Synthesis and fluorescence of 2H-pyrone derivatives for organic light-emitting diodes (OLED)

Article abstract of DOI:10.1002/jhet.5570440120

(Chemical Equation Presented) 2H-Pyrone derivatives were synthesized through the reaction of aryl acetyl compounds with ketene dithioacetals in the presence of sodium hydroxide, and they showed very strong fluorescence in the solid state. The light-emitti

Full text of DOI:10.1002/jhet.5570440120

Jan-Feb 2007
115
Synthesis and Fluorescence of 2H-Pyrone Derivatives for Organic
Light-emitting Diodes (OLED)
aNaoko Mizuyama, aYuka Murakami, aShinya Kohra, aKazuo Ueda, aKyoko Hiraoka,
bJunko Nagaoka, cKojiro Takahashi, dYasuhiro Shigemitsu and aYoshinori Tominaga
aFaculty of Environmental Studies and bFaculty of Engineering of Nagasaki University, 1-14, Bunkyo-machi,
c
Nagasaki 852-8521; Department of Hospital Pharmacy, University Hospital of Occupational Environmental
Health, Japan, 1-1, Iseigaoka, Yahata-nishiku, Kitakyushu, Fukuoka 807-8555; dTechnology Center of
Nagasaki, 2-1308-8, Ikeda, Omura, Nagasaki 856-0026, Japan.
Received March 30, 2006
O
MeS
MeS
CN
NaOH
+
Me
in DMSO
at r.t.
COOMe
SMe
Nu
CN
CN
O
Nu-
O
O
O
2H-Pyrone derivatives were synthesized through the reaction of aryl acetyl compounds with ketene
dithioacetals in the presence of sodium hydroxide, and they showed very strong fluorescence in the solid
state. The light-emitting region of these 2H-pyrones is 447-630 nm in the solid states.
J. Heterocyclic Chem., 44, 115 (2007).
INTRODUCTION
among the observed chemical and physical properties of
the investigated pyrone derivatives. Since some
interesting findings were obtained in our reexamination of
fluorescence of 2H-pyrone derivatives in the solid state,
they are reported here.
Synthesis of 2H-pyrones. The usefulness of ketene
dithioacetal derivatives for the synthesis of heterocyclic
compounds has already clarified by the author, who has
shown many examples hitherto [4,5].
In this study, in order to elucidate the structure-activity
relationships for each substituent and each pyrone
derivative, and to clarify the differences in effect between
the various types of aryl groups at position 6 of the 2-
pyrones and the various substituents on the aryl group,
many more derivatives were required than in the last
study. Therefore, many new pyrone derivatives were
synthesized in this study, and the method of synthesizing
2H-pyrone derivatives was also slightly improved.
Fluorescent dyes which show fluorescence in the solid
state have attracted attention as candidate materials for
emitters in electroluminescent (EL) devices [1]. Several
of the 4H-pyrone derivatives have already been shown to
have interesting organic electroluminescence properties
[2]. This suggested to us that 2H-pyrones might have red
electroluminescence, which has been very difficult to
harness. We first investigated the 6-aryl-2H-pyran-2-ones,
expecting them to have superior red fluorescence.
Komatsu, et al. has indicated that the phenyl group at
position 6 in 3,4,6-triphenyl-2H-pyrones is an important
functional group for fluorescence in these compounds [3].
However, our experiments showed that the substitution of
the phenyl group at position 6 in the 2H-pyrone ring did
not improve the fluorescence. In this study, no derivatives
except those with the phenyl group at position 3 and 4 in
the 2-pyrone moiety showed any fluorescence.
Here, we will discuss the structure-activity relationships
for each functional group at each position in these 2H-
pyrones and compare with them. In addition, we will
discuss the fluorescence activity of some of the related 6-
styryl-2H-pyran-2-ones. These compounds, which show
fluorescence in the solid state, have attracted attention as
potential electroluminescence (EL) sources. On 1975, it
was reported for the first time that 2H-pyrone derivatives
were easily obtained through the reaction of ketene
dithioacetals with active methylene or methyl compounds
in the presence of potassium hydroxide as the base [4].
However, in our experiments, fluorescence was not
MeS
MeS
COOMe
COOMe
MeS
MeS
CN
MeS
MeS
CN
O2S
R
COOMe
1a
1b
1c; R=H, 1d; R=Me
Figure 1. Ketene Dithioacetals.
A convenient method of producing 6-aryl- or 6-
styryl-4-methylthio-2-oxo-2H-pyran-3-carbonitriles and
3-carboxylates through the reaction of various methyl-
ketones with ketene dithioacetals, methyl 3,3-

116
N. Mizuyama, Y. Murakami, S. Kohra, K. Ueda, K. Hiraoka, J. Nagaoka,
K. Takahashi, Y. Shigemitsu and Y. Tominaga
Vol 44
bis(methylthio)acrylonitrilate (1a) and dimethyl
bis(methylthio)malonate (1b) has been reported
previously [4,5]. These reactions occur smoothly in the
presence of potassium hydroxide as the base and DMSO
(dimethyl sulfoxide) as the solvent. In this study,
however, the reaction was carried out in the presence of
sodium hydroxide as the base to obtain a slightly better
yield. The acetyl compounds used in this study were
acetophenone (2a), 2-methoxyacetophenone (2b), 3-
methoxyacetophenone (2c), 4-methoxyacetophenone
(2d), 2,4-dimethoxyacetophenone (2e), 2,5-dimeth-
oxyacetophenone (2f), 3,4-dimethoxyacetophenone
(2g), 3,4,5-trimethoxyacetophenone (2h), 4-dimethyl-
aminoacetophenone (2i), 4-bromoacetophenone (2j), 2-
chloroacetophenone (2k), 4-chloroacetophenone (2l), 4-
phenylacetophenone (2m), 4-cyanoacetophenone (2n),
1-acetylnaphthalene (2o), 2-acetylnaphthalene (2p), 3-
acetylpyridine (2q), 2-acetylthiophenone (2r), 2-
acetylbenzothiophenone (2s), 2-acetylfuran (2t), and 5-
methyl-2-acetylfuran (2u).
fluorescence compounds, which are the most important
and the most difficult to produce in the field of
electroluminescence. Fortunately, we were able to produce
6-(4-aminophenyl)-2-oxo-2H-pyran-3-carbonitriles (5c-e),
which showed red fluorescence, from 4-(N,N-disubstituted
aminophenyl)but-3-en-2-ones(4c-e) and 1a.
On the other hand, 4-methylthio-6-phenyl-2-oxo-2H-
pyran-5-carbonitrile (7), which is a positional isomer of
the cyano group of 3a, was obtained through the reaction
of benzoylacetonitrile (6) with 1a in the presence of
sodium hydroxide in DMSO. However, the yield was very
low (12%).
We
expected
methyl 6-aryl-2-oxo-2H-pyran-3-
carboxylates (8) and 3-sulfonyl-2-oxo-2H-pyran
derivatives (9) to have good fluorescence properties as
well. 6-Aryl-2-oxo-2H-pyran-3-carboxylates (8a,d) were
obtained from 1b and acetophenone (2a) or 4-
methoxyacetophenone (2d) in a manner similar to the
synthesis of 6-aryl-4-methylthio-2H-pyran-2-ones (3a-
u). The synthesis of these sulfonyl compounds was
carried out through the reaction of sulfonyl ketene
dithioacetal (1c, 1d) with 2. However, the desired 3-
The synthesis of 6-aryl-4-methylthio-2H-pyran-2-ones
(3a-u) proved to be useful in the preparation of red-
Scheme 1. Synthesis of 6-Aryl-4-methythio-2-oxo-2H-pyran-3-carbonitriles
SMe
O
CN
O
NaOH
+
1a
in DMSO
R
Me
R
O
3a-u
2a-u
SMe
O
NaOH
in DMSO
CN
O
O
Me
1a
1a
+
R
R
5a-e
4a-e
SMe
O
SMe
O
O
NC
H
O
NC
COOMe
NH
NaOH
CN
+
in DMSO
6
7
R
yield(%)
ꢀ
ꢀ
R
yield(%)
3a
3b
3c
3d
3e
3f
3g
3h
3i
3j
3k
3l
3m
3n
:
C6H5
ꢀ
61
58
53
64
33
27
40
56
85
42
65
44
88
66
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
3o
:
:
:
:
:
:
1-naphtyl
2-naphtyl
3-pyridyl
2-thienyl
2-benzothienyl
2-furyl
63
75
58
68
84
30
44
:
:
:
:
:
:
:
:
:
:
:
:
:
C6H4-OMe(2)
C6H4-OMe(3)
C6H4-OMe(4)
C6H3-(OMe)2(2,4)
C6H3-(OMe)2(2,5)
C6H3-(OMe)2(3,4)
C6H2-(OMe)3(3,4,5)
C6H4-NMe2(4)
C6H4-Br(4)
C6H4-Cl(2)
C6H4-Cl(4)
C6H4-Ph(4)
C6H4-CN(4)
3p
3q
3r
3s
3t
3u
2-furyl-Me(5)
5a
5b
5c
5d
5e
ꢀ
:
:
:
:
:
ꢀ
H
35
43
32
26
29
OMe
NMe2
NEt2
NPh2
ꢀ

Jan-Feb 2007
Synthesis and Fluorescence of 2H-Pyrone derivatives
117
For Organic Light-Emitting Diodes(OLED)
phenylsulfonyl-2H-pyran-2-one derivative was not
obtained through the reaction of 2a with sulfonyl
ketene dithioacetal, ethyl 2-benzenesulfonyl-3,3-
methoxide in methanol to give 4-methoxy-6-phenyl-2-
oxo-2H-pyran-3-carbonitriles (11a, 11d) in good yields,
i.e. 61% and 45%, respectively [4].
bis(methylthio)acrylate,
under
similar
reaction
Scheme 3. Synthesis of 6-arly-4-methoxy-2-oxo-2H-pyran-3-carbonitriles.
conditions. Lucky, this problem was easily solved by
using a different sulfonyl ketene dithioacetal (1d).
Compound 1e was allowed to react with 2a in the
presence of sodium hydroxide in DMSO followed by
treatment with hydrochloric acid to give the desired 3-
phenylsulfonyl-2-oxo-2H-pyran (9a) in 54% yield.
The other sulfonyl compounds (9b) were synthesized
through the reaction of 1d with 2a under the same
reaction conditions.
SMe
OMe
CN
O
CN
O
MeONa
in MeOH
R
O
R
O
3a,b
11a,d
Next, we will describe the synthesis of 4-amino-6-
aryl-2-oxo-2H-pyran derivatives. Previously, we have
reported the synthesis of 4-amino-6-aryl-2-oxo-2H-
pyran-3-carbonitriles through the displacement reaction
of 4-methylthio-2H-pyran-3-carbonitriles with various
amines in refluxing methanol. Many 4-amino-6-aryl-2-
oxo-2H-pyran derivatives (12a-x) were prepared by
this method. The disadvantage of this reaction is that
the reaction time is long. We tried a very simple
method of synthesizing 4-amino-2H-pyrones through
the direct reaction of 2-pyrones with amines under
heating at 100° for 5-10 minutes without any solvent.
This reaction gave a separable mixture of the desired
12a-x and butadiene derivatives (15a-m).
It was possible to easily separate this mixture into each
chemical compound due to differences in their solubility
in methanol. The structure of these butadienes after
purification of the crude products were 5-amino-3-
methylthio-5-phenyl-penta-2,4-dienitriles (15a-m) by the
IR, UV, NMR, Ms spectra and elemental analysis.
Finally, one of these products (15b) was determined by
X-ray crystallographic analysis. Figure 2 shows the
ORTEP drawings of the crystal structure.
Scheme 2. Synthesis of 6-arly-2-oxo-2H-pyran-3-carboxylic acids and
6-arly-3-tolylsulfonyl-2-oxo-2H-pyran-3-carbonitriles.
SMe
O
MeS
MeS
COOMe
COOMe
COOMe
O
NaOH
+
in DMSO
Me
R
R
O
8a,d
1b
2a,d
CN
MeS
O
+
R
MeS
O2S
R
Me
1c,d
1c; R=H,
1d; R=Me
2a
SMe
SMe
O2
O2
S
S
R
NaOH
in DMSO
R
+
R
N
H
O
R
O
9a,b
O
byproduct; 10a,b
The reaction of 2i with 1a was carried out in the
presence of sodium hydroxide as the base to obtain the
desired product, 6-(4-dimethylaminophenyl)-4-methyl-
thio-2-oxo-2H-pyran-3-carbonitrile (3i), in 43% yield.
The acetyl compounds, 4-(N,N-disubstituted amino-
phenyl)but-3-en-2-ones (4c-e) also reacted with 1a in a
manner similar to that described for the preparation of 3a,
and the corresponding 6-[2-(4-N,N-disubstituted amino-
phenyl)vinyl]-4-methylthio-2-oxo-2H-pyran-3-carbonitriles
(5c-e) were obtained in 32, 26, and 29% yields,
respectively.
In order to obtain strong fluorescent compounds, it is
important to give polarity to the molecule 2H-pyrone
derivatives show strong fluorescence when there is
electron-withdrawing group at position 3 and an electron-
donating group at position 4. The electron donation
property of alkoxy and amino groups at position 4 in 2-
pyrone is stronger than that of the methylthio group at the
same position. 2-Pyrone derivatives with very high
fluorescence can be synthesized, if an alkoxy and an
amino group can be introduced at position 4 of 2-pyron.
The displacement of 3a, 3b and 3c with a methoxide
anion occurred smoothly in the presence of sodium
Figure 2. ORTEP Drawing of 15b.
Methyl 4-amino-6-aryl-2-oxo-2H-pyran-3-carboxylates
(14a-f) were prepared using the method reported by us
previously. The compounds (13a, 13b) were allowed to
react with amines (methylamine, benzylamine,

118
N. Mizuyama, Y. Murakami, S. Kohra, K. Ueda, K. Hiraoka, J. Nagaoka,
K. Takahashi, Y. Shigemitsu and Y. Tominaga
Vol 44
dimethylamine, pyrrolidine) under refluxing methanol to
RESULTS AND DISCUSSION.
give 14a-f in good yields.
An efficient method of measuring fluorescence must be
used in order to obtain the exact fluorescence intensities of
many 2-pyrone derivatives. It is very easy to find the
fluorescence of the corresponding compounds in the solid
state: simple irradiation with a hand-held UV lamp (254 nm)
as the first stage of a screening test is sufficient for obtaining
the corresponding fluorescence values. In our study, we first
placed the compounds on filter paper then we irradiated them
with a UV lamp, and we assessed their fluorescence with the
naked eye. The fluorescence intensities were divided into 6
categories. By defining AlQuinoline3 (AlQ3) as the standard
compound, the fluorescence intensities of the other 2-pyrone
derivatives were determined. The results are shown in Table 1.
Scheme 4. Synthesis of 4-Amino-6-aryl-2-oxo-2H-pyrans.
SMe
NR2
H
CN
R2N
CN
O
CN
O
amines
H
+
SMe
in MeOH
R
O
R
O
12a-x
15a,b,e,f,h,l,m,p
3a,c,d,f,g,h,j,k,o,r,s
Me
O2S
NR2
COOMe
O
COOMe
O
amines
in MeOH
R
O
R
O
Table 1. Eye-measuring of 6-aryl-2-oxo-2H-pyransꢀ
Intensity
Compound No.
14a-f
13a, b
5
3b, 3d, 3f, 8d, 9b, 12d, 12e, 12f, 12g, 12h,
12k, 12m, 12n, 12r, 12u
4
3
2
1
0
3a, 3g, 3l, 3m, 3r, 11a, 12a, 12i, 12u, AlQ3
3i
3t, 3u
14b
3n, 7
R
NR2
12: yield(%) 15: yield(%)
a
b
c
d
e
f
g
h
i
j
k
l
m
n
o
p
q
r
s
t
u
v
w
x
:
C6H5
C6H5
C6H5
C6H4-OMe(3)
C6H4-OMe(4)
C6H4-OMe(4)
C6H4-OMe(4)
C6H4-OMe(4)
C6H4-OMe(4)
dimethyamino
pyrrolidino
morpholino
dimethyamino
dimethyamino
pyrrolidino
morpholino
thiomorpholino 38
phenethylamino 60
29
52
48
40
50
51
42
48
38
-
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
-
Next, a secondary evaluation of the fluorescence of these
2H-pyrones was carried out using a fluorophotometer. The
measurement of the absorption and fluorescence spectra
was carried out in ethanol solution and in the solid state,
respectively, at room temperature. The spectroscopic
properties, absorption maxima (ꢀmax), molar absorption (ꢁ),
fluorescence maxima (ꢀmax), and relative fluorescence
intensities (R.I.) are listed in Table 2-4.
47
30
-
22
-
C6H3-(OMe)2(2,5) morpholino
C6H3-(OMe)2(3,4) morpholino
78
69
64
44
50
-
-
28
51
-
C6H4-NMe2(4)
C6H4-NMe2(4)
C6H4-NMe2(4)
C6H4-NMe2(4)
C6H4-Br(4)
C6H4-Cl(2)
C6H4-Cl(4)
C6H4-Ph(4)
1-naphtyl
1-naphtyl
2-thienyl
2-thienyl
2-benzothienyl
dimethyamino
pyrrolidino
morpholino
thiomorpholino 58
-
pyrrolidino
morpholino
pyrrolidino
pyrrolidino
pyrrolidino
morpholino
pyrrolidino
morpholino
pyrrolidino
53
93
29
-
Table 2. Spectral data of 6-Aryl-2-oxo-2H-pyrans (3, 5).
46
44
-
-
No.
UVꢁmax(logꢂ) Ex max
Em max
SSa
R.I.b
nm(EtOH)
ꢀ
328(4.24)
nm(solid)
nm(solid)
86
88
-
-
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
3a
3b
3c
3d
3e
3f
358
480
122
136
145
239
237
228
257
207
307
214
195
128
183
-
195
174
169
254
245
223
223
218
1.54
1.67
1.16
1.23
0.57
0.71
0.76
0.28
0.15
0.76
0.68
1.29
1.11
0.00
0.66
2.01
0.06
0.84
0.37
0.59
0.21
0.39
58
47
-
-
387(4.35)
369(4.29)
395(4.45)
400(4.60)
402(4.28)
402(4.39)
391(4.33)
465(4.58)
337(4.33)
354(4.18)
336(4.34)
357
350
297
297
303
294
295
301
304
296
364
326
0.00
303
342
297
309
298
323
298
323
493
495
536
534
531
551
502
608
518
491
492
509
0.00
498
516
468
563
543
546
521
541
53
14: yield(%)
-
14a : C6H5
14b : C6H5
14c : C6H5
14d : C6H4-OMe(4)
14e : C6H4-OMe(4)
14f : C6H4-OMe(4)
methylamino
benzylamino
dimethyamino
methylamino
dimethyamino
pyrrolidino
95
75
98
95
72
72
3g
3h
3i
3j
3k
3l
3m
3n
3o
3p
3q
3r
3s
3t
c
388
Scheme 5. Reaction Pathway of 15
332(4.12)
371(4.22)
370(4.17)
327(4.24)
415(4.30)
408(4.40)
395(4.42)
404(4.47)
NR2
H
SMe
SMe
O
H
R2N:
CN
O
CN
R2N
H
O
15
CN
OH
O
Me
S
O
3u
5a
c
395
3

Jan-Feb 2007
Synthesis and Fluorescence of 2H-Pyrone derivatives
119
For Organic Light-Emitting Diodes(OLED)
Table 2 (continued)
important, materials which emit blue light are the most
fundamental and those which emit red light are the most
difficult to synthesize. In comparison with the
spectroscopic properties of 4-methylthio-2-oxo-6-phenyl-
2H-pyran-3-carbonitriles (3a-u), both the absorption and
the fluorescence maxima of 2-pyrones bearing electron-
rich aryl groups showed longer wavelength shifts,
together with an increase in molar absorption. The aryl
group at position 6 of the 2-pyrone derivatives was also
found to contribute to the fluorescence. Our study showed
No.
UVꢀmax(logꢁ) Ex max Em max
SSa
R.I.b
nm(EtOH)
nm(solid)
nm(solid)
5b
5c
5d
5e
415(4.30)
513(4.67)
529(4.69)
502(4.19)
ꢂꢂ
309
342
346
349
ꢂꢂ
563
699
705
645
254
357
359
296
ꢂꢂ
0.84
0.01>
0.01>
0.01>
ꢂꢂ
ꢂꢂ
ꢂꢂ
a
b
Stoke's Shift=Em(solid)-Ex(solid).
Relative intensity of
c
fluorescence in solid state, usingAlQ3 as a stadard. insufficient
d
solubility.
amorphus
Table 3. Spectral data of 6-Aryl-2-oxo-2H-pyrans (8, 9, 14).
No.
R, R', NR2
UVꢀmax(logꢁ) Ex
nm(EtOH)
max Em
nm(solid) nm(solid)
max SSa
R.I.b
8a
8d
9a
9b
R=C6H5
360(4.18)
386(4.41)
339(4.28)
387(4.54)
314(4.26)
305(4.28)
303(4.28)
341(4.38)
321(4.41)
311(4.46)
299
295
297
294
296
272
272
270
258
265
475
483
460
508
437
445
453
453
457
466
176
188
163
214
141
173
181
183
199
201
6.31
3.94
0.51
11.27
3.51
0.96
0.27
1.46
9.81
3.87
R=C6H5-OMe(4)
R=C6H5, R'=H
R=C6H5, R'=Me
14a R=C6H5, NR2=methylamino
14b R=C6H5, NR2=benzylamino
14c R=C6H5, NR2=dimethylamino
14d R=C6H5-OMe(4), NR2=methylamino
14e R=C6H5-OMe(4), NR2=dimethylamino
14f
R=C6H5-OMe(4), NR2=pyrrolidino
Table 4. Spectral data of 6-Aryl-2-oxo-2H-pyrans (11, 12).
No.
R
position 4
UVꢀmax(logꢁ)
nm(EtOH)
320(4.18)
376(4.49)
310(4.35)
308(4.36)
315(4.41)
324(4.25)
332(4.42)
331(4.41)
336(4.43)
339(4.47)
346(4.42)
364(4.15)
358(4.25)
400(4.57)
396(4.64)
409(4.54)
410(4.57)
315(4.42)
298(4.17)
314(4.38)
328(4.56)
320(4.30)
324(4.33)
336(4.36)
343(4.57)
349(4.45)
Ex max Em
nm(solid)
max SSa
R.I.b
nm(solid)
367
375
361
304
371
303
376
369
374
373
370
371
296
294
373
322
295
363
303
369
352
359
361
369
375
369
11a
11d
12a
12b
12c
12d
12e
12f
12g
12h
12i
12j
12k
12l
12m
12n
12o
12p
12q
12r
12s
12t
12u
12v
12w
12x
a; C6H5
e; C6H4-OMe(4)
a; C6H5
b; C6H5
c; C6H5
methoxy
methoxy
472
487
447
478
455
476
475
453
475
474
461
509
497
517
537
606
582
516
466
481
479
470
472
486
461
494
105
112
86
174
99
173
99
84
2.88
5.14
1.50
0.91
3.08
0.92
6.90
4.27
4.60
4.14
4.34
3.05
5.52
9.90(5.72d)
3.86
1.08
0.43
1.45
0.78
2.84
1.28
1.38
1.43
2.51
6.99
1.81
dimethylamino
pyrrolidino
morpholino
dimethylamino
dimethylamino
pyrrolidino
morpholino
thiomorpholino
phenethylamino
morpholino
morpholino
dimethylamino
pyrrolidino
morpholino
thiomorpholino
pyrrolidino
morpholino
pyrrolidino
pyrrolidino
pyrrolidino
morpholino
pyrrolidino
morpholino
pyrrolidino
d; C6H4-OMe(3)
e; C6H4-OMe(4)
f; C6H4-OMe(4)
g; C6H4-OMe(4)
h; C6H4-OMe(4)
j; C6H4-OMe(4)
k; C6H3-(OMe)2(2,5)
l; C6H3-(OMe)2(3,4)
n; C6H4-NMe2(4)
o; C6H4-NMe2(4)
p; C6H4-NMe2(4)
q; C6H4-NMe2(4)
r; C6H4-Br
s; C6H4-Cl(2)
t; C6H4-Cl(4)
u; C6H4-Ph
v; 1-naphtyl
w; 1-naphtyl
x; 2-thienyl
y; 2-thienyl
z; 2-benzothienyl
101
101
91
138
201
223
164
284
287
153
163
112
127
111
111
117
116
125
The discovery of intensely fluorescent materials
emitting light in the three primary colors (red, green and
blue; RGB) is crucial for the development of organic EL
materials. The three primary colors are RGB, and their
light-emission wavelengths are 440 nm, 550 nm, and 630
nm, respectively. Although each primary color is
that the fluorescence of 6-methyl-2-oxo-2H-pyran-3-
carbonitrile was very week [4]. Among the 6-phenyl-2-
pyrone derivatives, those with electron-donating groups
on the phenyl group (3a-c) showed the strongest
fluorescence. Compound 3a, which had an unsubstituted
phenyl group at position 6, emitted light in the shortest

120
N. Mizuyama, Y. Murakami, S. Kohra, K. Ueda, K. Hiraoka, J. Nagaoka,
K. Takahashi, Y. Shigemitsu and Y. Tominaga
Vol 44
wavelength region (480 nm). The light-emission region
was found to shift toward the longer-wavelength side
when, a methoxy group was introduced as the electron-
donating group on the phenyl group. On the other hand,
compound 3d emitted light at 536 nm, when a methoxy
group was introduced at position 4 on the phenyl group;
its light-emitting region was 56 nm further toward the red
side than that of 3a. The shift toward the longer-
wavelength side was slight considering the parting of the
localized system of the conjugated system between the
methoxy group at position 2 on phenyl group and the
pyrone ring by steric hindrance in 3b. In the case of 3c
however, there was no shift toward the longer wavelength
side because of the weak electronic effect of the meta-
position of the methoxy group. The fluorescence maxima
of 6-(4-dimethylaminophenyl)-2-oxo-2H-pyran-3-carbo-
nitrile (3i) appeared at 608 nm (R.I. = 0.15), which is
close to the red light region. Red fluorescence dyes are
currently of great interest in various fields, and are
expected to be used as emitters in electroluminescent
devices. In this type of application, red light emission
around 620-640 nm is anticipated for the light-emitting
materials to be used in EL devices.
Compound 3n, which bears a cyano group as the
electron-withdrawing substituent, did not emit any light.
Similarly, electron-deficient hetero aryl compounds such
as 6-pyrid-3-yl-2H-pyrone (3q) emitted very weak light.
The naphthyl and hetero aryl derivatives (3o, 3p, 3r-u)
also showed moderate fluorescence (Table 2). The light-
emission region of 3o (498 nm) shifted downward by 18
nm due to the twisting caused by steric hindrance with
both the naphthyl and the pyranyl group. The light-
emission regions of compounds 3r-u shifted toward the
longer-wavelength side (563, 543, 546, and 521 nm,
respectively), even when the aromatic substituent at
position 6 was changed to an electron-rich heterocyclic
compound. Notably, 6-thien-2-yl-2H-pyrone (3r) emitted
light at 563 nm. The styryl-2H-pyrone derivatives (5a-e)
introduced at the double bond between the aryl group at
position 6 and the pyrone ring can be supposed to emit
light of longer-wavelengths. 6-Styryl-4-methylthio-2H-
pyrone (5a) emitted light at 541 nm and the methoxy
derivative (5b) emitted light at 563 nm. The light
emission of this amino styryl (5c-e) was not as strong
when it was in crystal form. We found that the aryl and
the styryl group at position 6 of the pyrone derivatives
had the greatest effect on the fluorescence of the pyrone
compounds.
Therefore, we expected the compounds to show stronger
fluorescence when the methylthio group at position 4 was
substituted by an alkoxy or an amino group. The
fluorescences of the alkoxy and the amino derivatives
were considerably stronger than that of the methylthio
compounds. The light-emission region showed a 40-50
nm blue shift. The 4-amino compound (12a) emitted a
typically blue fluorescent light (447 nm), as shown in
Table 4.
However, the position of the cyano group on the pyrone
ring is also an important factor of the fluorescent
property. Almost all 6-aryl-2-oxo-2H-pyran-3-carbonitrile
derivatives except 3n and 3q showed fluorescence in the
solid state as shown in Table 2. Only, 2-oxo-6-phenyl-2H-
pyran-5-carbonitrile (7) showed absolutely no
fluorescence. This suggested to us that the position of the
electron-deficient group in the 2-pyrone derivatives is
crucial for electroluminescence.
Inserting an ester or a sulfonyl group at position 3 of
the 2-pyrones is also an effective way of inducing the
fluorescence in the solid state. The fluorescence was more
intense than that of the corresponding cyano compounds.
Remarkably, the fluorescence of the sulfonyl compound
(9b) was 11 times higher than that of the standard
compound (AlQ3). Contrary to expectations, the electron-
withdrawal seems not to be the cause of this phenomenon.
A detailed structural analysis of 8a was carried out using
X-ray crystallography (Figure 3, 4). The intra-molecular
distances between the non-bonded
S
and
O
(SMe…COOMe) was 2.735 Å, which is smaller than the
sum of the van der Waals radii of O and S (3.25 Å).
Similar strong interactions have been reported previously
for other compounds, and the distances were in the range
of 2.41-2.78 Å. The distance between the non-bonded O
and O (COOMe…C=O) was determined in ORTEP to be
2.713 Å. The eight central atoms, S(18), C(7), C(8), C(9),
C(10), C(11), C(12), and C(14), were almost planar. The
molecules were stacked along the c-axis due to their ꢀ–ꢀ
interaction force. The shortest intermolecular distance was
3.345 Å between O(13) and C(5), which would reflect the
distance of the charge transfer complex in chloranyl-
tetramethyl p-phenylendiamine (3.26 Å).
Next in importance is the effect of the electron-donating
substituent at position 4 and the electron-withdrawing
substituent at position 3. The light emission was intense in
the 2H-pyrones with electron donating substituents at
position 4. It is said that sulfur atoms in fluorescent
compounds generally weaken the fluorescence [6].
Figures 3. ORTEP Drawing of 8a.

Jan-Feb 2007
Synthesis and Fluorescence of 2H-Pyrone derivatives
121
For Organic Light-Emitting Diodes(OLED)
Figure 4. Asymmetric unit of 8a.
In the present study, the pyrone derivatives showed almost
no fluorescence in solution, although these compounds
showed strong fluorescence in the solid state. Remarkably, 4-
dimethylamino-6-(4-dimethylaminophenyl)-2-oxo-2H-
pyran-3-carbonitrile (12l), 6-(4-N,N-dimethylaminophenyl)-
4-morpholino-2-oxo-2H-pyran-3-carbonitrile (12n) and 6-(4-
dimethylaminophenyl)-4-pyrrolidino-2-oxo-2H-pyran-3-
carbonitrile (12m), also showed strong fluorescence in
ethanol, and the fluorescent quantum yields were 0.57, 0.45,
and 0.70 respectively. These compounds will be utilized as
fluorescent materials in an oxalate chemiluminescence
system [7]. A detailed structural analysis of 12l was carried
out using X-ray crystallography (Figure 5-8). The shortest
intermolecular distance in 4-amino-6-(4-dimethylamino-
phenyl)-2H-pyrone was found to be 3.120 Å between O(13)
and N(37). In addition, because the intermolecular distances
between O(13) and C(32) and between O(13) and C(38) are
3.236 Å and 3.293 Å respectively, intermolecular ꢀ electron
interaction can take place. Moreover, we think that the array
of molecules resembles the CT complex because the
intermolecular distance of the CT complex is 3.21 Å, and
that a very strong ꢀ electron interaction works because the
shortest intramolecular distance is 3.120 Å. We speculate
that the dimethylamino group at position 6 of the phenyl
group and the dimethylamino group at position 4 of the
pyrone ring are almost planar due to their torsion angles. On
the other hand, it appears that the angle of twisting between
the pyrone ring and a phenyl ring bearing the dimethylamino
group was approximately 10 degrees. Moreover, 12l has a
structure that allows easy intramolecular charge movement,
as shown in Figure 9; we believe that it is a betaine structure
which might explain the uncommonly strong fluorescence.
Figures 6. Asymmetric unit of 12l.
1.444
1.456
1.426
N
1
.
3 5 3
1.4
NC
3
6
1.410
1 . 3 3 8
1 . 4 0 5
1.3
1.460
1
1.22
7
7
1.391
1.375
O
O
1.369
1.3
9
6
1.372
1.362
7
0
N
1.446
1.4
1 . 4 3 3
Figures 7. Bond length(Å) of 12
1
23.3
N
121.3
118.8
124.3
126
.1
NC
116.9
121.1
112.8
127.1
121.0
118.2
121.0
127.2
121.7
O
122.3
116.7
121.8
O
111.8
121.2
121.1
.4
122.4
116.6
121
120.3
N
121.3
122.0
116.8
120.7
Figures 8. Bond angles(°) of 12l.
N+
N
CN
CN
O-
O
O-
O
N+
N
Figures 5. ORTEP Drawing of 12l.
Figure 9. Betaine Strucuture of 12l.

122
N. Mizuyama, Y. Murakami, S. Kohra, K. Ueda, K. Hiraoka, J. Nagaoka,
K. Takahashi, Y. Shigemitsu and Y. Tominaga
Vol 44
were recorded using potassium bromide pellets on a JASCO 810
or Shimazu IR-460 spectrometer, and the ultraviolet (UV)
absorption spectra were determined in 95% ethanol on a Hitachi
323 spectrometer. The fluorescence spectra were determined on
Shimazu UV3100. The nuclear magnetic resonance (NMR)
spectra were obtained on Gemini 300 NMR (300 MHz) and 500
NMR (500 MHz) spectrometers with tetramethylsilane as the
internal standard. The mass spectra (MS) were recorded on
JOEL DX-303 mass spectrometers. Microanalyses were per-
formed by H. Mazume on a Yanaco M-5 or Perkin Elmer 2002
at Nagasaki University. All chemicals were reagent-grade and
used without further purification unless otherwise specified.
Method of Fluorescence Measurement. In the Solid State.
A powder sample of the subject compound was heaped on a
tray. After covering the sample with a quartz plate, the tray was
fixed in the fluorescence spectrometer. After setting the
fluorescence wavelength, the excitation spectrum was
determined through scanning at the fluorescence wavelength.
Similarly, the fluorescence spectrum was obtained after
scanning at the excitation wavelength. Then, the excitation
wavelength was determined and the fluorescence spectrum was
measured.
Lastly, we describe about the twist angle between the
aryl and pyranyl groups in these fluorescent 2-pyrans. The
aryl group at position 6 on the pyrone ring in compounds
showing strong fluorescence was found to be twisted
relative to the pyrone ring at angle of 25 degrees. We
hypothesized that the angle of twisting is an important
factor of fluorescence, and the result of the X-ray
crystallographyic analysis (ORTEP) suggests that the
structure with minimum energy in the ground state has a
twist angle of 25 degrees. These results agree well with
the results of our calculations using MOPAC and Stork's
shift in our measurement analysis. The optimized
molecular structure of 8a was calculated by using
MOPAC (AM1), as summarized in Figures 10. It is
reasonable to assume that the design of fluorescent
materials will be possible if the correlation between the
relative fluorescence intensity and the HOMO and LUMO
energies is clarified. This is a future research topic.
The relative fluorescence intensity was determined using
AlQ3 as the standard sample. The fluorescence of the standard
sample and all subject compounds were measured at 272 nm
excitation.
In Solution. The fluorescence quantum yields of the subject
compounds were compared with those of 9,10-diphenyl-
anthracene or anthracene, which was used as the standard. The
concentration of the measured samples in the excitation
wavelength region was adjusted using a molar absorption
coefficient of 0.05. The fluorescence spectra in solution were
obtained in
a manner similar to that described for the
Figures 10. Calculated structure of 8a (by MOPAC/AM1).
measurement in the solid states. The quantum yields of 9,10-
diphenylanthracene and anthracene were ꢀ=0.81 and ꢀ=0.25 at
366nm and 254 nm excitation, respectively.
Conclusion. The 2H-pyrone derivatives synthesized
through the reaction of aryl acety compounds with ketene
dithioacetals in the presence of sodium hydroxide showed
very strong fluorescence in the solid state. The light-
emitting region of these 2H-pyrones was 440-630 nm in
the solid state. The structure-activity relationship in these
fluorescent 2H-pyrone derivatives was also clarified. The
presence of an amino group at position 4 on the aryl group
shifts the light-emitting region toward shorter
wavelengths. 2-Pyrone derivatives bearing an electron-
donating group a position 4 and an electron-withdrawing
group at position 3 on the 2-pyrone ring are fluorescent
both in solution and in the solid state. The aryl group at
position 6 on the 2-pyrone ring in compounds showing
strong fluorescence was twisted relative to the 2-pyrone
ring at an angle of 25 degrees. We believe that this twist
angle is an important factor of fluorescence.
4-Methylthio-2-oxo-6-phenyl-2H-pyran-3-carbonitrile (3a).
A mixture of 10 mmoles of acetophenone 2a and 10 mmoles of
ketenedithioacetal 1a, 20 mmoles of powdered sodium
hydroxide, and 30 ml of DMSO was stirred at room temperature
for 3 hours. The reaction mixture was poured into 300 ml of ice-
water and the whole was stirred at room temperature for 30
minutes. The yellow precipitates that appeared were collected by
filtration, washed with water, and recrystallized from a mixture
of toluene and methanol to give 1.48 g (6.1 mmoles) of 4-
methylthio-2-oxo-6-phenyl-2H-pyran-3-carbonitrile (3a) as
yellow needles, mp 200-201°, in 61% yield [4]. Previously, we
used potassium hydroxide as a base and new compounds were
1
only showed in here. H-nmr (deuteriochloroform) ꢁ: 2.82 (s,
3H, SMe), 7.15 (s, 3H, 5-H), 7.52-7.76 (m, 3H, 3', 4' and 5'-H),
7.84-7.99 (m, 2H, 2', 6'-H)[4].
6-(2-Methoxyphenyl)-4-methylthio-2-oxo-2H-pyran-3-carbo-
nitrile (3b). This compound (0.79 g, 2.9 mmoles) was obtained
in 58% yield from 1a (1.02 g, 5.0 mmoles) and 2b (0.75 g, 5.0
mmoles) in a manner similar to that described for the
preparation of 3a. An analytical sample was recrystallized from
methanol to give yellow needles, mp 209-211°; ir (potassium
bromide) ꢂ max cm-1: 2200 (CN), 1700 (C=O), 1580, 1550, 1475,
1430, 1330, 1270, 1240, 1160, 1125, 10 50, 1030, 1005;
uv(ethanol) ꢃ max nm (log ꢄ):254 nm (4.22), 317 nm (4.21), 387
EXPERIMENTAL
The identification of compounds and the measurement of their
properties were carried out using the following general
procedures and equipment. All melting points were determined
in a capillary tube and are uncorrected. The infrared (IR) spectra
1
nm (4.35); H-nmr (deuteriochloroform) ꢁ: 2.67 (s, 3H, SMe),
3.99 (s, 3H, OMe), 7.04 (d, 1H, 6'-H, J=8.5 Hz), 7.11 (dd, 1H,

Jan-Feb 2007
Synthesis and Fluorescence of 2H-Pyrone derivatives
123
For Organic Light-Emitting Diodes(OLED)
4'-H, J=7.4, 8.2 Hz), 7.37 (s, 1H, 5-H), 7.52 (dd, 1H, 5'-H, J=8.2,
8.5 Hz), 8.00 (d, 1H, 3'-H, J=7.4 Hz); ms m/z: 274 (M++1, 17),
273 (M+, 100), 245 (41), 136 (10), 135 (82), 111 (11), 97 (17),
96 (10), 95 (12), 92 (18), 85 (15), 84 (10), 83 (21), 82 (11), 81
(14), 77 (32), 75 (10), 71 (24), 70 (11), 69 (32), 67 (11), 57 (38),
56 (11), 55 (31), 44 (18), 43 (34). Anal. Calcd. for C14H11NO3S:
C, 61.53; H, 4.06; N, 5.12. Found: C, 61.56; H, 4.19; N, 5.04.
6-(3-Methoxyphenyl)-4-methylthio-2-oxo-2H-pyran-3-carbo-
nitrile (3c). This compound (0.72 g, 2.65 mmoles) was obtained
in 53% yield from 1a (1.02 g, 5.0 mmoles) and 2c (0.75 g, 5.0
mmoles) in a manner similar to that described for the
preparation of 3a. An analytical sample was recrystallized from
methanol to give yellow needles, mp 181-183°; ir(potassium
bromide) ꢀmax cm-1: 2210 (CN), 1700 (C=O), 1580, 1480, 1420,
1340, 1290, 1260, 1200, 1180, 1175, 1070; uv(ethanol) ꢁ maxnm
(log ꢂ): 218 nm (4.36), 254 nm (4.22), 323 nm (4.29), 369 nm
1050, 1010; uv(ethanol) ꢁ maxnm (log ꢂ): 221 nm (4.51), 254 nm
(4.17), 323 nm (4.29), 402 nm (4.28); 1H-nmr (deuterio-
chloroform) ꢃ: 2.66 (s, 3H, SMe), 3.83 (s, 3H, OMe), 3.94 (s,
3H, OMe), 6.97 (d, 1H, 4'-H, J=9.1 Hz), 7.07 (dd, 1H, 3'-H,
J=3.3, 9.1 Hz), 7.43 (s, 1H, 5-H), 7.49 (dd, 1H, 6'-H, J=3.3 Hz);
ms m/z: 304 (M++1, 18), 303 (M+, 100), 275 (10), 165 (49), 107
(10), 275 (10), 57 (15), 55 (12), 44 (22), 43 (14). Anal. Calcd.
for C15H13NO4S: C, 59.40; H, 4.32; N, 4.62. Found: C, 59.28; H,
4.35; N, 4.49.
6-(3,4,5-Trimethoxyphenyl)-4-methylthio-2-oxo-2H-pyran-
3-carbonitrile (3h). This compound (0.93 g, 2.8 mmoles) was
obtained in 56% yield from 1a (1.02 g, 5.0 mmoles) and 2h
(1.05 g, 5.0 mmoles) in a manner similar to that described for
the preparation of 3a. An analytical sample was recrystallized
from methanol to give yellow leaflets, mp 208-210°; ir
(potassium bromide) ꢀmax cm-1: 2205 (CN), 1720(C=O), 1630,
1590, 1570, 1480, 1420, 1360, 1300, 1250, 1190, 1130, 1085;
1
(4.29); H-nmr(deuteriochloroform) ꢃ: 2.72 (s, 3H, SMe), 3.89
1
(s, 3H, OMe), 6.70 (s, 1H, 5-H), 7.09-7.13 (m, 1H, 5'-H), 7.38
(d, 1H, 2'-H , J=1.6 Hz), 7.43 (d, 2H, 4', 6'-H, J=5.2 Hz); ms m/z:
274 (M++1, 17), 273 (M+, 100), 245 (41), 135 (82), 83 (21), 77
(32), 71 (24), 69 (31), 57 (38), 55 (31), 43 (34), 41 (20). Anal.
Calcd. for C14H11NO3S: C, 61.53; H, 4.06; N, 5.12. Found: C,
61.59; H, 4.10; N, 5.05.
UV(ethanol) ꢁ maxnm (log ꢂ): 391 nm (4.33); H-nmr (deuterio-
chloroform) ꢃ: 2.73 (s, 3H, SMe), 3.94 (s, 9H, OMe), 6.60 (s,
1H, 5-H), 7.04 (s, 2H, 2', 6'-H); ms m/z: 345 (M++1, 20), 333
(M+, 100), 318 (14), 307 (10), 210 (16), 196 (10), 195 (75), 75
(15), 60 (14), 57 (17), 55 (14), 45 (11), 44 (100). Anal. Calcd.
for C16H15NO5S: C, 57.65; H, 4.54; N, 4.20. Found: C, 57.28; H,
4.49; N, 4.33.
6-(4-Methoxyphenyl)-4-methylthio-2-oxo-2H-pyran-3-carbo-
nitrile (3d). This compound was prepared by the previous
6-(4-Dimethylamino)phenyl-4-methylthio-2-oxo-2H-pyran-
3-carbonitrile (3i). This compound (1.22 g, 4.25 mmoles) was
obtained in 85% yield from 1a (1.02 g, 5 mmoles) and 2i (0.82
g, 5 mmoles) in a manner similar to that described for the
preparation of 3a. An analytical sample was recrystallized from
methanol to give orange needles, mp 249-251°; ir (potassium
bromide) ꢀmax cm-1: 2200 (CN), 1700 (C=O), 1610, 1575, 1525,
1380, 1355, 1205; uv(ethanol) ꢁ maxnm (log ꢂ): 465 nm (4.58);
1H-nmr (deuteriochloroform) ꢃ: 2.66 (s, 3H, SMe), 3.11 (s, 6H,
2xNMe2), 6.47 (s, 1H, 5-H), 6.69 (d, 2H, 3', 5'-H, J=9.0 Hz),
7.75 (d, 2H, 2', 6'-H, J=9.0 Hz); ms m/z: 287 (M++1, 20), 286
(M+, 100), 285 (10), 258 (27), 215 (10), 183 (12), 148 (54), 77
(10), 44 (15), 42 (11). Anal. Calcd. for C15H14N2O2S: C, 62.92;
H, 4.93; N, 9.76; S, 11.20. Found: C, 62.91; H, 4.95; N, 9.77; S,
11.16.
1
method in 64% yield, mp 215°; H-nmr(deuteriochloroform) ꢃ;
2.79 (s, 3H, SMe), 3.99 (s, 3H, OMe), 7.09 (s, 1H, 5-H), 7.15
(dd, 2H, 3', 5'-H, J=1.0, 8.0 Hz), 7.99 (dd, 2H, 2', 6'-H, J=1.0,
8.0 Hz)[4].
6-(2,4-Dimethoxyphenyl)-4-methylthio-2-oxo-2H-pyran-3-
carbonitrile (3e). This compound (0.50 g, 1.65 mmoles) was
obtained in 33% yield from 1a (1.02 g, 5.0 mmoles) and 2e
(0.90 g, 5.0 mmoles) in a manner similar to that described for
the preparation of 3a. An analytical sample was recrystallized
from methanol to give yellow needles, mp 220-222°;
ir(potassium bromide) ꢀmax cm-1: 2220 (CN), 1715 (C=O), 1610,
1580, 1555, 1480, 1460, 1320, 1280, 1250, 1205, 1180, 1125,
1050, 1015; uv(ethanol) ꢁ maxnm (log ꢂ): 259 nm (4.31), 326 nm
1
(4.18), 343 nm (4.25), 400 nm (4.60); H-nmr(deuteriochloro-
form) ꢃ:2.65 (s, 3H, SMe), 3.90 (s, 3H, OMe), 3.96 (s, 3H,
OMe) 6.54 (d, 1H, 3'-H, J=2.5 Hz), 6.63 (dd, 1H, 5'-H, J=2.5,
8.8 Hz), 7.30 (s, 1H, 5-H), 8.01 (d, 1H, 6'-H, J=8.8 Hz); ms m/z:
303 (M+, 100), 287 (10), 275 (34), 256 (16), 232 (10), 165 (58),
149 (10), 98 (10), 97 (18), 96 (10), 95 (12), 85 (16), 84 (12), 83
(21), 82 (11), 81 (13), 73 (14), 71 (23), 70 (12), 69 (27), 67 (11),
60 (14), 57 (40), 56 (13), 55 (32), 44 (94). Anal. Calcd. for
C15H13NO4S: C, 59.40; H, 4.32; N, 4.62. Found: C, 59.11; H,
4.62; N, 4.32.
6-(3,4-Dimethoxyphenyl)-4-methylthio-2-oxo-2H-pyran-
3-carbonitrile (3g). This compound was prepared by the
previous method in 40% yield, mp 221°; 1H-nmr
(deuteriochloroform) ꢃ; 2.84 (s, 3H, SMe), 4.04 (s, 6H, OMe),
7.12 (s, 1H, 5-H), 7.16 (d, 1H, 5'-H, J=8.0 Hz), 7.61 (d, 1H, 2'-
H, J=1.5 Hz) [4].
6-(2,5-Dimethoxyphenyl)-4-methylthio-2-oxo-2H-pyran-3-
carbonitrile (3f). This compound (0.41 g, 1.35 mmoles) was
obtained in 27% yield from 1a (1.02 g, 5.0 mmoles) and 2f (0.90
g, 5.0 mmoles) in a manner similar to that described for the
preparation of 3a. An analytical sample was recrystallized from
methanol to give yellow needles, mp 225-226°; ir (potassium
bromide) ꢀmax cm-1: 3150, 2920, 2820, 2220 (CN), 1695 (C=O),
1560, 1480, 1360, 1310, 1260, 1250, 1230, 1190, 1165, 1130,
6-(4-Bromophenyl)-4-methylthio-2-oxo-2H-pyran-3-carbo-
nitrile (3j). This compound was prepared by the previous
method in 42% yield, mp 230°; H-nmr(deuteriochloroform) ꢃ;
2.81 (s, 3H, SMe), 7.18 (s, 1H, 5-H), 7.40 (d, 2H, 3', 5'-H, J=8.0
Hz), 7.95 (d, 2H, 2', 6'-H, J=8.0 Hz)[4].
1
6-(2-Chlorophenyl)-4-methylthio-2-oxo-2H-pyran-3-carbo-
nitrile (3k). This compound (0.90 g, 3.25 mmoles) was
obtained in 65% yield from 1a (1.02 g, 5 mmoles) and 2k (0.77
g, 5 mmoles) in a manner similar to that described for the
preparation of 3a. An analytical sample was recrystallized from
methanol to give yellow needles, mp 185-186°; ir (potassium
bromide) ꢀmax cm-1: 2220 (CN), 1720 (C=O), 1605, 1495, 1440,
1340, 1320, 1280, 1260, 1180, 1080, 1040; uv(ethanol) ꢁ maxnm
1
(log ꢂ): 240 nm (4.23), 314 nm (4.29), 354 nm (4.18); H-nmr
(deuteriochloroform) ꢃ: 2.68 (s, 3H, SMe), 6.93(s, 1H, 5-H),
7.43-7.56(m, 3H, 4', 5' and 6'-H), 7.75(dd, 1H, 3'-H, J=1.9, 7.7
Hz); ms m/z: 279 (M++2, 39), 278 (M++1, 17), 277 (M+,100),
251 (24), 249 (65), 139 (91), 111 (48), 75 (42), 57 (26), 44 (15),
43 (20). Anal. Calcd. for C13H8NO2SCl: C, 56.22; H, 2.90; N,
5.04. Found: C, 56.24; H, 3.09; N, 4.97.
6-(4-Chlorophenyl)-4-methylthio-2-oxo-2H-pyran-3-carbo-
nitrile (3l). This compound was prepared by the previous
1
method in 44% yield, mp 240°; H-nmr (deuteriochloroform) ꢃ:

124
N. Mizuyama, Y. Murakami, S. Kohra, K. Ueda, K. Hiraoka, J. Nagaoka,
K. Takahashi, Y. Shigemitsu and Y. Tominaga
Vol 44
2.73 (s, 3H, SMe), 6.86 (s, 1H, 5-H), 7.58 (dd, 2H, 3', 5'-H,
J=1.0, 8.0 Hz), 7.91 (dd, 2H, 2', 6'-H, J=1.0, 8.0 Hz) [4].
J=1.8 Hz); ms m/z: 294 (M++1, 15), 293 (M+, 64), 265 (32), 155
(100), 127 (82), 69 (48), 75 (20), 69 (20), 57 (34), 55 (22), 44
(24), 43 (29). Anal. Calcd.for C17H11NO2S: C, 69.61; H, 3.78;
N, 4.77. Found: C, 69.31; H, 3.70; N, 4.83.
4-Methylthio-6-2-oxo-(3-pyridyl)-2H-pyran-3-carbonitrile (3q).
This compound was prepared by the previous method in 58%
yield, mp 192°; 1H-nmr(deuteriochloroform) ꢂ; 2.88 (s, 3H,
SMe), 7.50 (s, 1H, 5-H), 8.34 (dd, 1H, 5'-H, J=7.0, 8.0 Hz), 9.06
(d, 1H, 6'-H, J=7.0 Hz), 9.25 (dd, 1H, 4'-H, J=1.0, 8.0 Hz), 9.61
(d, 1H, 2'-H, J=1.0 Hz) [4].
6-(2-Biphenyl)-4-methylthio-2-oxo-2H-pyran-3-carbonitrile
(3m). This compound (1.40 g, 4.4 mmoles) was obtained in 88%
yield from 1a (1.02 g, 5.0 mmoles) and 2m (0.98 g, 5.0 mmoles)
in a manner similar to that described for the preparation of 3a. An
analytical sample was recrystallized from methanol to give
yellow leaflets, mp 273-275°; ir (potassium bromide) ꢀmax cm-1:
3100, 2275, 2210 (CN), 1710 (C=O), 1590, 1555, 1480, 1430,
1410, 1345, 1200, 1185, 1060; uv (ethanol) ꢁ max nm: 388, 350,
267, 240; 1H-nmr (deuteriochloroform) ꢂ: 2.75 (s, 3H, SMe), 6.76
(s, 1H, 5-H), 7.38-7.55 (m, 3H, 3'', 4'' and 5''-H), 7.65 (d, 2H, 2",
6"-H, J=7.2 Hz), 7.75 (d, 2H, 3', 5'-H, J=8.5 Hz), 7.96 (d, 2H, 2',
6'-H, J=8.2 Hz); ms m/z: 320 (M++1, 24), 319 (M+, 100), 291
(38), 181 (38), 153 (20), 152 (31), 71 (21), 69 (24), 57 (35), 55
(23), 44 (60), 43 (27). Anal. Calcd. for C19H13NO2S: C, 71.45; H,
4.10; N, 4.39. Found: C, 71.49; H, 4.29; N, 4.52.
4-Methylthio-2-oxo-6-(2-thienyl)-2H-pyran-3-carbonitrile
(3r). This compound was prepared by the previous method in
68% yield, mp 253°; 1H-nmr(deuteriochloroform) ꢂ; 2.73 (s, 3H,
SMe), 6.97 (s, 1H, 5-H), 7.24 (dd, 1H, 4'-H, J=3.0, 5.0 Hz), 7.86
(d, 1H, 5'-H, J=5.0 Hz), 7.98 (d, 1H, 3'-H, J=3.5 Hz)[4].
6-(2-Benzothienyl)-4-methylthio-2-oxo-2H-pyran-3-carbo-
nitrile (3s). This compound (1.26 g, 4.2 mmoles) was obtain-
ed in 84% yield from 1a (1.02 g, 5.0 mmoles) and 2s (0.88 g, 5.0
mmoles) in a manner similar to that described for the
preparation of 3a. An analytical sample was recrystallized from
methanol to give orange leaflets, mp 287-289°; ir(potassium
bromide) ꢀmax cm-1: 2205 (CN), 1710 (C=O), 1640, 1580, 1510,
1470, 1340, 1170; uv(ethanol) ꢁ max nm(log ꢃ): 205 nm (4.37),
6-(4-Cyanophenyl)-4-methylthio-2-oxo-2H-pyran-3-carbo-
nitrile (3n). This compound (0.88 g, 3.3 mmoles) was prepared
in 66% yield from 1a (1.02 g, 5.0 mmoles) and 2n (0.73 g, 5.0
mmoles) in a manner similar to that described for the
preparation of 3a. An analytical sample was recrystallized from
methanol to give yellow needles, mp 251-254°; ir (potassium
bromide) ꢀmax cm-1: 2235 (CN), 2200 (CN), 1700 (C=O), 1610,
1575, 1525, 1380, 1355, 1205; uv(ethanol) ꢁ maxnm (log ꢃ): 259
nm (4.06), 332 nm (4.12), 370 nm (3.96), 450 nm (2.22); 1H-nmr
(deuteriodimethylsulfoxide) ꢂ: 2.52 (s, 3H, SMe), 7.40 (s, 1H,
5-H), 8.04 (d, 2H, 2', 6'-H, J=8.7 Hz), 8.24 (d, 2H, 3', 5'-H, J=8.7
Hz); ms m/z: 270 (M++2, 6), 269 (M++1, 17), 268 (M+, 100), 253
(12), 241 (12), 240 (77), 197 (19), 166 (14), 149 (29), 130 (66),
102 (55). Anal. Calcd. for C14H8N2O2S: C, 62.68; H, 3.01; N,
10.44; S, 11.95. Found: C, 62.51; H, 3.13; N, 10.21; S, 11.92.
4-Methylthio-6-(1-naphthyl)-2-oxo-2H-pyran-3-carbonitrile
(3o). This compound (0.85 g, 2.90 mmoles) was obtained in
58% yield from 1a (1.02 g, 5.0 mmoles) and 2o (0.85 g, 5.0
mmoles) in a manner similar to that described for the
preparation of 3a. An analytical sample was recrystallized from
methanol to give yellow leaflets, mp 222-224°; ir (potassium
bromide) ꢀmax cm-1: 2220 (CN), 1700 (C=O), 1585, 1480, 1420,
1390, 1360, 1315, 1260, 1230, 1170, 1020; uv(ethanol) ꢁ
1
269 nm (4.01), 408 nm (4.40); H-nmr(deuteriochloroform) ꢂ:
2.73 (s, 3H, SMe), 6.58 (s, 1H, 5-H), 7.45-7.50 (m, 2H, benzo-
thienyl 5', 6'-H, J=1.6, 6.6 Hz), 7.85-7.91 (m, 2H, benzothienyl
4', 7'-H, J=1.6, 8.5 Hz), 8.08 (s, 1H, benzothienyl 3'-H); ms m/z:
300 (M++1, 23), 299 (M+, 100), 272 (11), 271 (47), 228 (16),
196 (13), 161 (35), 133 (15), 89 (25), 55 (10), 44 (28), 43 (10).
Anal. Calcd. for C15H9NO2S2: C, 60.18; H, 3.03; N, 4.68. Found:
C, 59.25; H, 2.88; N, 4.71.
6-(2-Furyl)-4-methylthio-2-oxo-2H-pyran-3-carbonitrile
(3t). This compound (0.35 g, 1.5 mmoles) was obtained in 30%
yield from 1a (1.02 g, 5.0 mmoles) and 2t (0.55 g, 5.0 mmoles)
in a manne similar to that described for the preparation of 3a. An
analytical sample was recrystallized from methanol to give
yellow needles, mp 200-202°; ir(potassium bromide) ꢀmax cm-1:
3450, 2370, 2340, 2210 (CN), 1720 (C=O), 1620, 1540, 1480,
1460, 1420, 1320, 1250, 1175, 1095, 1005; uv(ethanol) ꢁ
max nm(log ꢃ): 220 nm (4.11), 261 nm (4.25), 344 nm (4.36), 395
1
1
max nm(log ꢃ): 289 nm (4.00), 371 nm (4.22); H-nmr (deuterio-
nm (4.42); H-nmr (deuteriochloroform) ꢂ: 2.70 (s, 3H, SMe),
chloroform) ꢂ: 2.68 (s, 3H, SMe), 6.64 (s, 1H, 5-H), 7.54-7.72
(m, 3H, naphthyl 3', 6' and 7'-H), 7.75 (d, 1H, naphthyl 2'-H,
J=9.0 Hz), 7.95(dd, 1H, naphthyl 4'-H, J=2.2, 9.0 Hz), 8.05 (d,
1H, naphthyl 8'-H, J=8.0 Hz), 8.15 (dd, 1H, naphthyl 5'-H,
J=0.5, 8.4 Hz); Ms m/z: 294 (M++1, 22), 293 (M+, 100), 265
(38), 155 (57), 127 (61), 71 (21), 57 (31), 44 (22), 43 (22).
Anal. Calcd. for C17H11NO2S: C, 69.61; H, 3.78; N, 4.77. Found:
C, 69.70; H, 3.70; N, 4.83.
6.65 (d, 1H, furyl 3'-H, J=0.8 Hz), 6.66 (s, 1H, 5-H), 7.26 (m,
1H, fury 4'-H), 7.64 (d, 1H, furyl 5'-H, J=1.9 Hz); ms m/z: 234
(M++1, 14), 233 (M+, 100), 205 (45), 162 (27), 95 (72), 75 (10),
45 (5). Anal. Calcd.for C11H7NO3S: C, 56.65; H, 3.03; N, 6.01.
Found: C, 56.78; H, 3.14; N, 6.06.
6-[2-(5-Methylfuryl)]-4-methylthio-2-oxo-2H-pyran-3-
carbonitrile (3u). This compound (0.54 g, 2.2 mmoles) was
obtained in 44% yield from 1a (1.02 g, 5.0 mmoles) and 2u
(0.62 g, 5.0 mmoles) in a manner similar to that described for
the preparation of 3a. An analytical sample was recrystallized
from methanol to give yellow needles, mp 206-207°; ir
(potassium bromide) ꢀmax cm-1: 3450, 2220 (CN), 1710 (C=O),
1600, 1570, 1520, 1470, 1380, 1360, 1220, 1190, 1090, 1030,
1000; uv(ethanol) ꢁ maxnm(log ꢃ): 225 nm (4.03), 265 nm (4.08),
4-Methylthio-6-(2-naphthyl)-2-oxo-2H-pyran-3-carbonitrile
(3p). This compound (1.10 g, 3.75 mmoles) was obtained in
75% yield from 1a (1.02 g, 5.0 mmoles) and 2p (0.85 g, 5.0
mmoles) in a manner similar to that described for the
preparation of 3a. An analytical sample was recrystallized from
methanol to give yellow leaflets, mp 245-247°; ir (potassium
bromide) ꢀmax cm-1: 2225 (CN), 1710 (C=O), 1590, 1490, 1430,
1380, 1345, 1320, 1280, 1190, 1130, 1060; uv(ethanol)
ꢁ max nm(log ꢃ): 289 nm (3.96), 299 nm (3.97), 337 nm (4.14),
352 nm (4.15), 370 nm (4.17);1H-nmr(deuteriochloroform)ꢂ:
2.77 (s, 3H, SMe), 6.84 (s, 1H, 5-H), 7.59-7.64 (m, 2H, naphtyl
6', 7'-H), 7.82 (dd, 1H, naphthyl 3'-H, J=1.8, 9.0 Hz), 7.88-7.98
(m, 3H, naphthyl 4', 5' and 8'-H), 8.50 (d, 1Hd, naphthyl 1'-H,
1
349 nm (4.22), 405 nm (4.47); H-nmr (deuteriochloroform) ꢂ:
2.44 (s, 3H, furyl-Me), 2.69 (s, 3H, SMe), 6.26 (d, 1H, furyl 3'-
H, J=3.5 Hz), 6.55 (s, 1H, 5-H), 7.16 (d, 1H, fury 4'-H, J=3.5
Hz); ms m/z:249 (M++2, 7), 248 (M++1, 15), 247 (M+, 100), 220
(6), 219 (42), 176 (34), 144 (9), 109 (22),53 (5). Anal. Calcd.for
C12H9NO3S: C, 58.29; H, 3.67; N, 5.66. Found: C, 58.63; H,
3.74; N, 5.85.

Jan-Feb 2007
Synthesis and Fluorescence of 2H-Pyrone derivatives
125
For Organic Light-Emitting Diodes(OLED)
4-Methylthio-2-oxo-6-styryl-2H-pyran-3-carbonitrile (5a).
This compound was prepared by the previous method in 35%
yield, mp 221°; H-nmr (deuteriochloroform) ꢀ: 2.64 (s, 3H,
SMe), 6.24 (s, 1H, 5-H), 6.28 (d, 1H, =CH, J=16.0 Hz), 7.70 (d,
1H, =CH, J=16.0 Hz), 7.24-7.56 (m, 5H, phenyl-H)[4].
6-[(4-Methoxyphenyl)vinyl]-4-methylthio-2-oxo-2H-pyran-
3-carbonitrile (5b). This compound was prepared by the
previous method in 43% yield, mp 255°; 1H-nmr (deuterio-
chloroform) ꢀ: 2.68 (s, 3H, SMe), 6.76 (s, 1H, 5-H), 6.92 (d, 1H,
=CH, J=16.0 Hz), 6.96 (d, 2H, 3', 5'-H, J=8.0 Hz), 7.52 (d, 1H,
=CH, J=16.0 Hz), 7.64 (d, 1H, 2', 6'-H, J=8.0 Hz)[4].
212-216°; ir (potassium bromide) ꢄ cm-1: 2205 (CN), 1720
(C=O), 1590, 1565, 1494, 1460, 1330, 1280; uv(ethanol) ꢂ maxnm
(log ꢃ): 305 nm (4.48), 502 nm (4.19); 1H-nmr (deuterio-
chloroform) ꢀ: 2.62 (s, 3H, SMe), 6.18 (s, 1H, 5-H), 6.48 (d, 1H,
=CH, J=15.1 Hz), 6.99 (d, 2H, 3', 5'-H, J=8.8 Hz), 7.14 (d, 2H,
2', 6'-H, J=7.7 Hz), 6.60-7.56 (m, 10H, phenyl-H), 7.61 (d, 1H,
=CH, J=15.1 Hz); ms m/z: 437 (M++1, 12), 436 (M+, 38), 313
(8), 298 (7), 53 (33), 42 (100). Anal. Calcd for C27H20N2O2S: C,
74.29; H, 4.62; N, 6.42. Found. C, 74.22; H, 4.71; N, 6.43.
4-Methylthio-2-oxo-6-phenyl-2H-pyran-5-carbonitrile (7).
A mixture of 0.73 g (5.0 mmoles) of benzoylacetonitrile, 1.02 g
(5.0 mmoles) of 1a, 0.40 g (10 mmoles) powdered sodium
hydroxide, and 20 ml of DMSO was stirred at room temperature
for 1 hour. The reaction mixture was poured into 300 ml of ice-
water and the whole was stirred at room temperature for 1 hour.
The brown precipitates that appeared were collected by
filtration. A solution of this product and 10 ml of 10%
hydrochloric acid in 50 ml methanol was refluxed for 2 hours.
After reaction, the solvent was removed by evaporation with
rotary evaporator to give brown solid. This product was washed
with water, and recrystallized from methanol to give 0.15 g
(0.60 mmol, 12%) as yellow leaflets, mp 239-241°; ir (potassium
bromide) ꢁmax cm-1: 2220 (CN), 1740 (C=O), 1590, 1570, 1520,
1
6-[2-(4-N,N-dimethylaminophenyl)vinyl]-4-methylthio-2-oxo-
2H-pyran-3-carbonitrile (5c). A mixture of 1.89 g (10
mmoles) of 4c, 2.03 g (10 mmoles) of 1a, 0.8 g (20 mmoles)
powdered sodium hydroxide, and 40 ml of DMSO was stirred at
room temperature for 1 hour. The reaction mixture was poured
into 500 ml of ice-water and the whole was stirred at room
temperature for 2 hours. The brown precipitates that appeared
were collected by filtration, washed with water, and
recrystallized from a mixture of dichloromethane and methanol
to give 0.999 g (3.2 mmoles, 32% yield) of black violet leaflets,
mp 280-284°; ir(potassium bromide) ꢁmax cm-1: 2202 (CN), 1705
(C=O), 1595, 1560, 1465, 1360, 1162; uv(ethanol) ꢂ maxnm (log
ꢃ): 253 nm (4.19), 309 nm (4.29), 374 nm (3.67), 397 nm (3.64),
513 nm (4.67); 1H-nmr (deuteriochloroform) ꢀ: 2.65 (s, 3H,
SMe), 3.10 (s, 6H, 2xNMe2), 6.12 (s, 1H, 5-H), 6.44 (d, 1H,
=CH, J=15.7 Hz), 6.72 (d, 2H, 3', 5'-H, J=9.1 Hz), 7.48 (d, 2H,
2', 6'-H, J=9.1 Hz), 7.68 (d, 2H, =CH, J=15.7 Hz) ; ms m/z: 312
(M+, 100), 284 (6), 241 (5), 209 (15), 174 (16), 44 (35). Anal.
Calcd for C17H16N2O2S: C, 65.36; H, 5.16; N, 8.97. Found. C,
65.19; H, 5.14; N, 8.88.
1490, 1445, 1360, 1325, 1205, 1130, 1080, 1050, 1030, 1000;
1
uv(ethanol) ꢂ maxnm (log ꢃ): 266 nm (4.58), 296 nm (4.23); H-
nmr (deuteriodimethylsulfoxide) ꢀ: 2.55 (s, 3H, SMe), 5.94 (s,
1H, 3-H), 7.52-7.62 (m, 1H, 3', 4' and 5'-H), 8.24 (d, 2H, 2', 6'-H,
J=6.9 Hz); ms m/z: 244 (M++1, 11), 243 (M+, 71), 216 (15), 215
(100), 214 (10), 105 (60), 85 (13), 83 (11), 77 (65), 71 (18), 69
(15), 57 (31), 55 (19), 51 (24), 43 (25). Anal. Calcd. for
C13H9NO2S: C, 64.18; H, 3.73; N, 5.76. Found: C, 64.05; H, 3.78;
N, 5.83.
6-[2-(4-N,N-diethylamino)vinyl]-4-methylthio-2-oxo-2H-
pyran-3-carbonitrile (5d). A mixture of 2.17 g (10 mmoles) of
4d, 2.03 g (10 mmoles) of 1a, 0.80 g (20 mmoles) powdered
sodium hydroxide, and 40 ml of DMSO was stirred at room
temperature for 1 hour. The reaction mixture was poured into
500 ml of ice-water and the whole was stirred at room
temperature for 10 hours. The brown oil that appeared was
collected and crystallized by the treatment with methanol to give
0.89 g (2.6 mmoles, 26% yield) of black solids. An analytical
sample was recrystallized from a mixture of dichloromethane
and methanol to give black violet leaflets, mp 242-246°; ir
(potassium bromide) ꢁmax cm-1: 2202 (CN), 1700 (C=O), 1590,
1560, 1460, 1180; uv(ethanol) ꢂ maxnm (log ꢃ):252 nm (4.09),
315 nm (4.25), 374 nm (3.52), 397 nm (3.42), 529 nm (4.69);1H-
nmr (deuteriochloroform) ꢀ: 1.21 (t, 6H, N-CH2-CH3, J=7.1 Hz),
2.61 (s, 3H, SMe), 3.43 (q, 4H, N-CH2-, J=7.1 Hz), 6.07 (s, 1H,
5-H), 6.37 (d, 1H, =CH, J=15.7 Hz), 6.65 (d, 2H, 3', 5'-H, J=9.1
Hz,), 7.42 (d 2H, 2', 6'-H, J=9.1 Hz), 7.63 (d, 1H, =CH, J=15.7
Hz,); ms m/z: 340 (M+, 76), 325 (100), 297 (3), 158 (6).
Methyl 4-Methylthio-2-oxo-6-phenyl-2H-pyran-3-carbox-
ylic acid methylate (8a). This compound was prepared by the
previous method in 32% yield, mp 186°; 1H-nmr (deuteriochloro-
form) ꢀ: 2.78 (s, 3H, SMe), 4.13 (s, 3H, OMe), 7.40 (s, 1H, 5-H),
7.59-7.77 (m, 1H, 3', 4', 5'-H), 7.95-8.04 (m, 2H, 2', 6'-H) [4].
Methyl 6-(4-Methoxyphenyl)-4-methylthio-2-oxo-2H-
pyran-3-carboxylate (8d). This compound was prepared by the
previous method in 39% yield, mp 181°; 1H-nmr (deuterio-
chloroform) ꢀ; 2.79 (s, 3H, SMe), 4.04 (s, 3H, OMe), 4.19 (s,
3H, OMe), 7.23 (d, 2H, 3', 5'-H, J=10.0 Hz), 7.41 (s, 1H, 5-H),
8.11 (d, 2H, 2', 6'-H, J=10.0 Hz) [4].
4-Methylthio-6-phenyl-3-phenylsulfonyl-2H-pyran-2-one
(9a). A mixture of 0.60 g (5.0 mmoles) of acetophenone (2a),
1.27 g (10.0 mmoles) of 1c, 0.40 g (10 mmoles) powdered
sodium hydroxide, and 20 ml of DMSO was stirred at room
temperature for 2 hours. The reaction mixture was poured into
300 ml of ice-water and was acidified with 10% hydrochloric
acid. The brown precipitates that appeared were collected by
filtration, washed with water, and recrystallized from methanol
to give a mixture of 9a and 4-methylthio-6-phenyl-3-phenyl-
sulfonyl-2H-2-one (10a). These products were separated by
recrystallization from toluene and methanol. Compound 9a was
easily dissolved with toluene to give 0.967 g (2.70 mmoles, 54
%) of yellow cotton needles, mp 221-225°; ir (potassium
bromide) ꢄ cm-1: 1715 (C=O), 1605, 1570, 1490, 1450, 1310,
1215, 1150, 1085, 1060;1H-nmr (deuteriochloroform) ꢀ: 2.62 (s,
3H, SMe), 6.76 (s, 1H, 5-H), 7.45-7.55 (m, 5H, phenyl-H), 7.62
(dd, 1H, 4"-H, J=6.9, 7.5 Hz), 7.81 (d, 2H, 2', 6'-H, J=7.2 Hz),
8.72 (d, 2H, 2", 6"-H, J=7.2 Hz); ms m/z: 358 (M+, 6), 330 (10),
294 (31), 293 (71), 161 (18), 146 (11), 105 (94), 78 (14), 77
Anal. Calcd for C19H20N2O2S: C, 67.03; H, 5.92; N, 8.23.
Found. C, 66.89; H, 5.96; N, 8.20.
6-[2-(4-N,N-diphenylamino)vinyl]-4-methylthio-2-oxo-2H-
pyran-3-carbonitrile (5e). A mixture of 3.13 g (10 mmoles) of
4e, 2.03 g (10 mmoles) of 1a, 0.80 g (20 mmoles) powdered
sodium hydroxide, and 40 ml of DMSO was stirred at room
temperature for 1 hour. The reaction mixture was poured into
500 ml of ice-water and the whole was stirred at room
temperature for 2 hours. The brown precipitates that appeared
were collected by filtration, washed with water, and
recrystallized from a mixture of dichloromethane and methanol
to give 1.26 g (2.9 mmoles, 29% yield) of red brown leaflets, mp

126
N. Mizuyama, Y. Murakami, S. Kohra, K. Ueda, K. Hiraoka, J. Nagaoka,
K. Takahashi, Y. Shigemitsu and Y. Tominaga
Vol 44
(100), 52 (26), 44 (7). Anal. Calcd. for C18H14O4S2: C, 60.32; H,
3.94. Found: C, 60.16; H, 3.77.
6-(4-Methoxyphenyl)-4-methylthio-3-tolylsulfonyl-2H-pyran-
77 (38), 57 (28), 55 (20), 44 (100). Anal. Calcd. for C16H14N2O2:
C, 72.17; H, 5.30; N, 10.52. Found: C, 72.22; H, 5.43; N, 10.17.
4-Morpholino-2-oxo-6-phenyl-2H-pyran-3-carbonitrile
(12c). This compound was prepared by Method A in 48% yield,
mp 221°; ir(potassium bromide) ꢂmax cm-1: 2180 (CN), 1690
(C=O). Anal. Calcd. for C16H14N2O3: C, 68.07; H, 5.00; N, 9.92.
Found: C, 68.03; H, 4.90; N, 9.98[4].
2-one (9b).
A mixture of 0.75 g (5.0 mmoles) of 4-
methoxyacetophenone (2d), 1.50 g (10.0 mmoles) of 1d, 0.40 g
(10 mmoles) powdered sodium hydroxide, and 20 ml of DMSO
was stirred at room temperature for 2 hours. The reaction
mixture was poured into 300 ml of ice-water and was acidified
with 10% hydrochloric acid. The brown precipitates that
appeared were collected by filtration, washed with water, and
recrystallized from methanol to give a mixture of 9b and 6-(4-
methoxyphenyl)-4-methylthio-3-tolylsulfonyl-1H-pyridin-2one
(10b). These products were separated by recrystallization from
toluene and methanol. Compound 9b was easily dissolved with
toluene to give 1.12 g (2.8 mmoles, 56%) of yellow cotton
needles, mp 220-221°; ir (potassium bromide) ꢀ cm-1: 1720
(C=O), 1610, 1580, 1520, 1465, 1430, 1320, 1310, 1275, 1225,
1200, 1190, 1160, 1095, 1075, 1020;1H-nmr (deuteriochloro-
form) ꢁ: 2.42 (s, 3H, Me), 2.60 (s, 3H, SMe), 3.88 (s, 3H, OMe),
6.64 (s, 1H, 5-H), 6.97 (d, 2H, 3", 5"-H, J=8.8 Hz), 7.31 (d, 2H,
3', 5'-H, J=8.0 Hz), 7.72 (d, 2H, 2", 6"-H, J=8.8 Hz), 8.04 (d,
2H, 2', 6'-H, J=8.0 Hz); ms m/z: 403 (M++1, 9), 402 (M+, 33),
374 (32), 368 (10), 339 (12), 338 (38), 337 (100), 291 (10), 235
(10), 191 (15), 135 (73), 92 (12), 91 (19), 83 (10), 77 (15), 73
(11), 71 (11), 69 (13), 60 (12), 57 (19), 55 (17), 45 (38), 44 (69),
43 (22). Anal. Calcd. for C20H18O5S2: C, 59.68; H, 4.51. Found:
C, 60.28; H, 4.53.
4-N,N-Dimethylamino-6-(3-methoxyphenyl)-2-oxo-2H-
pyran-3-carbonitrile (12d). Method B: A mixture of 3c (1.37
g, 5.0 mmoles) and 3 ml of 50% dimethylamine solution was
heated at 150-200°; After reaction, the reaction mixture was
cooled, and then crystallized with 20 ml of methanol. The
crystallized product that appeared was collected by filtration to
give 0.54 g (2.0 mmoles, 40%) of 12d. This filtrate included by-
product of 15d. An analytical sample was recrystallized from
methanol to give colorless cotton needles, mp 198-199°; ir
(potassium bromide) ꢂmax cm-1: 2200 (CN), 1690 (C=O), 1640,
1590, 1560, 1495, 1470, 1415, 1270, 1235, 1205, 1170, 1120,
1060, 1035, 1005; uv(ethanol) ꢃ maxnm (log ꢄ): 220 nm (4.45),
241 nm (4.42), 309 nm (4.27), 324 nm (4.25); 1H-nmr (deuterio-
chloroform) ꢁ: 3.45 (s, 6H, NMe2), 3.87 (s, 3H, OMe), 6.41 (s,
1H, 5-H), 7.03-7.07 (m, 1H, 5'-H), 7.33 (m, 1H, 2'-H), 7.36 (m,
2H, 4', 6'-H); ms m/z: 271 (M++1, 14), 270 (M+, 76), 242 (12),
163 (10), 135 (25), 92 (13), 77 (16), 44 (19), 43 (10). Anal.
Calcd. for C15H14N2O3: C, 66.66; H, 5.22; N, 10.39. Found: C,
66.61; H, 5.29; N, 10.26.
6-(4-Methoxyphenyl)-4-N,N-dimethylamino-2-oxo-2H-
pyran-3-carbonitrile (12e). This compound (0.675 g, 2.5
mmoles) was obtained in 50% yield from 3d (1.37 g, 5 mmoles)
and 3 ml of 50% dimethylamine solution in a manner similar to
that described for the synthesis of 12b (Method B). An analytical
sample was recrystallized from methanol to give greenish yellow
needles, mp 194-196°; ir (potassium bromide) ꢂmax cm-1: 2330,
2200 (CN), 1685 (C=O), 1635, 1605, 1550, 1510, 1460, 1420,
1360, 1300, 1260, 1190, 1130, 1050, 1020; uv(ethanol) ꢃ maxnm
4-N,N-Dimethylamino-2-oxo-6-phenyl-2H-pyran-3-carbo-
nitrile (12a). Method A: A solution of 1.22 g (5 mmoles) of 3a,
1.26 g (10 mmoles) of 50% dimethylamine solution in 100 ml of
methanol was refluxed for 5 hours. After reaction, the solvent
was evaporated in the rotary evaporator and the resulting residue
was crystallized from methanol to give 0.56 g (2.35 mmoles) of
pale yellow product in 47% yield. This compound was
recrystallized from to give pale yellow needles (12a), mp 243-
246°, in 21% yield [4].
1
(log ꢄ): 233 nm (443), 332 nm (4.42); H-nmr (deuteriochloro-
Method B: A mixture of 1.22 g (5.0 mmoles) of 3a and 3 ml
of 50% dimethylamine solution was heated at 100°C for 10
minutes. After cooling, the reaction mixture was treated with 10
ml of methanol. The precipitate that appeared was collected by
filtration to give 0.68 g (1.5 mmoles, 29%) of yellow crystals
(12a). The solvent of filtration was evaporated in the rotary
evaporator to give the yellow residue. The crude product was
purified by silica gel chromatography. Elution with hexane-
toluene gave 0.59 g (2.4 mmoles, 48% yield) of pale yellow
crystlas (13a). This compound was recrystallized from methanol
to give yellow prisms, mp 99-101°.
form) ꢁ: 3.43 (s, 6H, NMe2), 3.87 (s, 3H, OMe), 6.30 (s, 1H, 5-H),
6.96 (d, 2H, 3', 5'-H, J=8.8 Hz), 7.77 (dd, 2H, 2', 6'-H, J= 8.8 Hz);
ms m/z: 271 (M++1, 13), 270 (M+, 70), 266 (11), 256 (10), 242
(14), 136 (11), 135 (100), 121 (11), 107 (10), 97 (13), 95 (10), 92
(11), 91 (10), 85 (11), 84 (119, 83 (17), 81 (14), 77 (15), 73 (12),
71 (18), 70 (11), 69 (29), 67 (10), 60 (15), 57 (32), 56 (12), 55
(31), 45 (27), 44 (87). Anal. Calcd. for C15H14N2O3: C, 66.66; H,
5.22; N, 10.36. Found: C, 66.26; H, 5.22; N, 10.16.
6-(4-Methoxyphenyl)-2-oxo-4-pyrrolidino-2H-pyran-3-
carbonitrile (12f). This compound (0.76 g, 2.55 mmoles) was
obtained in 51% yield from 3d (1.37 g, 5 mmoles) and 2 ml of
pyrrolidine in a manner similar to that described for the
preparation of 12b (Method B). An analytical sample was
recrystallized from methanol to give colorless leaflets, mp 259-
260°; ir (potassium bromide) ꢂmax cm-1: 2200 (CN), 1685 (C=O),
1640, 1605, 1540, 1510, 1450, 1420, 1350, 1310, 1250, 1180,
1130, 1060, 1030; uv(ethanol) ꢃ maxnm (log ꢄ): 233 nm (4.33),
331 nm (4.41); 1H-nmr (deuteriochloroform) ꢁ: 2.07 (br, 4H, N-
CH2-CH2-), 3.67 (br, 2H, N-CH2-), 3.87 (s, 3H, OMe), 4.11 (br,
2H, N-CH2-), 6.23 (s, 1H, 5-H), 6.95 (d, 2H, 3', 5'-H, J=9.1 Hz),
7.76 (d, 2H, 2', 6'-H, J=9.1 Hz); ms m/z: 297 (M++1, 19), 296
(M+, 93), 268 (29), 178 (23), 135 (74), 77 (20), 69 (41), 57 (23),
55 (24), 44 (100). Anal. Calcd. for C17H16N2O3: C, 68.91;H,
5.44; N, 9.45. Found: C, 69.03;H, 5.57;N, 9.46.
2-Oxo-6-phenyl-4-pyrrolidino-2H-pyran-3-carbonitrile
(12b). Method B: A mixture of 3a (1.22 g, 5.0 mmoles) and
pyrrolidine (20 mmoles) was heated at 150-200°; after reaction,
the reaction mixture was cooled, and then crystallized with 20
ml of methanol. The crystallized product that appeared was
collected by filtration to give 0.69 g (2.6 mmoles, 52%) of 12b.
This filtrate included by-product of 13b. An analytical sample
was recrystallized from methanol to give colorless needles, mp
287-289°; ir(potassium bromide) ꢂmax cm-1: 2200 (CN), 1685
(C=O), 1630, 1580, 1540, 1460, 1350, 1240, 1160, 1020;
uv(ethanol) ꢃ maxnm (log ꢄ): 224 nm (4.26), 228 nm (4.27), 248
1
nm (4.47), 308 nm (4.36); H-nmr (deuteriochloroform) ꢁ: 2.09
(br, 4H, N-CH2-CH2-), 3.69 (br, 2H, N-CH2-), 4.12 (br, 2H, N-
CH2-), 6.35 (s, 1H, 5-H), 7.47 (m, 3H, 3', 4' and 5'-H), 7.79 (m,
2H, 2', 6'-H); ms m/z: 266 (M+, 12), 243 (40), 215 (24), 105 (45),
6-(4-Methoxyphenyl)-4-morpholino-2-oxo-2H-pyran-3-
carbonitrile (12g). This compound was prepared by Method A

Jan-Feb 2007
Synthesis and Fluorescence of 2H-Pyrone derivatives
127
For Organic Light-Emitting Diodes(OLED)
in 42% yield, mp 273°; ir(potassium bromide) ꢀmax cm-1: 2180
(CN), 1680 (C=O). Anal. Calcd. for C17H16N2O4: C, 65.37; H,
5.16; N, 8.97. Found: C, 65.25; H, 5.00; N, 8.64 [4].
the preparation of 12b (Method B). An analytical sample was
recrystallized from methanol to give yellow needles, mp 265-
267°; ir (potassium bromide) ꢀmax cm-1: 2900, 2220 (CN), 1685
(C=O), 1640, 1610, 1550, 1460, 1360, 1210, 1165, 1115, 1060;
uv(ethanol) ꢁ maxnm (log ꢂ): 237 nm (4.37), 322 nm (3.96), 400
6-(4-Methoxyphenyl)-2-oxo-4-thiomorpholino-2H-pyran-3-
carbonitrile (12h). This compound (0.84 g, 2.55 mmoles) was
obtained in 51% yield from 3d (1.37 g, 5.0 mmoles) in manner
similar to that described for the preparation of 12b (Method B).
An analytical sample was recrystallized from methanol to give
colorless leaflets, mp 218-220°; ir (potassium bromide) ꢀmax
cm-1: 2900, 2200 (CN), 1720 (C=O), 1620, 1605, 1570, 1510,
1460, 1360, 1310, 1260, 1250, 1180, 1120, 1060, 1020;
1
nm (4.57); H-nmr (deuteriochloroform) ꢃ: 3.06 (s, 6H, NMe2),
3.40 (s, 6H, phenyl-NMe2), 6.20 (s, 1H, 5-H), 6.67 (d, 1H, 3', 5'-
H, J=9.1 Hz), 7.70 (d, 2H, 2', 6'-H, J=9.1 Hz); ms m/z: 284
(M++1, 6), 283 (M+, 25), 148 (32), 97 (11), 83 (14), 73 (13), 71
(14), 69 (19), 60 (12), 57 (28), 56 (10), 55 (27), 44 (100). Anal.
Calcd. for C16H17N3O2: C, 67.83; H, 6.05; N, 14.83. Found: C,
67.84; H, 6.12; N, 14.69.
1
uv(ethanol) ꢁ maxnm (log ꢂ): 236 nm (4.41), 339 nm (4.47); H-
nmr (deuteriochloroform) ꢃ: 2.87 (nt, 4H, S-CH2-, J=5.0 Hz),
3.88 (s, 3H, OMe), 4.13 (nt, 4H, N-CH2-, J=5.0 Hz), 6.33 (s, 1H,
5-H), 6.97 (d, 2H, 3', 5'-H, J=8.8 Hz), 7.77 (d, 2H, 2', 6'-H, J=8.8
Hz); ms m/z: 330 (M++2, 7), 329 (M++1, 21), 328 (M+, 100), 327
(10), 255 (24), 254 (13), 226 (16), 135 (89). Anal. Calcd. for
C17H16N2O3S: C, 62.18; H, 4.91; N, 8.53. Found: C, 62.17; H,
4.97; N, 8.51.
6-(4-N,N-Dimethylaminophenyl)-4-pyrrolidino-2-oxo-2H-
pyran-3-carbonitrile (12m). This compound (0.68 g, 2.2
mmoles) was obtained in 44% yield 3i (1.43 g, 5.0 mmoles) and
2 ml of pyrrolidine in a manner similar to that described for the
preparation of 12b (Method B). An analytical sample was
recrystallized from methanol to give yellow needles, mp 270-
271°; ir (potassium bromide) ꢀmax cm-1: 2220 (CN), 1680 (C=O),
1620, 1600, 1515, 1450, 1370, 1340, 1280, 1235, 1200, 1170,
1060, 1015; uv(ethanol) ꢁ maxnm (log ꢂ): 237 nm (4.47), 327 nm
6-(4-Methoxyphenyl)-2-oxo-4-phenethylamino-2H-pyran-
3-carbonitrile (12i). This compound was prepared by Method
A in 60% yield, mp 224°; ir (potassium bromide) ꢀmax cm-1: 3280
(NH), 2200 (CN), 1680 (C=O). Anal. Calcd. for C21H18N2O3: C,
72.82; H, 5.24; N, 8.09. Found: C, 72.77; H, 5.23; N, 7.85[4].
6-(2,5-Dimethoxyphenyl)-4-morpholino-2-oxo-2H-pyran-
3-carbonitrile (12j). This compound (1.33 g, 3.9 mmoles) was
obtained in 78% yield from 3f (1.52 g, 5.0 mmoles) and 2 ml of
morpholine in a manner similar to that described for the
preparation of 12a (Method A). An analytical sample was
recrystallized from methanol to give yellow leaflets, mp 185-
187°; ir (potassium bromide) ꢀmax cm-1: 2930, 2190 (CN), 1690
(C=O), 1620, 1535, 1500, 1465, 1440, 1400, 1310, 1280, 1260,
1240, 1205, 1180, 1060, 1010; uv(ethanol) ꢁ maxnm (log ꢂ): 246
1
(4.06), 396 nm (4.64); H-nmr (deuteriochloroform) ꢃ: 2.05 (s,
4H, N-CH2-CH2-), 3.06 (s, 6H, NMe2), 3.65 (m, 2H, N-CH2-),
4.08 (m, 2H N-CH2-), 6.13 (s, 1H, 5-H), 6.67 (d, 2H, 3', 5'-H,
J=9.1 Hz), 7.70 (d, 2H, 2', 6'- H, J=9.1 Hz); ms m/z: 310 (M++1,
10), 309 (M+, 45), 256 (11), 178 (10), 148 (29), 129 (10), 97
(13), 95 (11), 92 (10), 91 (28), 84 (10), 83 (17), 82 (10), 81 (14),
77 (13), 73 (14), 71 (13), 70 (11), 69 (27), 67 (14), 60 (12), 57
(25), 56 (10), 55 (32), 45 (12), 44 (100). Anal. Calcd. for
C18H19N3O2: C, 63.15; H, 5.30; N, 8.18. Found: C, 62.55; H,
5.29; N, 7.96.
6-(4-N,N-Dimethylaminophenyl)-4-morpholino-2-oxo-2H-
pyran-3-carbonitrile (12n). This compound (0.81 g, 2.5
mmoles) was obtained in 50% yield 3i (1.43 g, 5.0 mmoles) and
2 ml of morpholine in a manner similar to that described for the
preparation of 12a (Method A). An analytical sample was
recrystallized from methanol to give orange needles, mp 273-
275°; ir (potassium bromide) ꢀmax cm-1: 2900, 2850, 2195 (CN),
1680 (C=O), 1590, 1520, 1460, 1360, 1250, 1220, 1200, 1160,
1110, 1060; uv(ethanol) ꢁ maxnm (log ꢂ): 240 nm (4.30), 4.09 nm
(4.42); 1H-nmr (deuteriochloroform) ꢃ: 3.06 (s, 6H, NMe2), 3.84
(m, 6H, morpholino-H), 6.21 (s, 1H, 5-H), 6.68 (d, 2H, 3', 5'-H,
J=9.1 Hz), 7.70 (d, 2H, 2', 6'-H, J=9.1 Hz); ms m/z: 326 (M++1,
18), 325 (M+, 82), 286 (34), 149 (12), 148 (100), 105 (10), 77
(10), 57 (12), 55 (11), 44 (23), 43 (12), 42 (13). Anal. Calcd. for
C18H19N3O3: C, 66.45; H, 5.89; N, 12.91. Found: C, 66.34; H,
5.84; N, 12.61.
1
nm (4.35), 303 nm (4.22), 364 nm (4.15); H-nmr (deuterio-
chloroform) ꢃ: 3.82 (s, 3H, OMe), 3.87 (br, 8H, morpholino-H),
3.91 (s, 3H, OMe), 6.95 (d, 1H, 4'-H, J=9.1 Hz), 7.04 (dd, 1H,
4'-H, J=3.0, 9.1 Hz), 7.10 (s, 1H, 5-H), 7.44 (d, 1H, 6'-H, J= 3.0
Hz); ms m/z: 343 (M++1, 19), 342 (M+, 90), 165 (87), 97 (25),
83 (32), 81 (20), 71 (29), 69 (44), 57 (56), 56 (22), 55 (53), 45
(45), 44 (100). Anal. Calcd. for C18H18N2O5: C, 63.15; H, 5.30;
N, 8.18. Found: C, 62.55;H, 5.29;N, 7.96.
6-(3,4-Dimethoxyphenyl)-4-morpholino-2-oxo-2H-pyran-
3-carbonitrile (12k). This compound (1.18 g, 3.45 mmoles)
was obtained in 69% yield from 3g (1.52 g, 5.0 mmoles) and
2ml of morpholine in a manner similar to that described for the
preparation of 12a (Method A). An analytical sample was
recrystallized from methanol to give greenish yellow leaflets,
mp 243-245°; ir (potassiumbromide) ꢀmax cm-1: 2200 (CN), 1690
(C=O), 1625, 1600, 1525, 1510, 1475, 1465, 1445, 1410, 1360,
1280, 1260, 1235, 1210, 1160, 1120, 1060, 1020; uv(ethanol) ꢁ
6-(4-N,N-Dimethylaminophenyl)-4-thiomorpholino-2-oxo-
2H-pyran-3-carbonitrile (12o). This compound (0.99 g, 2.9
mmoles) was obtained in 58% yield from 3i (1.43 g, 5.0
mmoles) and 2 ml of thiomorpholine in a manner similar to that
described for the preparation of 12a (Method A). An analytical
sample was recrystallized from methanol to give orange leaflets,
mp 275-277°; ir (potassium bromide) ꢀmax cm-1: 2910, 2200
(CN), 1680 (C=O), 1600, 1520, 1460, 1370, 1300, 1275, 1255,
1220, 1200, 1170, 1120, 1060; uv(ethanol) ꢁ maxnm (log ꢂ): 410
1
maxnm (log ꢂ): 239 nm (4.26), 358 nm (4.25); H-nmr (deuterio-
chloroform) ꢃ: 3.89 (br, 8H, morpholino-H), 3.96 (s, 6H,
OMeX2), 6.32 (s, 1H, 5-H), 6.92 (d, 1H, 6'-H, J=8.5 Hz), 7.31
(d, 1H, J=2.2 Hz, 2'-H), 7.40 (dd, 1H, 5'-H, J=2.2, 8.5 Hz); ms
m/z: 343 (M++1, 23), 342 (M+, 98), 165 (98), 97 (26), 85 (25), 83
(28), 71 (32), 69 (34), 57 (55), 55 (39), 45 (100), 43 (42), 41
(30). Anal. Calcd. for C18H18N2O5: C, 63.15; H, 5.30; N, 8.18.
Found: C, 63.36; H, 5.33; N, 8.14.
4-N,N-Dimethylamino-6-(4-dimethylaminophenyl)-2-oxo-
2H-pyran-3-carbonitrile (12l). This compound (0.91 g, 3.2
mmoles) was obtained in 64% yield 3i (1.43 g, 5.0 mmoles) and
2 ml of dimethylamine in a manner similar to that described for
1
nm (4.57); H-nmr (deuteriochloroform) ꢃ: 2.83-2.87 (m, 4H,
thiomorpholino 2, 5-H), 3.07 (s, 6H, NMe2), 4.07-4.11 (m, 4H,
thiomorpholino 3, 4-H), 6.22 (s, 1H, 5-H), 6.97 (d, 2H, J=9.3
Hz, 3', 5'-H), 7.70 (d, 2H, 2', 6'-H, J=9.3 Hz); ms m/z: 341 (M+,
47), 286 (55), 111 (22), 97 (22), 85 (32), 84 (20), 81 (23), 71
(49), 70 (22), 69 (43), 57 (78), 56 (23), 55 (52), 44(100).

128
N. Mizuyama, Y. Murakami, S. Kohra, K. Ueda, K. Hiraoka, J. Nagaoka,
K. Takahashi, Y. Shigemitsu and Y. Tominaga
Vol 44
Anal. Calcd. for C18H19N3O2S: C, 63.32; H, 5.61; N, 12.31.
Found: C, 63.25; H, 5.57; N, 12.15.
(C=O), 1640, 1540, 1470, 1410, 1350, 1240, 1070, 1010;
1
uv(ethanol) ꢁ max nm (log ꢂ): 328 nm (4.56); H-nmr (deuterio-
6-(4-Bromophenyl)-4-pyrrolidino-2-oxo-2H-pyran-3-carbo-
nitrile (12p). This compound (0.91 g, 2.65 mmoles) was
obtained in 53% yield from 3j (1.61 g, 5.0 mmoles) and 2 ml of
pyrrolidine in a manner similar to that described for the
preparation of 12b (Method B). An analytical sample was
recrystallized from methanol to give yellow leaflets, mp 282-
284°; ir (potassium bromide) ꢀmax cm-1: 3090, 2990, 2210 (CN),
1690 (C=O), 1640, 1590, 1540, 1500, 1470, 1410, 1350, 1260,
1240, 1200, 1100, 1080, 1060, 1010; uv(ethanol) ꢁ maxnm (log
ꢂ): 231 nm (4.37), 250 nm (4.40), 315 nm (4.42); 1H-nmr
(deuteriochloroform) ꢃ: 2.11 (br, 4H, N-CH2-CH2-), 3.69 (m,
2H, N-CH2), 4.12 (m, 2H, N-CH2-), 6.33 (s, 1H, 5-H), 7.59 (d,
2H, 2', 6'-H, J=9.1 Hz), 7.66 (d, 2H, 3', 5'-H, J=9.1 Hz); ms m/z:
344 (M+, 10), 323 (38), 321 (37), 295 (23), 293 (24), 289 (32),
185 (26), 151 (20), 75 (21), 57 (27), 55 (21), 44 (100). Anal.
Calcd. for C16H13N2O2Br: C, 55.67; H, 3.80; N, 8.12. Found: C,
56.11; H, 3.92; N, 8.23.
chloroform) ꢃ: 2.10 (br, 4H, N-CH2-CH2-), 3.71 (br, 2H, N-
CH2-), 4.14 (br, 2H, N-CH2-), 6.39 (s, 1H, 5-H), 7.42-7.49 (m,
1H, 3'', 4'' and 5''-H), 7.61 (d, 2H, 2', 6'-H, J=8.5 Hz), 7.67 (d,
2H, 3', 5'-H, J=8.5 Hz), 7.87 (m, 2H, 2'', 6''-H); ms m/z: 343
(M++1, 22), 342 (M+, 71), 313 (22), 312 (37), 181 (39), 153 (22),
152 (29), 135 (56), 111 (30), 109 (23), 99 (21), 98 (26), 97 (44),
95 (34), 85 (46), 84 (26), 83 (54), 82 (20), 81 (34), 77 (20), 71
(33), 69 (60), 67 (30), 57 (100), 56 (30), 55 (72), 44 (99). Anal.
Calcd. for C22H18N2O2: C, 77.17; H, 5.30; N, 8.18. Found: C,
77.40; H, 5.44; N, 8.14.
6-(1-Naphthyl)-2-oxo-4-pyrrolidino-2H-pyran-3-carbo-
nitrile (12t). This compound (1.36 g, 4.3 mmoles) was obtained
in 86% yield from 3o (1.47g, 5.0 mmoles) and 2 ml of
pyrrolidine in a manner similar to that described for the
preparation of 12a (Method A). An analytical sample was
recrystallized from methanol to give yellow leaflets, mp 259-
261°; ir (potassium bromide) ꢀmax cm-1: 2950, 2850, 2200 (CN),
1700 (C=O), 1640, 1530, 1465, 1350, 1260, 1240, 1180, 1110,
1060, 1010; uv(ethanol) ꢁ max nm (log ꢂ): 218 nm (4.87), 320 nm
6-(4-Chlorophenyl)-4-pyrrolidino-2-oxo-2H-pyran-3-carbo-
nitrile (12q). This compound (0.83 g, 2.75 mmoles) was
obtained in 55% yield from 3l (1.39 g, 5.0 mmoles) and 2 ml of
pyrrolidine in a manner similar to that described for the
preparation of 12b (Method B). An analytical sample was
recrystallized from methanol to give yellow cotton needles, mp
288-290°; ir (potassium bromide) ꢀmax cm-1: 2200 (CN), 1685
(C=O), 1640, 1535, 1495, 1465, 1400, 1345, 1240, 1170, 1090,
1060, 1010; uv(ethanol) ꢁ maxnm (log ꢂ): 249 nm (4.41), 314 nm
1
(4.30); H-nmr (deuteriochloroform) ꢃ: 2.08 (br, 4H, N-CH2-
CH2-), 3.63 (m, 2H, N-CH2-), 4.17 (m, 2H, N-CH2-), 6.25 (s,
1H, 5-H), 7.52 (dd, 1H, naphtyl 3'-H, J=7.2, 8.5 Hz), 7.55-7.59
(m, 2H, naphtyl 6, 7-H), 7.66 (dd, 1H, naphtyl 4'-H, J=1.3, 7.2
Hz), 7.91 (m, 1H, naphtyl 5'-H), 8.06 (d, 1H, naphtyl 2'-H, J=8.5
Hz), 8.13 (m, 1H, naphtyl 8'-H); ms m/z: 317 (M++1, 17), 316
(M+, 66), 155 (65), 127 (60), 97 (26), 85 (24), 83 (26), 71 (35),
70 (33), 69 (38), 57 (55), 56 (20), 55 (44), 44 (100). Anal.
Calcd. for C20H16N2O2: C, 75.93; H, 5.10; N, 8.85. Found: C,
76.44; H, 5.34; N, 9.03.
1
(4.38); H-nmr (deuteriochloroform) ꢃ: 2.12 (br, 4H, N-CH2-
CH2-), 3.72 (br, 2H, N-CH2-), 4.16 (br, 2H, N-CH2-), 6.33 (s,
1H, 5-H), 7.46 (d, 2H, 2', 6'-H, J=8.5 Hz), 7.76 (d, 2H, 3', 5'-H,
J=8.5 Hz); ms m/z: 302 (M++2, 28), 301 (M++1, 28), 300 (M+,
75), 271 (22), 141 (23), 139 (61), 133 (20), 111 (36), 98 (20), 97
(37), 95 (25), 85 (32), 84 (20), 83 (38), 81 (28), 71 (46), 70 (43),
69 (49), 68 (26), 67 (27), 57 (70), 56 (23), 55 (57), 44 (100).
Anal. Calcd. for C16H13N2O2Cl: C, 63.90; H, 4.36; N, 9.31.
Found: C, 64.53; H, 4.59; N, 8.86.
4-Morpholino-6-(1-naphthyl)-2-oxo-2H-pyran-3-carbo-
nitrile (12u). This compound (1.46 g, 4.4 mmoles) was
obtained in 88% yield from 3o (1.47 g, 5 mmoles) and 2 ml of
morpholine in a manner similar to that described for the
preparation of 12a (Method A). An analytical sample was
recrystallized from methanol to give colorless prisms, 206-208°;
ir (potassium bromide) ꢀmax cm-1: 2970, 2925, 2850, 2200 (CN),
1700 (C=O), 1635, 1585, 1530, 1465, 1440, 1390, 1355, 1315,
1260, 1240, 1110, 1065, 1010; uv(ethanol) ꢁ maxnm (log ꢂ): 219
6-(4-Chlorophenyl)-2-oxo-4-pyrrolidino-2H-pyran-3-carbo-
nitrile (12r). This compound (1.11 g, 3.7 mmoles) was obtained
in 73% yield from 3l (1.39 g, 5.0 mmoles) and 2 ml of
pyrrolidine in a manner similar to that described for the
preparation of 12b (Method B). An analytical sample was
recrystallized from methanol to give yellow cotton needles, mp
288-290°; ir (potassium bromide) ꢀmax cm-1: 2200 (CN), 1685
(C=O), 1640, 1535, 1495, 1465, 1400, 1345, 1240, 1170, 1090,
1060, 1010; uv(ethanol) ꢁ maxnm (log ꢂ): 249 nm (4.41), 314 nm
1
nm (4.88), 324 nm (4.33); H-nmr (deuteriochloroform) ꢃ: 3.89
(s, 8H, morpholino-H), 6.33 (s, 1H, 5-H), 7.52 (dd, 1H, naphthyl
3-H, J=7.2 ,8.4 Hz), 7.54-7.63 (m, 2H, naphthyl 6', 7'-H), 7.67
(d, 1H, naphthyl 2'-H, J=7.2 Hz), 7.92 (m, 1H, naphthyl 5'-H),
7.99 (d, 1H, naphthyl 4'-H, J=8.4 Hz, 8.10 (m, 1H, naphthyl 8'-
H); ms m/z: 333 (M++1, 20), 332 (M+, 79), 155 (100), 127 (46),
97 (11), 85 (12), 83 (13), 71 (16), 69 (16), 57 (26), 55 (18), 44
(14), 43 (19). Anal. Calcd. for C20H16N2O3: C, 72.28; H, 4.85;
N, 8.43. Found: C, 72.07; H, 4.92; N, 8.30.
1
(4.38); H-nmr (deuteriochloroform) ꢃ: 2.12 (br, 4H, N-CH2-
CH2-), 3.72 (m, 2H, N-CH2), 4.16 (m, 2H, N-CH2-), 6.35 (s, 1H,
5-H), 7.46 (d, 2H, 2', 6'-H, J=8.5 Hz), 7.76 (d, 2H, 3', 5'-H, J=8.5
Hz); ms m/z: 302 (M++2, 28), 301 (M++1, 28), 300 (M+, 75), 271
(22), 141 (23), 139 (61), 133 (20), 111 (36), 98 (20), 97 (37), 95
(25), 85 (32), 84 (20), 83 (38), 81 (28), 71 (46), 70 (43), 69 (49),
68 (26), 67 (27), 57 (70), 56 (23), 55 (57), 44 (100). Anal.
Calcd. for C16H13N2O2Cl: C, 63.90; H, 4.36; N, 9.31. Found: C,
64.53; H, 4.59; N, 8.86.
6-Biphenyl-2-oxo-4-pyrrolidino-2H-pyran-3-carbonitrile
(12s). This compound (0.75 g, 2.2 mmoles) was obtained in
44% yield from 3m (1.60 g, 5.0 mmoles) and 2 ml of pyrrolidine
in a manner similar to that described for the preparation of 12a
(Method A). An analytical sample was recrystallized from
methanol to give colorless cotton needles, mp 304-305°; ir
(potassium bromide) ꢀmax cm-1: 3100, 2960, 2220 (CN), 1700
2-Oxo-4pyrrolidino-6-(2-thienyl)-2H-pyran-3-carbonitrile
(12v). This compound (0.57 g, 2.1 mmoles) was obtained in
42% yield from 3r (1.09 g, 5.0 mmoles) and 2 ml of pyrrolidine
in a manner similar to that described for the preparation of 12a
(Method A). An analytical sample was recrystallized from
methanol to give greenish yellow needles, mp 283-285°; ir
(potassium bromide) ꢀmax cm-1: 3100, 2980, 2200 (CN), 1690
(C=O), 1630, 1540, 1460, 1420, 1380, 1360, 1330, 1250, 1065,
1030, 1000; uv(ethanol) ꢁ maxnm (log ꢂ): 253 nm (4.31), 331 nm
1
(4.36), 336 nm (4.36); H-nmr (deuteriochloroform) ꢃ: 2.08 (br,
4H, N-CH2-CH2-), 3.66 (m, 2H, N-CH2-), 4.11 (m, 2H, N-CH2-),
6.18 (s, 1H, 5-H), 7.13 (dd, 1H, thienyl 4'-H, J=3.8, 4.9 Hz),
7.51 (dd, 1H, thienyl 5'-H, J= 1.1, 4.9 Hz), 7.66 (dd, 1H, thienyl

Jan-Feb 2007
Synthesis and Fluorescence of 2H-Pyrone derivatives
129
For Organic Light-Emitting Diodes(OLED)
3'-H, J=1.1, 3.8 Hz); ms m/z: 273 (M++1, 18), 272 (M+, 100),
271 (10), 244 (27), 243 (19), 239 (19), 239 (16), 227 (13), 216
(12), 215 (14), 211 (20), 161 (10), 147 (11), 111 (91), 94 (12),
83 (12), 71 (13), 70 (38), 69 (14), 68 (10), 57 (19), 44 (28), 43
(19). Anal. Calcd. for C14H12N2O2S: C, 61.75; H, 4.44; N, 10.29.
Found: C, 61.52; H, 4.46; N, 10.29.
1660 (C=O), 1562, 1275; uv(ethanol)ꢁ
nm(log ꢂ): 241 nm
max
1
(4.43), 305 nm (4.28); H-nmr (deuteriochloroform)ꢃ: 3.90 (s,
3H, OMe), 4.64 (d, 2H, N-CH2-, J=5.8 Hz), 6.44 (s, 1H, 5-H),
7.32-7.52 (m, 8H, phenyl-H), 7.50-7.80 (m, 2H, phenyl-H),
10.44 (br, 1H, NH); ms m/z: 336 (M++1, 23), 335 (M+, 100), 303
(60), 245 (100), 274 (34), 230 (31),105 (44), 91 (75), 77 (30).
Anal. Calcd for C20H17NO4: C, 71.63; H, 5.11; N, 4.18. Found:
C, 71.37, H, 5.11; N, 4.14.
Methyl 4-N,N-Dimethylamino-2-oxo-6-phenyl-2H-pyran-3-
carboxylate (14c). A solution of 0.58 g (2 mmoles) of 14a and
2ml of 50% methylamine-water solution in 50 ml of methanol
was refluxed for 1 hour. After removal of the solvent, the
residue was recrystallized from methanol to give 0.54 g (1.96
mmoles, 98% yield) of colorless needles, mp 140-145°; ir
(potassium bromide) ꢄ max cm-1: 1720 (C=O), 1635, 1538, 1470;
4-Morpholino-2-oxo-6-(2-thienyl)-2H-pyran-3-carbonitrile
(12w). This compound (0.68 g, 2.35 mmoles) was obtained in
47% yield from 3r (1.09 g, 5.0 mmoles) and 2 ml of morpholine
in a manner similar to that described for the preparation of 12a
(Method A). An analytical sample was recrystallized from
methanol to give yellow leaflets, mp 249-250°; ir (potassium
bromide) ꢀmax cm-1: 2220 (CN), 1700 (C=O), 1620, 1530, 1470,
1375, 1305, 1250, 1115, 1060, 1030; uv(ethanol) ꢁ maxnm (log
1
ꢂ): 255 nm (4.27), 343 nm (4.57); H-nmr (deuteriochloroform)
1
ꢃ: 3.88 (br, 8H, morpholino-H), 6.26 (s, 1H, 5-H), 7.16 (dd, 1H,
thienyl 4'-H, J=3.8, 4.9 Hz), 7.56 (dd, 1H, thienyl 5'-H, J=1.1,
4.9 Hz), 7.70 (dd, 1H, thienyl 3'-H, J=1.1, 3.8 Hz); ms m/z: 289
(M++1, 11), 288 (M+, 55), 111 (64), 97 (24), 83 (21), 71 (25), 69
(44), 57 (55), 56 (26), 55 (61), 45 (20), 44 (100). Anal. Calcd.
for C14H12N2O3S: C, 58.32; H, 4.20; N, 9.72. Found: C, 58.39;
H, 4.14; N, 9.67.
uv(ethanol)ꢁmax nm(log ꢂ): 248 nm (4.47), 303 nm (4.28); H-
nmr (deuteriochloroform) ꢃ: 3.11 (s, 6H, NMe2), 3.89 (s, 3H,
OMe), 6.47 (s, 1H, 5-H), 7.40-7.52 (m, 3H, phenyl-H), 7.70-
7.85 (m, 2H, phenyl-H); ms m/z: 273 (M+, 77), 246 (16), 245
(41), 242 (66), 241 (79), 105 (100), 77 (79), 45 (48). Anal.
Calcd for C15H15NO4: C, 65.93; H, 5.53; N, 5.13. Found: C,
65.57, H, 5.39; N, 5.03.
6-(2-Benzothienyl)-2-oxo-4-piperidino-2H-pyran-3-carbo-
nitrile (12x). This compound (0.89 g, 2.65 mmoles) was
obtained in 53% yield from 3s (1.34 g, 5 mmoles) and 2 ml of
piperidine in a manner similar to that described for the
preparation of 12a (Method A). An analytical sample was
recrystallized from methanol to give yellow leaflets, mp 247-
248°; ir (potassium bromide) ꢀmax cm-1: 2920, 2850, 2200 (CN),
1710 (C=O), 1620, 1540, 1450, 1360, 1310, 1230, 1190, 1175,
1070, 1020; uv(ethanol) ꢁ maxnm (log ꢂ): 217 nm (4.52), 240 nm
Methyl 4-Methylamino-6-(4-methoxyphenyl)-2-oxo-2H-
pyran-3-carboxylate (14d). A solution of 0.64 g (2.0 mmoles)
of 14b and 2ml of 40% methylamine-water solution in 50 ml of
methanol was refluxed for 3 hours. After removal of the solvent,
the residue was recrystallized from methanol to give 0.55 g (1.9
mmoles, 95% yield) of colorless needles, mp 181-186°; ir
(potassium bromide) ꢄmax cm-1: 3220 (NH), 1742, 1722 (C=O),
1640, 1560, 1270; uv(ethanol)ꢁ maxnm (log ꢂ): 341 nm (4.38);
1H-nmr (deuteriochloroform) ꢃ: 3.11 (d, 3H, N-Me, J=5.1 Hz),
3.88 (s, 3H, OMe), 3.89 (s, 3H, OMe), 6.34 (s, 1H, 5-H), 6.97
(d, 2H, 3', 5'-H, J=8.8 Hz), 7.85 (d, 2H, 2', 6'-H, J=8.8 Hz), 9.96
(br, 1H, NH); ms m/z: 289 (M+, 59), 261 (26), 256 (19), 149
(12), 135 (38),69 (40), 45 (55), 41 (100). Anal. Calcd for
C15H15NO5: C, 62.28; H, 5.23; N, 4.84. Found: C, 62.17, H,
5.11; N, 4.82.
Methyl 4-Dimethylamino-6-(4-methoxyphenyl)-2-oxo-2H-
pyran-3-carboxylate (14e). A solution of 0.64 g (2.0 mmoles)
of 13b and 2ml of 40% methylamine-water solution in 50 ml of
methanol was refluxed for 1 hour. After removal of the solvent,
the residue was recrystallized from methanol to give 0.43 g
(1.44 mmoles, 72% yield) of colorless needles, mp 150-151°; ir
(potassium bromide) ꢀmax cm-1: 1730 (C=O), 1665 (C=O), 1635,
1550; uv(ethanol)ꢁ maxnm(log ꢂ): 321 nm (4.41); 1H-nmr
(deuteriochloroform) ꢃ: 3.09 (s, 3H, NMe2), 3.85 (s, 3H, OMe),
3.88 (s, 3H, OMe), 6.36 (s, 1H, 5-H), 6.93 (d, 2H, 3', 5'-H, J=9.1
Hz), 7.77 (d, 2H, 2', 6'-H, J=9.1 Hz); ms m/z: 304 (M++1, 16),
303 (M+, 75), 275 (33), 272 (34), 135 (89), 43 (100). Anal.
Calcd for C16H17NO5: C, 63.36; H, 5.65; N, 4.62. Found: C,
63.41, H, 5.73; N, 4.62.
1
(4.35), 256 nm (4.25), 349 nm (4.45); H-nmr (deuteriochloro-
form) ꢃ: 1.82 (br, 6H, piperidino 3, 4, 5-H), 3.83 (m, 4H, N-
CH2-), 6.35 (s, 1H, 5-H), 7.41-7.46 (m, 2H, benzothienyl 5', 6'-
H), 7.81-7.86 (m, 2H, benzothienyl 4', 7'-H), 7.97 (s, 1H, benzo-
thienyl 3'-H); ms m/z: 337 (M++1, 20), 336 (M+, 91), 303 (26),
236 (23), 161 (58), 111 (23), 98 (22), 97 (44), 96 (25), 95 (25),
85 (32), 84 (38), 83 (58), 82 (30), 71 (49), 70 (27), 69 (71), 68
(21), 67 (29), 60 (15), 58 (10), 57 (100), 56 (29), 55 (84),
54(16), 45(14), 44 (69), 43 (86). Anal. Calcd. for C19H16N2O2S:
C, 67.84; H, 4.79; N, 8.33. Found: C, 68.27; H, 4.85; N, 8.29.
Methyl 4-Methylamino-2-oxo-6-phenyl-2H-pyran-3-
carboxylate (14a). A solution of 0.58 g (2.0 mmoles) of 13a
and 2ml of 40% methylamine-water solution in 50 ml of
methanol was refluxed for 3 hours. After removal of the solvent,
the residue was recrystallized from methanol to give 0.49 g (1.9
mmoles, 95% yield) of colorless needles, mp 162-165°; ir
(potassium bromide) ꢄ max cm-1; 3220 (NH), 1715 (C=O), 1650,
1565; uv(ethanol) ꢁ maxnm(log ꢂ): 240 nm (4.52), 315 nm (4.38);
1H-nmr (deuteriochloroform) ꢃ: 3.12 (d, 3H, NMe, J=4.9 Hz),
3.89 (s, 3H, OMe), 6.46 (s, 1H, 5-H), 7.40-7.52 (m, 3H, phenyl-
H), 7.80-7.91 (m, 2H, phenyl-H), 10.00 (br, 1H, NH); ms m/z:
259 (M+, 16), 246 (16), 245 (100), 215 (46), 188 (30),147 (15),
105 (53), 77 (30). Anal. Calcd for C14H13NO4: C, 64.86; H,
5.05; N, 5.40. Found: C, 64.49, H, 4.88; N, 5.33.
Methyl 6-(4-Methoxyphenyl)-4-pyrrolidino-2-oxo-2H-
pyran-3-ccarboxylate (14f). A solution of 0.64 g (2.0 mmoles)
of 13b and 0.20 g (3.0 mmoles) of pyrrolidine in 50 ml of
methanol was refluxed for 3 hours. After removal of the solvent,
the residue was recrystallized from methanol to give 0.47 g
(1.44 mmole, 72% yield) of colorless needles, mp 185-186°;
ir(potassium bromide) ꢀmax cm-1: 1690 (C=O), 1640 (C=O),
1540, 1515, 1255; uv(ethanol)ꢁ maxnm (log ꢂ): 313 nm (4.37);
1H-nmr (deuteriochloroform) ꢃ: 1.58 (m, 4H, pyrrolidino-H),
3.48 (m, 4H, pyrrolidino-H), 3.86 (s, 3H, OMe), 3.90 (s, 3H,
OMe), 6.31 (s, 1H, 5-H), 6.95 (d, 2H, 3', 5'-H, J=9.1 Hz), 7.77
Methyl 4-Benzylamino-2-oxo-6-phenyl-2H-pyran-3-
carboxylate (14b). A solution of 0.58 g (2.0 mmoles) of 13a
and 0.27 g(2.5 mmoles) of benzylamine in 50 ml of methanol
was refluxed for 30 min. After removal of the solvent, the
residue was recrystallized from methanol to give 0.50 g (1.5
mmoles, 75% yield) of colorless needles, mp 197-198°; ir
(potassium bromide) ꢄmax cm-1: 3450 (br, NH), 1715 (C=O),

130
N. Mizuyama, Y. Murakami, S. Kohra, K. Ueda, K. Hiraoka, J. Nagaoka,
K. Takahashi, Y. Shigemitsu and Y. Tominaga
Vol 44
(d, 2H, 2', 6'-H, J=9.1 Hz); ms m/z: 330 (M++1, 10), 329 (M+,
51), 298 (42), 297 (80), 185 (29), 135 (100), 69 (62), 44 (87), 43
(84). Anal. Calcd for C18H19NO5: C, 65.64; H, 5.81; N, 4.25.
Found: C, 65.34, H, 5.79; N, 4.18.
120.32 (C7), 129.74 (C11), 130.82 (C12,16), 154.13 (C5),
160.33 (C14); ms m/z: 301 (M++1, 10), 300 (M+, 43), 285 (19),
254 (20), 253 (100), 213 (24), 184 (23), 70 (12), 44 (14), 43
(13). Anal. Calcd. for C17H20N2OS: C, 67.97; H, 6.71; N, 9.32.
Found: C, 68.05; H, 6.66; N, 9.41.
5-Dimethilamino-3-methylthiopenta-5-phenyl-2,4-diene-
nitirile (15a). This compound (0.59 g, 2.4 mmoles) was
obtained in 48% yield from 3a (1.22 g, 5 mmoles) and 3 ml of
50% of dimethylamine solution in a manner similar to that
described for the preparation of 12a (Method B). An analytical
sample was recrystallized from methanol to give yellow prisms,
mp 99-101˚. Ir (potassium bromide) ꢀmax cm-1: 2170 (CN), 1560,
1495, 1460, 1440, 1410, 1365, 1300, 1245, 1215, 1140, 1090,
1020; 1H-nmr (deuteriochloroform) ꢁ: 2.07 (s, 3H, SMe), 2.79 (s,
6H, NMe2), 4.37 (s, 1H, =CH-CN), 5.50 (s, 1H, =CH), 7.25-7.38
(m, 5H, phenyl-H); ms m/z: 245 (M++1, 10), 244 (M+, 59), 229
(18), 198 (16), 197 (100), 182 (14), 157 (13), 154 (20), 153 (12),
127 (18), 118 (10), 77 (18), 44 (14). Anal. Calcd. for C14H16N2S:
C, 68.81; H, 6.60; N, 11.46. Found: C, 68.48; H, 6.69; N, 11.40.
3-Methylthiopenta-5-phenyl-5-pyrrolidino-2,4-diene-
nitirile (15b). This compound (0.59 g, 2.4 mmoles) was
obtained in 48% yield from 3a (1.22 g, 5.0 mmoles) and 2 ml of
pyrrolidine in a manner similar to that described for the
preparation of 15a (Method B). An analytical sample was
recrystallized from methanol to give pale yellow needles, mp
99-101°; ir (potassium bromide) ꢀmax cm-1: 3100, 2960, 2850,
2180 (CN), 1560, 1490, 1430, 1380, 1290, 1230, 1210, 1180,
1120, 1070, 1020; 1H-nmr (deuteriochloroform) ꢁ: 2.03 (s, 4H,
pyrrolidino 3,4-H), 2.05 (s, 3H, SMe), 3.16 (s, 4H, pyrrolidino 2,
5-H), 4.26 (s, 1H, =CH-CN), 5.57 (s, 1H, =CH), 7.27-7.39 (m,
5H, phenyl-H); ms m/z: 271 (M++1, 7), 270 (M+, 35), 255 (15),
224 (18), 223 (100), 183 (21), 154 (14), 127 (13), 70 (22), 44
(3), 43 (5). Anal. Calcd. for C16H18N2S: C, 71.07; H, 6.71; N,
10.36. Found: C, 70.77; H, 6.89; N, 10.29.
5-Dimethylamino-5-(4-methoxyphenyl)-3-methylthiopenta-
2,4-dienenitirile (15e). This compound (0.64 g, 2.4 mmoles)
was obtained in 47% yield from 3d (1.37g, 5 mmoles) and 2 ml
of 50% of dimethylamine solution in a manner similar to that
described for the preparation of 15a (Method B). An analytical
sample was recrystallized from methanol to give yellow leaflets,
mp 103-105˚; ir (potassium bromide) ꢀmax cm-1: 2925, 2180
(CN), 1610, 1560, 1510, 1460, 1440, 1410, 1365, 1295, 1245,
1170, 1090, 1030; 1H-nmr (deuteriochloroform) ꢁ: 2.08 (s, 3H,
SMe), 2.79 (s, 6H, NMe2), 3.85 (s, 3H, OMe), 4.37 (s, 1H, =CH-
CN), 5.49 (s, 1H, =CH), 6.89 (d, 2H, 2', 6'-H, J=8.8 Hz), 7.20 (d,
2H, 3', 5'-H, J=8.8 Hz); ms m/z: 275 (M++1, 13), 274 (M+, 66),
259 (20), 228 (17), 227 (100), 184 (15), 135 (13), 44 (19). Anal.
Calcd. for C15H18N2OS: C, 65.66; H, 6.61; N, 10.21. Found: C,
66.83; H, 6.74; N, 10.32.
3-Methylthio-5-(4-methoxyphenyl)-penta-5-thiomorpholino-
2,4-dienenitirile (15h). This compound (0.37 g, 1.1 mmoles)
was obtained in 22% yield from 3d (1.37g, 5 mmoles) and 2 ml
of thiomorpholine in a manner similar to that described for the
preparation of 15a (Method B). An analytical sample was
recrystallized from methanol to give yellow leaflets, mp 104-
106˚; ir (potassium bromide) ꢀmax cm-1 : 2925, 2200 (CN), 1610,
1565, 1510, 1460, 1440, 1420, 1380, 1350, 1320, 1300, 1290,
1245, 1230, 1200, 1170, 1150, 1140, 1025; 1H-nmr
(deuteriochloroform) ꢁ: 2.11 (s, 3H, SMe), 2.62 (m, 4H,
thiomorpholino-H), 3.40 (m, 4H, thiomorpholino-H), 3.84 (s,
3H, OMe), 4.48 (s, 1H, =CH-CN), 5.53 (s, 1H, =CH), 6.87 (d,
2H, 2', 6'-H, J=8.8 Hz), 7.24 (d, 2H, 3', 5'-H, J=8.8 Hz); ms m/z:
333 (M++1, 10), 332 (M+, 44), 317 (10), 286 (21), 285 (100),
245 (7), 184 (13), 183 (8), 140 (8), 134 (8), 87 (13), 45 (8).
Anal. Calcd. for C17H20N2O2S2: C, 61.41; H, 6.06; N, 8.43.
Found: C, 60.86; H, 5.95; N, 8.29.
5-Dimethylamino-5-(4-dimethylaminophenyl)-3-methyl-
thiopenta-2,4-dienenitirile (15l). This compound (0.55g, 1.9
mmoles) was obtained in 38% yield from 3i (1.43g, 5 mmoles)
and 2 ml of 50% of dimethylamine solution in a manner similar
to that described for the preparation of 15a (Method B). An
analytical sample was recrystallized from methanol to give
yellow leaflets, mp 121-123˚; ir (potassium bromide) ꢀmax cm-1:
2900, 2800, 2175 (CN), 1605, 1560, 1520, 1440, 1400, 1360,
1
1295, 1220, 1190, 1170, 1120, 1090; H-nmr (deuteriochloro-
form) ꢁ: 2.09 (s, 3H, SMe), 2.80 (s, 6H, NMe2), 2.90 (s, 6H,
phenyl-NMe2), 4.35 (s, 1H, =CH-CN), 5.52 (s, 1H, =CH), 6.67
(d, 2H, 2', 6'-H, J=8.8 Hz), 7.11 (d, 2H, 3', 5'-H, J=9.1 Hz); ms
m/z: 288 (M++1, 14), 287 (M+, 70), 286 (12), 272 (21), 241 (18),
240 (100), 225 (16), 197 (15), 196 (10), 161 (13), 119 (10), 69
(11), 44 (11). Anal. Calcd. for C16H21N3S: C, 66.86; H, 7.36; N,
14.62. Found: C, 66.68; H, 7.29; N, 14.56.
5-(4-Dimethylaminophenyl)-3-methylthiopenta-5-pyrroli-
dino-2,4-dienenitirile (15m). This compound (0.80 g, 2.8
mmoles) was obtained in 51% yield from 3i (1.43g, 5 mmoles)
and 2 ml of pyrrolidine in a manner similar to that described for
the preparation of 15a (Method B). An analytical sample was
recrystallized from methanol to give yellow leaflets, mp 123-
125˚; ir (potassium bromide) ꢀmax cm-1: 3090, 2180 (CN), 1610,
1560, 1520, 1480, 1460, 1420, 1380, 1350, 1290, 1200, 1110;
1H-nmr (deuteriochloroform) ꢁ: 1.88 (s, 4, pyrrolidino 3, 4-H),
2.07 (s, 3H, SMe), 3.00 (s, 6H, NMe2), 3.19 (s, 4H, pyrrolidino
2, 5-H), 4.22 (s, 1H, =CH-CN), 5.59 (s, 1H, =CH), 6.68 (d, 2H,
2', 6'-H, J=8.8 Hz), 7.11 (d, 2H, 3', 5'-H, J=9.1 Hz); ms m/z: 314
(M++1, 10), 313 (M+, 45), 298 (17), 267 (20), 266 (100), 243
(10), 226 (24), 197 (32), 69 (20), 57 (11), 55 (11), 45 (14), 44
(17), 43 (14). Anal. Calcd. for C18H23N3S: C, 68.97; H, 7.40; N,
13.41. Found: C, 69.12; H, 7.25; N, 13.40.
5-(4-Bromophenyl)-3-methylthiopenta-5-pyrrolidino-2,4-
dienenitirile (15p). This compound (0.51 g, 1.5 mmoles) was
obtained in 29% yield from 3j (1.61g, 5 mmoles) and 2 ml of
pyrrolidine in a manner similar to that described for the
preparation of 15a (Method B). An analytical sample was
recrystallized from methanol to give yellow leaflets, mp 142-
144˚; ir (potassium bromide) ꢀmax cm-1: 2960, 2850, 2190 (CN),
1550, 1500, 1420, 1370, 1340, 1280, 1230, 1200, 1180, 1155,
3-Methylthio-5-(4-methoxyphenyl)-penta-5-pyrrolidino-
2,4-dienenitirile (15f). This compound (0.45 g, 1.5 mmoles)
was obtained in 30% yield from 3d (1.37g, 5 mmoles) and 2 ml
of pyrrolidine in a manner similar to that described for the
preparation of 15a (Method B). An analytical sample was
recrystallized from methanol to give yellow prisms, 132-134˚; ir
(potassium bromide) ꢀmax cm-1: 3100, 2950, 2870, 2180 (CN),
1605, 1550, 1510, 1470, 1420, 1370, 1290, 1250, 116 5, 1105,
1030; 1H-nmr (deuteriochloroform) ꢁ: 1.89 (s, 4H, pyrrolidino 3,
4-H), 2.06 (s, 3H, SMe), 3.85 (s, 4H, pyrrolidino 2, 5-H), 4.25
(s, 1H, =CH-CN), 5.56 (s, 1H, =CH), 6.89 (d, 2H, 2', 6'-H J=8.8
Hz), 7.20 (d, 2H, 3', 5'-H, J=8.8 Hz); 13C-nmr (deuteriochloro-
form) ꢁ: 16.14 (SMe), 25.34 (C2, 3), 49.10 (C1, 4), 55.24
(OMe), 77.98 (C8), 95.29 (C6), 113.57 (C13, 15), 114.53 (CN),

Jan-Feb 2007
Synthesis and Fluorescence of 2H-Pyrone derivatives
131
For Organic Light-Emitting Diodes(OLED)
1105, 1065, 1010.; 1H-nmr (deuteriochloroform) ꢀ: 1.89(s, 4H,
pyrrolidino 3, 4-H), 2.08 (s, 3H, SMe), 3.14 (s, 4H, pyrrolidino
2, 5-H), 4.30 (s, 1H, =CH-CN), 5.49 (s, 1H, =CH), 7.18 (d, 2H,
J=8.5 Hz, 2', 6'-H), 7.50 (d, 2H, 3', 5'-H, J=8.5 Hz); ms m/z: 350
(M++1, 33), 349 (M+, 9), 348 (34), 333 (16), 304 (18), 303 (98),
302 (20), 301 (100), 269 (11), 263 (17), 261 (20), 222 (26), 154
(10), 153 (40), 149 (11), 140 (10), 71 (12), 70 (38), 58 (17), 57
(11), 55 (16), 47 (10), 45 (10), 44 (63).
23±1°C to a maximum 2ꢃ value of 55.0°. A total of 464
oscillation images were collected. A sweep of data was done
using ꢅ scans from 0.0 to 190.0° in 0.5° step, at =0.0° and
ꢄ=0.0°. The exposure rate was 50.0[sec./°]. The detector is at
the zero swing position. A second sweep was performed using
scans from-190.0 to 23.0° in 0.5° step, at ꢄ=90.0° and ꢅ=0.0°.
The exposure rate was 50.0 [sec./°]. The detector is at the zero
swing position. The crystal-to-detector distance was 40.70 mm.
Readout was performed in the 0.000 mm pixel mode.
Anal. Calcd. for C16H17N2SBr: C, 55.02; H, 4.91; N, 8.02.
Found: C, 55.67; H, 5.10; N, 7.69.
Data Reduction. Of the 25309 reflections that were
collected, 3775 were unique (Rint=0.050); equivalent reflections
were merged. Data were collected and processed using
CrystalClear (Rigaku). Net intensities and sigmas were derived
as follows: m is the number of pixels in the integration area;
Bave is the background average; Lp is the Lorentz and
polarization factor; Bave= ꢆ(Bj)/n where n is the number of
pixels in the background area. Bj is the value of the jth pixel in
counts. ꢇ2(F2hkl)=[（ꢆPi + m((ꢆBave-Bj)2)/(n-1)]] · Lp · ermul +
(erradd · F2)2 where eraadd=0.00, errmul=1.00.
X-Ray Experimental Reports of 8a. Data Collection.
A
paleyellow prism crystal of C14H12O4S having approximate
dimensions of 0.35 x 0.20 x 0.10 mm was mounted on a glass
fiber. All measurements were made on a Rigaku with graphite
monochromated Mo-Kꢁ radiation. Indexing was performed
from 4 stills that were exposed for 15 seconds. The crystal-to-
detector distance was 40.70 mm.
Cell constants and an orientation matrix for data collection
corresponded to a primitive monoclinic cell with dimensions. a
=14.137(2)Å, b = 7.0687(7)Å, c = 13.9118(4) Å, V = 1295.4(2)
Å3, ꢂ = 111.2830(6)o. For Z = 4 and F.W. = 276.31, the
calculated density is 1.42 g/cm3. The systematic absences of:
h0l: l ± 2n, 0k0: k ± 2n. uniquely determine the space group to
be: P21/c (#14). The data were collected at a temperature of 22 +
1°C to a maximum 2ꢃ value of 55.1°. A total of 464 oscillation
images were collected. A sweep of data was done using scans
from -19.0 to 23.0° in 0.5° step, at ꢄ = 90.0° and ꢅ = 0.0°. The
exposure rate was 30.0 [sec./°]. The is detector at the zero swing
position. A second sweep was performed using ꢅ scans from 0.0
to 190.0° in 0.5° step, at = 0.0° and ꢄ = 90.0°. The exposure
rate was 30.0 [sec./°]. The detector is at the zero swing position.
The crystal-to-detector distance was 40.70 mm. Readout was
performed in the 0.000 mm pixel mode.
The linear absorption coefficient, μ, for Mo-Kꢁ radiation is
0.9 cm-1 was applied which resulted in transmission factors
ranging from 0.79 to 1.01. The data were corrected for Lorentz
and polarization effects.
X-Ray Experimental Reports of 15b. Data Collection. A
clear prism crystal of C16H18N2S having approximate dimensions
of 0.40 x 0.30 x 0.15 mm was mounted on a glass fiber. All
measurements were made on a Rigaku with graphitenmono-
chromated Mo-Kꢁ radiation. Indexing was performed from
4531 stills which were exposed for 0 seconds. The crystal-to-
detector distance was 40.70 mm.
Cell constants and an orientation matrix for data collection
corresponded to a primitive orthhombic cell with dimensions.
a=9.6123(13)Å, b=17.055(3)Å, c=9.5000(4)Å, V=1492.6(3) Å 3,
ꢂ=106.5908(7)°. For Z=4 and F.W.=270.39, the calculated
density is 1.20 g/cm3. The systematic absences of : h00: h±2n,
0k0:k±2n. uniquely determine the space group to be: P21/n(#14).
The data were collected at a temperature of 22±1°C to a
maximum 2ꢃ value of 55.0°. A total of 0 oscillation images
were collected. The crystal-to-detector distance was 40.70 mm.
Redout was performed in the 0.000 mm pixel mode.
Data Reduction. Of the 11177 reflections that were
collected, 2892 were unique (Rint
= 0.021); equivalent
reflections were merged. Data were collected and processed
using CrystalClear (Rigaku). Net intensities and sigmas were
derived as follows: F2 = [ꢆ(Pi - mBave)] . Lp-1 where Pi is the
value in counts of the ith pixel m is the number of pixels in the
integration area Bave is the background average. Lp is the
Lorentz and polarization factor. Bave = ꢆ(Bj)/n where n is the
number of pixels in the background area Bj is the value of the jth
pixel in counts. ꢇ2(F2hkl) = [(ꢆPi) + m((ꢆ(Bave - Bj)2)/(n-1))] .
Lp . errmul + ( erradd . F2)2 where erradd = 0.00. errmul = 1.00
The linear absorption coefficient, μ, for Mo-Kꢁ radiation is
2.6 cm-1. was applied which resulted in transmission factors
ranging from 0.89 to 1.00. The data were corrected for Lorentz
and polarization effects.
X-Ray Experimental Reports of 12l. Data Collection. A
pale greenish yellow crystal of C16H17N2O3 having approximate
dimensions of 0.40 x 0.12 x 0.08 mm was mounted on a glass
fiber. All measurements were made on a Rigaku with graphite
monochromated Mo-Kꢁ radiation. Indexing was performed
from 7 stills that were exposed for 30 seconds. The crystal-to-
detector distance was 40.70 mm.
Data Reduction. Of the 12846 reflections that were
collected, 3353 were unique (Rint=0.030); equivalent reflections
were merged. Data were collected and processed using
CrystalClear (Rigaku). Net intensities and sigmas were derived
as follows: F2=[ꢆ(Pi-mBave)] · Lp-1 where Pi is the value in
counts of the ith pixel, m is the number of pixels in the
intergration area , Bave is the background average, Lp is the
Lorentz and polarization factor. Bave=ꢆ(Bj)/n wehere n is the
number of pixels in the background area, Bj is the value of the jth
pixel in counts. ꢇ2(F2hkl)=[ ꢆPi + m((ꢆBave-Bj)2)/(n-1)]] · Lp ·
ermul + (erradd · F2)2 where eraadd=0.00, errmul=1.00.
The linear absorption coefficient, μ, for Mo-Kꢁ radiation is
2.10 cm-1. was applied which resulted in transmission factors
ranging from 0.83 to 1.06. The data were corrected for Lorentz
and polarization effects. A correction for secondary extinction
was applied (coefficient=181.619995).
Cell constants and an orientation matrix for data collection
corresponded to a primitive orthorhombic cell with dimensions.
a=7.59380(10)Å,
b=14.0254(4)Å,
c=27.4606(8)Å,
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P212121(#19). The data were collected at a temperature of
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