Push-Pull Chromophores for Nonlinear Optics
J . Org. Chem., Vol. 67, No. 1, 2002 217
135.7; 128.0; 127.5; 125.4; 122.3; 120.5; 114.7; 113.1; 112.3;
108.7; 105.3; 65.4; 65.2; 64.8; 64.6; 40.4. EI MS m/z (I%): 455
(M+•, 100); 326 (30); 227 (15); 190 (25); 158 (20). HRMS calcd
for C23H21N1O5S2: 455.0861; found, 455.0853. IR (KBr) ν cm-1
: 1638 (CdO). UV (CH2Cl2) λmax: 468 nm.
(CDCl3) δ: 180.2; 148.6; 141.8; 118.5; 110.8; 65.3; 64.4. EI MS
m/z (I%): 170 (M+•, 100). IR (KBr) ν cm-1 : 1647 (CdO).
2-[(Z,E)-(4-N,N-Dim et h yla m in ob en zylid en e)m et h yl]-
3,4-eth ylen ed ioxyth iop h en e (12h ). To a suspension of
phosphonium iodide 14 (4.6 g, 8.85 mmol) in 50 mL of a
mixture of anhydrous CH3CN/THF (1:1) at -60 °C under a
N2 atmosphere was added t-BuOK (0.99 g, 8.85 mmol) por-
tionwise, leading to a red solution which was further stirred
at -60 °C for 15 min before the dropwise addition of a solution
of compound 12g (1 g, 5.88 mmol) in anhydrous THF (20 mL).
The color of the solution turned rapidly to yellow-orange, and
the mixture was warmed to room temperature. After extraction
with CH2Cl2, the organic phases were washed with water,
dried over Na2SO4, and evaporated in vacuo. A purification
by chromatography on silica gel (eluent: CH2Cl2) led to a
brown solid (1.14 g, 68% yield) corresponding to a ca.. 6:4
5-(2,2-Dicya n oeth en yl)-5′-[(E)-(4-N,N-d im eth yla m in o-
b e n zylid e n e )m e t h yl]-2,2′-b is(3,4-e t h yle n e d ioxyt h io-
p h en e) (5b). A mixture of aldehyde 11j (150 mg, 0.33 mmol),
malononitrile (26 mg, 0.39 mmol), and one drop of triethy-
lamine in anhydrous CHCl3 (15 mL) under a N2 atmosphere
was refluxed for 18 h. After being cooled to room temperature,
the solvent was evaporated in vacuo, and the residue was
triturated with EtOH (10 mL). The black precipitate was
filtered, washed with hot EtOH (10 mL), and several times
with EtOH to eliminate unreacted malononitrile. A black solid
was obtained (140 mg, 86% yield). Mp 308 °C. 1H NMR (CDCl3)
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1
δ: 7.75 (s, 1H); 7.36 (d, 2H, J ) 8.8); 6.96 (d, 1H, J ) 16.1);
mixture of E and Z isomers, respectively. H NMR (CDCl3) E
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3
6.91 (d, 1H, J ) 16.1); 6.68 (d, 2H, J ) 8.8); 4.45 and 4.32
(2m, 8H, CH2O); 2.99 (s, 6H, CH3N). 13C NMR (CDCl3) δ: 150.3;
148.3; 144.0; 141.9; 137.9; 135.5; 129.4; 127.8; 125.6; 125.0;
123.5; 116.2; 115.3; 112.9; 112.3; 110.5; 105.9; 65.8; 65.7; 64.8;
64.6; 53.4; 40.4. EI MS m/z (I%): 503 (M+•, 100); 326 (30); 252
(15); 190 (30); 174 (10); 158 (25). HRMS calcd for C26H21N3O4S2:
503.0973; found, 503.0979. IR (KBr) ν cm-1: 2222 (CtN); 1603
(CdC); 1168 (C-O). UV (CH2Cl2) λmax: 588 nm. Anal. Calcd
for C26H21N3O4S2: C, 62.01; H, 4.20; N, 8.34; O, 12.71; S, 12.73.;
found: C, 61.84; H, 4.32; N, 7.94; O, 13.10; S, 12.46.
isom er δ: 7.36 (d, 2H, J ) 8.8); 6.96 (d, 1H, J ) 16.2); 6.81
3 3
(d, 1H, J ) 16.2); 6.69 (d, 2H, J ) 8.8); 6.15 (s, 1H); 4.30-
4.12 (m, 4H); 2.98 (s, 6H). 1H NMR (CDCl3) Z isom er δ: 7.29
(d, 2H, 3J ) 8.8); 6.69 (d, 2H, 3J ) 8.8); 6.49 (d, 1H, 3J ) 11.9);
6.44 (d, 1H, 3J ) 11.9); 6.11 (s,1H); 4.30-4.12 (m, 4H); 2.98
(s, 6H). 13C NMR (CDCl3) E+Z isomers δ: 149.8; 148.5; 141.9;
141.8; 141.1; 139.5; 138.0; 129.8; 128.1; 127.2; 126.6; 125.8;
118.5; 118.0; 116.4; 115.1; 114.0; 112.5; 111.9; 110.8; 98.0; 96.2;
65.3; 64.8; 64.7; 64.6; 64.4; 40.5; 40.4. IR (KBr) ν cm-1 : 1168
(C-O-C). UV (CH2Cl2) λmax : 368 nm.
5-[(1,3-Dia za -1,3-d iet h yl-4,6-d ioxo-2-t h ioxocycloh ex-
5-ylid e n e )m e t h yl]-5′-[(E )-(4-N ,N -d im e t h yla m in ob e n -
zylid en e)m et h yl]-2,2′-b is(3,4-et h ylen ed ioxyt h iop h en e)
(5c). A solution of aldehyde 11j (100 mg, 0.24 mmol) and 1,3-
diethylthiobarbiturc acid (58 mg, 0.24 mmol) in acetic anhy-
dride (2 mL) was warmed to 80 °C for 24 h. At rt, after addition
of CH2Cl2 (50 mL), the solution was washed with a saturated
aqueous solution of NaHCO3 and water. The organic phase
was then dried over Na2SO4 and evaporated in vacuo before a
column chromatography on silica gel (eluent: CH2Cl2) to lead
2-For m yl-3,4-eth ylen edioxy-5-[(E)-(4-N,N-dim eth ylam i-
n ob en zylid en e)m et h yl]t h iop h en e (12j). To a solution of
compound 12h [E/Z] (0.5 g, 1.75 mmol) and anhydrous DMF
(0.15 mL, 1.94 mmol) in anhydrous 1,2-dichloroethane (20 mL)
at 0 °C under a N2 atmosphere was added POCl3 (0.17 mL,
1.82 mmol) dropwise, and the mixture was then refluxed for
2 h. At rt, the mixture was hydrolyzed with an aqueous
solution of sodium acetate (1 M, 50 mL) under vigorous stirring
for 2 h. After extraction with CH2Cl2, the organic phases were
washed with water, dried over Na2SO4, and concentrated in
vacuo before chromatography on silica gel (eluent: CH2Cl2/
petroleum ether 1:1), affording a red solid (0.37 g, 68% yield).
1
to a black solid (90 mg, 60% yield). Mp 300 °C (dec). H NMR
(CDCl3) δ: 8.75 (s, 1H), 7.38 (d, 2H, 3J ) 8.8), 6.98 (s, 2H),
6.68 (d, 2H 3J ) 8.8), 4.62-4.53 (m, 6H), 4.49-4.45 (m, 4H),
4.37-4.36 (m, 2H); 3.00 (s, 6H), 1.35-1.30 (m, 6H). EI MS m/z
(I%): 637 (M+•, 100); 427 (25). HRMS calcd for C31H31N3O6S3:
637.1375; found, 637.1388. UV(CH2Cl2) λmax: 649 nm.
1
Mp 201-202 °C. H NMR (CDCl3) δ: 9.86 (s, 1H, CHO); 7.38
(d, 2H, 3J ) 8.8); 7.07 (d, 1H, 3J ) 16.1); 6.93 (d, 1H, 3J )
3
16.1); 6.67 (d, 2H, J ) 8.8); 4.37 (m, 2H, CH2O); 4.33 (m, 2H,
CH2O); 2.99 (s, 6H, CH3N). 13C NMR (CDCl3) δ: 179.0 (CHO);
150.6; 148.8; 137.4; 133.6; 132.3; 130.1; 129.8; 128.2; 124.2;
112.6; 112.1; 65.3; 64.4; 40.2. IR (KBr) ν cm-1: 1680 (CdO);
1168 (C-O). UV (CH2Cl2) λmax: 439 nm.
5-[1,3-Bis(dicyan om eth yliden e)in dan -2-yliden em eth yl]-
5′-[(E)-(4-N,N-d im et h yla m in ob en zylid en e)m et h yl]-2,2′-
bis(3,4-eth ylen ed ioxyth iop h en e) (5e). A mixture of alde-
hyde 11j (150 mg, 0.33 mmol) and 1,3-bis(dicyanomethyl-
idene)indane (81 mg, 0.33 mmol) in acetic anhydride (8 mL)
was refluxed for 2 h. After cooling to 0 °C, the resulting
precipitate was collected by filtration, washed several times
with Et2O, and dried under vacuum to afford a black powder
(130 mg, 58% yield). Mp 206 (dec). An analytical sample was
further purified by chromatography on silica gel (eluent: CH2-
Cl2 and then THF) and trituration in MeOH. 1H NMR (DMSO-
d6) δ: 8.53 (s, 1H), 8.34 (br s, 2H), 7.80-7.75 (m, 2H), 7.49 (br
2-(3-Dicya n om eth ylid en e-1-in d a n on -2-ylid en em eth yl)-
3,4-e t h y le n e d io x y -5-[(E )-(4-N ,N -d im e t h y la m in o b e n -
zylid en e)m eth yl]th iop h en e (6d ). 3-Dicyanomethylidene-1-
indanone (60 mg, 3.10 mmol) was added portionwise to a
solution of aldehyde 12j (100 mg, 3.32 mmol) in absolute EtOH
at 60-70 °C. The stirring was maintained for 0.5 h at this
temperature. After being cooled to room temperature, the
resulting black precipitate was collected by filtration, washed
with warmed EtOH, and dried in a vacuum to give a black
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s, 2H), 7.21 (d, 1H, J ) 15.8), 7.09 (d, 1H, J ) 15.8); 6.71 (d,
powder (117 mg, 71% yield). Mp > 230 °C. H NMR (CDCl3)
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2H, J ) 8.7); 4.65-4.48 (m, 6H); 4.45 (br s, 2H); 2.98 (s, 6H).
δ: 9.00 (s, 1H); 8.63 (d, 1H, J ) 7.3); 7.85 (m, 1H); 7.67 (m,
MALDI-TOF MS calcd for C38H25N5O4S2 679.1348, found
2H); 7.46 (d, 2H, 3J ) 8.7); 7.41 (d, 1H, 3J ) 16.0); 7.06 (d, 1H,
3J ) 15.8); 6.70 (d, 2H, 3J ) 8.7); 4.52 (m, 2H, CH2O); 4.38 (m,
679.1418 (M+•). IR (KBr) ν cm-1: 2207 (CtN). UV(CH2Cl2) λmax
:
830 nm. Anal. Calcd for C38H25N5O4S2: C, 67.14; H, 3.71; N,
10.30; O, 9.41; S, 9.43.; found: C, 67.09; H, 3.77; N, 9.93; O,
9.01; S, 9.29.
2H, CH2O); 3.05 (s, 6H, CH3N). EI MS m/z (I%): 491 (M+•
,
100); 190 (35); 158 (30). HRMS calcd for
C29H21N3O3S1,
491.1304; found, 491.1313. IR (KBr) ν cm-1: 2215 (CtN); 1696
(CdO); 1168 (C-O-C). UV (CH2Cl2) λmax: 673 nm.
3,4-Eth ylen ed ioxy-2-for m ylth iop h en e (12g). To a solu-
tion of 3,4-ethylenedioxythiophene 12f (2.0 g, 14 mmol) and
anhydrous DMF (2.2 mL, 28 mmol) in anhydrous 1,2-dichlo-
roethane (30 mL) at 0 °C under a N2 atmosphere was added
POCl3 (2.2 mL, 28 mmol) dropwise, and the mixture was
refluxed for 2 h. After being cooled to room temperature, the
reaction mixture was hydrolyzed with an aqueous solution of
sodium acetate (1 M, 250 mL). After extraction with CH2Cl2,
the organic phases were washed with water, dried over Na2-
SO4, and evaporated in vacuo. A column chromatography on
silica gel (eluent: CH2Cl2) gave a yellow solid (2.02 g, 84%
yield). Mp 146 °C (dec). 1H NMR (CDCl3) δ: 9.86 (s, 1H, CHO);
6.79 (s, 1H); 4.35 (m, 2H, CH2O); 4.25 (m, 2H, CH2O). 13C NMR
2-[1,3-Bis(dicyan om eth yliden e)in dan -2-yliden em eth yl]-
3,4-e t h y le n e d io x y -5-[(E )-(4-N ,N -d im e t h y la m in o b e n -
zylid en e)m eth yl]th iop h en e (6e). To a solution of aldehyde
12j (100 mg, 3.32 mmol) in acetic anhydride (5 mL) warmed
at 60-70 °C was added 1,3-bis(dicyanomethylidene)indane (82
mg, 3.38 mmol) portionwise. The mixture was further stirred
1 h at this temperature, and after cooling to room temperature,
it was poured into a saturated aqueous solution of NaHCO3.
After extraction with CH2Cl2, the organic phases were washed
with water, dried over Na2SO4, and evaporated in vacuo. The
residue was triturated in EtOH (50 mL), filtered, washed with
hot EtOH, and dried under vacuum to give a black solid (100