A novel ambident reactivity of azolylacroleins

Article abstract of DOI:10.1016/j.tet.2007.03.098

Reaction of azolylacroleins with phosphoranes bearing a conjugated double bond was found to yield either azolyltrienes in?a Wittig reaction, or to undergo cyclization to a dihydrobenzene containing the azole substituent. Transformation with an aza-Wittig reagent gave tetrazolylpyridines. The ambident reactivity was found to be dependent on the substituent of the phosphorane, which was rationalized by ab initio (DFT) calculation of the atomic charges of the reaction centres.

Full text of DOI:10.1016/j.tet.2007.03.098

Tetrahedron 63 (2007) 4730–4736
A novel ambident reactivity of azolylacroleins
*
Ildik ꢀo Nagy, Gy €o rgy Haj ꢀo s, Zsuzsanna Riedl, Orsolya Egyed and Imre P ꢀa pai
Chemical Research Center, H-1025 Budapest, Pusztaszeri uꢀ t 59, Hungary
Received 8 December 2006; revised 27 February 2007; accepted 15 March 2007
Available online 18 March 2007
Abstract—Reaction of azolylacroleins with phosphoranes bearing a conjugated double bond was found to yield either azolyltrienes in a
Wittig reaction, or to undergo cyclization to a dihydrobenzene containing the azole substituent. Transformation with an aza-Wittig reagent
gave tetrazolylpyridines. The ambident reactivity was found to be dependent on the substituent of the phosphorane, which was rationalized by
ab initio (DFT) calculation of the atomic charges of the reaction centres.
Ó 2007 Elsevier Ltd. All rights reserved.
1
. Introduction
was carried out with the related cinnamaldehyde (5), the
fully trans triene 6 was formed and no product reminiscent
of 4 was detected.
Conjugated polyene building blocks are present in several
biologically important compounds such as leukotrienes,
fatty acids, arachidonic acid, as well as in important natural
substances, e.g., in b-carotene or vitamin A. Furthermore,
some drugs like polyene antibiotics, amphotericin B, candi-
cidin, nystatin, etc. contain such structural units. Because of
the biological importance of conjugated polyene systems,
we have extended our earlier research activity on tetrazo-
lyldienes for trienes.
MeOOC
N
N
1
N
N
PPh3
3
N
Ar
O
N
2
Ar
N
N
N N
Ar
COOMe
2
N
N
3
,4
1
COOMe
Ar
Yield (%)
Recently we have described that tetrazolylacroleins (1) can
be prepared via a relatively easy pathway (a four-step
synthesis starting from 2-aminopyridine), and these com-
pounds easily undergo condensation reactions with C-
a
4-Cl-C6H6
6
68
66
4
3
b
4-MeO-C H
6
nucleophiles (e.g., with ethyl nitroacetate or acetylacetone)
and participate in Wittig reactions. The synthetic possibility
that phosphoranes bearing a conjugating double bond (e.g.,
COOMe
O
4
2
5
6
2
(
) could also be used in such reactions giving azolyltrienes
3), prompted us to explore this reactivity and to seek a syn-
thesis of such derivatives. To the best of our knowledge, only
5
2%
Scheme 1.
1
3–16
very few azolyltrienes have been reported earlier.
In order to decide if the unexpected formation of the dihy-
drobenzene (4) is due specifically to the presence of the
tetrazole moiety, the behaviour of three additional azolyl-
acroleins (triazolyl 1c,d and pyrazolyl 1e compounds) has
been studied. All these acroleins were synthesized according
to literature procedures. In each of these reactions, in con-
trast to the tetrazolylacroleins 1a,b, simultaneous formation
of a triene (3c–e) and a dihydrobenzene (4c–e) was experi-
enced (Scheme 2).
2
. Results and discussion
When tetrazolylacrolein 1 was reacted with methyl (2E)-4-
triphenylphosphoranylidene)but-2-enoate (2) (synthesized
from methyl 4-bromocrotonate in two steps according to
a literature procedure ), a substituted dihydrophenyltetr-
azole 4 was obtained instead of the expected triene (3)
(
6
,7
5
(
Scheme 1). Interestingly, when a similar transformation
The outcome of the transformations with phosphorane 2 is
summarized in Table 1. Comparison of these data reveals
that with a decrease of the nitrogen atoms in the azole ring
Keywords: Azolyltriene; Wittig reaction; Phosphorane; Ab initio calcula-
tion.
*
Corresponding author. Fax: +36 14381145; e-mail: ghajos@chemres.hu
0
040–4020/$ - see front matter Ó 2007 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2007.03.098

I. Nagy et al. / Tetrahedron 63 (2007) 4730–4736
4731
MeOOC
Inspection of Scheme 3 and Table 2 reveals that, in contrast
to the results obtained with phosphorane 2, every reaction
carried out with the phenyl substituted phosphorane 7
yielded only triene compounds in the form of the geometri-
cal isomers 8 and 9. Reaction of cinnamaldehyde (5) with
the phosphonium salt precursor of phosphorane (7), resulted
exclusively in only one isomer: the symmetrical trans–
cis–trans product (10) (Scheme 4).
Het
3
c-e
2
O
Het
Het
COOMe
1
4c-e
Het
1-(4-chlorophenyl[1,2,3]triazol)-4-yl
c
PPh3
d
e
1-(4-methoxyphenyl[1,2,3]triazol)-4-yl
1-(4-chlorophenylpyrazol-4-yl)
KOBut
abs. ether
5
Cl
Ph
Scheme 2.
10
Table 1. Products obtained from reaction of azolylacroleins (1a–e) with
phosphorane (2)
Scheme 4.
1
a
b
c
d
e
Comparison of the above results shows that the two extreme
cases are the tetrazolylacroleins (e.g., their reaction with
phosphorane 2 yields dihydrobenzene 4 only) and the phe-
nylacrolein (i.e., cinnamaldehyde yielding only triene 6),
whereas in all other cases dihydrobenzene and triene com-
pounds were formed simultaneously. At first sight, one could
assume that in the course of the cyclization to 4, the triene 3
could have been formed first, followed by electrocyclisation
to the dihydrobenzene 4 and, thus, 3 could be an intermedi-
ate along the pathway to 4. This supposition, however, seems
rather unlikely for three reasons:
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
Het
Cl
OMe
Cl
OMe
Cl
Product 3
Product 4
—
68%
—
66%
7%
78%
Not isolated
71%
24%
29%
(
i.e., with triazole and pyrazole rings), formation of the ex-
pected triene 3 took place to increasing extent. Moreover,
with the pyrazolylacrolein derivative (1e), the relative
amount of 3 substantially increased, and the two types of
products 3e and 4e were obtained in comparable amounts.
(
a) such an electrocyclisation can only take place if the tri-
ene has a trans–cis–trans geometry like 9 and 10. Even if
isomerization of a triene of another geometry could oc-
cur, the electrocyclisation would result in a product con-
taining the two double bonds in different locations (i.e.,
also the ester group should be attached to a saturated
ring-carbon atom);
Besides the study on the effect of the aryl or heteroaryl sub-
stituent on the ambident reactivity, a change of the terminal
moiety in the Wittig reagent also seemed of interest. To this
end, the phenyl substituted reagent (7) liberated in situ from
(b) literature data reveal that such electrocyclisations need
fairly drastic reaction conditions (e.g., heating the triene
8
the appropriate phosphonium salt has also been investi-
gated. The results are summarized in Scheme 3 and Table 2.
ꢀ
in pentane or heptane at 130–200 C in a sealed tube for
6–24 h );
1
7
Ph
(
c) transformation of 1a to 4a was also carried out
ꢀ
Het
successfully under very mild conditions (at ꢁ20 C),
8
a-d
PPh3
ether
which clearly contradicts the above-mentioned literature
data.
O
Het
+
+
1a-d
Het
Ph
7
All these results suggest that 3 and 4 were formed by two in-
dependent pathways. A literature search led us to an earlier
finding similar to the formation of 4. These authors reported
Ph
9
9a-d
the transformation of crotonaldehyde (11) with 2 yielding
a dihydrobenzene (13) derivative as the main product,
whereas the triene product 12 was also observed in trace
amounts (Scheme 5).
Scheme 3.
Table 2. Products obtained from reaction of azolylacroleins (1a–d) with
non-stabilized phosphorane (7)
1
a
N
b
c
N
d
These authors supposed that it is the conjugate carbon atom
in the Wittig reagent that attacks the b-carbon atom in acro-
lein to form an intermediate in which an internal Wittig re-
action yields the product (Fig. 1). Thus, movement of
electrons as shown in (a) can be anticipated to result in a
Michael addition to (b). In this species a hydrogen shift as
shown, followed by tautomerism can occur to give (c) and,
finally, an intramolecular Wittig reaction leads to the ring
closure to (d).
N
N
N
N
N
N
N
N
N
N
N
N
Het
Cl
OMe
Cl
OMe
Product
Product
8
9
38%
Not isolated
25%
20%
24%
24%
14%
15%

4732
I. Nagy et al. / Tetrahedron 63 (2007) 4730–4736
CH3
Het
Het
O
A
B
R
A
B
R
PPh3
Het
R
PPh3
12
COOMe
CH3
in traces
Figure 2. Rationalization of the ambident behaviour of heteroarylacroleins
in their transformations with phosphoranes.
CHO
COOMe
2
11
H3C
four steps) resulted in a similar course of transformations:
the Wittig reaction to 15-trans took place at room tempera-
ture, which compound is in equilibrium with the 15-cis iso-
mer in accordance with other literature observation, and the
reaction mixture—without isolation of this intermediate—
was heated at reflux in order to accomplish the cyclization
reaction to 16. This second intermediate underwent sponta-
neous oxidation during this transformation to yield azolyl-
pyridine 17 in moderate yield (Scheme 6).
COOMe
1
3
major product
Scheme 5.
Upon inspection of the data in Tables 1 and 2, the following
conclusion can be made. In the cases of the ester substituted
phosphorane, the outcome of the reaction essentially de-
pended on the structure of the starting heteroarylacrolein.
This indicates that formation of a cyclohexadiene is basi-
cally favoured by the presence of an electron withdrawing
In an attempt to rationalize our observations in the context of
the above mechanistic picture, DFT calculations for selected
aldehydes (1a and 5) and for the two Wittig reagents (2 and
7) have been carried out. The calculated net charges of the
carbon atoms relevant to reaction routes A and B are col-
lected in Table 3.
(e.g., COOR) group in the phosphorane reagent, and also
by high number of nitrogen atoms in the heteroaryl ring.
This ambident behaviour can be rationalized schematically
as represented in Figure 2. Thus, the investigated acroleins
can react in two different ways: (i) if the first step is the at-
tack of the phosphorane on the b-carbon atom of the acrolein
The calculations reveal that the partial charges associated
with the reacting carbon atoms on route B (C ) are invariant
B
(
route A), a Michael addition occurs followed by an intra-
with respect to the nature of the Het and R substituents of the
molecules, whereas those values calculated for the C atoms
molecular Wittig reaction with participation of the oxo-
phosphorane intermediate resulting in ring closure to the
cyclohexadiene product; (ii) an alternative pathway is route
B, which is a simple Wittig reaction between the formyl
group of the acrolein and the phosphorane moiety to yield
a triene.
A
show a noticeable variation. Namely, the electron density on
the C atom of 7 is calculated to be lower as compared to that
A
in 2 pointing to a reduced nucleophilic character of C in 7,
A
which may explain that all the reactions with the non-stabi-
lized phosphorane proceeded via route B yielding exclu-
sively triene products. On the other hand, the variation of
CA atomic charges in aldehydes does not account for the
observed reactivities, because one expects an enhanced elec-
1
0
A recent publication of Palacios and Rubiales called to our
attention the possibility of a further extension of our studies.
These authors described that treatment of cinnamaldehyde
or acrolein with the phosphazane 14 results in an aza-Wittig
reaction followed by electrocyclization of the intermediate
azatriene to yield pyridine derivatives.
trophilicity for the C atom in the aldehyde to drive the re-
A
action towards route A, but the calculated charges show
the opposite trend. It seems, therefore, that a more detailed
mechanistic study involving the identification of key ele-
mentary steps along the two reaction channels is required
to provide a satisfactory explanation for the observed
reactivities.
Treatment of the tetrazolylacroleines 1a,b with 14 (prepared
from propiolic acid according to literature procedure
1
1a–d
in
R3
MeOOC
R1
R1
R3
R1
R3
O
Michael
addition
O
H
O
MeOOC
PPh3
MeOOC
PPh3
PPh3
(b)
(
a)
(c)
-Ph3PO
R3
R1
MeOOC
(d)
Figure 1. Rationalization of the reaction of an acrolein derivative and a viniloguous phosphorane.

I. Nagy et al. / Tetrahedron 63 (2007) 4730–4736
4733
Ar
N
N
Ar
N
N
N
N
PPh2Me
N
N
N
N
O
N
dichloroethane
rt
N
COOMe
N
N
Ar
COOMe
14
N
1a,b
COOMe
5-trans
1
15-cis
reflux
Ar
Ar
Yield (%)
a
b
4-Cl-C H
30
24
6
4
4-MeO-C H
6
4
Ar
N
N
N
N
N
N
N
N
oxidation
COOMe
COOMe
N
17a,b
N 16
Scheme 6.
Table 3. Net NPA atomic charges for carbon atoms relevant to reaction
routes A and B as obtained from B3LYP/6-31G** calculations
4.1.1. (2E)-3-[2-(4-Methoxyphenyl)-2H-tetrazol-5-yl]-
acrylaldehyde (1b). This compound was prepared accord-
ing to the literature process. Yield: 36%. Yellow crystals.
3
C
A
C
B
ꢀ
Mp 105–106 C (CH CN). IR (KBr) n : 1682, 1511,
max
3
Aldehyde
1a
5
2
ꢁ0.21
ꢁ0.16
ꢁ0.43
ꢁ0.31
+0.36
+0.36
ꢁ0.89
ꢁ0.89
ꢁ1
1254, 1166, 1109, 1027, 1009, 993, 839 cm . dH
(200 MHz, CDCl ) 9.84 (1H, d, J 8.0 Hz, CHO), 8.06 (2H,
Phosphorane
3
00 00
7
m, 2 +6 -H), 7.62 (1H, d, J 16.0 Hz, 3-H), 7.25 (1H, dd, J
0 0
.0, 16.0 Hz, 2-H), 7.06 (2H, m, 3 +5 -H), 3.90 (3H, s,
OMe); dC (CDCl ) 192.9, 161.9, 161.3, 135.8, 134.8,
8
3
3. Conclusion
130.2, 121.8, 115.2, 56.0. Anal. Calcd for C H N O : C,
1
1 10 4 2
57.39; H, 4.38; N, 24.34. Found: C, 57.68; H, 4.30; N, 24.33.
From these results one can conclude that by selection of an
appropriate reagent, the ambident reactivity can be directed
to the desired pathway and, thus, valuable azolyltrienes or
azolyldihydrobenzene derivatives can be synthesized in ac-
ceptable yields. The DFT calculations provided satisfactory
rationalization for the sensitivity of the reaction on the
change of substituents.
4.2. General procedure for the reaction of acroleins with
methyl (2E)-4-(triphenylphosphoranylidene)but-2-
enoate
A solution of acrolein (1.0 mmol) and phosphorane (2)
(1.1 mmol) in dichloromethane (15 mL) was stirred at
room tempetarure for periods specified below. The reaction
was monitored by TLC. The reaction mixture was separated
by flash chromatography on Kieselgel 60H, using dichloro-
methane as an eluent.
4
. Experimental part
4
.1. General methods
4
.2.1. Methyl 6-[2-(4-chlorophenyl)-2H-tetrazol-5-yl]-
Melting points were determined by a B €u chi apparatus and
are uncorrected. The IR spectra were recorded on a Thermo
Nicolet Avatar 320 FTIR spectrometer, the NMR spectra
were determined on a Varian Unity Inova spectrometer
cyclohexa-1,3-diene-1-carboxylate (4a). This compound
was obtained from 1a, reaction time: 2 h. Yield: 0.215 g,
68%, yellow oil. IR (KBr) nmax: 1702, 1492, 1272, 1233,
ꢁ
1
1089, 1002, 830 cm . d (400 MHz, CDCl ) 8.02 (2H, m,
H
3
1
13
00
00
00
00
(
200 MHz and 400 MHz for H and 100 MHz for C),
2 +6 -H), 7.44 (2H, m, 3 +5 -H), 7.31 (1H, dd, J 2.0,
5.0 Hz, 2-H), 6.17 (1H, ddd, J 3.0, 5.5, 9.5 Hz, 4-H), 6.12
(1H, dddd, J 1.0, 2.7, 5.0, 9.5 Hz, 3-H), 4.46 (1H, dd,
J 2.0, 9.2 Hz, 6-H), 3.80 (3H, s, COOMe), 3.03 (1H, ddd,
J 2.7, 5.5, 18.0 Hz, 5-H), 2.83 (1H, dddd, J 1.0, 3.0, 9.2,
and the elemental analysis has been carried out with an
Elementar Vario EL III apparatus.
Computational details: Density functional calculations have
been carried out at the B3LYP/6-31G** level to describe the
charge distribution in selected aldehydes (1a and 5) and in
Wittig reagents 2 and 7. For the latter two compounds, the
bulky PPh groups were replaced by PH moieties. The re-
18.0 Hz, 5-H); dC (CDCl ) 168.0, 167.2, 135.6, 135.5,
3
135.2, 131.8, 129.9 (2C), 126.1, 124.3, 121.3 (2C), 52.1,
28.8, 28.6. HRMS (EI): M(-N ) , found 288.0663.
+
2
C H ClN O requires 288.0666.
15 13 2 2
3
3
ported net atomic charges were obtained for the geometry
optimized structures using the NPA (natural population
analysis) procedure as implemented in the Gaussian03
4.2.2. Methyl-6-[2-(4-methoxyphenyl)-2H-tetrazol-5-yl]-
cyclohexa-1,3-diene-1-carboxylate (4b). This compound
was obtained from 1b, reaction time: 2 h. Yield: 0.205 g,
1
2
program.

4734
I. Nagy et al. / Tetrahedron 63 (2007) 4730–4736
6
1
8
7
6
3
6%, yellow oil. IR (KBr) nmax: 2955, 2835, 1708, 1609,
573, 1513, 1435, 1275, 1251, 1170, 1092, 1068, 998,
4.2.6. Methyl-(2E,4E,6E)-7-[1-(4-chlorophenyl)-1H-pyr-
azol-4-yl]hepta-2,4,6-trienoate (3e). This compound was
obtained from 1e, reaction time: 4 h. Yield: 0.076 g, 24%,
yellow needles. Mp 192–195 C (CH CN). IR (KBr) nmax:
3
3117, 1705, 1594, 1543, 1498, 1432, 1405, 1335, 1293,
ꢁ1
00
00
33 cm . dH (200 MHz, CDCl ) 7.97 (2H, m, 2 +6 -H),
3
00
00
ꢀ
.31 (1H, dd, J 1.1, 4.8 Hz, 2-H), 6.99 (2H, m, 3 +5 -H),
.15 (2H, m, 3+4-H), 4.43 (1H, dd, J 1.1, 9.2 Hz, 6-H),
.86 (3H, s, COOMe), 3.79 (3H, s, OMe), 3.04 (1H, ddd,
ꢁ
1
1254, 1212, 1131, 1092, 998, 944, 827 cm . d
H
0 0
(400 MHz, DMSO-d ) 8.71 (1H, s, 5 -H), 8.04 (1H, s, 3 -
6
J 2.2, 5.2, 18.3 Hz, 5-H), 2.81 (1H, dddd, J 2.2, 4.0, 9.2,
0
0
00
00
00
1
1
5
8.3 Hz, 5-H); dC (CDCl ) 167.6, 167.3, 160.6, 135.2,
3
H), 7.82 (2H, m, 2 +6 -H), 7.54 (2H, m, 3 +5 -H), 7.31
(1H, dd, J 11.2, 15.1 Hz, 3-H), 6.88 (1H, dd, J 10.9,
14.6 Hz, 6-H), 6.82 (1H, dd, J 10.9, 14.0 Hz, 5-H), 6.72
(1H, d, J 14.6 Hz, 7-H), 6.45 (1H, dd, J 11.2, 14.0 Hz, 4-
H), 5.96 (1H, d, J 15.1 Hz, 2-H), 3.64 (3H, s, COOMe); dC
32.0, 130.8, 126.4, 124.3, 121.7 (2C), 114.8 (2C), 55.9,
2.2, 29.0, 28.6. HRMS (EI): M(-N ) , found 284.1161.
+
2
C H N O requires 284.1146.
16 16 2 3
4
.2.3. Methyl-(2E,4Z,6E)-7-[1-(4-chlorophenyl)-1H-
,2,3-triazol-4-yl]hepta-2,4,6-trienoate (3c). This com-
(DMSO-d ) 167.6, 145.7, 142.7, 140.9, 139.0, 131.4,
6
1
pound was obtained from 1c, reaction time: 4 h. Yield:
130.4 (2C), 129.6, 128.5, 127.6, 127.1, 123.2, 120.8 (2C),
120.4, 52.1. Anal. Calcd for C H N O Cl: C, 64.87; H,
4.80; N, 8.90. Found: C, 64.86; H, 4.63; N, 8.73.
1
7 15 2 2
ꢀ
KBr) nmax: 3129, 1696, 1606, 1498, 1435, 1311, 1260,
0
(
.021 g, 7%, white crystals. Mp 166–168 C (CH CN). IR
3
ꢁ1
1
209, 1134, 1092, 1047, 1014, 980, 830 cm . dH
4.2.7. Methyl-6-[1-(4-chlorophenyl)-1H-pyrazol-4-yl]-
cyclohexa-1,3-diene-1-carboxylate (4e). This compound
was obtained from 1e, reaction time: 4 h. Yield: 0.091 g,
29%, pale yellow oil. IR (KBr) nmax: 2943, 1702, 1594,
1573, 1498, 1435, 1395, 1272, 1236, 1089, 1065, 1023,
0
1H, dd, J 12.0, 15.1 Hz, 3-H), 7.78 (2H, m, 2 +6 -H),
(
400 MHz, CDCl +DMSO-d ) 8.30 (1H, s, 5 -H), 7.87
3
6
0
.62 (1H, dd, J 11.7, 15.4 Hz, 6-H), 7.53 (2H, m, 3 +5 -
0
00
(
00 00
7
H), 6.79 (1H, d, J 15.4 Hz, 7-H), 6.50 (1H, dd, J 10.3,
1.7 Hz, 5-H), 6.23 (1H, dd, J 10.3, 12.0 Hz, 4-H), 5.96
ꢁ
950, 830, 773, 731 cm . d (200 MHz, CDCl ) 7.70 (1H,
H 3
1
1
0 0 00 00
s, 5 -H), 7.59 (1H, s, 3 -H), 7.56 (2H, m, 2 +6 -H), 7.36
(
(
1H, d, J 15.1 Hz, 2-H), 3.80 (3H, s, COOMe); d
0
C
00
00
CDCl +DMSO-d ) 167.4 (C]O), 146.5 (4 -C), 139.0 (3-
3
(2H, m, 3 +5 -H), 7.14 (1H, dd, J 2.2, 4.8 Hz), 6.15 (2H,
m), 4.00 (1H, d, J 9.2 Hz), 3.76 (3H, s, COOMe), 2.80
(1H, ddd, J 1.8, 9.2, 18.3 Hz), 2.59 (1H, ddd, J 1.8, 5.1,
6
00
00
00
00
C), 136.6 (5-C), 135.5 (1 -C), 134.5 (4 -C), 130.0 (3 +5 -
C), 127.9 (6-C), 126.0 (2-C+4-C), 124.1 (2-C+4-C), 122.0
0
0
00
0
C H N O Cl: C, 60.86; H, 4.47; N, 13.31. Found: C,
(
7-C), 121.6 (2 +6 -C), 119.4 (5 -C), 51.7. Anal. Calcd for
18.3 Hz); dC (CDCl ) 167.7, 140.8, 134.4, 133.0, 132.3,
3
131.8, 129.9, 129.7 (2C), 125.6, 124.9, 124.2, 120.3 (2C),
52.1, 31.1, 26.8. HRMS (EI): M , found 314.0832.
1
6 14 3 2
+
6
0.92; H, 4.29; N, 13.24.
C H ClN O requires 314.0822.
1
7
15
2 2
4.2.4. Methyl-6-[1-(4-chlorophenyl)-1H-1,2,3-triazol-4-
yl]cyclohexa-1,3-diene-1-carboxylate (4c). This com-
4.2.8. Methyl-(2E,4E,6E)-7-phenylhepta-2,4,6-trienoate
1
8
pound was obtained from 1c, reaction time: 4 h. Yield:
0
(6). This compound is known from the literature. This
compound was obtained from 5, reaction time: 1.5 h. Yield:
0.112 g, 52%, yellow crystals. d (400 MHz, CDCl ) 7.42
ꢀ
KBr) nmax: 2949, 1705, 1573, 1501, 1435, 1398, 1272,
.246 g, 78%, beige crystals. Mp 70–72 C (CH CN). IR
3
(
H
3
ꢁ
1
1
236, 1095, 1044, 1026, 992, 833, 770, 734 cm . dH
(2H, m, H-2Ph), 7.38 (1H, dd, J 11.5, 15.0 Hz, 3-H), 7.33
(2H, m, H-3Ph), 7.26 (1H, m, H-4Ph), 6.86 (1H, dd,
J 10.5, 15.0 Hz, 6-H), 6.73 (1H, d, J 15.0 Hz, 7-H), 6.71
(1H, dd, J 10.5, 15.0 Hz, 5-H), 6.42 (1H, dd, J 11.5,
15.0 Hz, 4-H), 5.93 (1H, d, J 15.0 Hz, 2-H), 3.78 (3H,
0
0
00
-H), 7.45 (2H, m, 3 +5 -H), 7.24 (1H, dd, J 1.8, 4.4 Hz,
(
200 MHz, CDCl ) 7.65 (2H, m, 2 +6 -H), 7.62 (1H, s,
3
0
00 00
5
2
6
1
-H), 6.15 (2H, m, 3+4-H), 4.29 (1H, dd, J 1.8, 9.0 Hz,
-H), 3.77 (3H, s, COOMe), 2.98 (1H, ddd, J 1.8, 5.2,
8.0 Hz, 5-H), 2.80 (1H, ddd, J 1.8, 9.0, 18.0 Hz, 5-H); dC
s, COOMe); dC (CDCl ) 167.7, 144.8, 141.1, 137.0,
3
(
CDCl ) 167.6, 149.9, 136.0, 134.7, 134.4, 133.1, 130.1
3
2C), 128.0, 123.8, 121.8 (2C), 119.4, 52.2, 29.7, 28.3.
136.9, 130.4, 129.0 (2C), 128.6, 128.2, 127.0 (2C), 120.6,
51.7.
(
Anal. Calcd for C H N O Cl: C, 60.86; H, 4.47; N,
1
6 14 3 2
1
3.31. Found: C, 60.84; H, 4.61; N, 13.09.
4.3. General procedure for the reaction of acroleins with
triphenylcinnamylphosphonium chloride
4
4
.2.5. Methyl-6-[1-(4-methoxyphenyl)-1H-1,2,3-triazol-
-yl]cyclohexa-1,3-diene-1-carboxylate (4d). This com-
To a stirred suspension of triphenylcinnamylphosphonium
chloride (0.456 g, 1.1 mmol) in abs ether (10 mL) was added
potassium tert-butoxide (0.118 g, 1.05 mmol) and the mix-
ture was stirred for 30 min under an argon atmosphere. To
the resulting red coloured mixture was added dropwise the
solution or suspension of the acrolein (1 mmol) in dichloro-
methane (5 mL) and the reaction mixture was stirred for ad-
ditional 1 h. The reaction mixture was poured into water
(30 mL) and was extracted with dichloromethane (15 mL)
three times. The combined organic layer was washed with
water (30 mL) and dried over sodium sulfate. The solvent
was evaporated in vacuo and the two isomers were separated
by flash chromatography on Kieselgel 60H or neutral alu-
minium oxide (as indicated below) by using dichloro-
methane/hexane (2:1) as an eluent.
pound was obtained from 1d, reaction time: 4 h. Yield:
0
ꢀ
KBr) nmax: 3141, 1693, 1519, 1426, 1280, 1244, 1223,
.223 g, 71%, white crystals. Mp 79–81 C (CH CN). IR
3
(
ꢁ
1
1
186, 1095, 1047, 1038, 947, 828, 777, 744 cm . dH
00
00
-H), 7.23 (1H, dd, J 1.8, 4.4 Hz, 2-H), 6.96 (2H, m,
+5 -H), 6.15 (2H, m, 3+4-H), 4.29 (1H, dd, J 1.8,
(
200 MHz, CDCl ) 7.57 (2H, m, 2 +6 -H), 7.55 (1H, s,
3
0
0
5
3
9
2
0
00
.2 Hz, 6-H), 3.84 (3H, s, COOMe), 3.76 (3H, s, OMe),
.98 (1H, ddd, J 1.8, 5.0, 18.2 Hz, 5-H), 2.78 (1H, ddd,
J 1.8, 9.2, 18.2 Hz, 5-H); d (CDCl ) 167.6, 159.9, 149.4,
C
3
1
(
34.6, 133.1, 131.0, 128.2, 123.8, 122.3 (2C), 119.7, 114.9
2C), 55.9, 52.1, 29.8, 28.3. Anal. Calcd for C H N O :
1
7 17 3 3
C, 65.58; H, 5.50; N, 13.50. Found: C, 65.41; H, 5.74; N,
3.23.
1

I. Nagy et al. / Tetrahedron 63 (2007) 4730–4736
4735
ꢁ
989, 833, 752, 692 cm . d (200 MHz, CDCl +TFA) 8.35
H 3
1
4
1
.3.1. 2-(4-Chlorophenyl)-5-[(1E,3E,5E)-6-phenylhexa-
,3,5-trien-1-yl]-2H-tetrazole (8a). This compound was
0
0
(1H, s, 5-H), 7.60–7.74 (3H, m), 7.42 (2H, m, 2 +6 -H),
0
0
obtained from 1a, and the crude product was purified on neu-
tral aluminium oxide. Yield: 0.128 g, 38%, yellow crystals.
7.32 (2H, m, 3 +5 -H), 7.27 (2H, m), 7.20 (1H, dd, J 10.0,
14.3 Hz), 6.86 (1H, dd, J 11.0, 14.8 Hz), 6.74 (2H, d,
ꢀ
218, 1089, 1002, 992, 830, 752, 686 cm . d (400 MHz,
00
C H N Cl: C, 71.96; H, 4.83; N, 12.59. Found: C, 71.97;
00
Mp 152–153 C (CH CN). IR (KBr) n : 1603, 1492,
3
J 15.4 Hz, 1 +6 -H), 6.48 (2H, m). Anal. Calcd for
max
ꢁ1
1
CDCl ) 8.06 (2H, m, 2 +6 -H), 7.54 (1H, dd, J 11.0,
H
20 16 3
0
0
H, 4.81; N, 12.41.
3
0
0
0
0
1
5.8 Hz, 2 -H), 7.51 (2H, m, 3 +5 -H), 7.42 (2H, m, H-
Ph), 7.32 (2H, m, H-3Ph), 7.26 (1H, m, H-4Ph), 6.90
2
4.3.5. 1-(4-Chlorophenyl)-4-[(1E,3Z,5E)-6-phenylhexa-
1,3,5-trien-1-yl]-1H-1,2,3-triazole (9c). This compound
was obtained from 1c. The crude product was purified on
00
1H, dd, J 10.5, 15.8 Hz, 5 -H), 6.69 (1H, d, J 15.8 Hz,
(
0
0
00
-H), 6.68 (1H, d, J 15.8 Hz, 1 -H), 6.67 (1H, dd, J 10.5,
5.5 Hz, 4 -H), 6.55 (1H, dd, J 11.0, 15.5 Hz, 3 -H); d
6
1
0
0
00
Kieselgel 60H. Yield: 0.079 g, 24%, pale yellow crystals.
Mp 128–130 C (CH CN). IR (KBr) nmax: 3141, 3027,
C
ꢀ
1495, 1447, 1233, 1089, 1044, 986, 959, 842, 815, 740,
(
CDCl ) 164.8, 138.0, 137.6, 137.1, 137.0, 135.6, 135.5,
3
3
1
1
31.8, 130.1 (2C), 128.9 (2C), 128.6, 128.3, 126.9 (2C),
21.1 (2C), 116.1. Anal. Calcd for C H N Cl: C, 68.16;
ꢁ
1
683 cm . d (400 MHz, CDCl ) 7.92 (1H, s, 5-H), 7.70
3
1
9
15
4
H
0
0
0
0
0
H, 4.52; N, 16.73. Found: C, 68.47; H, 4.48; N, 16.78.
(2H, m, 2 +6 -H), 7.68 (1H, dd, J 11.0, 15.5 Hz, 2 -H),
7.50 (2H, m, 3 +5 -H), 7.47 (2H, m, H-2Ph), 7.39 (1H,
0
0
dd, J 11.0, 15.1 Hz, 5 -H), 7.33 (2H, m, H-3Ph), 7.24 (1H,
00
0
m, H-4Ph), 6.64 (1H, d, J 15.1 Hz, 6 -H), 6.61 (1H, d, J
4
.3.2. 2-(4-Methoxyphenyl)-5-[(1E,3E,5E)-6-phenyl-
0
15.5 Hz, 1 -H), 6.29 (1H, dd, J 10.8, 11.0 Hz, 4 -H), 6.22
hexa-1,3,5-trien-1-yl]-2H-tetrazole (8b). This compound
was obtained from 1b. The crude product was purified on
neutral aluminium oxide. Yield: 0.083 g, 25%, yellow crys-
0
(1H, dd, J 10.8, 11.0 Hz, 3 -H); d (CDCl ) 147.2 (4-C),
0
0
C
3
0
ꢀ
0
3Ph), 129.3 (2 -C), 128.9 (C-2Ph), 128.1 (C-4Ph), 127.3
tals. Mp 145–148 C (CH CN). IR (KBr) nmax: 1609, 1594,
3
137.4, 135.6, 134.7, 134.6 (6 -C), 131.7 (5 -C), 130.2 (C-
0
(4 -C), 126.9 (3 +5 -C), 124.3 (3 -C), 121.7 (2 +6 -C),
1
6
7
7
1
516, 1471, 1254, 1218, 1167, 1107, 995, 833, 749,
0
ꢁ
1
0
0
00
00
0
00
00
89 cm . dH (400 MHz, C D ) 7.91 (2H, m, 2 +6 -H),
6
6
0
0
0
71.96; H, 4.83; N, 12.59. Found: C, 71.93; H, 4.89; N, 12.35.
.70 (1H, dd, J 10.9, 15.7 Hz, 2 -H), 7.20 (2H, m, H-2Ph),
.09 (2H, m, H-3Ph), 7.00 (1H, m, H-4Ph), 6.73 (1H, d, J
5.7 Hz, 1 -H), 6.62 (1H, dd, J 10.4, 15.4 Hz, 5 -H), 6.54
0
120.3 (1 -C), 118.4 (5-C). Anal. Calcd for C H N Cl: C,
20 16 3
0
0
00
0
00
(
dd, J 10.4, 14.9 Hz, 4 -H), 6.18 (1H, dd, J 10.8, 14.9 Hz,
2H, m, 3 +5 -H), 6.35 (1H, d, J 15.4 Hz, 6 -H), 6.29 (1H,
4.3.6. 1-(4-Methoxyphenyl)-4-[(1E,3E,5E)-6-phenyl-
hexa-1,3,5-trien-1-yl]-1H-1,2,3-triazole (8d). This com-
pound was obtained from 1d. The crude product was
00
0
0
irrad.)/7.20; 7.70 (irrad.)/6.29; 7.20 (irrad.)/6.35, 6.62,
3
(
-H), 3.14 (3H, s, OMe); NOE: 6.73 (irrad.)/6.18; 6.62
purified on Kieselgel 60H. Yield: 0.047 g, 14%, white crys-
tals. Mp 185–186 C (CH CN). IR (KBr) nmax: 1525, 1510,
00
ꢀ
1302, 1248, 1179, 1167, 1041, 1008, 995, 833, 788, 749,
7
.09; d (CDCl ) 164.4, 160.7, 137.6 (2 -C), 137.2, 137.0
C
3
00
3
0
0
00
28.7 (C-4Ph), 128.2 (3 -C), 126.8 (C-2Ph), 121.5 (2 +6 -
(
4 -C), 135.2 (6 -C), 132.0 (5 -C), 130.6, 128.9 (C-3Ph),
0
00
0
ꢁ1
1
C), 116.6 (1 -C), 114.9 (3 +5 -C), 55.9 (OCH ). Anal. Calcd
689 cm . dH (400 MHz, DMSO-d ) 8.77 (1H, s, 5-H),
6
0
0
0
0
for C H N O: C, 72.71; H, 5.49; N, 16.96. Found: C,
0
0
H-3Ph), 7.24 (1H, m, H-4Ph), 7.14 (2H, m, 3 +5 -H), 7.12
7.79 (2H, m, 2 +6 -H), 7.49 (2H, m, H-2Ph), 7.35 (2H, m,
0 0
3
2
0 18 4
00
(1H, dd, J 10.0, 15.8 Hz, 5 -H), 7.04 (1H, dd, J 10.0,
7
2.57; H, 5.39; N, 16.89.
00 00 00
5.8 Hz, 2 -H), 6.70 (2H, d, J 15.8 Hz, 1 +6 -H), 6.60–
1
00 00
6.65 (2H, m, 3 +4 -H), 3.85 (3H, s, OMe); d (DMSO-d )
C 6
4
1
.3.3. 2-(4-Methoxyphenyl)-5-[(1E,3Z,5E)-6-phenylhexa-
,3,5-trien-1-yl]-2H-tetrazole (9b). This compound was
obtained from 1b. The crude product was purified on neutral
160.0, 146.8, 137.7, 134.7, 133.8, 133.5, 131.5, 130.7,
129.8, 129.4 (2C), 128.3, 127.0 (2C), 122.4 (2C), 121.3,
120.6, 115.6 (2C), 56.3. Anal. Calcd for C H N O: C,
aluminium oxide. Yield: 0.067 g, 20%, yellow crystals. Mp
2
1 19 3
ꢀ
513, 1468, 1444, 1374, 1254, 1167, 1023, 998, 965, 824,
55, 731, 689 cm . dH (400 MHz, CDCl ) 8.06 (2H, m,
3
1
1
7
2
04–106 C (CH CN). IR (KBr) nmax: 1630, 1609, 1597,
3
76.57; H, 5.81; N, 12.76. Found: C, 76.55; H, 5.82; N, 12.39.
ꢁ
1
4.3.7. 1-(4-Methoxyphenyl)-4-[(1E,3Z,5E)-6-phenylhexa-
1,3,5-trien-1-yl]-1H-1,2,3-triazole (9d). This compound
was obtained from 1d. The crude product was purified on
0
0
00
00
+6 -H), 8.00 (1H, dd, J 12.0, 15.8 Hz, 2 -H), 7.52 (2H,
m, H-2Ph), 7.42 (1H, dd, J 11.5, 15.5 Hz, 5 -H), 7.37 (2H,
m, H-3Ph), 7.26 (1H, m, H-4Ph), 7.04 (2H, m, 3 +5 -H),
0
.72 (1H, d, J 15.8 Hz, 1 -H), 6.69 (1H, d, J 15.5 Hz, 6 -
0
Kieselgel 60H. Yield: 0.050 g, 15%, pale yellow crystals.
Mp 133–135 C (CH CN). IR (KBr) nmax: 1525, 1510,
00
00
H), 6.42 (1H, dd, J 10.5, 11.5 Hz, 4 -H), 6.28 (1H, dd,
ꢀ
1444, 1299, 1251, 1170, 1110, 1038, 965, 830, 782, 749,
6
3
00
0
64.4, 160.7, 137.2, 135.8, 134.1, 132.0, 130.6, 128.9
0
ꢁ1
J 10.5, 12.0 Hz, 3 -H), 3.88 (3H, s, OMe); d (CDCl3)
C
695 cm . dH (400 MHz, CDCl +DMSO-d ) 7.96 (1H, s,
3
6
0
0
H), 7.48 (2H, m, H-2Ph), 7.40 (1H, m), 7.34 (2H, m, H-
1
5-H), 7.66 (1H, dd, J 10.5, 15.8 Hz), 7.65 (2H, m, 2 +6 -
(
2C), 128.5, 128.4, 127.1 (2C), 124.0, 121.6 (2C), 117.4,
0 0
3Ph), 7.24 (1H, m, H-4Ph), 7.02 (2H, m, 3 +5 -H), 6.63
1
5
14.9 (2C), 55.9. Anal. Calcd for C H N O: C, 72.71; H,
2
.49; N, 16.96. Found: C, 72.53; H, 5.16; N, 16.85.
0 18 4
0
0
00
(2H, d, J 16.0 Hz, 1 +6 -H), 6.25 (2H, m), 3.79 (3H, s,
OMe); d (CDCl +DMSO-d ) 160.0, 146.7, 137.4, 134.6,
C
3
6
4
1
.3.4. 1-(4-Chlorophenyl)-4-[(1E,3E,5E)-6-phenylhexa-
,3,5-trien-1-yl]-1H-1,2,3-triazole (8c). This compound
134.5, 131.2, 129.5 (2C), 128.8, 128.0, 126.8 (2C), 126.6,
124.3, 122.2 (2C), 120.8, 119.0, 115.0 (2C), 55.8. Anal.
Calcd for C H N O: C, 76.57; H, 5.81; N, 12.76. Found:
was obtained from 1c. The product was precipitated from
the reaction mixture. This was filtered off, washed with
water and ether. Yield: 0.080 g, 24%, pale yellow crystals,
2
1 19 3
C, 76.21; H, 5.78; N, 12.64.
ꢀ
0
ene (10). This compound is known from the literature.
insoluble in CDCl and DMSO-d . Mp 208–210 C. IR
3
4.3.8. 1,1 -(1E,3Z,5E)-Hexa-1,3,5-triene-1,6-diyldibenz-
6
1
9
(
KBr) nmax: 3117, 3015, 1495, 1447, 1233, 1092, 1038,

4736
I. Nagy et al. / Tetrahedron 63 (2007) 4730–4736
The crude product was purified on Kieselgel 60H using di-
chloromethane/hexane (1:1) as an eluent. Yield: 0.121 g,
2. Kothler-Brajtburg, J.; Medoff, G.; Kobayashi, G. S.; Boggs, S.;
Schlessinger, D.; Pandey, R. C.; Rinehart, K. L., Jr. Antimicrob.
Agents Chemother. 1979, 15, 716–722.
3. Nagy, I.; K ꢀo nya, D.; Riedl, Zs.; Kotschy, A.; Tim ꢀa ri, G.;
Messmer, A.; Haj ꢀo s, Gy Tetrahedron 2003, 59, 7485–7489.
4. Nagy, I.; Haj ꢀo s, Gy.; Riedl, Zs Heterocycles 2004, 63, 2287–
2307.
ꢀ
2%, yellow crystals. Mp 122–124 C (EtOH). IR (KBr)
nmax: 3015, 1483, 1444, 995, 911, 854, 743, 689 cm . dH
5
ꢁ1
(
400 MHz, CDCl +DMSO-d ) 7.42 (4H, m, H-2Ph), 7.31
3 6
(
6
4H, m, H-3Ph), 7.22 (2H, m, H-4Ph), 6.85–6.92 (2H, m),
.60 (2H, d, J 15.6 Hz), 6.54 (2H, m).
5
6. Tanaka, S.; Wachi, K.; Terada, A. Chem. Pharm. Bull. 1980, 28,
. Buchta, A.; Andree, F. Chem. Ber. 1959, 92, 3111–3116.
4.4. General procedure for the synthesis of 4-substituted
methyl nicotinate (17a,b)
2083–2088.
. Tanaka, S.; Wachi, K.; Terada, A. Chem. Pharm. Bull. 1980, 28,
7
A solution of aldehyde 1 (1 mmol) and phosphazane (14)
1.2 mmol) in dichloroethane (20 mL) was stirred for 24 h
1265–1269.
8. McDonald, R. N.; Campbell, T. W. Org. Synth. Coll. Vol. 1973,
(
under argon atmosphere and then heated at reflux for the pe-
riod specified. The reaction was monitored by TLC. The sol-
vent was removed in vacuo and the residue was purified by
flash chromatography on Kieselgel 60H using dichloro-
methane as an eluent.
5, 499–501.
9. Bohlmann, F.; Zdero, C. Chem. Ber. 1973, 106, 3779–
3787.
10. Palacios, F.; Rubiales, G. Tetrahedron Lett. 1996, 37, 6379–
6382.
1
1. (a) Kurtz, A. N.; Billups, W. E.; Greenlee, R. B.; Hamil, H. F.;
Pace, W. T. J. Org. Chem. 1965, 30, 3141–3146; (b) Truce,
W. E.; Tichenor, G. J. W. J. Org. Chem. 1972, 37, 2391–
2394; (c) Oikawa, T.; Kanomata, N.; Tada, M. J. Org. Chem.
1993, 58, 2046–2051; (d) Palacios, F.; Perez de Heredia, I.;
Rubiales, G. J. Org. Chem. 1995, 60, 2384–2390.
4.4.1. Methyl 4-[2-(4-chlorophenyl)-2H-tetrazol-5-yl]-
nicotinate (17a). This compound was obtained from 1a,
reflux time: 62 h. Yield: 0.095 g, 30%, pale yellow crystals.
Mp 168 C (CH CN, decomp.). IR (KBr) nmax: 1711, 1600,
ꢀ
489, 1441, 1423, 1275, 1197, 1143, 1113, 1098, 998, 830,
46 cm . dH (200 MHz, CDCl ) 9.41 (1H, s, 6-H), 8.52
3
3
1
7
ꢁ1
12. Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.;
Robb, M. A.; Cheeseman, J. R.; Montgomery, J. A., Jr.;
Vreven, T.; Kudin, K. N.; Burant, J. C.; Millam, J. M.;
Lyengar, S. S.; Tomasi, J.; Barone, V.; Mennucci, B.; Cossi,
M.; Scalmani, G.; Rega, N.; Petersson, G. A.; Nakatsuji, H.;
Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.;
Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.;
Klene, M.; Li, X.; Knox, J. E.; Hratchian, H. P.; Cross, J. B.;
Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.;
Yazyev, O.; Austin, A. J.; Camml, R.; Pomelli, C.; Ochterski,
J. W.; Ayala, P. Y.; Morokuma, K.; Voth, G. A.; Salvador, P.;
Dannenberg, J. J.; Zakrzewski, V. G.; Dapprich, S.; Daniels,
A. D.; Strain, M. C.; Farkas, O.; Malick, D. K.; Rabuck,
A. D.; Raghavachari, K.; Foresman, J. B.; Ortiz, J. V.; Cui,
Q.; Baboul, A. G.; Clifford, S.; Cioslowski, J.; Stefanov,
B. B.; Liu, G.; Liashenko, A.; Piskorz, P.; Komaromi, I.;
Martin, R. L.; Fox, D. J.; Keith, T.; Al-Laham, M. A.; Peng,
C. Y.; Nanayakkara, A.; Challacombe, M.; Gill, P. M. W.;
Johnson, B.; Chen, W.; Wong, M. W.; Gonzalez, C.; Pople,
J. A. Gaussian 03, Revision C.02; Gaussian: Pittsburgh, PA,
2004.
(
(
1H, d, J 5.2 Hz, 2-H), 8.43 (1H, d, J 5.2 Hz, 3-H), 8.24
0
0
00
00
00
2H, m, 2 +6 -H), 7.58 (2H, m, 3 +5 -H), 4.01 (3H, s,
COOMe); dC (CDCl ) 165.1, 163.6, 151.2, 149.5, 138.4,
3
1
Anal. Calcd for C H N O Cl: C, 53.26; H, 3.19; N,
36.1, 129.9 (2C), 127.0, 122.3, 121.3 (2C), 108.6, 52.6.
1
4 10 5 2
2
2.18. Found: C, 53.46; H, 3.04; N, 22.02.
4.4.2. Methyl 4-[2-(4-methoxyphenyl)-2H-tetrazol-5-yl]-
nicotinate (17b). This compound was obtained from 1b,
reflux time: 50 h. Yield: 0.075 g, 24%, white crystals.
Mp 169–170 C (CH CN). IR (KBr) nmax: 1708, 1594,
1
1
J 2.2 Hz, 6-H), 8.51 (1H, dd, J 2.2, 5.4 Hz, 2-H), 8.42 (1H,
d, J 5.4 Hz, 3-H), 8.18 (2H, m, 2 +6 -H), 7.07 (2H, m,
3
ꢀ
510, 1435, 1405, 1293, 1272, 1251, 1185, 1143, 1113,
3
ꢁ1
023, 827, 752 cm . d (200 MHz, CDCl ) 9.41 (1H, d,
H
3
0
0
00
0
0
00
+5 -H), 4.01 (3H, s, COOMe), 3.90 (3H, s, OMe); d
C
(
CDCl ) 165.5, 164.3, 161.2, 151.8, 150.3, 138.6, 130.5
3
(2C), 127.1, 122.5 (2C), 122.1(2C), 115.1 (2C), 56.0, 52.9.
Anal. Calcd for C H N O : C, 57.87; H, 4.21; N, 22.50.
Found: C, 57.59; H, 4.24; N, 22.75.
1
5 13 5 3
1
3. Pooranchand, D.; Satyanarayana, J.; Ila, H.; Junjappa, H.
Synthesis 1993, 2, 241–244.
Acknowledgements
14. Purkayastha, M. L.; Patro, B.; Ila, H.; Junjappa, H.
J. Heterocycl. Chem. 1991, 28, 1341–1350.
Financial supports OTKA T047317, NKFP 1A/005/2004
and project (GVOP-3.2.1-2004-04-0311/3.0) for elemental
analyzer are gratefully acknowledged.
15. Thomas, A.; Chakaraborty, M.; Ila, H.; Junjappa, H.
Tetrahedron 1990, 46, 577–586.
16. Tsuruta, H.; Kurabayashi, K.; Mukai, T. Bull. Chem. Soc. Jpn.
1
972, 45, 2822–2828.
1
7. Marvell, E. N.; Caple, G.; Delphey, C.; Platt, J.; Polston, N.;
Tashiro, J. Tetrahedron 1973, 29, 3797–3806.
8. Asokan, C. V.; Ila, H.; Junjappa, H. Synthesis 1985, 163–165.
References and notes
1
1
. Wermuth, C. G. The Practice of Medicinal Chemistry;
Academic: London, 1996; pp 29–39, 182–200, 827–840.
19. Sonoda, Y.; Suzuki, Y. J. Chem. Soc., Perkin Trans. 2 1996,
401–404.