Substituent effects on the iodine-catalyzed thermal cyclization of 3,4-diphenylbuta-1,3-dienyl isocyanates: Mechanistic studies

Article abstract of DOI:10.1021/jo2017247

The thermal cyclization of 3,4-diphenylbuta-1,3-dienyl isocyanates 1, generated in situ from the corresponding azides, was investigated using iodine as a catalyst. Diphenylpyridinones 2, phenylnaphthalenes 3, and indenes 4 were produced via intramolecular ring closure. The nature of the substituents on the phenyl rings was found to be crucial to the distribution of cyclized products 2 - 4. The mechanism of the reaction is also discussed.

Full text of DOI:10.1021/jo2017247

Article
pubs.acs.org/joc
Substituent Effects on the Iodine-Catalyzed Thermal Cyclization of
3,4-Diphenylbuta-1,3-dienyl Isocyanates: Mechanistic Studies
Ta-Hsien Chuang,* Wei-Yu Chang, Chien-Fu Li, Yu-Chia Wen, and Chia-Chen Tsai
School of Pharmacy, China Medical University, No. 91, Hsueh-Shih Road, Taichung 40402, Taiwan, Republic of China
S
* Supporting Information
ABSTRACT: The thermal cyclization of 3,4-diphenylbuta-
1,3-dienyl isocyanates 1, generated in situ from the
corresponding azides, was investigated using iodine as a
catalyst. Diphenylpyridinones 2, phenylnaphthalenes 3, and
indenes 4 were produced via intramolecular ring closure. The
nature of the substituents on the phenyl rings was found to be
crucial to the distribution of cyclized products 2−4. The
mechanism of the reaction is also discussed.
(2a) in 11% yield via the cyclization of the butadienyl
isocyanate moiety and also furnished another intriguing
compound in 9% yield, which was identified as 2-phenyl-
naphthalene (3a, entry 1). The latter compound 3a was
confirmed by comparing its spectral data with literature
values.11 A less polar product, 6a, and 2-phenylnaphthalene
3a were obtained in the initial trial while the isocyanate of azide
(2E,4Z)-5a disappeared within 1 h.9 The product 6a was
deduced as N-(3,4-diphenylbuta-1,3-dienylcarbamoyl)-3,4-di-
phenyl-1H-pyridin-2-one, an adduct of 3,4-diphenylpyridinone
2a and 3,4-diphenylbuta-1,3-dienyl isocyanate 1a (eq 1). As
INTRODUCTION
■
The modes of intramolecular cyclization of conjugated
isocyanates have attracted considerable attention because they
could provide the key intermediates for the syntheses of many
biological pyridines, isoquinolines, and other heterocyclic
derivatives.1−8 Eloy and Washburne extensively applied the
thermal cyclization of penta-2,4-dienoyl isocyanates to
synthesize 1H-pyridin-2-ones.1,4 Recently, our laboratory
utilized the intramolecular cyclization of styryl isocyanates to
produce isoquinolinones and discovered that the reaction
temperature could be lowered to the refluxing temperature of o-
dichlorobenzene in the presence of mercury(II) acetate.9 In
addition, molecular iodine has proven to be a useful Lewis acid
catalyst for the activation of carbonyl compounds, including in
the [2 + 2] cyclization of isocyanates with alkenes.10 Therefore,
we envisioned that iodine would facilitate the cyclization of
conjugated isocyanates. This led us to begin a systematic
investigation of the feasibility of the intramolecular cyclization
of 3,4-diphenylbuta-1,3-dienyl isocyanates 1. To our surprise,
not only 3,4-diphenylpyridin-2(1H)-ones 2 but also phenyl-
naphthalenes 3 or benzylidene-1H-indenes 4 were obtained by
the iodine-catalyzed thermal cyclization of isocyanates,
generated in situ from the corresponding azides 5 (Scheme
1). We found that the cyclized product distribution depends on
the substituents of the two phenyl rings, and a mechanistic
rationale for the formation of 3,4-diphenylpyridin-2(1H)-ones
2, phenylnaphthalene 3, and benzylidene-1H-indene 4 is also
presented.
long as the transformation of isocyanate was completed, the
spot of a more polar pyridinone 2a on the TLC plate developed
gradually, while 6a simultaneously faded away slowly with
prolonged heating. We are confident that 1a produces both 2a
and 3a. The reaction could be monitored by the disappearance
of the spots of isocyanate 1 and dimer 6 on the TLC plate.
Apparently, the unexpected product 3a was produced via the
intramolecular cyclization of the triene,12 composed of the two
double bonds of the 1,3-butadiene and one double bond of
terminal phenyl ring (4-phenyl group), followed by the loss of
cyanic acid (HNCO). It is well-known that the tricyclic
chemical structural pattern, consisting of a phenyl ring attached
to the 2-position of a naphthalene moiety, displays various
pharmacological activities.13,14 Unfortunately, only Curtius
rearrangement products (1E,3Z)-1a and (1E,3E)-1a were
obtained quantitatively from (2E,4Z)-5a after refluxing in o-
RESULTS AND DISCUSSION
■
The initial model compound was unsubstituted 3,4-diphenyl-
buta-1,3-dienyl isocyanate (1a). The effects of various reaction
conditions on the thermal cyclization of 1a are summarized in
Table 1. First, heating a solution of the geometrically pure 4,5-
diphenylpenta-(2E,4Z)-dienoyl azide [(2E,4Z)-5a] in diphenyl
ether at 240 °C for 3 h gave 3,4-diphenylpyridin-2(1H)-one
Received: August 17, 2011
Published: October 19, 2011
© 2011 American Chemical Society
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Scheme 1. Iodine-Catalyzed Cyclization of 3,4-Diphenylpenta-1,3-dienoyl Isocyanates 1
of the steric effects, the C-1 and C-2 isomerization of (1E,3Z)-
1a to (1Z,3Z)-1a is slightly more difficult than the C-3 and C-4
isomerization of (1E,3Z)-1a to (1E,3E)-1a. Therefore, the
cyclization, proceeding under milder temperature conditions
(150 °C), resulted in naphthalene 3a as the major product
(60%, entry 4). When the reactions were performed at
temperatures below 150 °C, the reaction time was longer,
and the combined yield of 2a and 3a was slightly less (entries 5
and 6). We proposed the yield in naphthalene 3a would
decrease, probably because the loss of cyanic acid would be
slightly more difficult below 150 °C. Intriguingly, heating a
solution of the geometric isomer (2E,4E)-5a under the same
conditions as entry 4 afforded the same cyclized products 2a
and 3a in essentially the same yields (entry 7). This
phenomenon led us to make the preliminary conclusion that
the identical cyclized result was obtained regardless of the E or
Z geometry of the terminal double bond in the dienoyl azide 5.
To investigate the effect of substituents on the phenyl rings
on the thermal cyclization of 3,4-diphenylbuta-1,3-dienyl
isocyanates 1, a series of 4,5-diphenylpenta-2,4-dienoyl azides
Table 1. Formation of 2a and 3a from Dienoyl Azide
(2E,4Z)-5a
product (%)
entry
solvent
temp (°C)
time (h)
2a
3a
a
1
diphenyl ether
240
3
5
11
−
66
32
45
40
31
9
−
25
60
40
20
60
a
2
o-dichlorobenzene
o-dichlorobenzene
o-dichlorobenzene
o-dichlorobenzene
o-dichlorobenzene
reflux
reflux
150
3
4
5
6
5
7
130
15
96
7
110
b
7
o-dichlorobenzene
150
a
b
No iodine added. Dienoyl azide (2E,4E)-5a was used.
dichlorobenzene (bp 180 °C) for 5 h (entry 2). We successfully
used 2 mol % of iodine to catalyze the cyclization of isocyanates
1a in refluxing o-dichlorobenzene. The result revealed that
iodine is an efficient catalyst to promote the conversion of
butadienyl isocyanate into pyridin-2(1H)-one 2a (66%) and
butadienylbenzene into naphthalene 3a (25%, entry 3). Because
Scheme 2. Synthesis of 4,5-Diphenylpenta-2,4-dienoyl Azides 5
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Table 2. Iodine-Catalyzed Thermal Cyclization of 1 To Give Products 2, 3, and 4
substituent
time
(h)
a
entry
reactant
R3′
R4′
R3″
R4″
product (%)
1
5a (96/4)
5b (70/30)
5c (82/18)
5d (60/40)
5e (80/20)
5f (88/12)
5g (91/9)
5h (96/4)
5i (94/6)
7
4
6
4
4
4
7
4
4
4
1
5
H
H
H
H
2a (32)
2b (32)
2c (8)
3a (60)
3b (50)
3c (83)
3d (22)
3e (25)
3f (81)
2
H
H
H
OCH3
OCH3
H
3
H
H
OCH3
H
4
H
OCH3
OCH3
OCH3
OCH3
OCH3
OCH3
OCH3
OCH3
NO2
2d (63)
2e (58)
2f (11)
2g (88)
2h (55)
2i (45)
2j (30)
2k (12)
2l (13)
5
H
H
OCH3
OCH3
NO2
6
H
OCH3
H
7
H
8
OCH3
OCH3
OCH3
OCH3
H
H
H
4h (32)
4i (25)
4j (67)
9
H
OCH3
NO2
10
11
12
5j (75/25)
5k (89/11)
5l (100/0)
H
OCH3
OCH3
OCH3
OCH3
3k (61)
3l (77)
a
1
A mixture of dienoyl azides (2E,4E)-5 and (2E,4Z)-5 was used. The (2E,4Z)-5/(2E,4E)-5 ratio determined by H NMR spectrum is shown in
parentheses.
5 were synthesized. The strategy for the preparation of dienoyl
azides 5 is shown in Scheme 2. First, a Knoevenagel
condensation between phenylacetonitriles 7 and benzaldehydes
8 generated thermodynamically stable (Z)-2,3-diphenylacrylo-
nitriles 9.15,16 Subsequently, reduction of 9 with DIBAL-H
yielded a geometric mixture of (E)- and (Z)-2,3-diphenylacry-
laldehydes 10. The two isomers, (Z)- and (E)-10, were
carefully separated by column chromatography. Compound 10
was predominantly in the E-form, as identified by the NOE
correlation between aldehydic proton and olefinic proton. The
Wittig reaction between 2,3-diphenylacrylaldehydes 10 and
(carboethoxymethylene)triphenylphosphorane, followed by
hydrolysis, produced the conjugated acids 11. Finally, 4,5-
diphenylpenta-2,4-dienoyl azides 5 were readily prepared
quantitatively by the reaction of the corresponding acids 11
with oxalyl chloride followed by the addition of sodium azide.17
Because the identical cyclized results from (2E,4E)- and
(2E,4Z)-5a were observed (Table 1, entries 4 and 7), the
mixtures of the geometric isomers (E)- and (Z)-10, (2E,4E)-
and (2E,4Z)-11, and (2E,4E)- and (2E,4Z)-5 were used directly
in the acid, azide formation, and iodine-catalyzed thermal
cyclization, respectively.
The results of the iodine-catalyzed thermal cyclization of 4,5-
diphenylpenta-2,4-dienoyl azides 5 at 150 °C in o-dichlor-
obenzene are shown in Table 2. The reactions were monitored
using TLC. First, in the cases of the dienoyl azides 5d and 5e,
possessing the 4′-OCH3 on the middle phenyl ring (3-phenyl
group), the yields of pyridinones 2d and 2e increased, while the
yields of naphthalenes 3d and 3e decreased (see entries 1 and 4
and entries 2 and 5). The electrophilic NCO, in
conjugation with the butadiene moiety, was activated by the
resonance effect of the 4′-OCH3 and facilitated the cyclization
of buta-1,3-dienyl isocyanates to produce pyridinones.
Furthermore, when the dienoyl azide 5g bearing a deactivated
terminal phenyl ring with a 4″-NO2 was utilized, the cyclization
of butadienylbenzene was retarded and only product
pyridinone 2g was obtained in the good yield (88%, entry 7).
Second, the dienoyl azides 5c and 5f, bearing the electron-
donating group 3″-OCH3 para to the C-6″ on the terminal
phenyl ring, produced the regiospecific 6-aryl-2,3-dimethox-
ynaphthalenes 3c and 3f in high yields (83% and 81%,
respectively). The regiospecific selection is probably due to the
steric effect of the 3″-OCH3 which hinders the attack on the C-
2″. The results reveal that the cyclization of butadienylbenzene
can be promoted by the resonance effect of 3″-OCH3, which
increased the electron density on the C-6″ position (compare
entries 2 and 3 and entries 5 and 6). Even in the case of entry
12, dienoyl azide 5l with a 4′-NO2 on the middle phenyl ring
and a 3″-OCH3 on the terminal phenyl ring gave naphthalene
3l in a comparatively high yield (77%). This result suggests
that, no matter what kinds of groups are on the middle phenyl
ring in the dienoyl azide 5, a −OCH3 on the C-3″ position of
terminal phenyl ring increases the formation of naphthalene 3.
To our surprise, when 4-(3′,4′-dimethoxyphenyl)-5-phenyl-
pentadienoyl azide (5h) was subjected to the same conditions,
it was found that 1-benzylidene-5,6-dimethoxy-1H-indene (4h,
32%), instead of 2-(3′,4′-dimethoxyphenyl)naphthalene, and
pyridinone 2h (55%) were obtained (entry 8). A similar result
was also obtained when the dienoyl azides 5i and 5j were used
(entries 9 and 10). The stereochemistry of the indenes 4 was
determined by 2D-NMR analysis. For example, in the NOESY
spectrum of 4j, the indenyl H-2 (δ 6.73) showed NOE
correlations with the phenyl H-2″ and -6″ (δ 7.65), suggesting
that the geometry of 4j was in an E configuration. This
configuration was also confirmed by a single-crystal X-ray
diffraction study (see Supporting Information). We supposed
that the 3′-OCH3 could activate the C-6′ position of the middle
phenyl ring by the resonance effect and that it not only
promoted the intramolecular cyclization of the middle phenyl
ring to the CC double bond to produce indenes 4 but also
inhibited the production of naphthalene derivatives 3. More-
over, in the case of entry 10, the dienoyl azide 5j, bearing a
strong electron-withdrawing group (4″-NO2) on the terminal
phenyl ring as well as a 3′-OCH3 on the middle phenyl ring, led
to further encouragement of the cyclization based on the yields
of indene 4j (67%). Finally, as mentioned above, 3″-OCH3
could increase the yield of naphthalenes 3; therefore,
naphthalene 3k (61%) and pyridinone 2k (12%) were
produced by the thermal reaction of 5k with a 3′-OCH3 on
the middle phenyl ring accompanied by a 3″-OCH3 on the
terminal phenyl ring (entry 11), as in the case of 5c, 5f, and 5l.
Based on the above analysis, the intramolecular cyclization of a
butadienyl isocyanate moiety to form pyridinone 2, a
butadienylbenzene moiety to form naphthalene 3, and a 3-
phenylethene moiety to form indene 4 competed with one
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another. The cyclized product distribution depends on the
properties and the location of substituents.
addition of s-cis geometric isomer 12 gave the cycloadduct 13
and, after the loss of cyanic acid, produced the stereospecific
indenes 4. The carbocation of the intermediate 13 can be
stabilized by the resonance effect of the electron-donating
substituent on the middle phenyl ring, such as R3′ = OCH3.
However, the carbanion of the intermediate 13 can also be
stabilized by the resonance effect of the electron-withdrawing
substituent, NO2 in the para position of the terminal phenyl
ring. Hence, 1(E)-(4″-nitrobenzylidene)-5,6-dimethoxy-1H-in-
dene (4j) can be obtained in higher yields.
MECHANISTIC STUDY
■
Based on the above results, a complete mechanistic route for
the formation of pyridinone 2, naphthalene 3, and indene 4
through an iodine-catalyzed thermal cyclization of 3,4-
diphenylbuta-1,3-dienyl isocyanates 1, generated in situ from
corresponding azides 5, is proposed as depicted in Scheme 3.
Scheme 3. Mechanism of the Iodine-Catalyzed Cyclization of
(1E,3Z)-Dienyl Isocyanate
CONCLUSION
■
This paper describes, to our knowledge, the first observation of
the intramolecular cyclization of 3,4-diphenylbuta-1,3-dienyl
isocyanates 1, generated from 4,5-diphenylpenta-2,4-dienoyl
azides 5, to give naphthalenes 3, indenes 4, and pyridinones 2
using iodine as a catalyst under thermal conditions. The effect
of the substituents on the two phenyl rings in the reaction of
butadienyl isocyanates is shown. An electron-donating group
(OCH3) attached to the meta position of the terminal phenyl
ring, regardless of the other substituents, favors the formation
of naphthalenes 3. A OCH3 on the para position of the middle
phenyl ring enhances the reaction to yield pyridinones 2.
However, a OCH3 on the meta position of the middle phenyl
ring will inhibit the production of naphthalenes 3 and facilitate
the production of indenes 4, especially with an extra electron-
withdrawing group NO2 on the para position of the terminal
phenyl ring.
EXPERIMENTAL SECTION
■
General Procedure for the Preparation of 4,5-Diphenylpen-
tadienoic Acid 11. A mixture of aldehyde 10 (10 mmol) and
(carboethoxymethylene)triphenylphosphorane (12 mmol) in toluene
(50 mL) was refluxed under N2 for 4 h. After cooling, the resulting
solution was directly purified by column chromatography over silica
gel, eluting with hexane−EtOAc to give ethyl 4,5-diphenylpentadie-
noate. Subsequently, a solution of 1 N KOH (20 mL) was added to a
solution of the above ester (8 mmol) in EtOH (40 mL), and the
reaction mixture was heated to reflux for 3 h. After cooling, the
solution was evaporated, and the residue was dissolved in water (50
mL), acidified with 10% HCl, and extracted with EtOAc (5 × 50 mL).
The combined extracts were dried with anhydrous MgSO4, filtered,
and evaporated under reduced pressure to give a geometric mixture of
acids (2E,4E)- and (2E,4Z)-11. To identify the isomers, the pure
acides (2E,4E)-11a and (2E,4Z)-11a−11l were obtained from the
correspounding aldehydes (Z)-10a and (E)-10a−10l for spectral
analysis. The full spectral data of (2E,4E)-11a and (2E,4Z)-11a−11l
are described as follows.
First, the reactants 5 underwent a Curtius rearrangement to
form the corresponding isocyanates 1. The (1E,3Z)-1 should
isomerize to the (1E,3E)-1 and (1Z,3Z)-1 required for the
intramolecular ring closure by molecular iodine. The iodine-
catalyzed E/Z isomerization of conjugated dienes involves a
thermal radical mechanism that has previously been pro-
posed.18 Subsequently, the cyclization of the butadienylbenzene
moiety in (1E,3E)-1 followed by the loss of cyanic acid
produced naphthalene 3. The intramolecular cyclization can be
promoted when R3″ is an electron-donating methoxy group,
and the product 3 is then obtained in higher yields.
Alternatively, the cyclic reaction of the butadienyl isocyanate
moiety in (1Z,3Z)-1, followed by a hydrogen shift, produced
pyridinone 2. Because the isocyanate involved in the cyclic
reaction was apparently electron-deficient, the cyclization can
be facilitated when the substituent R4′ is a methoxy group, and
its competing reaction to produce naphthalene will be inhibited
when the substituent R4″ is a nitro group. Therefore, the
product 2g was obtained in the best yield. In addition, the
conformer 12 of isocyanate (1E,3Z)-1 was formed via rotation
about the C-2 and C-3 single bond. The intramolecular
4,5-Diphenylpenta-(2E,4E)-dienoic Acid [(2E,4E)-11a]. Yield
70% from aldehyde (Z)-10a; white granule, mp 185−186 °C
1
(hexane−EtOAc). H NMR (500 MHz, CDCl3): δ 5.91 (1H, d, J =
15.7 Hz), 6.95 (1H, s), 7.39 (10H, m), 8.07 (1H, d, J = 15.7 Hz),
11.10 (1H, br s). 13C NMR (125 MHz, CDCl3): δ 122.4, 128.0, 128.3,
128.4, 128.5, 129.0, 129.8, 136.2, 138.6, 138.8, 140.3, 144.5, 172.8. IR
(KBr): 1684 cm−1. EIMS m/z (rel int): 250 (43, M+). Anal. Calcd for
C17H14O2: C, 81.58; H, 5.64. Found: C, 81.50; H, 5.57.
4,5-Diphenylpenta-(2E,4Z)-dienoic Acid [(2E,4Z)-11a]. Yield
72% from aldehyde (E)-10a; white granule, mp 169−170 °C
1
(hexane−EtOAc). H NMR (400 MHz, CDCl3): δ 5.50 (1H, d, J =
15.4 Hz), 6.96 (3H, m), 7.13 (5H, m), 7.40 (3H, m), 7.76 (1H, d, J =
15.4 Hz), 11.10 (1H, br s). 13C NMR (100 MHz, CDCl3): δ 119.3,
128.0, 128.2, 128.5, 129.1, 129.2, 130.1, 135.5, 136.6, 139.4, 139.7,
151.9, 172.8. IR (KBr): 1678 cm−1. EIMS m/z (rel int): 250 (38, M+).
Anal. Calcd for C17H14O2: C, 81.58; H, 5.64. Found: C, 81.52; H, 5.66.
5-(4″-Methoxyphenyl)-4-phenylpenta-(2E,4Z)-dienoic Acid
[(2E,4Z)-11b]. Yield 100% from aldehyde (E)-10b; bright yellow
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granule, mp 216−217 °C (hexane−CHCl3). 1H NMR (500 MHz,
CDCl3): δ 3.73 (3H, s), 5.42 (1H, d, J = 15.3 Hz), 6.66 (2H, d, J = 8.9
Hz), 6.89 (2H, d, J = 8.9 Hz), 6.90 (1H, s), 7.16 (2H, d, J = 7.4 Hz),
7.39 (1H, t, J = 7.4 Hz), 7.43 (2H, t, J = 7.4 Hz), 7.75 (1H, d, J = 15.3
Hz), 11.46 (1H, br s). 13C NMR (125 MHz, CDCl3): δ 55.2, 113.7,
118.0, 127.9, 128.3, 129.2, 129.3, 131.8, 137.0, 137.4, 139.6, 152.3,
159.8, 172.6. IR (KBr): 1676 cm−1. EIMS m/z (rel int): 280 (99, M+).
Anal. Calcd for C18H16O3: C, 77.12; H, 5.75. Found: C, 77.41; H, 5.84.
5-(3″,4″-Dimethoxyphenyl)-4-phenylpenta-(2E,4Z)-dienoic
Acid [(2E,4Z)-11c]. Yield 90% from aldehyde (E)-10c; bright yellow
4-(3′,4′-Dimethoxyphenyl)-5-(4″-methoxyphenyl)penta-
(2E,4Z)-dienoic Acid [(2E,4Z)-11i]. Yield 85% from aldehyde (E)-
10i; pale yellow granule, mp 189−190 °C (hexane−EtOAc). 1H NMR
(500 MHz, CDCl3): δ 3.76 (3H, s), 3.81 (3H, s), 3.95 (3H, s), 5.50
(1H, d, J = 15.2 Hz), 6.70 (4H, m), 6.88 (1H, s), 6.95 (3H, m), 7.74
(1H, d, J = 15.2 Hz). 13C NMR (125 MHz, CDCl3): δ 55.2, 55.9, 56.0,
112.0, 112.1, 113.8, 117.8, 121.5, 128.3, 129.3, 131.8, 137.1, 139.5,
148.6, 149.7, 152.5, 159.8, 172.5. IR (KBr): 1682 cm−1. EIMS m/z (rel
int): 340 (100, M+). Anal. Calcd for C20H20O5: C, 70.57; H, 5.92.
Found: C, 70.44; H, 5.96.
1
needle, mp 219−221 °C (EtOAc). H NMR (400 MHz, CDCl3): δ
4-(3′,4′-Dimethoxyphenyl)-5-(4″-nitrophenyl)penta-(2E,4Z)-
3.36 (3H, s), 3.83 (3H, s), 5.44 (1H, d, J = 15.3 Hz), 6.33 (1H, s), 6.74
(2H, m), 6.90 (1H, s), 7.21 (2H, d, J = 7.3 Hz), 7.38 (1H, t, J = 7.3
Hz), 7.46 (2H, t, J = 7.3 Hz), 7.76 (1H, d, J = 15.3 Hz). 13C NMR
(100 MHz, CDCl3): δ 55.0, 55.7, 110.4, 111.6, 118.0, 124.9, 127.9,
128.4, 129.3, 129.4, 137.1, 137.4, 139.6, 148.1, 149.4, 152.1, 172.6. IR
(KBr): 1679 cm−1. EIMS m/z (rel int): 310 (M+, 42). Anal. Calcd for
C19H18O4: C, 73.53; H, 5.85. Found: C, 73.28; H, 6.02.
dienoic Acid [(2E,4Z)-11j]. Yield 82% from aldehyde (E)-10j;
1
yellow granule, mp 224−225 °C (hexane−EtOAc). H NMR (400
MHz, DMSO-d6): δ 3.66 (3H, s), 3.79 (3H, s), 5.46 (1H, d, J = 15.4
Hz), 6.64 (1H, d, J = 7.9 Hz), 6.70 (1H, s), 7.03 (1H, d, J = 7.9 Hz),
7.21 (3H, m), 7.61 (1H, d, J = 15.4 Hz), 8.02 (2H, d, J = 7.9 Hz),
12.39 (1H, br s). 13C NMR (100 MHz, DMSO-d6): δ 55.6, 55.8,
112.4, 112.7, 121.2, 123.1, 123.5, 128.1, 130.6, 135.5, 142.8, 142.9,
146.4, 148.4, 149.0, 149.6, 167.5. IR (KBr): 1681 cm−1. EIMS m/z (rel
int): 355 (100, M+). Anal. Calcd for C19H17NO6: C, 64.22; H, 4.82; N,
3.94. Found: C, 64.54; H, 5.04; N, 3.70.
4-(4′-Methoxyphenyl)-5-phenylpenta-(2E,4Z)-dienoic Acid
[(2E,4Z)-11d]. Yield 85% from aldehyde (E)-10d; white granule,
1
mp 177−178 °C (hexane−CHCl3). H NMR (500 MHz, CDCl3): δ
3.84 (3H, s), 5.54 (1H, d, J = 15.3 Hz), 6.92 (1H, s), 6.95 (2H, d, J =
8.7 Hz), 6.99 (2H, d, J = 7.9 Hz), 7.06 (2H, d, J = 8.7 Hz), 7.14 (3H,
m), 7.75 (1H, d, J = 15.3 Hz), 11.90 (1H, br s). 13C NMR (125 MHz,
CDCl3): δ 55.2, 114.7, 119.2, 128.2, 128.3, 128.6, 130.1, 130.3, 135.7,
139.1, 139.7, 152.2, 159.2, 172.9. IR (KBr): 1682 cm−1. EIMS m/z (rel
int): 280 (100, M+). Anal. Calcd for C18H16O3: C, 77.12; H, 5.75.
Found: C, 76.92; H, 5.66.
4,5-Bis(3′,4′-dimethoxyphenyl)penta-(2E,4Z)-dienoic Acid
[(2E,4Z)-11k]. Yield 92% from aldehyde (E)-10k; pale yellow
granule, mp 237−238 °C (hexane−EtOAc). 1H NMR (400 MHz,
DMSO-d6): δ 3.35 (3H, s), 3.69 (6H, s), 3.80 (3H, s), 5.28 (1H, d, J =
15.3 Hz), 6.45 (1H, d, J = 1.7 Hz), 6.67 (1H, dd, J = 8.1, 1.7 Hz), 6.72
(2H, m), 6.82 (1H, d, J = 8.1 Hz), 7.01 (1H, s), 7.07 (1H, d, J = 8.1
Hz), 7.56 (1H, d, J = 15.3 Hz). 13C NMR (100 MHz, DMSO-d6): δ
55.0, 55.8, 56.0, 56.1, 111.8, 112.7, 113.0, 113.2, 119.7, 121.6, 124.4,
128.8, 129.8, 137.3, 138.6, 148.3, 148.8, 149.6, 149.9, 150.1, 168.0. IR
(KBr): 1665 cm−1. EIMS m/z (rel int): 370 (100, M+). Anal. Calcd for
C21H22O6: C, 68.10; H, 5.99. Found: C, 68.48; H, 6.12.
4,5-Bis(4′-methoxyphenyl)penta-(2E,4Z)-dienoic Acid
[(2E,4Z)-11e]. Yield 91% from aldehyde (E)-10e; pale yellow
granule, mp 189−190 °C (hexane−EtOAc). 1H NMR (500 MHz,
CDCl3): δ 3.75 (3H, s), 3.86 (3H, s), 5.46 (1H, d, J = 15.3 Hz), 6.68
(2H, d, J = 9.0 Hz), 6.88 (1H, s), 6.94 (2H, d, J = 9.0 Hz), 6.97 (2H, d,
J = 8.6 Hz), 7.07 (2H, d, J = 8.6 Hz), 7.73 (1H, d, J = 15.3 Hz), 11.43
(1H, br s). 13C NMR (125 MHz, CDCl3): δ 55.2, 55.3, 113.7, 114.8,
117.8, 128.5, 129.0, 130.4, 131.7, 137.1, 139.6, 152.6, 159.2, 159.8,
172.5. IR (KBr): 1676 cm−1. EIMS m/z (rel int): 310 (100, M+). Anal.
Calcd for C19H18O4: C, 73.53; H, 5.85. Found: C, 73.72; H, 5.64.
5-(3″,4″-Dimethoxyphenyl)-4-(4′-methoxyphenyl)penta-
(2E,4Z)-dienoic Acid [(2E,4Z)-11f]. Yield 83% from aldehyde (E)-
10f; pale yellow granule, mp 106−107 °C (hexane−CHCl3). 1H NMR
(400 MHz, CDCl3): δ 3.45 (3H, s), 3.83 (3H, s), 3.84 (3H, s), 5.49
(1H, d, J = 15.3 Hz), 6.42 (1H, d, J = 1.5 Hz), 6.70 (1H, d, J = 8.4
Hz), 6.74 (1H, dd, J = 8.4, 1.5 Hz), 6.87 (1H, s), 6.99 (2H, d, J = 8.6
Hz), 7.11 (2H, d, J = 8.6 Hz), 7.74 (1H, d, J = 15.3 Hz), 11.83 (1H, br
s). 13C NMR (100 MHz, CDCl3): δ 55.1, 55.3, 55.7, 110.6, 111.9,
114.8, 118.0, 124.6, 128.7, 129.1, 130.6, 137.2, 139.7, 148.2, 149.4,
152.4, 159.3, 172.8. IR (KBr): 1681 cm−1. EIMS m/z (rel int): 340
(84, M+). Anal. Calcd for C20H20O5: C, 70.57; H, 5.92. Found: C,
70.80; H, 5.90.
4-(4′-Methoxyphenyl)-5-(4″-nitrophenyl)penta-(2E,4Z)-di-
enoic Acid [(2E,4Z)-11g]. Yield 82% from aldehyde (E)-10g; yellow
granule, mp 231−234 °C (hexane−CHCl3). 1H NMR (500 MHz,
CDCl3): δ 3.87 (3H, s), 5.67 (1H, d, J = 15.5 Hz), 6.97 (3H, m), 7.05
(2H, d, J = 8.8 Hz), 7.12 (2H, d, J = 8.8 Hz), 7.73 (1H, d, J = 15.5
Hz), 8.00 (2H, d, J = 8.8 Hz). 13C NMR (125 MHz, CDCl3): δ 55.3,
115.0, 121.5, 123.4, 127.4, 130.2, 130.5, 136.3, 142.2, 142.9, 146.8,
150.7, 159.8, 170.6. IR (KBr): 1687 cm−1. EIMS m/z (rel int): 325
(100, M+). HREIMS m/z calcd for C18H15NO5: 325.0950; found:
325.0956 [M]+.
5-(3″,4″-Dimethoxyphenyl)-4-(4′-nitrophenyl)penta-(2E,4Z)-
dienoic Acid [(2E,4Z)-11l]. Yield 80% from aldehyde (E)-10l; pale
1
yellow granule, mp 236−237 °C (hexane−CH2Cl2). H NMR (400
MHz, CDCl3): δ 3.48 (3H, s), 3.83 (3H, s), 5.34 (1H, d, J = 15.5 Hz),
6.35 (1H, d, J = 1.8 Hz), 6.62 (1H, dd, J = 8.5, 1.8 Hz), 6.70 (1H, d, J
= 8.5 Hz), 7.00 (1H, s), 7.42 (2H, d, J = 8.7 Hz), 7.75 (1H, d, J = 15.5
Hz), 8.33 (2H, d, J = 8.7 Hz). 13C NMR (100 MHz, DMSO-d6): δ
54.9, 55.7, 111.7, 112.6, 120.1, 124.2, 124.9, 127.8, 131.2, 135.3, 139.4,
145.1, 147.4 (2 × C), 148.4, 149.7, 167.9. IR (KBr): 1678 cm−1. EIMS
m/z (rel int): 355 (42, M+). Anal. Calcd for C19H17NO6: C, 64.22; H,
4.82; N, 3.94. Found: C, 64.15; H, 4.92; N, 3.93.
General Procedure for the Preparation of 4,5-Diphenylpen-
tadienoyl Azide 5. A mixture of the acids (2E,4E)- and (2E,4Z)-11
(5 mmol) and oxalyl chloride (10 mmol) in toluene (50 mL) was
heated for 5 h at 80 °C. After cooling, the resulting mixture was
concentrated under reduced pressure to afford 4,5-diphenylpenta-2,4-
dienoyl chloride. Subsequently, the pentadienoyl chloride was added
immediately into a suspension of NaN3 (15 mmol) in dry acetone (30
mL) in an ice bath. The reaction mixture was stirred gently for 2 h at
room temperature and filtered. The solvent was evaporated in vacuo,
and the residue was purified by column chromatography over silica gel
and eluted with hexane−CH2Cl2 to yield a geometric mixture of azides
(2E,4E)- and (2E,4Z)-5. Because the isomers produced the same
products in the next step, it was not necessary to separate them, and
they could be used directly. To identify the isomers, the pure azides
(2E,4E)-5a and (2E,4Z)-5a−5l were obtained from the correspound-
ing acids (2E,4E)-11a and (2E,4Z)-11a−11l for spectral analysis. The
full spectral data of (2E,4E)-5a and (2E,4Z)-5a−5l are described as
follows.
4,5-Diphenylpenta-(2E,4E)-dienoyl Azide [(2E,4E)-5a]. Yield
100% from acid (2E,4E)-11a; yellow syrup. 1H NMR (500 MHz,
CDCl3): δ 5.90 (1H, d, J = 15.6 Hz), 6.99 (1H, s), 7.36 (10H, m), 8.04
(1H, d, J = 15.6 Hz). 13C NMR (125 MHz, CDCl3): δ 124.1, 128.1,
128.5 (2 × C), 128.6, 129.0, 129.9, 136.1, 138.9, 139.6, 140.1, 144.2,
172.4. IR (KBr): 2143, 1686 cm−1. EIMS m/z (rel int): 247 (5, [M −
N2]+). HREIMS m/z calcd for C17H13NO: 247.0997; found: 247.0991
[M − N2]+.
4-(3′,4′-Dimethoxyphenyl)-5-phenylpenta-(2E,4Z)-dienoic
Acid [(2E,4Z)-11h]. Yield 93% from aldehyde (E)-10h; pale yellow
granule, mp 158−159 °C (hexane−EtOAc). 1H NMR (400 MHz,
CDCl3): δ 3.79 (3H, s), 3.94 (3H, s), 5.57 (1H, d, J = 15.3 Hz), 6.65
(1H, d, J = 1.6 Hz), 6.72 (1H, dd, J = 8.1, 1.6 Hz), 6.94 (2H, m), 7.01
(2H, m), 7.16 (3H, m), 7.75 (1H, d, J = 15.3 Hz). 13C NMR (100
MHz, CDCl3): δ 55.9, 66.0, 111.9, 112.2, 119.2, 121.5, 128.2, 128.5,
129.0, 130.1, 135.6, 139.1, 139.7, 148.7, 149.7, 152.0, 172.4. IR (KBr):
1682 cm−1. EIMS m/z (rel int): 310 (100, M+). Anal. Calcd for
C19H18O4: C, 73.53; H, 5.85. Found: C, 73.21; H, 6.21.
9682
dx.doi.org/10.1021/jo2017247|J. Org. Chem. 2011, 76, 9678−9686

The Journal of Organic Chemistry
Article
4,5-Diphenylpenta-(2E,4Z)-dienoyl Azide [(2E,4Z)-5a]. Yield
100% from acid (2E,4Z)-11a; yellow solid. 1H NMR (500 MHz,
CDCl3): δ 5.48 (1H, d, J = 15.3 Hz), 6.96 (2H, d, J = 7.3 Hz), 6.99
(1H, s), 7.16 (5H, m), 7.42 (3H, m), 7.74 (1H, d, J = 15.3 Hz). 13C
NMR (125 MHz, CDCl3): δ 121.1, 128.1, 128.3, 128.7, 129.1, 129.3,
130.3, 135.4, 136.4, 139.4, 140.9, 151.7, 172.2. IR (KBr): 2152, 1679
cm−1. EIMS m/z (rel int): 275 (8, M+). HREIMS m/z calcd for
C17H13N3O: 275.1059; found: 275.1057 [M]+.
5-(4″-Methoxyphenyl)-4-phenylpenta-(2E,4Z)-dienoyl Azide
[(2E,4Z)-5b]. Yield 100% from acid (2E,4Z)-11b; yellow solid. 1H
NMR (500 MHz, CDCl3): δ 3.71 (3H, s), 5.41 (1H, d, J = 15.2 Hz),
6.65 (2H, d, J = 8.9 Hz), 6.89 (2H, d, J = 8.9 Hz), 6.92 (1H, s), 7.12
(2H, d, J = 8.0 Hz), 7.39 (3H, m), 7.72 (1H, d, J = 15.2 Hz). 13C
NMR (125 MHz, CDCl3): δ 55.1, 113.7, 119.6, 127.9, 128.0, 129.1,
129.3, 131.9, 136.7, 137.2, 140.8, 152.0, 160.0, 172.0. IR (KBr): 2140,
1680 cm−1. EIMS m/z (rel int) 305 (4, M+). HREIMS m/z calcd for
C18H15N3O2: 305.1164; found: 305.1157 [M]+.
Hz), 6.93 (1H, d, J = 8.1 Hz), 6.96 (1H, s), 7.01 (2H, dd, J = 7.6, 1.8
Hz), 7.16 (3H, m), 7.73 (1H, d, J = 15.2 Hz). 13C NMR (100 MHz,
CDCl3): δ 55.9, 56.0, 111.9, 112.0, 121.0, 121.4, 128.3, 128.7, 128.8,
130.2, 135.4, 139.1, 140.8, 148.8, 149.7, 151.9, 172.2. IR (KBr): 2141,
1686 cm−1. EIMS m/z (rel int) 307 (100, [M − N2]+). HREIMS m/z
calcd for C19H17NO3: 307.1208; found: 307.1202 [M − N2]+.
4-(3′,4′-Dimethoxyphenyl)-5-(4″-methoxyphenyl)penta-
(2E,4Z)-dienoyl Azide [(2E,4Z)-5i]. Yield 95% from acid (2E,4Z)-
1
11i; yellow solid. H NMR (400 MHz, CDCl3): δ 3.76 (3H, s), 3.81
(3H, s), 3.95 (3H, s), 5,48 (1H, d, J = 15.1 Hz), 6.63 (1H, s), 6.69
(3H, m), 6.94 (4H, m), 7.71 (1H, d, J = 15.1 Hz). 13C NMR (100
MHz, CDCl3): δ 55.1, 55.8, 55.9, 111.9, 112.0, 113.8, 119.6, 121.3,
128.1, 129.0, 131.9, 136.9, 140.7, 148.6, 149.7, 152.3, 160.0, 172.1. IR
(KBr): 2137, 1674 cm−1. EIMS m/z (rel int) 337 (100, [M − N2]+).
HREIMS m/z calcd for C20H19NO4: 337.1314; found: 337.1323 [M −
N2]+.
4-(3′,4′-Dimethoxyphenyl)-5-(4″-nitrophenyl)penta-(2E,4Z)-
dienoyl Azide [(2E,4Z)-5j]. Yield 95% from acid (2E,4Z)-11j;
yellow solid. 1H NMR (400 MHz, CDCl3): δ 3.80 (3H, s), 3.95
(3H, s), 5.67 (1H, d, J = 15.2 Hz), 6.61 (1H, d, J = 1.9 Hz), 6.68 (1H,
dd, J = 8.2, 1.9 Hz), 6.95 (1H, d, J = 8.2 Hz), 7.00 (1H, s), 7.15 (2H, d,
J = 8.9 Hz), 7.72 (1H, d, J = 15.2 Hz), 8.00 (2H, d, J = 8.9 Hz). 13C
NMR (100 MHz, CDCl3): δ 55.8, 55.9, 111.6, 112.0, 121.2, 123.3,
123.4, 127.4, 130.5, 137.1, 141.8, 142.8, 146.8, 149.2, 149.8, 150.2,
171.8. IR (KBr): 2141, 1684 cm−1. EIMS m/z (rel int) 352 (100, [M
− N2]+). HREIMS m/z calcd for C19H16N2O5: 352.1059; found:
352.1051 [M − N2]+.
4,5-Bis(3′,4′-dimethoxyphenyl)penta-(2E,4Z)-dienoyl Azide
[(2E,4Z)-5k]. Yield 92% from acid (2E,4Z)-11k; yellow solid. 1H
NMR (400 MHz, CDCl3): δ 3.47 (3H, s), 3.81 (3H, s), 3.83 (3H, s),
3.91 (3H, s), 5.49 (1H, d, J = 15.1 Hz), 6.46 (1H, s), 6.67 (1H, s),
6.72(3H, m), 6.91 (1H, s), 6.96 (1H, d, J = 8.1 Hz), 7.72 (1H, d, J =
15.1 Hz). 13C NMR (100 MHz, CDCl3): δ 54.9, 55.5, 55.8 (2 × C),
110.4, 111.8, 111.9, 112.0, 119.6, 121.4, 124.8, 128.2, 128.9, 136.9,
140.7, 148.1, 148.5, 149.6, 149.7, 151.9, 171.9. IR (KBr): 2136, 1687
cm−1. EIMS m/z (rel int) 395 (1, M+). HREIMS m/z calcd for
C21H21N3O5: 395.1481; found: 395.1488 [M]+.
5-(3″,4″-Dimethoxyphenyl)-4-phenylpenta-(2E,4Z)-dienoyl
Azide [(2E,4Z)-5c]. Yield 96% from acid (2E,4Z)-11c; yellow solid.
1H NMR (400 MHz, CDCl3): δ 3.35 (3H, s), 3.81 (3H, s), 5.42 (1H,
d, J = 15.2 Hz), 6.31 (1H, s), 6.70 (1H, d, J = 8.4 Hz), 6.76 (1H, d, J =
8.4 Hz), 6.92 (1H, s), 7.18 (2H, d, J = 7.4 Hz), 7.38 (1H, t, J = 8.4
Hz), 7.45 (2H, t, J = 7.4 Hz), 7.73 (1H, d, J = 15.2 Hz). 13C NMR
(100 MHz, CDCl3): δ 54.8, 55.6, 110.3, 111.4, 119.6, 125.1, 127.8,
128.1, 129.2, 129.3, 136.7, 137.1, 140.8, 148.0, 149.6, 151.7, 171.9. IR
(KBr): 2133, 1682 cm−1. EIMS m/z (rel int): 307 (86, [M − N2]+).
HREIMS m/z calcd for C19H17NO3: 307.1208; found: 307.1219 [M −
N2]+.
4-(4′-Methoxyphenyl)-5-phenylpenta-(2E,4Z)-dienoyl Azide
1
[(2E,4Z)-5d]. Yield 100% from acid (29E,4Z)-11d; yellow solid. H
NMR (500 MHz, CDCl3): δ 3.85 (3H, s), 5.52 (1H, d, J = 15.3 Hz),
6.95 (2H, d, J = 8.6 Hz), 6.96 (1H, s), 6.99 (2H, d, J = 6.7 Hz), 7.05
(2H, d, J = 8.6 Hz), 7.15 (3H, m), 7.73 (1H, d, J = 15.3 Hz). 13C
NMR (125 MHz, CDCl3): δ 55.3, 114.7, 120.9, 128.2, 128.3, 128.6,
130.2, 130.3, 135.5, 139.1, 140.9, 152.1, 159.4, 172.2. IR (KBr): 2142,
1681 cm−1. EIMS m/z (rel int): 305 (5, M+). HREIMS m/z calcd for
C18H15N3O2: 305.1164; found: 305.1160 [M]+.
5-(3″,4″-Dimethoxyphenyl)-4-(4′-nitrophenyl)penta-(2E,4Z)-
dienoyl Azide [(2E,4Z)-5l]. Yield 96% from acid (2E,4Z)-11l;
yellow solid. 1H NMR (400 MHz, CDCl3): δ 3.48 (3H, s), 3.83
(3H, s), 5.32 (1H, d, J = 15.4 Hz), 6.35 (1H, s), 6.63 (1H, d, J = 8.4
Hz), 6.70 (1H, d, J = 8.4 Hz), 7.03 (1H, s), 7.41 (2H, d, J = 8.4 Hz),
7.73 (1H, d, J = 15.4 Hz), 8.33 (2H, d, J = 8.4 Hz). 13C NMR (100
MHz, CDCl3): δ 55.2, 55.8, 110.9, 112.3, 119.9, 124.5, 124.6, 127.3,
130.8, 134.8, 141.8, 144.2, 147.6, 148.5, 150.2, 150.3, 171.7. IR (KBr):
2133, 1682 cm−1. EIMS m/z (rel int) 380 (1, M±). HREIMS m/z
calcd for C19H16N4O5: 380.1121; found: 380.1128 [M]±.
General Procedure for the Iodine-Catalyzed Cyclization of
an 4,5-Diphenylpenta-2,4-dienoyl Azide, 5. A mixture of azide 5
(1 mmol) and iodine (5.1 mg, 0.02 mmol) in o-dichlorobenzene (5
mL) was heated at 150 °C under N2 for 1−7 h. Reaction completion
was monitored by the disappearance of the spots of isocyanate 1 and
dimer 6 on the TLC plate. After cooling, the resulting solution was
directly purified by column chromatography over silica gel and eluted
with hexane−CH2Cl2 to give 3,4-diphenylpyridin-2(1H)-one 2 and 2-
phenylnaphthalene 3 or 1(E)-benzylidene-1H-indene 4. The full
spectral data of these compounds are described as follows.
4,5-Bis(4′-methoxyphenyl)penta-(2E,4Z)-dienoyl Azide
[(2E,4Z)-5e]. Yield 91% from acid (2E,4Z)-11e; yellow solid. 1H
NMR (500 MHz, CDCl3): δ 3.74 (3H, s), 3.86 (3H, s), 5.45 (1H, d, J
= 15.2 Hz), 6.68 (2H, d, J = 8.8 Hz), 6.94 (5H, m), 7.05 (2H, d, J =
8.8 Hz), 7.71 (1H, d, J = 15.2 Hz). 13C NMR (125 MHz, CDCl3): δ
55.2, 55.3, 113.8, 114.8, 119.6, 128.3, 128.7, 130.3, 131.9, 137.0, 140.9,
152.5, 159.3, 160.0, 172.2. IR (KBr): 2137, 1675 cm−1. EIMS m/z (rel
int) 335 (3, M+). HREIMS m/z calcd for C19H17N3O3: 335.1270;
found: 335.1265 [M]+.
5-(3″,4″-Dimethoxyphenyl)-4-(4′-methoxyphenyl)penta-
(2E,4Z)-dienoyl Azide [(2E,4Z)-5f]. Yield 83% from acid (2E,4Z)-
1
11f; yellow solid. H NMR (500 MHz, CDCl3): δ 3.44 (3H, s), 3.83
(3H, s), 3.84 (3H, s), 5.47 (1H, d, J = 15.1 Hz), 6.41 (1H, s), 6.71
(1H, d, J = 8.4 Hz), 6.75 (1H, d, J = 8.4 Hz), 6.91 (1H, s), 6.99 (2H, d,
J = 8.7 Hz), 7.09 (2H, d, J = 8.7 Hz), 7.72 (1H, d, J = 15.1 Hz). 13C
NMR (125 MHz, CDCl3): δ 55.1, 55.3, 55.7, 110.5, 111.9, 114.8,
119.7, 124.9, 128.5, 128.8, 130.5, 137.1, 140.9, 148.2, 149.7, 152.2,
159.3, 172.1. IR (KBr): 2129, 1682 cm−1. EIMS m/z (rel int): 337
(100, [M − N2]+). HREIMS m/z calcd for C20H19N3O4: 337.1314;
found: 337.1321 [M − N2]+.
3,4-Diphenylpyridin-2(1H)-one (2a). Yield 32%; white granules,
mp 284−285 °C (hexane−CHCl3) (lit.19 mp 284−284.5 °C). 1H
NMR (500 MHz, DMSO-d6): δ 6.22 (1H, d, J = 6.7 Hz), 7.04 (4H,
m), 7.15 (6H, m), 7.41 (1H, d, J = 6.7 Hz), 11.78 (1H, br s). 13C
NMR (125 MHz, DMSO-d6): δ 107.9, 126.7, 127.6, 127.8, 128.2,
128.9, 129.3, 131.2, 134.0, 136.1, 139.5, 150.5, 162.1. IR (KBr): 1643
cm−1. EIMS m/z (rel int) 247 (58, M+). Anal. Calcd for C17H13NO:
C, 82.57; H, 5.30; N, 5.66. Found: C, 82.88; H, 5.65; N, 5.60.
2-Phenylnaphthalene (3a). Yield 60%; pale yellow granule, mp
4-(4′-Methoxyphenyl)-5-(4″-nitrophenyl)penta-(2E,4Z)-di-
enoyl Azide [(2E,4Z)-5g]. Yield 80% from acid (2E,4Z)-11g; yellow
1
solid. H NMR (500 MHz, CDCl3): δ 3.87 (3H, s), 5.64 (1H, d, J =
15.2 Hz), 6.97 (3H, m), 7.03 (2H, m), 7.12 (2H, d, J = 8.8 Hz), 7.72
(1H, d, J = 15.2 Hz), 8.00 (2H, d, J = 8.8 Hz). 13C NMR (125 MHz,
CDCl3): δ 55.3, 115.0, 123.4, 123.5, 127.1, 130.1, 130.5, 137.3, 142.0,
142.8, 146.8, 150.4, 159.8, 172.0. IR (KBr): 2137, 1683 cm−1. EIMS
m/z (rel int) 322 (100, [M − N2]+). HREIMS m/z calcd for
C18H14N2O4: 322.0954; found: 322.0959 [M − N2]+.
4-(3′,4′-Dimethoxyphenyl)-5-phenylpenta-(2E,4Z)-dienoyl
Azide [(2E,4Z)-5h]. Yield 93% from acid (2E,4Z)-11h; yellow solid.
1H NMR (400 MHz, CDCl3): δ 3.79 (3H, s), 3.05 (3H, s), 5.55 (1H,
100−101 °C (hexane−CHCl3) (lit.11 mp 100−101 °C). H NMR
1
(400 MHz, CDCl3): δ 7.37 (1H, t, J = 7.3 Hz), 7.48 (4H, m), 7.73
(3H, m), 7.88 (3H, m), 8.04 (1H, s). 13C NMR (100 MHz, CDCl3): δ
125.6, 125.8, 125.9, 126.2, 127.3, 127.4, 127.6, 128.2, 128.4, 128.8,
d, J = 15.2 Hz), 6.62 (1H, d, J = 1.9 Hz), 6.69 (1H, dd, J = 8.1, 1.9
9683
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Article
132.6, 133.7, 138.5, 141.1. IR (KBr): 2925, 1597 cm−1. EIMS m/z (rel
int) 204 (100, M+). Anal. Calcd for C16H12: C, 94.08; H, 5.92. Found:
C, 94.09; H, 6.25.
7.00 (2H, d, J = 8.8 Hz), 7.16 (2H, m), 7.63 (2H, d, J = 8.8 Hz), 7.67
(1H, dd, J = 8.5, 1.9 Hz), 7.77 (1H, d, J = 8.5 Hz), 7.78 (1H, d, J = 8.5
Hz), 7.91 (1H, d, J = 1.9 Hz). 13C NMR (100 MHz, CDCl3): δ 55.3,
55.4, 105.6, 114.3, 119.1, 124.9, 125.9, 127.2, 128.2, 129.3, 129.5,
133.4, 133.8, 136.0, 157.6, 159.0. IR (KBr): 2932, 1605 cm−1. EIMS
m/z (rel int) 264 (100, M+). Anal. Calcd for C18H16O2: C, 81.79; H,
6.10. Found: C, 81.42; H, 5.94.
3-(4″-Methoxyphenyl)-4-phenylpyridin-2(1H)-one (2b).
1
Yield 32%; white granules, mp 249−251 °C (hexane−CHCl3). H
NMR (600 MHz, CDCl3): δ 3.77 (3H, s), 6.35 (1H, d, J = 6.6 Hz),
6.77 (2H, d, J = 6.6 Hz), 7.10 (4H, m), 7.21 (3H, d, J = 6.6 Hz), 7.36
(1H, d, J = 6.6 Hz). 13C NMR (150 MHz, CDCl3): δ 55.1, 109.7,
113.4, 127.4, 127.6, 128.0, 128.9, 129.2, 132.2, 132.7, 139.4, 151.7,
158.5, 164.8. IR (KBr): 1637 cm−1. EIMS m/z (rel int): 277 (81, M+).
Anal. Calcd for C18H15NO2: C, 77.96; H, 5.45; N, 5.05. Found: C,
78.25; H, 5.10; N, 5.16.
3-(3″,4″-Dimethoxyphenyl)-4-(4′-methoxyphenyl)pyridin-
2(1H)-one (2f). Yield 11%; white granules, mp 284−285 °C
1
(hexane−CHCl3). H NMR (400 MHz, DMSO-d6): δ 3.51 (3H, s),
3.70 (6H, s), 6.18 (1H, d, J = 6.6 Hz), 6.62 (2H, m), 6.77 (3H, m),
7.02 (2H, d, J = 8.4 Hz), 7.33 (1H, d, J = 6.6 Hz), 11.50 (1H, br s);
13C NMR (100 MHz, DMSO-d6): δ 55.1, 55.5 (2 × C), 107.7, 111.3,
2-Methoxy-6-phenylnaphthalene (3b). Yield 50%; pale yellow
granules, mp 151−152 °C (hexane−CHCl3) (lit.20 mp 150−151 °C).
1H NMR (500 MHz, CDCl3): δ 3.92 (3H, s), 7.16 (2H, m), 7.34 (1H,
t, J = 7.7 Hz), 7.46 (2H, t, J = 7.7 Hz), 7.70 (3H, m), 7.77 (1H, d, J =
8.2 Hz), 7.79 (1H, d, J = 8.2 Hz), 7.96 (1H, s). 13C NMR (125 MHz,
CDCl3): δ 55.3, 105.6, 119.1, 125.6, 126.0, 127.0, 127.2, 127.3, 128.8,
113.5, 115.8, 123.6, 128.4, 128.5, 129.9, 131.8, 133.1, 147.6, 147.8,
149.6, 158.6, 161.9. IR (KBr) 1636 cm−1. EIMS m/z (rel int) 337
(100, M+); HREIMS m/z calcd for C20H19NO4: 337.1314; found:
337.1304 [M]+.
2,3-Dimethoxy-6-(4′-methoxyphenyl)naphthalene (3f).
Yield 81%; white needles, mp 164−165 °C (hexane−CHCl3) (lit.24
mp 158−159 °C). 1H NMR (400 MHz, CDCl3): δ 3.83 (3H, s), 3.98
(3H, s), 3.99 (3H, s), 6.99 (2H, d, J = 8.7 Hz), 7.10 (1H, s), 7.14 (1H,
s), 7.55 (1H, dd, J = 8.4, 1.5 Hz), 7.61 (2H, d, J = 8.7 Hz), 7.70 (1H, d,
J = 8.4 Hz), 7.83 (1H, s). 13C NMR (100 MHz, CDCl3): δ 55.3, 55.8
(2 × C), 106.0, 106.4, 114.2, 123.6 (2 × C), 126.7, 128.0, 128.1, 129.5,
133.8, 136.5, 149.3, 149.7, 159.0. IR (KBr): 2963, 1605 cm−1. EIMS
m/z (rel int) 294 (100, M+). Anal. Calcd for C19H18O3: C, 77.53; H,
6.16. Found: C, 77.52; H, 6.42.
4-(4′-Methoxyphenyl)-3-(4″-nitrophenyl)pyridin-2(1H)-one
(2g). Yield 88%; pale yellow granules, mp 272−274 °C (hexane−
CHCl3). 1H NMR (500 MHz, CDCl3): δ 3.77 (3H, s), 6.41 (1H, d, J
= 6.8 Hz), 6.75 (2H, d, J = 8.6 Hz), 6.99 (2H, d, J = 8.6 Hz), 7.40 (3H,
m), 8.11 (2H, d, J = 8.6 Hz), 12.93 (1H, s). 13C NMR (125 MHz,
CDCl3): δ 55.2, 109.9, 113.9, 123.1, 126.9, 130.2, 130.3, 132.2, 133.9,
143.0, 146.6, 152.8, 159.8, 163.8. IR (KBr): 1639 cm−1; EIMS m/z
(rel int) 322 (87, M+). HREIMS m/z calcd for C18H14N2O4:
322.0954; found: 322.0958 [M]+.
129.2, 129.7, 133.8, 136.4, 141.2, 157.8. IR (KBr): 2960, 1603 cm−1
.
EIMS m/z (rel int) 234 (100, M+). Anal. Calcd for C17H14O: C,
87.15; H, 6.02. Found: C, 86.84; H, 6.26.
3-(3′,4′-Dimethoxyphenyl)-4-phenylpyridin-2(1H)-one (2c).
Yield 8%; white granules, mp 228−230 °C (hexane−CHCl3). 1H
NMR (500 MHz, CDCl3): δ 3.60 (3H, s), 3.85 (3H, s), 6.36 (1H, d, J
= 6.7 Hz), 6.60 (1H, s), 6.78 (1H, d, J = 8.3 Hz), 6.88 (1H, d, J = 8.3
Hz), 7.10 (2H, m), 7.21 (3H, m), 7.38 (1H, d, J = 6.7 Hz), 12.90 (1H,
br s). 13C NMR (125 MHz, CDCl3): δ 55.6, 55.7, 109.6, 110.7, 114.6,
123.7, 127.5, 127.7, 128.1, 128.8, 129.4, 132.6, 139.5, 148.1, 148.2,
151.8, 164.6. IR (KBr): 1641 cm−1. EIMS m/z (rel int) 307 (100, M+).
HREIMS m/z calcd for C19H17NO3: 307.1208; found: 307.1197 [M]+.
2,3-Dimethoxy-6-phenylnaphthalene (3c). Yield 83%; white
needles, mp 136−137 °C (hexane−EtOAc) (lit.21 mp 134−135 °C).
1H NMR (400 MHz, CDCl3): δ 3.98 (6H, s), 7.11 (1H, s), 7.14 (1H,
s), 7.34 (1H, t, J = 7.5 Hz), 7.45 (2H, t, J = 7.5 Hz), 7.58 (1H, dd, J =
8.4, 1.7 Hz), 7.70 (3H, m), 7.88 (1H, s). 13C NMR (100 MHz,
CDCl3): δ 55.8 (2 × C), 105.9, 106.4, 123.7, 124.3, 126.7, 126.9,
127.1, 128.3, 128.7, 129.3, 136.8, 141.2, 149.4, 149.7. IR (KBr): 2963,
1601 cm−1. EIMS m/z (rel int): 264 (100, M+). Anal. Calcd for
C18H16O2: C, 81.79; H, 6.10. Found: C, 81.59; H, 6.15.
4-(3′,4′-Dimethoxyphenyl)-3-phenylpyridin-2(1H)-one
(2h). Yield 55%; white granules, mp 250−252 °C (hexane−CHCl3).
1H NMR (400 MHz, DMSO-d6): δ 3.36 (3H, s), 3.69 (3H, s), 6.28
(1H, d, J = 6.8 Hz), 6.47 (1H, d, J = 1.9 Hz), 6.74 (1H, dd, J = 8.3, 1.9
Hz), 6.82 (1H, d, J = 8.3 Hz), 7.05 (2H, d, J = 8.3 Hz), 7.18 (3H, m),
7.39 (1H, d, J = 6.8 Hz), 11.7 (1H, br s). 13C NMR (100 MHz,
DMSO-d6): δ 55.1, 55.5, 107.7, 111.4, 113.3, 121.4, 126.5, 127.6,
128.7, 131.1, 131.4, 133.7, 136.7, 147.9, 148.5, 150.0, 162.1. IR (KBr):
1636 cm−1. EIMS m/z (rel int) 307 (94, M+). HREIMS m/z calcd for
C19H17NO3: 307.1208; found: 307.1202 [M]+.
4-(4′-Methoxyphenyl)-3-phenylpyridin-2(1H)-one (2d). Yield
1
63%; white granules, mp 245−246 °C (hexane−CHCl3). H NMR
(400 MHz, DMSO-d6): δ 3.69 (3H, s), 6.21 (1H, d, J = 6.8 Hz), 6.74
(2H, d, J = 8.6 Hz), 6.99 (2H, d, J = 8.6 Hz), 7.05 (2H, d, J = 7.6 Hz),
7.16 (3H, m), 7.36 (1H, d, J = 6.8 Hz), 11.57 (1H, br s). 13C NMR
(100 MHz, DMSO-d6): δ 55.0, 107.7, 113.5, 126.3, 127.3, 128.6,
130.0, 130.9, 131.4, 133.5, 136.2, 149.8, 158.7, 161.9. IR (KBr): 1639
cm−1. EIMS m/z (rel int): 277 (74, M+). Anal. Calcd for C18H15NO2:
C, 77.96; H, 5.45; N, 5.05. Found: C, 77.91; H, 5.68; N, 5.05.
2-(4′-Methoxyphenyl)naphthalene (3d). Yield 22%; pale
yellow granules, mp 138−139 °C (hexane−EtOAc) (lit.22 mp 139−
140 °C). 1H NMR (500 MHz, CDCl3): δ 3.87 (3H, s), 7.02 (2H, d, J
= 8.7 Hz), 7.47 (2H, m), 7.66 (2H, d, J = 8.7 Hz), 7.71 (1H, d, J = 8.7
Hz), 7.86 (3H, m), 7.98 (1H, s). 13C NMR (125 MHz, CDCl3): δ
55.4, 114.3, 125.0, 125.4, 125.6, 126.2, 127.6, 128.0, 128.3, 128.4,
132.3, 133.6, 133.8, 138.2, 159.3. IR (KBr): 2947, 1597 cm−1. EIMS
m/z (rel int) 234 (100, M+); HREIMS m/z calcd for C17H14O:
234.1045; found: 234.1039 [M]+.
1(E)-Benzylidene-5,6-dimethoxy-1H-indene (4h). Yield 32%;
1
yellow granules, mp 104−105 °C (hexane−CHCl3). H NMR (400
MHz, CDCl3): δ 3.91 (3H, s), 3.96 (3H, s), 6.89 (3H, m), 7.27 (1H,
s), 7.32 (1H, t, J = 7.3 Hz), 7.37 (1H, s), 7.41 (2H, t, J = 7.3 Hz), 7.58
(2H, d, J = 7.3 Hz). 13C NMR (100 MHz, CDCl3): δ 56.1, 56.4, 104.0,
104.9, 124.8, 127.8, 128.1, 128.6, 130.0, 130.1, 134.1, 135.4, 137.0,
140.4, 147.5, 149.3. IR (KBr): 2970, 1597 cm−1. EIMS m/z (rel int)
264 (100, M+). Anal. Calcd for C18H16O2: C, 81.79; H, 6.10. Found:
C, 81.49; H, 6.17.
4-(3′,4′-Dimethoxyphenyl)-3-(4″-methoxyphenyl)pyridin-
2(1H)-one (2i). Yield 45%; white granules, mp 286−288 °C
1
(hexane−CHCl3). H NMR (500 MHz, DMSO-d6): δ 3.42 (3H, s),
3,4-Bis(4′-methoxyphenyl)pyridin-2(1H)-one (2e). Yield 58%;
1
3.69 (6H, s), 6.25 (1H, d, J = 6.8 Hz), 6.51 (1H, d, J = 1.8 Hz), 6.72
(1H, dd, J = 8.3, 1.8 Hz), 6.77 (2H, d, J = 8.7 Hz), 6.83 (1H, d, J = 8.3
Hz), 6.97 (2H, d, J = 8.7 Hz), 7.35 (1H, d, J = 6.8 Hz), 11.64 (1H, s).
13C NMR (125 MHz, DMSO-d6) δ 55.2 (2 × C), 55.5, 107.8, 111.4,
white granules, mp 254−256 °C (hexane−CHCl3). H NMR (600
MHz, DMSO-d6): δ 3.69 (3H, s), 3.70 (3H, s), 6.19 (1H, d, J = 6.6
Hz), 6.75 (2H, d, J = 8.4 Hz), 6.78 (2H, d, J = 8.4 Hz), 6.97 (2H, d, J
= 9.0 Hz), 7.01 (2H, d, J = 9.0 Hz), 7.35 (1H, d, J = 6.6 Hz), 11.66
(1H, br s). 13C NMR (150 MHz, DMSO-d6): δ 54.9, 55.0, 107.8,
112.9, 113.5, 128.1 (2 × C), 130.1, 131.6, 132.1, 133.1, 149.4, 157.7,
158.5, 162.1. IR (KBr): 1636 cm−1. EIMS m/z (rel int) 307 (95, M+).
Anal. Calcd for C19H17NO3: C, 74.25; H, 5.58; N, 4.56. Found: C,
73.97; H, 5.87; N, 4.65.
113.1, 113.2, 121.4, 128.4, 128.6, 131.7, 132.2, 133.3, 147.9, 148.4,
149.7, 158.0, 162.3. IR (KBr): 1636 cm−1. EIMS m/z (rel int) 337
(100, M+). HREIMS m/z calcd for C20H19NO4: 337.1314; found:
337.1307 [M]+.
1(E)-(4″-Methoxybenzylidene)-5,6-dimethoxy-1H-indene
(4i). Yield 25%; yellow granules, mp 134−135 °C (hexane−CHCl3).
1H NMR (500 MHz, CDCl3): δ 3.86 (3H, s), 3.93 (3H, s), 3.97 (3H,
2-Methoxy-6-(4′-methoxyphenyl)naphthalene (3e). Yield
25%; white granules, mp 201−202 °C (hexane−CHCl3) (lit.23 mp
1
190 °C). H NMR (400 MHz, CDCl3): δ 3.86 (3H, s), 3.93 (3H, s),
s), 6.91 (3H, m), 6.96 (2H, d, J = 8.7 Hz), 7.26 (1H, s), 7.33 (1H, s),
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7.57 (2H, d, J = 8.7 Hz). 13C NMR (125 MHz, CDCl3): δ 55.3, 56.1,
56.4, 103.7, 104.7, 114.2, 124.6, 127.7, 129.7, 130.3, 131.6, 133.4,
135.1, 138.5, 147.4, 149.0, 159.8. IR (KBr): 2928, 1601 cm−1. EIMS
m/z (rel int) 294 (100, M+). Anal. Calcd for C19H18O3: C, 77.53; H,
6.16. Found: C, 77.68; H, 5.97.
6.84 (2H, m), 7.06 (3H, m), 7.10 (2H, m), 7.13 (2H, m), 7.22 (6H,
m), 7.27 (2H, m), 7.38 (3H, m), 8.41 (1H, d, J = 7.8 Hz), 12.68 (1H,
d, J = 10.0 Hz). 13C NMR (125 MHz, CDCl3): δ 110.6, 123.1, 124.8,
126.6, 127.7 (2 × C), 127.9, 128.1, 128.2, 128.5, 128.8, 129.1, 129.2,
129.4, 129.7, 130.0, 130.8, 131.3, 134.6, 136.8, 137.7, 137.9, 139.7,
149.7, 151.9, 164.8. IR (KBr): 1721, 1634 cm−1. ESIMS m/z (rel int)
495 (100, [M + 1]+). Anal. Calcd for C34H26N2O2: C, 82.57; H, 5.30;
N, 5.66. Found: C, 82.35; H, 5.62; N, 5.60.
4-(3′,4′-Dimethoxyphenyl)-3-(4″-nitrophenyl)pyridin-2(1H)-
one (2j). Yield 30%; pale yellow granules, mp 256−257 °C (hexane−
1
CHCl3). H NMR (400 MHz, CDCl3): δ 3.59 (3H, s), 3.85 (3H, s),
6.45 (1H, d, J = 6.7 Hz), 6.50 (1H, d, J = 1.9 Hz), 6.69 (1H, dd, J =
8.3, 1.9 Hz), 6.74 (1H, d, J = 8.3 Hz), 7.41 (3H, m), 8.12 (2H, d, J =
8.9 Hz), 13.11 (1H, br s); 13C NMR (100 MHz, CDCl3) δ 55.7, 55.8,
109.8, 110.9, 112.3, 121.8, 123.1, 126.8, 130.4, 132.1, 134.1, 143.1,
146.6, 148.6, 149.4, 152.9, 163.9. IR (KBr): 1641 cm−1. EIMS m/z (rel
int) 352 (100, M+). HREIMS m/z calcd for C19H16N2O5: 352.1059;
found: 352.1061 [M]+.
1(E)-(4″-Nitrobenzylidene)-5,6-dimethoxy-1H-indene (4j).
Yield 67%; black granules, mp 130−131 °C (hexane−CHCl3). 1H
NMR (400 MHz, CDCl3): δ 3.91 (3H, s), 3.96 (3H, s), 6.73 (1H, d, J
= 5.6 Hz), 6.86 (1H, s), 6.93 (1H, d, J = 5.6 Hz), 7.23 (1H, s), 7.29
(1H, s), 7.65 (2H, d, J = 8.6 Hz), 8.22 (2H, d, J = 8.6 Hz); 13C NMR
(100 MHz, CDCl3) δ 56.0, 56.3, 104.4, 105.1, 123.7, 123.8, 124.4,
129.3, 130.4, 135.6, 136.4, 143.4, 143.5, 146.8, 147.7, 149.9. IR (KBr):
2988, 1589, 1513 cm−1. EIMS m/z (rel int) 309 (100, M+). Anal.
Calcd for C18H15NO4: C, 69.89; H, 4.89; N, 4.53. Found: C, 69.55; H,
5.02; N, 4.26.
ASSOCIATED CONTENT
■
S
* Supporting Information
1H and 13C NMR spectra of all compounds 2−6 and 9−11,
preparation of starting materials 9 and 10, and X-ray
crystallographic data as well as ORTEP structure, including
CIF file for 4j. This material is available free of charge via the
Internet at http://pubs.acs.org.
AUTHOR INFORMATION
Corresponding Author
*E-mail: thchuang@mail.cmu.edu.tw.
■
ACKNOWLEDGMENTS
■
Financial support from the National Science Council of the
Republic of China (NSC 99-2113-M-039-001-MY2) and China
Medical University (CMU98-N2-07 and CMU99-COL-12) is
gratefully acknowledged.
3,4-Bis(3′,4′-dimethoxyphenyl)pyridin-2(1H)-one (2k). Yield
1
12%; white granules, mp >300 °C (hexane−CHCl3). H NMR (400
MHz, CDCl3): δ 3.57 (3H, s), 3.69 (3H, s), 3.85 (3H, s), 3.86 (3H, s),
6.40 (1H, d, J = 6.7 Hz), 6.54 (1H, d, J = 1.4 Hz), 6.71 (1H, d, J = 1.1
Hz), 6.79 (4H, m), 7.39 (1H, d, J = 6.7 Hz), 13.19 (1H, br s); 13C
NMR (100 MHz, CDCl3): δ 55.6, 55.7, 55.8 (2 × C), 109.5, 110.5,
110.8, 112.4, 114.2, 121.4, 123.5, 128.0, 128.8, 131.7, 132.8, 148.0,
148.1, 148.4, 148.6, 151.4, 164.8. IR (KBr): 1632 cm−1. EIMS m/z (rel
int) 367 (100, M+). HREIMS m/z calcd for C21H21NO5: 367.1420;
found: 367.1426 [M]+.
REFERENCES
■
(1) Eloy, F.; Deryckere, A. J. Heterocycl. Chem. 1970, 7, 1191−1193.
(2) Mikol, G. J.; Boyer, J. H. J. Org. Chem. 1972, 37, 724−726.
(3) Ozaki, S. Chem. Rev. 1972, 72, 457−496.
(4) MacMillan, J. H.; Washburne, S. S. J. Org. Chem. 1973, 38, 2982−
2984.
2,3-Dimethoxy-6-(3′,4′-dimethoxyphenyl)naphthalene
(3k). Yield 61%; yellow granules, mp 165−166 °C (hexane−CHCl3)
(lit.25 mp 168−170 °C). 1H NMR (400 MHz, CDCl3): δ 3.94 (3H, s),
3.99 (3H, s), 4.02 (3H, s), 4.03 (3H, s), 6.98 (1H, d, J = 8.2 Hz), 7.14
(1H, s), 7.18 (1H, s), 7.23 (1H, m), 7.26 (1H, s), 7.57 (1H, dd, J =
8.2, 1.8 Hz), 7.74 (1H, d, J = 8.2 Hz), 7.85 (1H, s). 13C NMR (100
MHz, CDCl3): δ 55.9 (2 × C), 56.0 (2 × C), 106.1, 106.5, 110.7,
111.6, 119.5, 123.7, 123.8, 126.8, 128.2, 129.5, 134.5, 136.9, 148.5,
149.3, 149.5, 149.9. IR (KBr): 2928, 1601 cm−1; EIMS m/z (rel int)
324 (100, M+). Anal. Calcd for C20H20O4: C, 74.06; H, 6.21. Found:
C, 74.39; H, 6.62.
(5) Luo, L.; Bartberger, M. D.; Dolbier, W. R. Jr. J. Am. Chem. Soc.
1997, 119, 12366−12367.
(6) Kobayashi, K.; Kitamura, T.; Yoneda, K.; Morikawa, O.; Konishi,
H. Chem. Lett. 2000, 29, 798−799.
(7) Choshi, T.; Hibino, S. Heterocycles 2011, 83, 1205−1239.
(8) Showalter, H.D. H.; Sercel, A. D.; Stier, M. A.; Turner, W. R. J.
Heterocycl. Chem. 2001, 38, 961−964.
(9) Chuang, T. H.; Wu, P. L. J. Chin. Chem. Soc. 2006, 53, 413−420.
(10) Jiang, B.; Li, C.; Tu, S. J.; Shi, F. J. Comb. Chem. 2010, 12, 482−
487.
(11) Qin, C.; Lu, W. J. Org. Chem. 2008, 73, 7424−7427.
(12) Aubert, C.; Betschmann, P.; Eichberg, M. J.; Gandon, V.;
Heckrodt, T. J.; Lehmann, J.; Malacria, M.; Masjost, B.; Paredes, E.;
Vollhardt, K. P. C.; Whitener, G. D. Chem.Eur. J. 2007, 13, 7443−
7465.
3-(3″,4″-Dimethoxyphenyl)-4-(4′-nitrophenyl)pyridin-2(1H)-
one (2l). Yield 13%; yellow needles, mp 243−245 °C (hexane-
1
EtOAc). H NMR (500 MHz, CDCl3) δ 3.70 (3H, s), 3.85 (3H, s),
6.34 (1H, d, J = 6.6 Hz), 6.69 (1H, s), 6.72 (1H, d, J = 8.2 Hz), 6.76
(1H, d, J = 8.2 Hz), 7.29 (2H, d, J = 8.3 Hz), 7.44 (1H, d, J = 6.6 Hz),
8.09 (2H, d, J = 8.3 Hz), 13.36 (1H, br s). 13C NMR (125 MHz,
CDCl3) δ 55.7, 55.8, 108.7, 110.9, 114.1, 123.4, 123.7, 126.5, 129.8,
130.2, 133.4, 146.1, 147.1, 148.5, 148.6, 149.4, 164.5; IR (KBr) 1636
cm−1. EIMS m/z (rel int) 352 (100, M+). Anal. Calcd for
C19H16N2O5: C, 64.77; H, 4.58; N, 7.95. Found: C, 64.51; H, 4.84;
N, 7.63.
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4232.
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Chem. Soc. Jpn. 1993, 66, 687−691.
2,3-Dimethoxy-6-(4′-nitrophenyl)naphthalene (3l). Yield
1
77%; yellow granules, mp 169−170 °C (hexane-EtOAc). H NMR
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Chem. 2006, 4, 860−867.
(400 MHz, CDCl3) δ 4.01 (6H, s), 7.13 (1H, s), 7.18 (1H, s), 7.56
(1H, dd, J = 8.5, 1.9 Hz), 7.77 (3H, m), 7.91 (1H, s), 8.26 (2H, d, J =
8.5 Hz). 13C NMR (100 MHz, CDCl3): δ 55.8 (2 × C), 106.0, 106.7,
123.1, 124.0, 125.1, 127.2, 127.5, 129.2, 129.3, 134.2, 146.7, 147.7,
150.1, 150.3; IR (KBr) 2966, 1591 cm−1; EIMS m/z (rel int) 309
(100, M+). Anal. Calcd for C18H15NO4: C, 69.89; H, 4.89; N, 4.53.
Found: C, 69.90; H, 5.15; N, 4.73.
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4654.
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Kametani, T. J. Chem. Soc., Perkin Trans. 1 1990, 469−475.
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230−235.
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N-(3,4-Diphenylbuta-1,3-dienylcarbamoyl)-3,4-diphenyl-1H-
pyridin-2-one (6a). Yellow granules, mp 233−235 °C (hexane−
1
EtOAc). H NMR (500 MHz, CDCl3): δ 6.42 (1H, d, J = 14.2 Hz),
6.46 (1H, s), 6.53 (1H, d, J = 7.7 Hz), 6.56 (1H, dd, J = 14.2, 10.0 Hz),
9685
dx.doi.org/10.1021/jo2017247|J. Org. Chem. 2011, 76, 9678−9686

The Journal of Organic Chemistry
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