1148 Bull. Chem. Soc. Jpn., 78, No. 6 (2005)
Photochromism of Diarylmaleimide
was extracted with chloroform. The extracts were dried over anhy-
drous magnesium sulfate and concentrated in vacuo to give 0.150
g of 7 in 62% yield. 7: Yellow crystals. mp. 106–107 ꢃC. 1H NMR
(CDCl3) ꢀ 2.00 (s, 3H), 2.22 (s, 3H), 2.28 (s, 3H), 3.35 (s, 2H).
N-Cyanomethyl-2-(2-methoxybenzothien-3-yl)-3-(2,4,5-tri-
methylthien-3-yl)maleimide (1a). Oxalyl chloride (0.17 mL, 1.4
mmol) was added to a benzene solution (10 mL) containing 104
mg (0.55 mmol) of 8. The mixture was stirred for 1 h, and refluxed
for 1 h. After evaporating benzene and excess oxalyl chloride in
vacuo, 10 mL of 1,2-dichloromethane solution containing 153
mg (0.55 mmol) of 9 and 5 mL of triethylamine was added drop-
wise. After stirring for 40 h at room temperature, the reaction mix-
ture was extracted with chloroform (100 mL) following the addi-
tion of 50 mL of water. The organic phase was washed with 2 M
hydrochloric acid, and dried over anhydrous magnesium sulfate,
and evaporated in vacuo. The residue was purified by thin-layer
chromatography on silica gel (hexane/ethyl acetate = 7/3) to
give 77 mg of 1a in 32% yield. 1a: Orange crystals. mp. 171–
172 ꢃC. 1H NMR (CDCl3) ꢀ 1.84 (s, 3H), 1.95 (s, 3H), 2.20 (s,
3H), 3.74 (s, 2H), 4.50 (s, 2H), 7.00–7.70 (m, 4H). Mass (EI)
422 (Mþ).
N-Octadecyl-2-methyl-5-methoxyindole (10). Commercial
60% sodium hydride (0.75 g, 19 mmol) in DMSO (21 mL) was
added to 2-methyl-5-methoxyindole (15 mg, 9.3 mmol) with cool-
ing in an ice bath, and then the mixture was stirred for 1 h at room
temperature. This was then cooled in an ice bath, and octadecyl-
bromide (3.5 g, 10 mmol) was added to the mixture. The reaction
mixture was stirred for 3 h at room temperature and then poured
into water. It has then extracted with hexane; the organic phase
was dried over anhydrous magnesium sulfate and evaporated in
vacuo. The mixture was purified by recrystallization with ethanol
to give 2.9 g 10 in 75% yield. 10: Yellow crystals. 1H NMR
(CDCl3) ꢀ 0.86–1.71 (m, 3H), 2.39 (s, 3H), 3.83 (s, 3H), 4.00
(t, J ¼ 8 Hz, 2H), 6.15–7.25 (m, 4H).
evaporated in vacuo, 5 mL of a 1,2-dichloromethane solution con-
taining 0.375 mg (0.71 mmol) of 11 and 5 mL of triethylamine
was added dropwise. After stirring for 40 h at room temperature,
the reaction mixture was extracted with chloroform (100 mL) fol-
lowing the addition of 50 mL of water. The organic phase was
washed with 2 M hydrochloric acid, dried over anhydrous magne-
sium sulfate, and evaporated in vacuo. The residue was purified
by thin-layer chromatography on silica gel (hexane/ethyl ace-
tate = 7/3) to give 0.342 mg of 2a in 68% yield. 2a: Orange crys-
tals. mp. 73–74 ꢃC. 1H NMR (CDCl3) ꢀ 0.70–1.60 (m, 35H), 2.20
(s, 3H), 3.20 (s, 3H), 3.58 (s, 3H), 3.90 (t, J ¼ 8 Hz, 2H), 4.53 (s,
2H), 6.36–7.55 (m, 7H). Mass (EI) 709 (Mþ). Anal. Calcd for
C43H55N3O4S: C, 72.74; H, 7.81; N, 5.92%. Found: C, 72.84;
H, 7.84; N, 5.85%.
N-Cyanomethyl-2-[2-ethoxy-1-benzothiophen-3-yl]-3-[2-
methyl-1-octadecylindol-3-yl]maleimide (3a). 3a was synthe-
sized from 13, which was produced from 100 mg (0.424 mmol)
of 2-ethoxybenzothiophen-3-ylacetic acid and 229 mg (0.424
mmol) of 11 by the same procedure as that used for 2a. The crude
product was purified by thin-layer chromatography on silica gel
(hexane/ethyl acetate = 7/3) to give 74 mg of 3a in 24% yield.
3a: Orange crystals. mp. 92–93 ꢃC. 1H NMR (CDCl3) ꢀ 0.72–
1.60 (m, 38H), 2.20 (s, 3H), 3.20 (s, 3H), 3.58 (s, 3H), 4.12 (q, J ¼
8 Hz, 2H), 4.53 (s, 2H), 6.36–7.55 (m, 7H). Mass (EI) 723 (Mþ).
Anal. Calcd for C44H57N3O4S: C, 72.99; H, 7.94; N, 5.80%.
Found: C, 73.15; H, 7.98; N, 5.76%.
References
1
M. Irie, Chem. Rev., 100, 1685 (2000).
2
(1998).
3
M. Irie and K. Uchida, Bull. Chem. Soc. Jpn., 71, 985
M. Irie, ‘‘Photo-Reactive Materials for Ultrahigh-Density
Optical Memory,’’ Elsevier, Amsterdam (1994).
M. Hanazawa, R. Sumiya, Y. Horikawa, and M. Irie,
J. Chem. Soc., Chem. Commun., 1992, 206.
N-Cyanomethyl-2-methyl-1-(N-octadecyl)indole-3-glycoxyl-
amide (11). A dichloromethane solution (130 mL) containing 78
mg (0.37 mmol) of aminoacetonitrile sulfate and 0.13 mL (0.96
mmol) of triethylamine was refluxed for 4 h. In another flask,
30 mg (0.24 mmol) of oxalyl chloride was added to a 1,2-di-
chloroethane solution (8 mL) of N-octadecyl-2-methyl-5-me-
thoxyindole (10) (0.10 g, 0.24 mmol) and the mixture was re-
fluxed for 3 h. To this reaction mixture, the dichloromethane solu-
tion was added, and the resulting mixture was stirred for 12 h at
room temperature. The reaction mixture was extracted with
chloroform, after the addition of 50 mL of 2 M hydrochloric acid.
The organic phase was dried over anhydrous magnesium sulfate
and evaporated in vacuo. The residue was recrystallized from eth-
yl acetate to give 96 mg of 11 in 77% yield. 11: Yellow crystals.
mp. 119–120 ꢃC. 1H NMR (CDCl3) ꢀ 0.70–1.82 (m, 35H), 2.65
(s, 3H), 3.83 (s, 3H), 4.00 (t, 2H), 4.23 (d, J ¼ 8 Hz, 2H),
6.70–7.83 (m, 3H).
4
5
6
M. Irie and M. Mohri, J. Org. Chem., 53, 803 (1988).
Y. Nakayama, K. Hayashi, and M. Irie, Bull. Chem. Soc.
Jpn., 64, 789 (1991).
7
8
T. Yamaguchi and M. Irie, Chem. Lett., 2005, 64.
T. Yamaguchi, K. Uchida, and M. Irie, J. Am. Chem. Soc.,
119, 6066 (1997).
9 K. Uchida, Y. Kido, T. Yamaguchi, and M. Irie, Bull.
Chem. Soc. Jpn., 71, 1101 (1998).
10 T. Yamaguchi, Y. Fujita, and M. Irie, Chem. Lett., 2004,
1398.
´
11 M. M. Krayushkin, V. Z. Shirinyan, L. I. Berenkil, A. A.
Shirnkin, A. Y. Martynkin, and B. M. Uzhinov, Russ. J. Org.
Chem., 38, 1335 (2002).
12 H. Tian, C. Bingzhi, and P. Liu, Chem. Lett., 2001, 990.
13 D. G. Crowe, Appl. Opt., 30, 4480 (1991).
14 M. Hamano and M. Irie, Jpn. J. Appl. Phys., 35, 1764
(1996).
15 M. Irie and K. Sayo, J. Phys. Chem., 96, 7671 (1992).
´
16 H. Kaczmarek, A. Kaminska, and A. van Herk, Eur.
Polym. J., 36, 767 (2000).
17 R. Salo and S. Jan, Acta Chem. Scand., 24, 304 (1970).
N-Cyanomethyl-2-[2-methoxy-1-benzothiophen-3-yl]-3-[2-
methyl-1-octadecylindol-3-yl]maleimide (2a). A 0.14 mL (1.78
mmol) volume portion of oxalyl chloride was added to a benzene
solution (14 mL) of 2-methoxy-1-benzothiophen-3-ylacetic acid
(0.16 g, 0.71 mmol).17 The mixture was stirred for 1 h, followed
by 1 h of reflux. After benzene and excess oxalyl chloride were