Synthesis and photochromism of photochromic spiro compounds having a reactive pendant group

Article abstract of DOI:10.1002/jhet.5570390126

The photochromic spiropyrans and spirooxazines having a reactive pendant group, including carboxyl, halide, succinimidyl ester and isothiocyanate, were synthesized. Their photochromic behaviors in solution and solid state were studied.

Full text of DOI:10.1002/jhet.5570390126

Jan-Feb 2002
Synthesis and Photochromism of Photochromic Spiro Compounds
Having a Reactive Pendant Group
179
Peng Zhang [a], Jiben Meng [a*], Xiaoliu Li [a], Teruo Matsuura [b],
and Yongmei Wang [a]
[a] Department of Chemistry, Nankai University, Tianjin, P. R. China, 300071
[b] 21-26 Kawashima-Gondencho, Saikyoku, Kyoto 615-8195, Japan
Received July 23, 2001
The photochromic spiropyrans and spirooxazines having a reactive pendant group, including carboxyl,
halide, succinimidyl ester and isothiocyanate, were synthesized. Their photochromic behaviors in solution
and solid state were studied.
J. Heterocyclic Chem., 39, 179 (2002).
Introduction.
The reversible transformation between the closed spiro
form (SP) and the open photo-merocyanine form (PMC)
results in a color change.
The chemistry of photochromic spiro compounds has
been studied with regard to industrial applications and bio-
molecules modification as photoresponsive materials
Photochromism involving reversible change in the visi-
ble absorption spectrum has attracted much attention in the
last decades due to the various potential application of the
photochromic system [1,2]. Spiropyrans and spiroox-
azines, the important classes of photochromic materials,
have been extensively investigated [3,4]. The pho-
tochromic processes of these compounds are based on
intramolecular pericyclic reactions [1] (Scheme 1).
[
5-8]. It is necessary to synthesize the spiro compounds
having a reactive pendant group that may be used for bio-
molecules modification. Some groups, such as carboxyl,
halide, succinimidyl ester and isothiocyanate, are suitable
for biomolecules modification [9-11]. Here we report the
photochromic spiropyrans and spirooxazines containing
these groups and their photochromic properties.
Results and Discussion.
Synthesis.
The reference compounds 1 [12] and 7 [12] were synthe-
sized according to the literatures and used as standards for
comparisons with a series of spiropyrans and spirooxazines,

1
80
P. Zhang, J. Meng, X. Li, T. Matsuura, and Y. Wang
Vol. 39
Scheme 2 (continued)
respectively. Their structures and synthetic routes are
shown in Schemes 2 and 3. The reactive pendant groups
including carboxyl, succinimidyl ester, chloroacetyl and
isothiocyanate, were connected to the indoline 1-nitrogen
(1-12) or 5-carbon (14-17, 20, 21, 23 and 24) of a pho-
tochromic spiro compound. The compounds 1 and 7, which

Jan-Feb 2002
Synthesis and Photochromism of Photochromic Spiro Compounds
181
have a carboxyl group, reacted with N-hydroxysuccinimide
in the presence of DCC to form succinimidyl esters 2 and 8,
respectively. These esters reacted with various amino acids
to give new compounds having a longer chain pendant
group such as compounds 3, 5, 9 and 11 which were further
converted in a similar manner into 4, 6, 10 and 12, respec-
tively. The functionalization at 5-carbon was carried out
starting from 2-methylindoleninium iodide 13 and 2-meth-
yleneindoline 18 (Scheme 3). The key intermediate isothio-
cyanate 19 and chloroacetylamide 22 were synthesized from
the corresponding amine 18. The structures of these func-
tionalized spiro compounds were confirmed by their micro-
analytical and spectral data.
Photochromism.
The photochromic behaviors of the functionalized spiro
compounds 1-12, 14-17, 20, 21, 23 and 24 were examined
with the aid of electronic spectral measurements. They
showed a broad band in the visible region (546-589 nm) by
the irradiation of the ethanol solution with a high-pressure
mercury lamp (Table 1), indicating the formation of their
open colored form (PMC in Scheme 1). The absorption
maxima of 1-substituted spiro compounds 2-6 and 8-12
appeared at similar wavelengths to those of the reference
compounds 1 and 7. The 5-substituted compounds 14, 15,
Figure 1. The absorption spectra of compound 4 in ethanol before and
after irradiation.
20, 23 showed a shorter maxima than that of reference com-
pounds 1 and the compounds 16, 17, 21, 24 showed a shorter
maxima than that of reference compounds 7. As a typical
example, the spectral chart of compound 4 in ethanol before
and after irradiation for 30 seconds is shown in Figure 1.
Table 1
0
10
20
30
40
50
60
The Absorption Maxima (λmax) of the Spiro-photochromic
Time (sec)
Compounds in Ethanol after Irradiation
Comp. λ (nm) Comp. λ (nm) Comp. λ (nm) Comp. λ (nm)
Figure 2. The intensity decrease at the absorption maximum (578 nm) of
compound 2 after irradiation.
1
2
3
4
5
6
575
578
569
576
570
572
7
8
9
10
11
12
587
589
576
577
575
577
14
15
16
17
560
564
572
575
20
21
23
24
562
571
546
570
A semiquantitative study of the decolorlization process
of the open colored form of compound 2 was carried out.
Figure 2 shows the decrease of the absorbance at the
absorption maximum (578 nm) of the compound. The
decolorization process of succinimidyl esters was found to
be faster than the corresponding carboxyl compounds.
Thus spirooxazine derivatives (8-12, 17, 21 and 24) decol-
orlized so fast that measurements were difficult on the
available spectrophotometer.
after irradiation
2
00
300
400
500
600
700
λ/nm
In the solid state, the synthesized spiro compounds also
showed a color change on irradiation. Figure 3 shows the
solid UV-VIS reflection spectra of compound 4 before and
Figure 3. The solid UV-VIS reflection spectra of compound 4 before and
after irradiation.

182
P. Zhang, J. Meng, X. Li, T. Matsuura, and Y. Wang
Vol. 39
after irradiation. The maximum of this open colored form
showed a blue shift compared to that in ethanol solution.
N-Succinimidyl 3-[2-[3,3-Dimethyl-6'-nitrospiro[2'H-chromene-
2,2'-(2,3-dihydro-1H-indole)]-1-yl]]-propionylglycylglycinate (4).
The compound 4 was synthesized with the similar process to
that for compound 2 from 3 and N-hydroxysuccinimide to give
yellow crystals. 0.49 g (83%), mp 126-127°; ir (potassium bro-
mide): ν 3380 (NH), 1735, 1700, 1660 (C=O), 1610 (C=N), 1270
EXPERIMENTAL
General.
-1 1
(
C-O) cm ; H nmr (deuteriochloroform): δ 1.18 (s, 3H, CH ),
3
Melting points were determined with a Yanagimoto MP-35 melt-
ing point apparatus and are uncorrected. The H nmr spectra were
1.28 (s, 3H, CH ), 2.52~2.65 (m, 2H, CH ), 2.86 (s, 4H, 2CH ),
3.00~3.10 (m, 2H, CH ), 3.60~3.72 (m, 2H, CH ), 3.89 (s, 2H,
2 2
3 2 2
1
measured with a BRUKER AC-200 spectrometer using tetram-
ethylsilane as the internal standard. Coupling constants are given in
Hertz. The mass spectra were recorded on a 7070E-HE spectrome-
ter operating in electron impact mode at 70 eV. The IR spectra were
recorded on a Bio-Rad FTS135 spectrophotometer. A Yamaco
CHN corder MT-3 apparatus was used for elemental analysis. A
Shimadzu UV-240A and a 2101PC spectrometers were used for
electronic absorption spectra and solid reflection spectra.
CH ), 6.00 (d, J=10,8Hz, 1H, vinyl-H), 6.74-7.28 (m, 6H, ArH
and vinyl-H), 8.00-8.10 (m, 2H, ArH); ms: m/z 591 (M ).
2
+
Anal. Cacld. for C H N O : C, 58.88; H, 4.94; N, 11.84.
2
9 29 5 9
Found: C, 58.75; H, 4.93; N, 11.97.
6
-[3-[3,3-Dimethyl-6'-nitrospiro[2'H-chromene-2,2'-(2,3-dihy-
dro-1H-indole)]-1-yl]propionylamino]-hexanoic Acid (5).
The compound 5 was synthesized with the similar process to
that for compound 3 from 4 and 6-aminohexoic acid to give a rose
pink solid. 0.42 g (85%), mp 80-81°; ir (potassium bromide): ν
3300 (NH), 3060, 2930 (OH), 1725, 1675 (C=O), 1615 (C=N),
Synthesis of Spiro Compounds.
The starting materials were all commercially available.
-
1 1
5-Nitrosalicylaldehyde was prepared according to literature pro-
1275(C-O) cm ; H nmr (deuteriochloroform): ν 1.15 (s, 3H,
CH ), 1.26 (s, 3H, CH ), 1.32-1.66 (m, 6H, 3CH ), 2.20-2.60 (m,
cedure [13]. Compounds 18 and 22 were synthesized as
3
3
2
described previously [14].
4H, 2CH ), 3.08-3.28 (m, 2H, CH ), 3.50-3.68 (m, 2H, CH ), 5.72
2 2 2
(
br, 1H, NH), 5.89 (d, J=10.8Hz, 1H, vinyl-H), 6.65-7.25 (m, 6H,
N-Succinimidyl 3-[3,3-Dimethyl-6'-nitrospiro[2'H-chromene-
+
ArH and vinyl-H), 8.00-8.15 (m, 2H, ArH); ms: m/z 493 (M ).
2,2'-(2,3-dihydro-1H-indole)]-1-yl]-propionate (2).
Anal. Cacld. for C H N O : C, 65.71; H, 6.33; N, 8.51.
2
7 31 3 6
A mixture of 0.76 g (2 mmol) of compound 1, 0.29 g (2.5
mmol) of N-hydroxysuccinimide and 0.52 g (2.5 mmol) of DCC
Found: C, 65.65 H, 6.38 N 8.57.
N-Succinimidyl 6-[3-[3,3-Dimethyl-6'-nitrospiro[2'H-chromene-
2
(
(
dicylohexylcarbodiimide) in 20 ml of dried dimethyl formamide
DMF) was stirred at room temperature for 24 hours. After evap-
,2'-(2,3-dihydro-1H-indole)]-1-yl]-propionylamino]-hexanoate (6).
oration of DMF in vacuo, the residue was dissolved in ethyl
acetate, washed with a saturated sodium hydrocarbonate solution
and then with water and purified by silica gel column chromatog-
raphy (eluent, acetone:petroleum ether = 1:4, v:v) to give a yel-
low solid which was recrystallized from ethyl acetate-petroleum
The compound 6 was synthesized with the similar process to
that for compound 2 from 5 and N-hydroxysuccinimide to give
yellow crystals. 0.44 g (76%), mp 137-138°; ir (potassium
bromide): ν 3300 (NH), 1782, 1735 (C=O), 1609 (C=N), 1275
-1 1
(C-O) cm ; H nmr (deuteriochloroform): δ 1.15 (s, 3H, CH ),
3
ether to give 2 as yellow crystals; 0.81 g (84%), mp 140-141°; ir
1.26 (s, 3H, CH ), 1.34-1.48 (m, 4H, 2CH ), 1.60-1.82 (m, 2H,
CH ), 2.38-2.68 (m, 4H, 2CH ), 2.82 (s, 4H, 2CH ), 3.10~3.32
2 2 2
3 2
-
(
potassium bromide): ν 1732 (C=O),1605 (C=N),1275 (C-O) cm
1
1
;
H nmr (deuteriochloroform): δ 1.22 (s, 3H, CH ), 1.30 (s, 3H,
(m, 2H, CH ), 3.50-3.70 (m, 2H, CH ), 5.91 (d, J=10.8Hz, 1H,
3
2 2
CH ), 2.89 (s, 4H, 2CH ), 3.00 (t, J=7.2Hz, 2H, CH ), 3.73 (t,
vinyl-H), 6.68-7.28 (m, 6H, ArH and vinyl-H), 8.04-8.12 (m, 2H,
ArH); ms: m/z 590 (M ).
3
2
2
+
J=7.2Hz, 2H, CH ), 6.00 (d, J=10.8Hz, 1H, vinyl-H), 6.68~7.38
2
+
(
m, 6H, ArH and vinyl-H), 8.10 (m, 2H, ArH); ms: m/z 477 (M ).
Anal. Cacld. for C H N O : C, 63.04; H, 5.80; N, 9.49.
31 34 4 8
Anal. Cacld. for C H N O : C, 62.89; H, 4.86; N, 8.80.
Found: C, 63.12; H, 5.68; N, 9.40.
2
5 23 3 7
Found: C, 62.98; H, 4.74; N, 8.92.
N-Succinimidyl 3-[3,3-Dimethylspiro[2,3-dihydro-1H-indole-
2,3'-(3'H-naphtho[2,1-b][1,4]oxazine)]-1-yl]-propionate (8).
3
-[2-[3,3-Dimethyl-6'-nitrospiro[2'H-chromene-2,2'-(2,3-dihy-
dro-1H-indole)]-1-yl]]-propionylglycylglycine (3).
The compound 8 was synthesized with the similar process to
that for compound 2 from 7 and N-hydroxysuccinimide to give
white crystals. 0.78 g (82%), mp 184-185°; ir (potassium
To a solution of 0.48 g (1 mmol) of compound 2 in 3 ml of DMF,
0.13 g (1 mmol) of glycylglycine in 4 ml of aqueous sodium hydro-
-1 1
carbonate solution was added and the mixture was stirred at room
temperature for 6 hours. After evaporation in vacuo, 10 ml of 10%
aqueous citric acid solution was added and the insoluble solid was
collected by filtration, and recrystallized from acetone-petroleum
ether to give 3 as a rose pink solid. 0.42 g (85%), mp 118-120°; ir
bromide): ν 1730 (C=O), 1615 (C=N), 1240 (C-O) cm ; H nmr
(deuteriochloroform): δ 1.30 (s, 3H, CH ), 1.35 (s, 3H, CH ),
3
3
2.80 (s, 4H, 2CH ), 3.00-3.12 (m, 2H, CH ), 3.52-3.70 (m, 2H,
2
2
CH ), 6.68 (d, J=8.1Hz, 1H, vinyl-H), 6.94-7.81 (m, 9H, ArH),
2
+
8.57 (d, J=9.0Hz, 1H, ArH); ms: m/z 483 (M ).
(
potassium bromide): ν 3400 (NH), 3050, 2920 (OH), 1720, 1660
Anal. Cacld. for C H N O : C, 69.55; H, 5.21; N, 8.69.
Found: C, 69.41; H, 5.26; N, 8.84.
2
8 25 3 5
-1 1
(C=O), 1604 (C=N), 1270 (C-O) cm ; H nmr (deuteriochloro-
form): δ 1.16 (s, 3H, CH ), 1.26 (s, 3H, CH ), 2.62 (t, J=7.2Hz, 2H,
3
3
3
-[2-[3,3-Dimethylspiro[2,3-dihydro-1H-indole-2,3'-(3'H-naph-
CH ), 3.40 (s, 2H, CH ), 3.59 (t, J=7.2Hz, 2H, CH ), 3.87 (s, 2H,
2
2
2
tho[2,1-b][1,4]oxazine)]-1-yl]propionylglycylglycine (9).
CH ), 6.10 (d, J=10.8Hz, 1H, vinyl-H), 6.72-7.39 (m, 6H, ArH and
2
+
vinyl-H), 8.00-8.17 (m, 2H, ArH); ms: m/z 494 (M ).
The compound 9 was synthesized with the similar process to
that for compound 3 from 8 and glycylglycine to give a rose pink
solid. 0.45 g (90%), mp 110-112°; ir (potassium bromide): ν 3300
Anal. Cacld. for C H N O : C, 60.72; H, 5.30; N, 11.33.
2
5 26 4 7
Found: C, 60.65; H, 5.23; N, 11.47.

Jan-Feb 2002
Synthesis and Photochromism of Photochromic Spiro Compounds
183
(
NH), 3050, 2960 (OH), 1725, 1650 (C=O), 1601 (C=N), 1245
was added. The mixture was refluxed for 7 hours. After evapora-
tion of the solvent in vacuo, the residue was neutralized with an
aqueous sodium carbonate solution and extracted with diethyl
ether and the separated ether layer was dried with anhydrous mag-
nesium sulfate. After evaporation of diethyl ether, the residue was
added to 1.2 ml of iodomethane in 30 ml of chloroform. The mix-
ture was refluxed for 5 hours under nitrogen atmosphere. The pre-
cipitate began to appear 1 hour later. After cooling, a white solid
-1 1
(C-O) cm ; H nmr (deuteriochloroform): δ 1.30 (s, 6H, 2CH ),
3
3
.50-3.70 (m, 2H, CH ), 3.82 (d, J= 5.6Hz, 4H, 2CH ), 4.00-4.20
2
2
(m, 2H, CH ), 6.70-7.81 (m, 9H, ArH and vinyl-H), 8.08 (m, 1H,
2
+
ArH), 8.54 (d, J=7.2Hz, 1H, ArH); ms: m/z 500 (M ).
Anal. Cacld. for C H N O ,: C, 67.19; H, 5.64; N, 11.19.
2
8 28 4 5
Found: C, 67.25; H, 5.56; N, 11.27.
N-Succinimidyl 3-[2-[3,3-Dimethylspiro[2,3-dihydro-1H-indole-
2
glycylglycinate (10).
13 (1.1 g) was collected by filtration and used for the next reaction
,3'-(3'H-naphtho[2,1-b][1,4]oxazine)]-1-yl]propionyl-
without further purification.
1
1
,3,3-Trimethyl-6'-nitrospiro[2'H-chromene-2,2'-(2,3-dihydro-
H-indole)]-5-yl-formic Acid (14).
The compound 10 was synthesized with the similar process to that
for compound 2 from 9 and N-hydroxysuccinimide to give yellow
crystals. 0.43 g (72%), mp 144-145°; ir (potassium bromide): ν 3320
A mixture of 6.9 g of compound 13, 3.3 g of 5-nitrosalicy-
(
NH), 3060, 2970 (OH), 1765, 1735 (C=O), 1605 (C=N), 1240
laldehyde and 1.5 ml of piperidine in 50 ml ethanol was refluxed
for 5 hours. After evaporation of solvent, the residue was purified
by silica gel thin layer chromatography (eluent, acetone:petro-
leum ether = 1:2, v:v) to give a yellow solid which was recrystal-
lized from acetone-petroleum ether to give 14 as yellow crystals.
3.1 g (42%), mp163-165°; ir (potassium bromide): ν 3300-2500
-1 1
(C-O) cm ; H nmr (deuteriochloroform): δ 1.31 (s, 3H, CH ), 1.34
3
(s, 3H, CH ), 2.82 (s, 4H, 2CH ), 3.34-3.58 (m, 2H, CH ), 3.74-3.89
3 2 2
(m, 4H, 2CH ), 3.96-4.10 (m, 2H, CH ), 6.67-7.98 (m, 10H, ArH
2 2
+
and vinyl-H), 8.52 (d, J=7.2Hz, 1H); ms: m/z 597 (M ).
Anal. Cacld. for C H N O : C, 64.31; H, 5.23; N, 11.72.
3
2 31 5 7
-1 1
Found: C, 64.25; H, 5.29; N, 11.67.
(OH), 1704 (C=O), 1614 (C=N), 1240 (C-O) cm ; H nmr (deu-
teriochloroform): δ 1.19 (s, 3H, CH ), 1.34 (s, 3H, CH ), 2.60 (s,
3
3
6
-[3-[3,3-Dimethylspiro[2,3-dihydro-1H-indole-2,3'-(3'H-naph-
3
H, CH ), 5.84 (d, J=5.4Hz, 1H, vinyl-H), 6.52-7.25 (m, 5H,
3
tho[2,1-b][1,4]oxazine)]-1-yl]propionylamino]-hexanoic Acid (11).
+
ArH and vinyl-H), 7.75-8.00 (m, 2H, ArH)?ms: m/z 366 (M ).
The compound 11 was synthesized with the similar process to
that for compound 3 from 8 and 6-aminohexoic acid to give a
rose pink solid. 0.42 g (84%), mp 86-88°; ir (potassium bromide):
ν 3300 (NH), 3060, 2930 (OH), 1720, 1660 (C=O), 1604 (C=N),
Anal. Cacld. for C20H18N O : C, 65.57; H, 4.95; N 7.65.
Found: C, 65.62; H, 4.89; N, 7.72.
2 5
N-Succinimidyl 1,3,3-Trimethyl-6'-nitrospiro[2'H-chromene-
,2'-(2,3-dihydro-1H-indole)]-5-yl-formate (15).
2
-1 1
1
2
3
270 (C-O) cm ; H nmr (deuteriochloroform): δ 1.28 (s, 6H,
CH ), 1.34-1.67 (m, 6H, 3CH ), 2.31-2.62 (m, 4H, 2CH ), 3.10-
The compound 15 was synthesized with the similar process to
that for compound 2 from 14 and N-hydroxysuccinimide to give
3
2
2
.28 (m, 2H, CH ), 3.52-3.66 (m, 2H, CH ), 6.65-7.85 (m, 10H,
2
2
+
ArH and vinyl-H), 8.54 (d, J=7.2Hz, 1H); ms: m/z 499 (M ).
Anal. Cacld. for C H N O : C, 72.12; H, 6.66; N, 8.41.
yellow crystals. 0.78 g (85%), mp 128-129°; ir (potassium bro-
-1 1
mide): ν 1780 (C=O), 1620 (C=N), 1235 (C-O) cm ; H nmr
(deuteriochloroform): δ 1.22 (s, 3H, CH ), 1.30 (s, 3H, CH ),
3
0 33 3 4
Found: C, 72.25; H, 6.53; N, 8.37.
3
3
2
1
.58 (s, 3H, CH ), 2.87 (s, 4H, 2CH ), 5.88, 5.91 (d, J=5.4Hz,
3 2
N-Succinimidyl 6-[3-[3,3-Dimethylspiro[2,3-dihydro-1H-indole-
H, vinyl-H), 6.60-7.15 (m, 5H, ArH and vinyl-H), 7.68~7.99
2
,3'-(3'H-naphtho[2,1-b][1,4]oxazine)]-1-yl]-propionylamino]-
+
(m, 2H, ArH); ms: m/z 463 (M ).
hexanoate (12).
Anal. Cacld. for C H N O : C, 62.20; H, 4.57; N, 9.07.
2
4 21 3 7
The compound 12 was synthesized with the similar process to
that for compound 2 from 11 and N-hydroxysuccinimide to give
yellow crystals. 0.41 g (69%), mp 140-141°; ir (potassium bro-
mide): ν 3350 (NH), 1780, 1725 (C=O), 1606 (C=N), 1240 (C-O)
Found: C, 62.11; H, 4.64; N, 9.01.
1
,3,3-Trimethylspiro[2,3-dihydro-1H-indole-2,3'-(3'H-naph-
tho[2,1-b][1,4]oxazine)]-5-yl-formic Acid (16).
-1 1
cm ; H nmr (deuteriochloroform): δ 1.24 (s, 3H, CH ), 1.31 (s,
To a solution of 2.8 g of 1-nitroso-2-naphthol in 20 ml of
ethanol, a solution of 5.7 g of 13 and 4 ml trimethylamine in 20
ml ethanol was dropwise added. The mixture was refluxed for 5
hours. After evaporation of solvent, the residue was purified by
silica gel thin layer chromatography (eluent, acetone:petroleum
ether = 1:2, v:v) to give a yellow solid which was recrystallized
from acetone-petroleum ether to give 16 as yellow crystals. 2.3g
3
3
H, CH ), 1.36-1.65 (m, 6H, 3CH ), 2.28-2.60 (m, 4H, 2CH ),
3 2 2
2
.87 (s, 4H, 2CH ), 3.15-3.32 (m, 2H, CH ), 3.56-3.68 (m, 2H,
2
2
CH ), 6.70-7.81 (m, 10H, ArH, vinyl-H), 8.52 (d, J=7.2Hz, 1H);
2
+
ms: m/z 596 (M ).
Anal. Cacld. for C H N O : C, 68.44; H, 6.08; N, 9.39.
3
4 36 4 6
Found: C, 68.59; H, 6.03; N, 9.47.
(
(
38%), mp 158-160°; ir (potassium bromide): ν 3050, 2960
OH), 1705 (C=O), 1615 (C=N), 1225 (C-O) cm ; H nmr (deu-
5-Carboxyl-1,2,3,3-tetramethylindoleninium Iodide (13).
-1 1
To an aqueous concentrated hydrochloric acid (20 ml) and ice
teriochloroform): δ 1.25 (s, 6H, 2CH ), 2.62 (s, 3H, CH ), 6.63
3 3
water (30 ml) of p-amino benzoic acid (6.8 g, 0.05 mol) was
added an aqueous solution (18 ml) of sodium nitrite (3.5 g, 0.05
mol) at 0 °C. After 30 minutes of stirring, an aqueous concen-
trated hydrochloric acid solution (35 ml), and stannous chloride
dihydrate (34 g, 0.15 mol) was added to the mixture at 0 °C. The
reaction mixture was stirred for additional 30 minutes and filtered
to give a milk white solid (p-carboxylphenylhydrazine hydrochlo-
ride). To a mixture of 3.6 g of this solid, 4.4 ml of 3-methyl-2-
butanone in 40 ml ethanol, 2.4 ml of concentrated sulfuric acid
(d, J=4.8Hz, 1H, vinyl-H), 6.90-7.80 (m, 8H, ArH), 8.62 (d,
J=7.2Hz, 1H); ms: m/z 372 (M ).
+
Anal. Cacld. for C H N O : C, 74.18; H, 5.41; N, 7.52.
2
3 20 2 3
Found: C, 74.25; H, 5.36; N, 7.32.
N-Succinimidyl 1,3,3-Trimethylspiro[2,3-dihydro-1H-indole-
2,3'-(3'H-naphtho[2,1-b][1,4]oxazine)]-5-yl-formate (17).
The compound 17 was synthesized with the similar process to
that for compound 2 from 16 and N-hydroxysuccinimide to give

184
P. Zhang, J. Meng, X. Li, T. Matsuura, and Y. Wang
Vol. 39
yellow crystals. 0.73 g (78%), mp 120-121°; ir (potassium bro-
The compound 23 was synthesized with the similar process to
that for compound 20 from 22 and 5-nitrosalicylaldehyde to give
orange crystals. 0.38 g (47%), mp196-198°; ir (potassium bro-
-1 1
mide): ν 1765 (C=O), 1610 (C=N), 1220 (C-O) cm ; H nmr (deu-
teriochloroform): δ 1.22 (s, 3H, CH ), 1.31 (s, 3H, CH ), 2.60 (s,
3
3
-1 1
3
H, CH ), 2.89 (s, 4H, 2CH ), 6.63 (d, J=4.8Hz, 1H, vinyl-H), 6.88-
mide): ν 1659 (C=O), 1605 (C=N) cm ; H nmr (deuteriochloro-
form): δ 1.26 (s, 6H, 2CH ), 2.65 (s, 3H, CH ), 4.20 (s, 2H, CH )
3
2
+
7.82 (m, 8H, ArH), 8.62 (d, J=7.2Hz, 1H, ArH); ms: m/z 469 (M ).
Anal. Cacld. for C H N O : C, 69.07; H, 4.94; N, 8.95.
3
3
2
5.83 (d, J=5.4Hz, 1H, vinyl-H), 6.50~7.35 (m, 5H, ArH and
2
7 23 3 5
+
Found: C, 69.25; H, 4.86; N, 8.87.
vinyl-H), 8.00-8.04 (m, 2H, ArH); ms: m/z 413 (M ).
Anal. Cacld. for C H ClN O : C, 60.95; H, 4.87; N, 10.15.
Found: C, 61.06; H, 4.79; N, 10.08.
2
1
20
3 4
5-Isothiocyanato-1,3,3-trimethyl-2-methyleneindoline (19).
A mixture of 1.1 g of compound 18, 0.84 ml of 25% aqueous
5
-Chloroacetylamino-1,3,3-trimethylspiro[2,3-dihydro-1H-
ammonia and 0.42 ml of carbon disulfide was stirred. After a precip-
itate was formed, 0.3 ml of water was added and the mixture was
stirred at 35-40 °C for 1 hour. The precipitate was collected by filtra-
tion and washed with 3% aqueous ammonium chloride solution and
water, successively, to give a yellow solid. The solid was mixed with
indole-2,3'-(3'H-naphtho[2,1-b][1,4]oxazine] (24).
The compound 24 was synthesized with the similar process to
that for compound 21 from 22 and 1-nitroso-2-naphthol to give
yellow crystals. 0.31 g (37%) mp184-185°; ir (potassium bro-
mide): ν 1670 (C=O), 1605 (C=N) cm ; H nmr (deuteriochloro-
form): δ 1.24 (s, 6H, 2CH ), 2.70 (s, 3H, CH ), 4.25 (s, 2H,
-1 1
5
ml of water and a sodium chloroacetic acid solution (0.56 g of
chloroacetic acid dissolved in 0.6 ml of water and neutralized with a
solution of 0.36 g of sodium carbonate in 1.4 ml of water). After stir-
rng for 10 minutes, 5 ml of water was added and the mixture was
stirred at 35-40 °C for 1 hour. To the reaction mixture was added
dropwise an aqueous zinc chloride solution (0.4 g of zinc chloride in
3
3
CH ), 6.60 (d, J=4.8Hz, 1H, vinyl-H), 6.90~7.71 (m, 8H, ArH),
8.64 (d, J=7.2Hz, 1H, ArH); ms: m/z 419 (M ).
2
+
Anal. Cacld. for C H ClN O , C 68.65 H 5.28 N 10.01,
2
4
22
3 2
Found: C 68.75 H 5.16 N 10.12.
1
.5 ml of water) keeping the pH 7-8 with 4 mol/l of aqueous sodium
The Spectroscopic Properties Determination of Photochromic
Compounds.
hydroxide solution. The reaction mixture was stirred for 3 hours.
After cooling, the precipitate was filtered and extracted with
dimethyl ether. Evaporation of the extract gave a yellow solid 0.8 g,
which was used for the next reaction without further purification.
The absorption spectra of photochromic compounds 1-12, 14-
17, 20, 21, 23 and 24 in ethanol solution with the concentration of
-5
1
0
mol/l after irradiation with a 400W high-pressure lamp for
5
-Isothiocyanato-3,3-dimethyl-6'-nitrospiro[2'H-chromene-2,2'-
30 seconds were recorded on a UV-240A spectrophotometer. The
(2,3-dihydro-1H-indole)] (20).
maxima of the open colored form of the compounds were listed
in Table1.
A mixture of 0.44 g of compound 19 and 0.34 g of 5-nitrosali-
cylaldehyde in 12 ml of ethanol was refluxed for 5 hours. After
evaporation of the solvent, the residue was purified by silica gel
thin layer chromatography (eluent, acetone:petroleum ether =
Acknowledgement.
This study was supported by National Natural Science
Foundation of China (No. 29872015, 29832030).
1:4, v:v) to give a yellow solid which was recrystallized from
ethyl acetate-petroleum ether to give 20 as yellow crystals. 0.33 g
(
1
44%), mp 167-168°; ir (potassium bromide): ν 2120 (S=C=N),
607 (C=N) cm ; H nmr (deuteriochloroform): δ 1.17 (s, 3H,
REFERENCES AND NOTES
-1 1
CH ), 1.26 (s, 3H, CH ), 2.73 (s, 3H, CH ), 5.83 (d, J=5.4Hz, 1H,
3
3
3
[
1] H. Durr, H. Bouas-Laurent, ed. 'Photochromism and System',
Elsevier, Amsterdam, 1990.
2] J. M. Kelly, C. B. McArdle, M. J. deF. Maunder,
vinyl-H), 6.43-7.25 (m, 5H, ArH and vinyl-H), 8.00-8.04 (m, 2H,
+
ArH); ms: m/z 379 (M ).
[
Anal. Cacld. for C H N O S: C, 63.31; H, 4.52; N, 11.07.
2
0
17
3
3
'Photochemistry and Polymetric System', the Royal Society of Chemistry,
Cambridge, 1993.
Found: C, 63.25; H, 4.61; N, 11.02.
[
3] R. C. Bertelson, Mol. Cryst. Liq. Cryst., 246, 1 (1994).
5
2
-Isothiocyanate-1,3,3-trimethylspiro[2,3-dihydro-1H-indole-
,3'-(3'H-naphtho[2,1-b][1,4]oxazine (21).
[4] J. D. Winkler, C. M. Bowen and V. Michelet, J. Am. Chem.
Soc., 120, 3237 (1998).
A mixture of 0.44 g of compound 19 and 0.35 g of 1-nitroso-2-
[5] I. Willner and S. Rubin, Angew. Chem. Int. Ed. Engl., 35, 367
1996).
(
naphthol in 15 ml of ethanol was refluxed for 5 hours. After evap-
oration of the solvent, the residue was purified by silica gel thin
layer chromatograph (eluent, acetone:petroleum ether = 1:2, v:v) to
give a yellow solid which was recrystallized from ethyl acetate-
petroleum ether to give 21 as yellow crystals. 0.27 g (36%), mp
[
[
6] I. Willner, Acc. Chem. Res., 30, 347 (1997).
7] A. D. Turner, S. V. Pizzo, G. W. Rozakis and N. A. Porter, J.
Am. Chem. Soc., 109, 1274 (1987).
8] N. A. Porter and J. O. Bruhuke, Photochem. Photobiol., 51, 37
1990).
9] I. Willner, S. Rubin and A. Riklin, J. Am. Chem. Soc., 113,
3321 (1991).
[10] I. Willner, S. Rubin and T. Zor, J. Am. Chem. Soc., 113, 4013
(1991).
[11] I. Willner and S. Rubin, J. Am. Chem. Soc., 114, 3150 (1992).
12] X. L. Li, Y. M. Wang, T. Matsuura and J. B. Meng,
[
(
1
(
2
8
42-143°; ir (potassium bromide): ν 2120 (S=C=N), 1615, 1605
[
-1 1
C=N) cm ; H nmr (deuteriochloroform): δ 1.22 (s, 6H, 2CH ),
3
.72 (s, 3H, CH ), 6.62 (d, J=4.8Hz, 1H, vinyl-H), 6.88-7.69 (m,
3
+
H, ArH), 8.62 (d, J=7.2Hz, 1H, ArH); ms: m/z 385 (M ).
Anal. Cacld. for C H N OS: C, 71.66; H, 4.97; N, 10.90.
2
3 19 3
[
Found: C, 71.85; H, 4.86; N, 10.82.
Heterocycles, 51, 2639 (1999).
5
2
-Chloroacetylamino-3,3-dimethyl-6'-nitrospiro[2'H-chromene-
,2'-(2,3-dihydro-1H-indole)] (23).
[13] R. L. Liu and Shanxi Hua Gong, 1, 1 (1998).
[14] D. J. Gale and J. F. K. Wilshire, J. Soc. Dyers Color, 94 (1974).