D. Gudeika et al. / Dyes and Pigments 91 (2011) 13e19
15
C20H25N3O2: C, 70.77; H, 7.42; N, 12.38; O, 9.43. Found: C, 70.81; H,
7.39; N, 12.33; O, 9.48.
was filtered, and the solvent was evaporated. The crude product
was purified by silica gel column chromatography using the
mixture of acetone and n-hexane (vol. ratio 1:3) as an eluent. Yield:
0.38 g (53%) of red crystals. Mp ¼ 94e95 ꢀC 1H NMR spectrum
2.3.4. 4,40-diformyl-400-methoxyphenylamine bis(N-(2-ethylhexyl)-
1,8-naphthalimide) hydrazone (3)
(300 MHz, CDCl3, d, ppm): 8.67e8.58 (m, 5H, HNaphthalene), 7.72 (dd,
4,40-Diformyl-400-methoxyphenylamine (b) (0.1 g, 0.03 mmol)
and 25 ml of methanol were placed into 250 ml 2-neck round
bottom flask equipped with reflux condenser and mechanical
stirrer and heated at 60 ꢀC untill the homogeneous solution was
obtained. Then the solution of 4-hydrazino-N-(2-ethylhexyl)-1,8-
naphthalimide (0.026 g, 0.08 mmol) in 15 ml of methanol was
added drop-wise. The mixture was refluxed until the dialdehyde
(b) fully reacted (1.5 h, TLC control: eluent acetone/n-hexane 1:3).
After the reaction, the mixture was slowly cooled to the room
temperature. Crystals formed upon standing were filtered off,
washed with methanol and dried to obtain 0.02 g (70%) of
compound 3. Mp ¼ 158e159 ꢀC 1H NMR spectrum (300 MHz,
3H, JHH ¼ 7.33 Hz, JHH ¼ 8.53 Hz, HNaphthalene), 7.65 (s, 2H, HNaph-
thalene), 7.53 (dd, 6H, JHH ¼ 2.34 Hz, JHH ¼ 8.48 Hz, ar), 7.13e7.07 (m,
4H, ar), 6.92e6.88 (m, 2H, ar), 4.18e4.16 (m, 4H, 2ꢂNeCH2,
aliphatic), 3.85 (s, 3H, eOCH3), 2.04e1.95 (m, 2H, 2ꢂCH, alihatic),
1.46e1.36 (m, 20H, 10ꢂCH2, aliphatic), 1.13e0.74 (m, 18H, 6ꢂCH3,
aliphatic). IR, (in Br), cmꢁ1: 3063
n
(CHar); 2955, 2926, 2856
n
(CHaliphatic); 1691
Car); 1465, 1426
13C NMR spectrum (300 MHz, CDCl3,
n
(C]Oanhydride); 1696, 1656, 1585, 1505
(eOCH3); 1386, 1352 (CeN); 828, 779
, ppm): 165.08, 164.54,
n
(C]
g
n
g (CHar);
d
150.96, 148.32, 139.97, 137.74, 132.22, 131.76, 131.65, 130.23, 129.74,
128.01, 127.54, 127.44, 126.19, 119.68, 118.40, 115.20, 55.76, 47.06,
44.35, 38.21, 31.04, 29.01, 24.34, 23.37, 14.39, 11.25, 10.96. MS
(APCIþ, 20 V), m/z: 1030 ([M þ H]þ). Anal. Calcd. for C65H71N7O5: C,
75.77; H, 6.95; N, 9.52; O, 7.76. Found: C, 75.68; H, 6.88; N, 9.59; O,
7.71.
CDCl3,
d
, ppm): 8.80 (s, 2H, 2ꢂNeCH), 8.61 (kv, 6H, JHH ¼ 7.70 Hz,
JHH ¼ 17.57 Hz, HNaphthalene), 8.25 (d, 2H, JHH ¼ 8.58 Hz, HNaphthalene),
8.07 (d, 2H, JHH ¼ 4.21 Hz, HNaphthalene), 7.81e7.59 (m, 10H, ar), 7.54
(kv, 2H, JHH ¼ 3.34 Hz, JHH ¼ 5.74 Hz, ar), 4.09 (p, 4H, JHH ¼ 6.59 Hz,
JHH ¼ 13.41 Hz, 2ꢂNeCH2, aliphatic), 3.84 (s, 3H, eOCH3), 3.49 (s,
2H, 2ꢂNH), 1.44e1.32 (m, 16H, 8ꢂCH2, aliphatic), 0.98e0.85 (m,
2.3.7. 4-(Di(4-methoxyphenyl)amine)benzaldehyde N-ethyl-N-(2-
ethylhexyl)-1,8-naphthalimide hydrazone (6)
Compound 6 was synthesized by the same procedure as
compound 5, only compound 4 was used instead of compound 3.
The yield of red crystals was 0.2 g (80%). Mp ¼ 67e68 ꢀC 1H NMR
12H, 4ꢂCH3, aliphatic). IR, (in Br), cmꢁ1: 3284
n
(NH); 3060
n
(CHar); 2954, 2926, 2856
n
(CHaliphatic); 1691
n
(C]Oanhydride); 1651,
(OCH3); 1387, 1352
(CHar); 13C NMR spectrum (300 MHz, CDCl3,
1614, 1578, 1504
(CeN); 827, 774
n
(C]Car); 1460, 1427
g
n
g
d
,
spectrum (300 MHz, CDCl3,
d
, ppm): 7.71 (d, 2H, JHH ¼ 1.25 Hz,
ppm): 165.16, 164.73, 152.42, 151.31, 149.06, 145.40, 134.18, 131.62,
131.50, 131.42, 129.89, 128.86, 128.42, 125.82, 120.03, 118.97, 115.58,
115.40, 55.80, 44.31 38.22, 31.05, 29.02, 24.35, 23.36, 14.37, 10.95.
MS (APCIþ, 20 V), m/z: 973 ([M þ H]þ). Anal. Calcd. for C16H63N7O5:
C, 75.21; H, 6.52; N, 10.06; O, 8.21. Found: C, 75.30; H, 6.56; N, 10.12;
O, 8.23.
HNaphthalene), 7.68 (d, 1H, JHH ¼ 4.13 Hz, HNaphthalene), 7.53 (s, 1H,
HNaphthalene), 7.49 (d, 1H, JHH ¼ 4.13 Hz, HNaphthalene), 7.16e7.07 (m,
4H, ar), 7.02e6.81 (m, 8H, ar), 4.18e4.13 (m, 2H, NeCH2, aliphatic),
3.83 (s, 6H, 2ꢂOCH3), 2.02e1.94 (m, 1H, NeCH, aliphatic), 1.47e1.33
(m, 10H, 5ꢂCH2, aliphatic), 1.01e0.86 (m, 9H, 3ꢂCH3, aliphatic). IR,
(in Br), cmꢁ1: 3037
n
(CHar); 2954, 2927, 2856
(C]Oanhydride); 1655, 1585, 1504 (C]Car); 1464, 1441, 1427
(OCH3); 1400 1385, 1353 (CeN); 826, 779
spectrum (300 MHz, CDCl3, , ppm): 165.17, 164.57, 156.44, 151.31,
n
(CHaliphatic); 1695
n
n
g
2.3.5. 4-(Di(4-methoxyphenyl)amine)benzaldehyde
N-(2-ethylhexyl)-1,8-naphthalimide hydrazone (4)
n
g
(CHar); 13C NMR
d
Compound 4 was synthesized by the same procedure as
compound 3, only compound (a) was used instead of compound
(b). The yield of red crystals 4 was 0.09 g (56%). Mp ¼ 125e126 ꢀC
149.69, 140.66, 138.80, 132.25, 131.94, 131.59, 127.55, 127.42, 127.15,
126.01, 120.12, 119.24, 118.04, 115.02, 55.77, 44.23 38.24, 31.08,
29.04, 24.38, 23.36, 14.37, 10.96. MS (APCIþ, 20 V), m/z: 683
([M þ H]þ). Anal. Calcd. for C43H46N4O4: C, 75.63; H, 6.79; N, 8.20;
O, 9.37. Found: C, 75.58 H, 6.83; N, 8.15; O, 9.32.
1H NMR spectrum (300 MHz, CDCl3,
d, ppm): 8.59 (d, 1H,
JHH ¼ 7.71 Hz, HNaphthalene), 8.53 (d, 1H, JHH ¼ 8.30 Hz, HNaphthalene),
8.21 (d, 2H, JHH ¼ 8.40 Hz, HNaphthalene), 7.74 (d, 1H, JHH ¼ 8.3 Hz,
HNaphthalene), 7.55 (d, 2H, JHH ¼ 8.74 Hz, ar), 7.18e7.09 (m, 4H, ar),
6.96e6.84 (m, 6H, ar), 4.12 (p, 2H, JHH ¼ 5.49 Hz, JHH ¼ 12.98 Hz,
NeCH2, aliphatic), 3.82 (s, 6H, 2ꢂOCH3), 3.49 (s, 1H, eNH),
1.43e1.29 (m, 8H, 4ꢂCH2, aliphatic), 0.96e0.84 (m, 6H, 2ꢂCH3,
3. Results and discussion
Compounds 3 and 4 containing electron-withdrawing naph-
thalimide moiety and electron-donating triphenylamino moiety
were synthesized by the synthetic route, shown in Scheme 1. The
first step was condensation of 4-bromo-1,8-naphtalic anhydride
with 2-ethylhexylamine in DMF to obtain 4-bromo-N-(2-ethyl-
aliphatic). IR, (in Br), cmꢁ1: 3282
n
(NH); 3038, 2994
(C]Oanhydride); 1647, 1575, 1503
(OCH3); 1387, 1370, 1352 (CeN); 822,
(CHar); 13C NMR spectrum (300 MHz, CDCl3,
, ppm): 165.19,
n (CHar); 2953,
2926, 2836
(C]Car); 1462, 1440, 1427
775
n
(CHaliphatic); 1688
n
n
g
n
g
d
hexyl)-1,8-naphthalimide (1). Compound
hydrazine hydrate to yield 4-hydrazino-N-(2-ethylhexyl)-1,8-
naphthalimide (2). Compounds and were obtained by
1 was treated with
164.70, 161.67, 156.82, 140.15, 134.42, 131.82, 131.70, 128.43, 128.32,
127.52, 125.60, 125.33, 123.53, 119.33, 116.98, 115.33, 115.13, 55.77,
44.23 38.24, 31.08, 29.04, 24.38, 23.36, 14.37, 10.96. MS (APCIþ,
20 V), m/z: 655 ([M þ H]þ). Anal. Calcd. for C41H42N4O4: C, 75.20; H,
6.47; N, 8.56; O, 9.77. Found: C, 75.15; H, 6.42; N, 8.63; O, 9.84.
3
4
condensation of compound 2 with an excess of 4-(di(4-methox-
yphenyl)amine)benzaldehyde (a) and 4,40-diformyl-400-methox-
yphenylamine (b).
Compounds 5 and 6 were synthesized by alkylation of 3 and 4 in
the presence of potassium hydroxide (Scheme 2).
2.3.6. 4,40-diformyl-400-methoxyphenylamine bis(N-ethyl-N-
(2-ethylhexyl)-1,8-naphthalimide) hydrazone (5)
The chemical structures of the newly synthesized compounds
(1e6) were confirmed by 1H NMR, 13C NMR, IR, and mass spec-
trometries. Hydrazones 3e6 are soluble in common organic
solvents such as chloroform, acetone, tetrahydrofuran (THF).
The behaviour under heating of compounds 3e6 was studied by
DSC and TGA under a nitrogen atmosphere. The values of glass
transition temperatures (Tg) and the temperatures of the onset of
the thermal decomposition (Tdec) are summarized in Table 1.
Compound 3 (0.5 g, 0.51 mmol) and 30 ml of acetone were
placed into a 100 ml 3-neck round bottom flask equipped with
reflux condenser, thermometer and mechanical stirrer. The mixture
was stirred vigorously at 50e60 ꢀC for 10 min, during which of
powdered potassium hydroxide KOH (0.072 g, 1.29 mmol), 1-
iodoethane (0.094 g, 1.18 mmol) and tetrabutylammonium bromide
(0.01 g, 0.032 mmol) were added. After 30 min the reaction mixture