Vol. 25, No. 6 (2013)
Green Synthesis of Schiff Bases Derived from 4,5-Diazafluorene-9-one 3391
precipitate was filtered after cooling, washed with ethanol 3
times and dried in vacuum oven at 50 ºC. The results of yield,
melt point and UV-visible spectra were listed in Table-1.
9-Imine-4,5-diazafluorene (L1): 1H NMR (CDCl3, 300
MHz): δ 8.82 (dd, 2H, J1 = 5.1, J2 = 1.5 Hz, pyridyl H ortho to
N), 8.05 (dd, 2H, J1 = 5.1, J2 = 1.5 Hz, pyridyl H para to N),
7.38 (t, 2H, J1 = 7.6, J2 = 5.1 Hz, pyridyl H meta to N), 5.45 (s,
1H, =NH). IR (KBr, νmax, cm-1): 3314, 3058, 1655, 1590, 1555,
1420, 1200, 801, 726. Elemental analysis calcd. (%) for
C11H7N3: C, 72.92; H, 3.89; N, 23.19. Found (%): C, 72.89; H,
3.92; N, 23.15. MS: m/z = 181.01 (Calcd.: 181.06).
Found (%): C, 79.30; H, 4.35; N, 16.36. MS: m/z = 257.13
(calcd.: 257.10).
1
9-(4-Methyanilino)-4,5-diazafluorene (L5): H NMR
(CDCl3, 300 MHz): δ 8.80 (dd, 1H, J1 = 5.0, J2 = 1.6Hz, pyridyl
H ortho to N), 8.64 (dd, 1H, J1 = 4.9, J2 = 1.6 Hz, pyridyl H
ortho to N), 8.25 (dd, 1H, J1 = 7.6, J2 = 1.5 Hz, pyridyl H para
to N), 7.39 (t, 1H, J1 = 7.6, J2 = 5.1 Hz, pyridyl H meta to N),
7.25 (m, 2H, pyridyl H meta to N and Ar-H), 6.98 (m, 2H,
pyridyl H para to N and Ar-H), 6.90 (d, 2H, J = 8.2Hz, Ar-H),
2.43 (s, 3H, -CH3). IR (KBr, νmax, cm-1): 3046, 2954, 2869,
1642, 1590, 1557, 1399, 752, 729. Elemental analysis calcd.
(%) for C18H13N3: C, 79.68; H, 4.83; N, 15.49. Found (%): C,
79.62; H, 4.85; N, 15.46. MS: m/z = 271.13 (calcd.: 271.11).
9-(4-Methoxyanilino)-4,5-diazafluorene (L6): 1H NMR
(CDCl3, 300 MHz): δ 8.80 (dd, 1H, J1 = 5.0, J2 = 1.6 Hz,
pyridyl H ortho to N), 8.65 (dd, 1H, J1 = 5.0, J2 = 1.6 Hz,
pyridyl H ortho to N), 8.23 (dd, 1H, J1 = 7.7, J2 = 1.5 Hz,
pyridyl H para to N), 7.38 (t, 1H, J1 = 7.7, J2 = 5.0 Hz, pyridyl
H meta to N), 7.09 (dd, 1H, J1 = 7.8, J2 = 1.7 Hz, pyridyl H
para to N), 6.98 (m, 5H, pyridyl H meta to N and Ar-H), 3.92
(s, 3H, -OCH3). IR (KBr, νmax, cm-1): 3043, 2999, 2837, 1634,
1590, 1559, 1497, 1400, 1234, 1023, 845, 757. Elemental
analysis calcd. (%) for C18H13N3O: C, 75.25; H, 4.56; N, 13.95.
Found (%): C, 75.20; H, 4.58; N, 13.97. MS: m/z = 287.07
(calcd.: 287.11).
9-Hydrazone-4,5-diazafluorene (L2): 1H NMR (CDCl3,
300 MHz): δ 8.75 (dd, 1H, J1 = 5.1, J2 = 1.6 Hz, pyridyl H
ortho to N), 8.65 (dd, 1H, J1 = 5.0, J2 = 1.6Hz, pyridyl H ortho
to N), 8.27 (dd, 1H, J1 = 7.7, J2 = 1.6 Hz, pyridyl H para to N),
8.16 (dd, 1H, J1 = 7.8, J2 = 1.6 Hz, pyridyl H para to N), 7.50
(t, 1H, J1 = 7.7, J2 = 5.1 Hz, pyridyl H meta to N), 7.39 (t, 1H,
J1 = 7.7, J2 = 5.0 Hz, pyridyl H meta to N), 6.65 (s, 2H, -NH2).
IR (KBr, νmax, cm-1): 3376, 3320, 3058, 1646, 1593, 1561,
1206, 799, 723. Elemental analysis calcd. (%) for C12H9N3: C,
67.34; H, 4.11; N, 28.55. Found (%): C, 67.30; H, 4.10; N,
28.52. MS: m/z = 196.01 (calcd.: 196.06).
9-Oxime-4,5-diazafluorene (L3): Sodium carbonate (0.016
g, 1.5 mmol) was used as a neutralizer in the reaction. 1H NMR
(CDCl3, 300 MHz): δ 13.14 (s, 1H, -OH), 8.73 (dd, 1H, J1 =
5.1, J2 = 1.6 Hz, pyridyl H ortho to N), 8.67 (dd, 1H, J1 = 5.0,
J2 = 1.6 Hz, pyridyl H ortho to N), 8.27 (dd, 1H, J1 = 7.7, J2 =
1.6 Hz, pyridyl H para to N), 8.17 (dd, 1H, J1 = 7.8, J2 = 1.6
Hz, pyridyl H para to N), 7.53 (t, 1H, J1 = 7.7, J2 = 5.1 Hz,
pyridyl H meta to N), 7.46 (t, 1H, J1 = 7.7, J2 = 5.0 Hz, pyridyl
H meta to N). IR (KBr, νmax, cm-1): 3141, 3036, 1627, 1593,
1564, 1495, 1399, 1008, 949, 748. Elemental analysis calcd.
(%) for C11H7N3O: C, 67.00; H, 3.58; N, 21.31. Found (%): C,
69.92.; H, 3.56; N, 21.36. MS: m/z = 197.10 (calcd.: 197.06).
9-Anilino-4,5-diazafluorene (L4): 1H NMR (CDCl3, 300
MHz): δ 8.81 (dd, 1H, J1 = 4.9, J2 = 1.5 Hz, pyridyl H ortho to
N), 8.65 (dd, 1H, J1 = 4.9, J2 = 1.6 Hz, pyridyl H ortho to N),
8.26 (dd, 1H, J1 = 7.8, J2 = 1.6 Hz, pyridyl H para to N), 7.43
(m, 3H, pyridyl H meta to N and Ar-H), 7.28 (t, 1H, J1 = 7.7,
J2 = 5.1 Hz, pyridyl H meta to N), 7.02 (m, 3H, Ar-H), 6.87
(dd, 1H, J1 = 7.8, J2 = 1.5 Hz, pyridyl H para to N). IR (KBr,
νmax, cm-1): 3045, 1656, 1592, 1561, 1401, 748, 710. Elemental
analysis calcd. (%) for C17H11N3: C, 79.36; H, 4.31; N, 16.33.
9-(4-Hydroxyanilino)-4,5-diazafluorene (L7): 1H NMR
(CDCl3, 300 MHz): δ 9.53 (s, 1H, -OH), 8.79 (dd, 1H, J1 =
4.9, J2 = 1.5 Hz, pyridyl H ortho to N), 8.67 (dd, 1H, J1 = 4.9,
J2 = 1.5 Hz, pyridyl H ortho to N), 8.27 (dd, 1H, J1 = 7.6, J2 =
1.5 Hz, pyridyl H para to N), 7.54 (t, 1H, J1 = 7.6, J2 = 4.9 Hz,
pyridyl H meta to N), 7.27 (t, 1H, J1 = 7.6, J2 = 4.9 Hz, pyridyl
H meta to N), 7.13 (dd, 1H, J1 = 7.6, J2 = 1.5 Hz, pyridyl H
para to N), 6.90 (m, 4H, Ar-H). IR (KBr, νmax, cm-1): 3144,
3037, 1638, 1592, 1561, 1504, 1401, 1276, 1230, 1165, 758,
708. Elemental analysis calcd. (%) for C17H11N3O: C, 74.71;
H, 4.06; N, 15.38. Found (%): C, 74.65; H, 4.00; N, 15.42.
MS: m/z = 272.85 (calcd.: 273.09).
9-(4-Carboxyanilino)-4,5-diazafluorene (L8): 1H NMR
(CDCl3, 300 MHz): δ 12.93 (s, 1H, -COOH), 8.82 (dd, 1H, J1
= 4.9, J2 = 1.5 Hz, pyridyl H ortho to N), 8.68 (dd, 1H, J1 =
4.9, J2 = 1.5 Hz, pyridyl H ortho to N), 8.29 (dd, 1H, J1 = 7.7,
J2 = 1.5 Hz, pyridyl H para to N), 8.02 (d, 2H, J = 8.6 Hz, Ar-
H), 7.56 (t, 1H, J1 = 7.7, J2 = 4.9 Hz, pyridyl H meta to N),
TABLE-1
RESULTS OF YIELD, MELTING POINT AND UV-VISIBLE SPECTRA OF L1-11
UV-VIS λmax (> 235 nm, ε × 104)a
No.
Yield (%)
m.p. (ºC)
78
82
80
87
89
85
90
81
93
85
83
195-196
208-210
>300
188-189
225-226
202-203.
>300
249 (2.40), 304 (0.99), 317 (1.01).
245 (2.45), 303 (0.98), 313 (1.13).
242 (2.41), 308 (1.00), 315 (0.96).
240 (2.40), 302 (0.95), 315 (1.02).
244 (2.56, 302 (0.98), 314 (1.13), 416 (0.20).
252 (3.80), 300 (1.44), 314 (1.04), 435 (0.29).
244 (2.69), 302 (1.15), 314 (0.97), 433 (0.26)
245 (2.73), 265 (2.51), 302 (1.01), 314 (0.91), 394 (0.16)
246 (3.24), 302 (1.15), 314 (1.01), 405 (0.20)
242 (2.03), 303 (1.22), 314 (1.18), 396 (2.50)
CH3CN: 303 (0.58), 385 (1.30), 406 (1.27), 562 (0.32)
L1
L2
L3
L4
L5
L6
L7
L8
L9
L10
L11
>300
216-217
188-189
>300
aL1-L10 in CHCl3 and L11 in CH3CN.