.64 g (70%); mp 198–200°C; IR: 3300–3200 (broad, medium, -NH-
stretching), 1695 (strong, sharp, -CO- stretching), 1665 cm-1 (strong,
6-Bromo-4-oxo-1,4-dihydro-[1,8]naphthyridine-3-carboxylic
acid [1-(4-methyl-phenyl)-ethylidene]-hydrazide (9h)ꢀYield
3.15 g (79%); mp 138–140°C; IR: 3400–3000 (broad, medium, -NH-
stretching), 1699 (strong, sharp, -CO- stretching), 1670 cm-1 (strong,
sharp, -CO- stretching); 1H NMR: δ 1.32 (s, 3H, -CH3), 2.29 (s, 3H, -CH3),
7.19–8.40 (m, 6H, Ar-H), 8.86 (s, 1H, -CH, α-proton to the enamine
nitrogen), 10.05 (s, 1H, -NH), 12.65 (sharp, s, 1H, -NH, D2O exchange-
able); MS: m/z 400 [M+H]+. Anal. Calcd for C18H15BrN4O2: C, 54.15; H,
3.79; N, 14.03. Found: C, 54.12; H, 3.76; N, 14.00.
1
sharp, due to -CO- stretching); H NMR: δ 7.20–8.45 (m, 7H, Ar-H),
8.72 (s, 1H, -CH, α-proton to the enamine nitrogen), 9.10 (s, 1H, -CHO),
9.25 (s, 1H, pyrazole -CH), 11.25 (sharp, s, 1H, -NH, D2O exchangea-
ble); MS: m/z 379 [M+H]+. Anal. Calcd for C19H11ClN4O3: C, 60.25; H,
2.93; N, 14.79. Found: C, 60.21; H, 2.90; N, 14.76.
1-(6-Bromo-4-oxo-1,4-dihydro-[1,8]naphthyridine-3-carbonyl)-
3-(4-chloro-phenyl)-1H-pyrazole-4-carbaldehyde
(10d)ꢀYield
3.29 g (72%); mp 204–206°C; IR: 3400–2900 (broad, medium, -NH-
4-Oxo-1,4-dihydro-[1,8]naphthyridine-3-carboxylic acid [1-(4- stretching), 1692 (strong, sharp, -CO- stretching), 1670 cm-1 (strong,
methoxy-phenyl)-ethylidene]-hydrazide (9i)ꢀYield 2.35 g (70%); sharp, -CO- stretching); H NMR: δ 7.26–8.30 (m, 6H, Ar-H), 8.72 (s,
1
mp 152–154°C; IR: 3400–3150 (broad, medium, -NH- stretching) 1690 1H, -CH, α-proton to the enamine nitrogen), 9.15 (s, 1H, -CHO), 9.27 (s,
(strong, sharp, -CO- stretching), 1674 cm-1 (strong, sharp, -CO- stretch- 1H, pyrazole -CH), 11.55 (sharp, s, 1H, -NH, D2O exchangeable); MS:
ing); 1H NMR: δ 1.25 (s, 3H, -CH3), 2.56 (s, 3H, -CH3), 7.10–8.20 (m, 7H, m/z 458 [M+H]+. Anal. Calcd for C19H10ClBrN4O3: C, 49.86; H, 2.20; N,
Ar-H), 8.80 (s, 1H, -CH, α-proton to the enamine nitrogen), 10.15 (s, 12.24. Found: C, 49.84; H, 2.18; N, 12. 22.
Brought to you by | Brown University Rockefeller Library
Authenticated | 128.148.252.35
Download Date | 2/21/13 4:54 PM