Synthesis and photochromism of spirobenzopyrans and spirobenzothiapyran derivatives bearing monoazathiacrown ethers and noncyclic analogues in the presence of metal ions

Article abstract of DOI:10.1021/jo0162843

Spirobenzopyrans bearing monoazathiacrown ethers and noncyclic analogues were synthesized, and their ion-responsive photochromism depending on the dual metal ion interaction with the crown ether and the phenolate anion moieties was examined using alkali and alkaline-earth metal ions, Ag⁺, TI⁺, Pb²⁺, Hg²⁺, and Zn²⁺. The prepared spirobenzopyrans showed a selective binding ability to Mg²⁺ and Ag⁺ with negative and positive photochromism, respectively. Among the metal ions, only Ag⁺ facilitated photoisomerization to the corresponding merocyanine form. Depending on the ring size of the monoazathiacrown ether moieties, soft metal ions such as Hg²⁺ and Ag⁺ showed significant shifts in the UV-vis absorption spectra, while hard metal ions such as Mg²⁺, Zn²⁺, and Pb²⁺ did not afford any meaningful shift. This result reflects that the monoazathiacrown ether and phenolate anion moieties prefer soft and hard metal ions, respectively. Therefore, the Mg²⁺ and Ag⁺ selectivities are mainly derived from the phenolate anion and monoazathiacrown ether moieties, respectively. On the other hand, a spirobenzothiapyran bearing 3,9-dithia-6-monoazaundecane showed a remarkable selectivity to Ag⁺.

Full text of DOI:10.1021/jo0162843

J . Org. Chem. 2002, 67, 2223-2227
2223
Syn th esis a n d P h otoch r om ism of Sp ir oben zop yr a n s a n d
Sp ir oben zoth ia p yr a n Der iva tives Bea r in g Mon oa za th ia cr ow n
Eth er s a n d Non cyclic An a logu es in th e P r esen ce of Meta l Ion s
Mutsuo Tanaka,† Tomokazu Ikeda,‡ Qiang Xu,§ Hisanori Ando,† Yasuhiko Shibutani,‡
Makoto Nakamura,| Hidefumi Sakamoto,| Setsuko Yajima,| and Keiichi Kimura*,|
Special Division for Human Life Technology, National Institute of Advanced Industrial Science and
Technology, 1-8-31, Midorigaoka, Ikeda, Osaka 563-8577, J apan, Department of Chemistry,
Faculty of Engineering, Osaka Institute of Technology, 5-16-1, Ohmiya, Asahi-ku, Osaka 535-8585,
J apan, Special Division for Green Life Technology, National Institute of Advanced Industrial
Science and Technology, 1-8-31, Midorigaoka, Ikeda, Osaka 563-8577, J apan, and Department of
Applied Chemistry, Faculty of Systems Engineering, Wakayama University, 930, Sakae-dani,
Wakayama, Wakayama 640-8510, J apan
kkimura@sys.wakayama-u.ac.jp
Received November 14, 2001
Spirobenzopyrans bearing monoazathiacrown ethers and noncyclic analogues were synthesized,
and their ion-responsive photochromism depending on the dual metal ion interaction with the crown
ether and the phenolate anion moieties was examined using alkali and alkaline-earth metal ions,
Ag+, Tl+, Pb2+, Hg2+, and Zn2+. The prepared spirobenzopyrans showed a selective binding ability
to Mg2+ and Ag+ with negative and positive photochromism, respectively. Among the metal ions,
only Ag+ facilitated photoisomerization to the corresponding merocyanine form. Depending on the
ring size of the monoazathiacrown ether moieties, soft metal ions such as Hg2+ and Ag+ showed
significant shifts in the UV-vis absorption spectra, while hard metal ions such as Mg2+, Zn2+, and
Pb2+ did not afford any meaningful shift. This result reflects that the monoazathiacrown ether
and phenolate anion moieties prefer soft and hard metal ions, respectively. Therefore, the Mg2+
and Ag+ selectivities are mainly derived from the phenolate anion and monoazathiacrown ether
moieties, respectively. On the other hand, a spirobenzothiapyran bearing 3,9-dithia-6-monoaza-
undecane showed a remarkable selectivity to Ag+.
In tr od u ction
photochromism switching between positive and negative,
depending on the metal ion.3 There are two metal ion
interactions in the merocyanine form of a crowned spiro-
benzopyran as shown Scheme 1, where the metal ion
interaction with the phenolate anion moiety induces the
photoisomerization back to the corresponding spiropyran
form upon UV irradiation, resulting in appearance of
negative photochromism.4
Photochromic properties of recently synthesized com-
pounds have been examined extensively to explore their
potentiality in optical devices.1 Spirobenzopyrans are
well-known photochromic compounds that isomerize from
spiropyran to merocyanine forms by UV light and vice
versa by visible light or heat.1 It has been recognized that
incorporation of a crown ether moiety into a spiroben-
zopyran affords ion-responsive photochromic materials,
reflecting the metal-ion binding ability of the crown ether
moieties.2
In the case of crowned spirobenzothiapyrans, not only
alkali and alkaline-earth metal ions but also Ag+ influ-
enced photochromism through a strong affinity of the
thiophenolate anion moiety to Ag+.5 It is well-known that
oxygen atoms prefer hard metal ions such as alkali and
alkaline-earth metal ions, while sulfur atoms tend to bind
with soft metal ions.6 Therefore, spirobenzopyrans bear-
ing monoazathiacrown ether moieties were designed and
examined for the influence of the combination of a soft
metal ion preferred monoazathiacrown ether and a hard
metal ion preferred phenolate anion on photochromism.
In this paper, we report the synthesis of spirobenzopy-
rans and spirobenzothiapyran derivatives bearing mono-
In our previous work, spirobenzopyrans bearing a
crown ether moiety, crowned spirobenzopyrans, showed
† Special Division for Human Life Technology.
‡ Osaka Institute of Technology.
§ Special Division for Green Life Technology.
| Wakayama University.
(1) Organic Photochromic and Thermochromic Compounds; Ple-
num: New York and London, 1999; Vols. 1 and 2.
(2) (a) Sasaki, H.; Ueno, A.; Anzai, J .; Osa, T. Bull. Chem. Soc. J pn.
1986, 59, 1953-1956. (b) Inouye, M.; Ueno, M.; Kitao, T.; Tsuchiya,
K. J . Am. Chem. Soc. 1990, 112, 8977-8979. (c) Kimura, K.; Ya-
mashita, T.; Yokoyama, M. J . Chem. Soc., Perkin Trans. 2 1992, 613-
619. (d) Kimura, K.; Yamashita, T.; Yokoyama, M. J . Phys. Chem. 1992,
96, 5614-5617. (e) Inouye, M.; Ueno, M.; Kitao, T. J . Org. Chem. 1992,
57, 1639-1641. (f) Inouye, M.; Ueno, M.; Tsuchiya, K.; Nakayama, N.;
Konishi, T.; Kitao, T. J . Org. Chem. 1992, 57, 5377-5383. (g) Inouye,
M.; Noguchi, Y.; Isagawa, K. Angew. Chem., Int. Ed. Engl. 1994, 33,
1163-1166. (h) Inouye, M.; Akamatsu, K.; Nakazumi, H. J . Am. Chem.
Soc. 1997, 119, 9160-9165. (i) Kimura, K.; Teranishi, T.; Yokoyama,
M.; Yajima, S.; Miyake, S.; Sakamoto, H.; Tanaka, M. J . Chem. Soc.,
Perkin Trans. 2 1999, 199-204. (j) Kimura, K.; Kado, S.; Sakamoto,
H.; Sakai, A.; Yokoyama, M.; Tanaka, M. J . Chem. Soc., Perkin Trans.
2 1999, 2539-2544. (k) Sakamoto, H.; Tanaka, M.; Kimura, K. Chem.
Lett. 2000, 928-929.
(3) Tanaka, M.; Nakamura, M.; Salhin, M. A. A.; Ikeda, T.; Kamada,
K.; Ando, H.; Shibutani, Y.; Kimura, K. J . Org. Chem. 2001, 66, 1533-
1537.
(4) Salhin, A. M. A.; Tanaka, M.; Kamada, K.; Ando, H.; Ikeda, T.;
Shibutani, Y.; Yajima, S.; Nakamura, M.; Kimura, K. Eur. J . Org.
Chem., in press.
(5) (a) Tanaka, M.; Kamada, K.; Ando, H.; Kitagaki, K.; Shibutani,
Y.; Yajima, S.; Sakamoto, H.; Kimura, K. Chem. Commun. 1999, 1453-
1454. (b) Tanaka, M.; Kamada, K.; Kimura, K. Mol. Cryst. Liq. Cryst.
2000, 344, 319-324. (c) Tanaka, M.; Kamada, K.; Ando, H.; Kitagaki,
K.; Shibutani, Y.; Kimura, K. J . Org. Chem. 2000, 65, 4342-4347.
(6) Bu¨hlmann, P.; Pretsch, E.; Bakker, E. Chem. Rev. 1998, 98,
1593-1687.
10.1021/jo0162843 CCC: $22.00 © 2002 American Chemical Society
Published on Web 03/08/2002

2224 J . Org. Chem., Vol. 67, No. 7, 2002
Tanaka et al.
Sch em e 1. Tw o Meta l In ter a ction s
Sch em e 2. Syn th esis of Sp ir oben zop yr a n s
F igu r e 1. Absorption spectra of 1 in the presence of an alkali
metal ion.
F igu r e 2. Absorption spectra of 1 in the presence of an
alkaline-earth metal ion.
irradiation because of the strong interaction between
Mg2+ and the phenolate anion moiety in the merocyanine
form of 1.4 Similarly, Ca2+ induced considerable thermal
isomerization to show negative photochromism, but posi-
tive photochromism appeared with Sr2+ and Ba2+. Nega-
tive photochromism induced by Mg2+ and Ca2+ was
observed for 2-5, but the Mg2+ preference over Ca2+ was
not very drastic compared with that in 1. The wavelength
of maximal absorption for the merocyanine form with
Mg2+ before UV irradiation was 513, 512, 516, 516, and
514 nm for 1-5, respectively. These similar values
indicate that the Mg2+ interaction with the phenolate
anion moiety is predominant in 1-5 and causes thermal
isomerization,8 which is supported by the fact that the
phenolate anion in the merocyanine form of spiroben-
zopyrans prefers metal ions possessing a higher charge
azathiacrown ethers and noncyclic analogues and their
photochromism in the presence of various metal ions.
Resu lts a n d Discu ssion
Synthetic procedures are outlined in Scheme 2. Mono-
azathiacrown ethers and noncyclic analogues were pre-
pared according to the procedures reported elsewhere.7
Spirobenzopyrans bearing monoazathiacrown ethers 1-3
were prepared by the reaction of monoazathiacrown
ethers with chloromethyl spirobenzopyran derivative in
dry THF in the presence of triethylamine under a
nitrogen atmosphere. Noncyclic analogues 4 and 5 were
also prepared in a similar fashion.
density such as Li+ and Mg2+ 9
. As only the monoaza-
trithia-12-crown-4 ring shows some binding ability to
Mg2+ in solvent extraction experiments,7 the significant
Mg2+ preference over Ca2+ in the binding ability of 1
seems to be derived from the cooperation of the monoaza-
thiacrown ether moiety with the phenolate anion moiety.
The absorption spectra of 1 with a heavy metal ion are
depicted in Figure 3 with the wavelength of maximal
absorption in parentheses. Significant thermal isomer-
ization of 1 was observed with other divalent metal ions
Absorption spectra of 1 acetonitrile solution with an
alkali metal ion before and after 365 nm UV irradiation
for 3 min at room temperature are shown in Figure 1.
Only Li+ suppressed the photoisomerization to the mero-
cyanine form slightly through the interaction with the
phenolate anion moiety,4 and no influence in absorption
spectra was observed with other metal ions. Similar
results were obtained with other spirobenzopyran deriva-
tives 2-5. This is consistent with the results of the
solvent extraction experiments where monoazathiacrown
ethers did not extract alkali metal ions.7
(7) Tanaka, M.; Nakamura, M.; Ikeda, T.; Ikeda, K.; Ando, H.;
Shibutani, Y.; Yajima, S.; Kimura, K. J . Org. Chem. 2001, 66, 7008-
7012.
(8) The shift in absorption spectra is reported to reflect solvent
polarity, where the blue shift is observed in a polar media. According
to this fact, the metal ion interaction with the phenolate anion moiety
will induce the blue shift: Reichardt, C. Chem. Rev. 1994, 94, 2319-
2358.
In the case of alkaline-earth metal ions (Figure 2), 1
showed significant spectral change before UV irradiation
in the presence of Mg2+, reflecting that the Mg2+ interac-
tion with 1 induced isomerization even without UV
irradiation, namely, thermal isomerization.
(9) Fedorova, O. A.; Gromov, S. P.; Pershina, Y. V.; Sergeev, S. S.;
Strokach, Y. P.; Barachevsky, V. A.; Alfimov, M. V.; Pe´pe, G.; Samat,
A.; Guglielmetti, R. J . Chem. Soc., Perkin Trans. 2 2000, 563-570.
The thermal isomerization induced by Mg2+ resulted
in the appearance of negative photochromism upon UV

Spirobenzopyrans and Spirobenzothiapyran Derivatives
J . Org. Chem., Vol. 67, No. 7, 2002 2225
F igu r e 3. Absorption spectra of 1 in the presence of a heavy
F igu r e 6. Absorption spectra of 4 in the presence of a heavy
metal ion.
metal ion.
F igu r e 4. Absorption spectra of 2 in the presence of a heavy
metal ion.
F igu r e 7. Absorption spectra of 5 in the presence of a heavy
metal ion.
nm for 1-3, respectively) and Pb2+ (498, 501, and 499
nm for 1-3, respectively) did not show such a shift in
absorption spectra. It is well-known that Mg2+, Zn2+, and
Pb2+ are hard metal ions, while Hg2+ and Ag+ are soft
metal ions. Furthermore, the strong affinity of the
monoazathiacrown ether rings for Hg2+ and Ag+ was
observed in the solvent extraction experiments.7 There-
fore, this red shift in absorption spectra clearly reflects
that soft metal ions such as Hg2+ and Ag+ are separated
from phenolate anion moieties by monoazathiacrown
ether moieties with increasing their ring size. In the case
of Pb2+, thermal isomerization depended significantly on
the ring size of the monoazathiacrown ether moieties,
although the Pb2+ interaction with the phenolate anion
moiety was predominant, as is the case with Mg2+. This
phenomenon suggests that the weak Pb2+ interaction
with the monoazathiacrown ether moiety also contributes
to thermal isomerization. A similar tendency was ob-
served with 4 and 5 as shown in Figures 6 and 7, respec-
tively. The close similarity in photochromism between the
spirobenzopyrans bearing monoazathiacrown ethers and
noncyclic analogues with heavy metal ions10 suggests that
the combination of sulfur and oxygen atoms around the
spiropyran moiety is a predominant factor in controlling
heavy metal ion-responsive photochromism.
F igu r e 5. Absorption spectra of 3 in the presence of a heavy
metal ion.
such as Hg2+, Pb2+, and Zn2+ that induced negative
photochromism upon UV irradiation in a similar way to
Mg2+. In the case of monovalent metal ions, Ag+ also
showed considerable thermal isomerization, but Ag+
induced significant facilitation of photoisomerization to
the merocyanine form in contrast to the divalent metal
ion systems. This tendency might reflect that Ag+ inter-
acts with the monoazathiacrown ether moiety much
stronger than with the phenolate anion moiety in the
merocyanine form of 1, judging from its longer wave-
length of maximal absorption compared with the divalent
metal ions. On the other hand, Tl+ did not show any
interaction with 1.
Absorption spectra of 2 and 3 in the presence of a heavy
metal ion are shown in Figures 4 and 5. By increasing
the ring size of the monoazathiacrown ether moieties
from 12 to 18, we observed a red shift in absorption
spectra with Hg2+ and Ag+, where the wavelengths of
maximal absorption were 472, 509, and 522 nm with
Hg2+ and 540, 545, and 551 nm with Ag+ for 1-3,
respectively. On the other hand, Zn2+ (463, 466, and 465
Taking the above results into account, we designed a
spirobenzothiapyran bearing 3,9-dithia-6-monoazaunde-
cane 6 as a Ag+-responsive photochromic material (Scheme
3). The absorption spectra of 6 in the presence of a heavy
metal ion are shown in Figure 8. In the presence of Ag+,
(10) The lack of difference between cyclic and noncyclic systems in
heavy metal ion binding ability has been reported: (a) Sakamoto, H.;
Ishikawa, J .; Mizuno, T.; Doi, K.; Otomo, M. Chem. Lett. 1993, 609-
612. (b) Ishikawa, J .; Sakamoto, H.; Mizuno, T.; Otomo, M. Bull. Chem.
Soc. J pn. 1995, 68, 3071-3076. (c) Ishikawa, J .; Sakamoto, H.; Wada,
H. J . Chem. Soc., Perkin Trans. 2 1999, 1273-1279.

2226 J . Org. Chem., Vol. 67, No. 7, 2002
Tanaka et al.
merocyanine form for 6. This significant stabilization
effect of Ag+ for 6 is evidently derived from the coopera-
tion of sulfur atoms in 3,9-dithia-6-monoazaundecane and
thiophenolate anion moieties.
Con clu sion s
In conclusion, spirobenzopyran derivatives bearing a
monoazathiacrown moiety showed selective binding abili-
ties to Mg2+ and Ag+ with negative and positive photo-
chromism, respectively. Among all metal ions, only Ag+
facilitated the photoisomerization to the merocyanine
form. As the monoazathiacrown ether rings and the
phenolate anion moieties prefer soft and hard metal ions,
respectively, Mg2+ selectivity is derived mainly from the
phenolate anion moiety and Ag+ selectivity from the
monoazathiacrown ether moiety.
F igu r e 8. Absorption spectra of 6 in the presence of a heavy
metal ion.
Sch em e 3. Syn th esis of Sp ir oben zoth ia p yr a n
Exp er im en ta l Section
All chemicals for the synthesis were of available purity and
used without further purification. For measurements, spec-
troscopic-grade acetonitrile was used as the solvent for the
absorption spectra, while all metal salts were of the highest
available purity and used without further purification. The
preparation of monoazathiacrown ethers and noncyclic ana-
logues were carried out according to the method reported in
ref 7. Procedures for the absorption-spectral measurement and
the determination of the decoloration and coloration rate
constants are described in refs 4 and 3, respectively. Chlo-
romethyl spirobenzopyran was prepared with the method in
ref 3.
Syn th esis of Mon oa za th ia cr ow n ed Sp ir oben zop yr a n s
a n d Der iva tives. Mon oa za tr ith ia -12-cr ow n -4 Sp ir oben -
zop yr a n (1). Under a nitrogen atmosphere, monoazatrithia-
12-crown-4 (223 mg, 1 mmol), chloromethylspirobenzopyran
(741 mg, 2 mmol), triethylamine (1.11 g, 11 mmol), and dry
THF (100 mL) were put into a three-necked flask, and the
reaction mixture was refluxed for 6 h. The product obtained
by solvent evaporation was purified by gel permeation chro-
matography to give an 11% yield of 1 as a red-purple solid:
mp 123-125 °C; 1H NMR (CDCl3, 400 MHz) δ 1.20 (3H, s,
CH3), 1.28 (3H, s, CH3), 2.43 (4H, t, J ) 7.0 Hz, SCH2CH2N),
2.58 (4H, t, J ) 7.0 Hz, NCH2), 2.7-2.8 (8H, m, SCH2), 2.71
(3H, s, NCH3), 3.3-3.5 (2H, m, PhCH2), 5.88 (1H, d, J ) 10.4
Hz, CHd), 6.55 (1H, d, J ) 7.6 Hz, ArH), 6.89 (1H, t, J ) 7.4
Hz, ArH), 6.94 (1H, d, J ) 10.4 Hz, CHd), 7.08 (1H, d, J ) 6.8
Hz, ArH), 7.20 (1H, t, J ) 8.2 Hz, ArH), 7.94 (1H, s, ArH),
thermal isomerization and facilitated photoisomerization
to the merocyanine form were observed. By contrast,
other metal ions did not show meaningful effects on
photochromism. Among alkali and alkaline-earth metal
ions, only Mg2+ facilitated the photoisomerization to the
merocyanine form slightly. The results show that the Ag+
interaction with 3,9-dithia-6-monoazaundecane and the
thiophenolate anion moieties is strong enough to induce
thermal isomerization of spirobenzothiapyran, although
spirobenzothiapyran is notorious for its thermal instabil-
ity in the merocyanine form.
To evaluate complex formation ability with various
metal ions, the decoloration and coloration rate constants
were determined for the positive and negative photo-
chromism systems, respectively. While a smaller value
for the positive photochromism system means more
stable complex formation, a greater value for the negative
photochromism indicates more stable complex formation.
The constants are summarized in Table 1.
Among alkali metal ions, the stabilization of the
merocyanine form was observed only with Li+ for 1. In
the case of alkaline-earth metal ions, significant stabi-
lization by Mg2+ was observed, especially for 1 and 6. The
stabilization effect of heavy metal ions decreased on
increasing the ring size of the monoazathiacrown ether
moieties for 1-3, and the effect decreased on increasing
the monoazathiacrown ether moiety for 4 and 5. On the
other hand, Ag+ showed remarkable stabilization of the
8.17 (1H, s, ArH); m/z 557 (M+); IR (neat, cm-1) 2960 (-CH2-
), 1520 (NO2), 1180 (C-N), 750 (CdC). Anal. Calcd for
28H35N3O3S3: C, 60.32; H, 6.28; N, 7.54; S, 17.24. Found: C,
C
60.05; H, 5.97; N, 7.19; S, 17.46.
Mon oa za tetr a th ia -15-cr ow n -5 Sp ir oben zop yr a n (2).
Under a nitrogen atmosphere, monoazatetrathia-15-crown-5
(283 mg, 1 mmol), chloromethylspirobenzopyran (741 mg, 2
mmol), triethylamine (1.11 g, 11 mmol), and dry THF (100 mL)
were put into a three-necked flask, and the reaction mixture
was refluxed for 36 h. The product obtained by solvent
evaporation was purified by gel permeation chromatography
to give a 44% yield of 2 as a red-purple solid: mp 58-61 °C;
1H NMR (CDCl3, 400 MHz) δ 1.18 (3H, s, CH3), 1.27 (3H, s,
CH3), 2.39 (4H, t, J ) 7.8 Hz, SCH2CH2N), 2.56 (4H, t, J )
7.6 Hz, NCH2), 2.8-2.9 (15H, m, SCH2, NCH3), 3.3-3.5 (2H,
m, PhCH2), 5.86 (1H, d, J ) 10.4 Hz, CHd), 6.54 (1H, d, J )
7.6 Hz, ArH), 6.87 (1H, t, J ) 7.4 Hz, ArH), 6.92 (1H, d, J )
10.4 Hz, CHd), 7.07 (1H, d, J ) 6.8 Hz, ArH), 7.18 (1H, t, J )
7.8 Hz, ArH), 7.91 (1H, s, ArH), 8.12 (1H, s, ArH); m/z
(intensity) 507 (M+ - 110, 60), 336 (M+ - 281, 100); IR (neat,
cm-1) 2920 (-CH2-), 1520 (NO2), 1182 (C-N), 750 (CdC).
Anal. Calcd for C30H39N3O3S4: C, 58.34; H, 6.32; N, 6.81; S,
20.75. Found: C, 58.44; H, 5.94; N, 6.84; S, 20.41.
Mon oa za tetr a th ia -18-cr ow n -6 Sp ir oben zop yr a n (3).
Under a nitrogen atmosphere, monoazapentathia-18-crown-6

Spirobenzopyrans and Spirobenzothiapyran Derivatives
J . Org. Chem., Vol. 67, No. 7, 2002 2227
Ta ble 1. Ra te Con sta n ts for Decolor a tion or Color a tion a
blank
Li+
Na+
K+
Rb+
Cs+
Mg2+
Ca2+
Sr2+
Ba2+
Ag+
Tl+
Pb2+
Hg2+
Zn2+
1
2
3
4
5
6
3.0
1.6
1.4
1.8
1.3
nd
1.7
1.5
1.3
1.1
1.0
nd
2.9
1.7
1.6
1.8
1.3
nd
3.0
1.5
1.1
1.8
1.4
nd
3.2
1.7
1.4
1.8
1.3
nd
2.8
1.6
1.5
1.6
1.3
nd
(0.59)
(0.19)
(0.29)
(0.26)
(0.32)
1.0
(0.37)
(0.18)
(0.28)
(0.24)
(0.25)
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
0.33
0.48
1.2
0.54
0.90
<0.1
2.4
1.2
nd
1.2
1.3
nd
(0.84)
nd
nd
(0.27)
nd
nd
(0.13)
nd
nd
(0.16)
(0.10)
nd
(0.31)
(0.36)
(0.23)
(0.20)
(0.16)
nd
a
Values in parentheses are coloration rate constants, and “nd” indicates that the constant was not determined due to a small change
in spectra.
(343 mg, 1 mmol), chloromethylspirobenzopyran (741 mg, 2
mmol), triethylamine (1.11 g, 11 mmol), and dry THF (100 mL)
were put into a three-necked flask, and the reaction mixture
was refluxed for 48 h. The product obtained by solvent
evaporation was purified by gel permeation chromatography
to give a 35% yield of 3 as a red-purple liquid: 1H NMR (CDCl3,
400 MHz) δ 1.19 (3H, s, CH3), 1.27 (3H, s, CH3), 2.4-2.9 (27H,
m, SCH2, NCH2, NCH3), 3.3-3.5 (2H, m, PhCH2), 5.87 (1H, d,
J ) 10.4 Hz, CHd), 6.55 (1H, d, J ) 7.6 Hz, ArH), 6.89 (1H,
t, J ) 7.4 Hz, ArH), 6.93 (1H, d, J ) 10.8 Hz, CHd), 7.09 (1H,
d, J ) 7.2 Hz, ArH), 7.20 (1H, t, J ) 7.6 Hz, ArH), 7.93 (1H,
s, ArH), 8.18 (1H, s, ArH); m/z (intensity) 507 (M+ - 170, 30),
223 (M+ - 454, 100); IR (neat, cm-1) 2920 (-CH2-), 1520
(NO2), 1182 (C-N), 750 (CdC). Anal. Calcd for C32H43N3O3S5:
C, 56.72; H, 6.35; N, 6.20; S, 23.63. Found: C, 56.81; H, 6.09;
N, 6.13; S, 23.36.
3,9-Dith ia -6-m on oa za u n d eca n e Sp ir oben zop yr a n (4).
Under a nitrogen atmosphere, 3,9-dithia-6-monoazaundecane
(193 mg, 1 mmol), chloromethylspirobenzopyran (741 mg, 2
mmol), triethylamine (1.11 g, 11 mmol), and dry THF (100 mL)
were put into a three-necked flask, and the reaction mixture
was refluxed for 3 h. The product obtained by solvent evapora-
tion was purified by gel permeation chromatography to give a
24% yield of 4 as a red-purple liquid: 1H NMR (CDCl3, 400
MHz) δ 1.19 (6H, t, J ) 7.4 Hz, CH2CH3), 1.20 (3H, s, CH3),
1.28 (3H, s, CH3), 2.3-2.5 (8H, m, SCH2), 2.5-2.6 (4H, m,
NCH2), 2.71 (3H, s, NCH3), 3.3-3.5 (2H, m, PhCH2), 5.86 (1H,
d, J ) 10.4 Hz, CHd), 6.54 (1H, d, J ) 7.6 Hz, ArH), 6.88 (1H,
t, J ) 7.4 Hz, ArH), 6.93 (1H, d, J ) 10.0 Hz, CHd), 7.08 (1H,
d, J ) 7.2 Hz, ArH), 7.19 (1H, t, J ) 7.4 Hz, ArH), 7.92 (1H,
s, ArH), 8.17 (1H, s, ArH); m/z 527 (M+); IR (neat, cm-1) 2960
(-CH2-), 1520 (NO2), 1180 (C-N), 750 (CdC). Anal. Calcd.
for C28H37N3O3S2: C, 63.76; H, 7.02; N, 7.97; S, 12.14. Found:
C, 63.86; H, 6.81; N, 7.94; S, 12.35.
3,6,12,15-Tetr a th ia -9-m on oa za h ep ta d eca n e Sp ir oben -
zopyr an (5). Under a nitrogen atmosphere, 3,6,12,15-tetrathia-
9-monoazaheptadecane (313 mg, 1 mmol), chloromethyl-
spirobenzopyran (741 mg, 2 mmol), triethylamine (1.11 g, 11
mmol), and dry THF (100 mL) were put into a three-necked
flask, and the reaction mixture was refluxed for 3 h. The
product obtained by solvent evaporation was purified by gel
permeation chromatography to give a 27% yield of 5 as a red-
purple liquid: 1H NMR (CDCl3, 400 MHz) δ 1.0-1.2 (12H, m,
CH2CH3, CH3), 2.4-2.8 (23H, m, SCH2, NCH2, NCH3), 3.3-
3.5 (2H, m, PhCH2), 5.86 (1H, d, J ) 10.4 Hz, CHd), 6.55 (1H,
d, J ) 7.6 Hz, ArH), 6.89 (1H, t, J ) 7.6 Hz, ArH), 6.93 (1H,
d, J ) 10.4 Hz, CHd), 7.08 (1H, d, J ) 7.2 Hz, ArH), 7.20 (1H,
t, J ) 7.6 Hz, ArH), 7.93 (1H, s, ArH), 8.17 (1H, s, ArH); m/z
(intensity) 507 (M+ - 140, 10), 252 (M+ - 375, 100); IR (neat,
cm-1) 2960 (-CH2-), 1520 (NO2), 1180 (C-N), 750 (CdC).
Anal. Calcd for C32H45N3O3S4: C, 59.35; H, 6.96; N, 6.49; S,
19.78. Found: C, 59.20; H, 6.71; N, 6.48; S, 19.78.
crude brown liquid product (>95%) obtained by solvent
evaporation was used for the subsequent preparation after
drying.
N-(2′-N,N-Dim eth ylth ioca r ba m oyloxy-3′-for m yl-5′-n i-
tr oben zyl)-3,9-d ith ia -6-m on oa za u n d eca n e. Under a nitro-
gen atmosphere, N-(2′-hydroxy-3′-formyl-5′-nitrobenzyl)-3,9-
dithia-6-monoazaundecane (860 mg, 2.4 mmol), triethylamine
(727 mg, 7.2 mmol), and dry DMF (60 mL) were put into a
three-necked flask at 0 °C, and a dry DMF solution (30 mL)
of N,N-dimethylcarbamoyl chloride (890 mg, 7.2 mmol) was
added to the mixture dropwise. The reaction mixture was
stirred at 0 °C for 3 h and then at room temperature for 12 h.
The reaction mixture was poured into water and extracted
with chloroform twice. The crude brown liquid product (>95%)
obtained by solvent evaporation was used for the subsequent
preparation after drying.
N-(2′-N,N-Dim eth ylcar bam oylth io-3′-for m yl-5′-n itr oben -
zyl)-3,9-d ith ia -6-m on oa za u n d eca n e. Under a nitrogen at-
mosphere, N-(2′-N,N-dimethylthiocarbamoyloxy-3′-formyl-5′-
nitrobenzyl)-3,9-dithia-6-monoazaundecane (1.06 g, 2.4 mmol)
and dry toluene (50 mL) were put into a three-necked flask,
and the reaction mixture was refluxed for 6 h. The product
(32%) obtained by solvent evaporation was purified by gel
permeation chromatography.
(2′-Me r ca p t o-3′-for m yl-5′-n it r ob e n zyl)-3,9-d it h ia -6-
m on oa za u n d eca n e. Under a nitrogen atmosphere, N-(2′-
N,N-dimethylcarbamoylthio-3′-formyl-5′-nitrobenzyl)-3,9-dithia-
6-monoazaundecane (340 mg, 0.77 mmol) and ethanol (50 mL)
were put into a three-necked flask, and the aqueous solution
(50 mL) of KOH (431 mg, 7.7 mmol) was added to the mixture.
The reaction mixture was stirred at room temperature for 2 h
under a nitrogen atmosphere. Acetic acid (462 mg, 7.7 mmol)
was added to the reaction mixture, and stirring was continued
for 10 min. The reaction mixture was poured into water and
extracted with chloroform twice. The crude brown liquid
product (>95%) obtained by solvent evaporation was used for
the subsequent preparation after drying.
3,9-Dith ia -6-m on oa za u n d eca n e Sp ir oben zoth ia p yr a n
(6). Under nitrogen atmosphere, (2′-mercapto-3′-formyl-5′-
nitrobenzyl)-3,9-dithia-6-monoazaundecane (286 mg, 0.77 mmol),
2-methylene-1,3,3-trimethylindoline (133 mg, 0.77 mmol), and
dry ethanol (50 mL) were put into a three-necked flask, and
the reaction mixture was refluxed for 12 h. The product
obtained by solvent evaporation was purified by gel permeation
chromatography to give a 56% yield of 6 as a red-brown
liquid: 1H NMR (CDCl3, 500 MHz) δ 1.20 (6H, t, J ) 7.25 Hz,
CH2CH3), 1.23 (3H, s, CH3), 1.37 (3H, s, CH3), 2.47 (4H, q, J
) 7.33 Hz, SCH2CH3), 2.5-2.6 (4H, m, NCH2), 2.6-2.8 (7H,
s, SCH2, NCH3), 3.5-3.7 (2H, m, PhCH2), 6.00 (1H, d, J ) 11.0
Hz, CHd), 6.50 (1H, d, J ) 7.5 Hz, ArH), 6.86 (1H, t, J ) 7.75
Hz, ArH), 6.93 (1H, d, J ) 11.0 Hz, CHd), 7.06 (1H, d, J ) 8.0
Hz, ArH), 7.17 (1H, t, J ) 8.25 Hz, ArH), 7.95 (1H, s, ArH),
8.30 (1H, s, ArH); m/z 543 (M+); IR (neat, cm-1) 2960 (-CH2-
), 1520 (NO2), 1060 (C-N), 750 (CdC). Anal. Calcd for
N-(2′-H yd r oxy-3′-for m yl-5′-n it r ob en zyl)-3,9-d it h ia -6-
m on oa za u n d eca n e. Under
a nitrogen atmosphere, 3,9-
C
28H37N3O2S3‚1/2H2O: C, 60.87; H, 6.88; N, 7.61; S, 17.39.
dithia-6-monoazaundecane (463 mg, 2.4 mmol), triethylamine
(485 mg, 4.8 mmol), and dry THF (20 mL) were put into a
three-necked flask at 0 °C, and a dry THF solution (10 mL) of
3-chloromethyl-5-nitrosalycylaldehyde (518 mg, 2.4 mmol) was
added to the mixture dropwise. The reaction mixture was
stirred at 0 °C for 3 h and then at room temperature for 12 h
under a nitrogen atmosphere. The reaction mixture was
poured into water and extracted with chloroform twice. The
Found: C, 60.98; H, 6.81; N, 7.75; S, 17.55.
Ack n ow led gm en t. We thank Mrs. J inko Okuno
(Special Division for Human Life Technology, National
Institute of Advanced Industrial Science and Technol-
ogy) for assistance in the experimental analysis.
J O0162843