Water-acetone media enforced chemoselective synthesis of 2-substituted pyrrole stable phosphorus ylides from reaction between pyrrole and acetylenic esters in the presence of triphenylphosphine

Article abstract of DOI:10.3184/030823407X255560

Pyrrole undergoes a smooth reaction with dialkyl acetylenedicarboxylates in the presence of triphenylphosphine in a mixture of water-acetone (50:50) as a solvent pathway to produce phosphorus ylides of 2-substituted pyrrole in good yield.

Full text of DOI:10.3184/030823407X255560

566 RESEARCH PAPER
OCTOBER, 566–568
JOURNAL OF CHEMICAL RESEARCH 2007
Water–acetone media enforced chemoselective synthesis of
2-substituted pyrrole stable phosphorus ylides from reaction between
pyrrole and acetylenic esters in the presence of triphenylphosphine
Malek Taher Maghsoodloua*, Nourollah Hazeria, Sayyed Mostafa Habibi-Khorassania,
Zohreh Moeenia, Ghasem Marandia, Mojtaba Lashkaria, Marjan Ghasemzadeha and
Hamid Reza Bijanzadehb
aDepartment of Chemistry, The University of Sistan & Baluchestan, PO Box 98135-674, Zahedan, Iran
bDepartment of Chemistry, Tarbiat Moallem University, Tehran, Iran
Pyrrole undergoes a smooth reaction with dialkyl acetylenedicarboxylates in the presence of triphenylphosphine in
a mixture of water–acetone (50:50) as a solvent pathway to produce phosphorus ylides of 2-substituted pyrrole in
good yield.
Keywords: stable phosphorus ylides, acetylenic ester, 2-substituted pyrrole, triphenylphosphine, one geometrical rotamer
Nitrogen-containing heterocyclic compounds such as pyrrole
and its derivatives are important in organic chemistry
since their structures can be found in many natural or
therapeutic compounds.1 In recent years, the syntheses of
organophosphorus compounds,2-6 have been the subject of
great interest.
This interest has resulted from the recognition of the value
of such compounds in a variety of biological, industrial, and
chemical synthetic systems.7 A large number of methods
have been introduced to describe the novel syntheses of
organophosphorus compounds. In the relevant synthesis,
the successful attack by nucleophilic trivalent phosphine on
the carbon atom is facilitated when the latter is conjugated
with a carbonyl group, or when it is the specified part of an
unsaturated bond otherwise unactivated.2-13
report a simple one-pot synthesis of 2-substituted stable
crystalline phosphorus ylides 3 (C-substitued ylide).15-21
Because of the importance of pyrrole moiety and its
derivatives in biological activity and organic polymers and
also its antibiotic property,25,26 for the present work generation
of stable phosphorus ylides was undertaken in a mixture of
water-acetone (50:50) in comparison with dry ethyl acetate
solvent.20 In an aqueous-organic solution the outlined reaction
of triphenylphosphine with dialkyl acetylenedicarboxylates 1
in the presence of NH-acid 2 led to the corresponding ylides 3
in excellent yields (see Scheme 1).
On the basis of the well established chemistry of phosphorus
nucleophiles2-4 it is reasonable to assume that ylides 3
results from initial addition of triphenylphosphine to dialkyl
acetylenedicarboxylates and concomitant protonation of the
reactive 1:1 adduct, to generate an ion pair intermediate
(see Scheme 2) which is subsequently attacked by the carbon
of conjugated base the pyrrole.
There are many systematic investigations on the synthesis
of the reactions between trivalent phosphorus nucleophiles
and α,β-unsaturated carbonyl compounds in the presence of a
proton source such as alcohols or CH-acids.2,13-24
The structure 3 was assigned to the isolated products on the
1
basis of assessment of their IR, H NMR, 13C NMR spectra
Results and discussion
and mass spectral data. The NMR spectroscopy was used
to distinguish the structure 3 and 5. Compounds 3a–c show
one geometrical rotamer because of the intraction between
Recently we have reported synthesis of N-substituted stable
phosphorus ylides of pyrrole in ethyl acetate.19 Herein we
H
CO2R
PPh3
N
water/acetone
only product
RO2C
H
(C-substituted ylide)
CO2R
C
C
CO2R
1
3
Ph3P +
+
N
H
2
dry ethyl acetate
CO2R
N
PPh3
(N-substituted ylide)
RO2C
H
m)a
3, 5
a
% Yield of 3 and 5
R
(M
5
68 32
Me
95
93
93
92
b
c
Et
71 29
But
96
96
98
2
a: These Major and minor are only for compound 5
Scheme 1
* Correspondent. E-mail:mt_maghsoodlou@yahoo.com
PAPER: 07/4825

JOURNAL OF CHEMICAL RESEARCH 2007 567
O
H
OR
CO2R
C
C
H
CO2R
N
water/ acetone
+
PPh3
+
PPh3
N
H
RO2C
PPh
3 N
RO2C
H
CO2R
4
(zwitterionic form)
Ion pair intermediate
3
2
1
dry ethyl acetate
CO2R
PPh3
(N-substituted ylide)
N
RO2C
H
5
Scheme 2
were recorded on a Shimadzu GC/MS QP 1100 EX mass spectrometer
operating at an ionisation potential of 70 eV. Triphenylphosphine,
dialkyl acetylenedicarboxylates (1a–c) and pyrrole (2) were obtained
from Fluka and used without further purification.
CO2R
CO2R
H
N
N
H
O
OR
Ph3P
Ph3P
General procedures (exemplified by 3a)
OR
O
Dimethyl 2-(1H-pyrrol-2-yl)-3-(triphenylphosphoranylidene)butane-
dioate (3a): To a magnetically stirred solution of triphenylphosphine
(0.26 g, 1 mmol) and pyrrole (0.67 g, 1 mmol) in 8 ml of
acetone/H2O (50:50) was added dropwise a mixture of dimethyl
acetylendicarboxylate (0.14 g, 1 mmol) in 3 ml of acetone at –5°C
over 10 min. After 8 hours stirring at room temperature, the product
was filtered and recrystallised from ethyl acetate solvent. The product
3a was obtained as:
5
5
-E; Major
-Z; Minor
Scheme 3
hydrogen of pyrrole and negative oxygen of ylide moiety
(see Scheme 1 and 2); but in compounds 5a–c two geometrical
rotamer was observed in corresponding with these structures
because the ylide moiety of these compounds is strongly
conjugated with the adjacent carbonyl group and rotation
about the partial double bond in (E)-5 and (Z)-5 geometrical
isomers is slow on the NMR timescale at ambient temperature
(Scheme 3). Any product other than 3 and 5 could not
be detected by the NMR spectroscopy. The structures of
compounds 3a–c and 5a–c were deduced from their IR,
1H, 13C, and 31P NMR spectra. The mass spectra of these
stable phosphorus ylides displayed molecular ion peaks at
appropriate m/z values. Any initial fragmentation involves
loss of the side chains.
In summary, we have prepared the novel pyrrole-
containing phosphorus yield using a one-pot reaction between
triphenylphosphine and dialkyl acetylenedicarboxylates in the
presence of NH-acid such as pyrrole in a mixture of aqueous-
organic media (water–acetone, 50:50) (3a–c) and dry ethyl
acetate (5a–c). The present method, carries the advantage
that, not only the reaction is performed under the neutral
conditions, but also the substances can be mixed without any
activation or modification. Furthermore, pyrrole-containing
stable phosphorus ylides 3a–c and 5a–c may be considered as
the potentially useful synthetic intermediates. It seems that the
procedure described here may be employed as an acceptable
method for the preparation of 2-substituted and N-substituted
pyrrole stable phosphorus ylides with variable functionalities.
Light yellow needles, 0.45 g, yield 93%, m.p. 146–148°C;
IR (KBr) νmax 1621 and 1720 (C=O), 1600 (C=C) cm-1. MS (m/z,%):
471 (M, 4), 412 (M–CO2Me, 87), 288 (M–PPh2, 3), 262 (PPh3,
100), 183 (PPh2, 19), 108 (PPh, 14), 77 (Ph, 4). Anal. Calcd for
C28H26NO4P (471.50) C, 71.33; H, 5.56; N, 2.97%, Found: C, 70.85;
H, 5.55; N, 2.95%. 1H NMR (500.1 MHz, CDCl3): δH 3.14 and 3.67
(6H, 2 s, 2 OCH3), 3.55 (1H, d, 3JHP = 17.5 Hz, P–C–CH), 5.25 (1H,
br s, C4H4N), 5.95 (1H, dd, J1 = 5.5, J2 = 2.6 Hz, C4H4N), 6.70 (1H,
d, J = 1.5 Hz, C4H4N), 7.43–7.72 (15H, m, 3 C6H5), 10.24 (1H, s,
2
NH). 13C NMR (125.8 MHz, CDCl3): δC 43.18 (d, JCP = 13.4 Hz,
1
P–C–CH), 44.93 (d, JCP = 125.0 Hz, P–C), 49.28 and 52.28 (2 s,
2
OCH3), 104.44, 105.94 and 116.76 (3C, C4H4N), 127.04
1
3
(d, JCP = 91.7 Hz, Cipso), 128.67 (d, JCP = 11.9 Hz, Cmeta), 131.98
(d, 4JCP = 2.5 Hz, Cpara), 133.76 (d, 2JCP = 9.7 Hz, Cortho), 134.05 (d,
3JCP = 3.5 Hz, Cα, C4H4N), 171.30 (d, 2JCP = 13.1 Hz, C=O), 175.31
(d, 3JCP = 9.0 Hz, C=O). 31P NMR (202.4 MHz, CDCl3): δP 23.52 (s,
Ph3P+-C).
Diethyl 2-(1H pyrrol-2-yl)-3-(triphenylphosphoranylidene)butane-
dioate (3b): Light yellow crystal, 0.46 g, yield 92%, m.p. 135–137°C;
IR (KBr) νmax 1623 and 1718 (C=O), 1600 (C=C) cm-1. MS (m/z,%):
499(M, 6), 426 (M–CO2Et, 98), 316 (M–PPh2, 2), 262 (PPh3, 72),
237 (M–PPh3, 16), 183 (PPh2, 75), 108 (PPh, 9). Anal. Calcd for
C30H30NO4P (499.54) C, 72.13; H, 6.05; N, 2.80%, Found: C, 71.85;
H, 6.12; N, 2.65%. 1H NMR (500.1 MHz, CDCl3): δH 0.43 and 1.22
3
(6H, 2t, 2 OCH2CH3), 3.54 (1H, d, JHP = 17.8 Hz, P–C–CH), 3.66
and 4.18 (4H, 2 ABX3 system, 2 OCH2CH3), 5.27 (1H, br s, C4H4N),
5.94 (1H, dd, J1 = 5.5, J2 = 2.7 Hz, C4H4N), 6.69 (1H, d, J = 1.7
Hz, C4H4N), 7.42–7.70 (15H, m, 3 C6H5), 10.25 (1H, s, NH). 13C
NMR (125.8 MHz, CDCl3): δC 13.92 and 14.04 (2 s, 2 OCH2CH3),
43.05 (d, 2JCP = 12.9 Hz, P–C–CH), 44.50 (d, 1JCP = 124.8 Hz, P–C),
57.74 and 60.60 (2 s, 2 OCH2CH3), 104.33, 105.84 and 116.55 (3C,
1
3
C4H4N), 127.17 (d, JCP = 91.7 Hz, Cipso), 128.45 (d, JCP = 12.2
Hz, Cmeta) 131.90 (d, 4JCP = 2.5 Hz, Cpara), 131.99 (d, 2JCP = 9.8 Hz,
Cortho), 134.17 (d, 3JCP = 3.6 Hz, Cα, C4H4N), 170.74 (d, 2JCP = 13.2
Experimental
Hz, C=O), 174.50 (d, JCP = 8.7 Hz, C=O), 31P NMR (202.4 MHz,
3
Melting points and IR spectra were measured on an Electrothermal
9100 apparatus and a Shimadzu IR-460 spectrometer respectively.
Elemental analyses for C, H, and N were performed using a Heraeus
CDCl3): δP 23.42 (s, Ph3P+-C).
Di-tert-butyl 2-(1H pyrrole-2-yl)-3-(triphenylphosphoranylidene)
butanedioate (3c): Pale yellow powder, 0.53 g, yield 96%,
m.p. 163–165°C; IR (KBr) νmax 1628 and 1718 (C=O), 1600
(C=C) cm-1. MS (m/z,%): 555 (M, 7), 489 (M-heterocycle, 22), 454
CHN–O–Rapid analyser. The H, 13C, and 31P NMR spectra were
1
obtained from a Bruker DRX-500 Avence instrument with CDCl3 as
solvent at 500.1, 125.8, and 202.4 MHz respectively. The mass spectra
PAPER: 07/4825

568 JOURNAL OF CHEMICAL RESEARCH 2007
(M-CO2CMe3, 42), 293 (M-PPh3, 1), 262 (PPh3, 44), 183 (PPh2,
47), 108 (PPh, 8). Anal. Calcd for C34H38NO4P (555.64) C, 73.50;
H, 6.89; N, 2.52%, Found: C, 73.45; H, 6.77; N, 2.58%. 1H NMR
(500.1 MHz, CDCl3): δH 0.94 and 1.49 (18H, 2 s, 2 OCMe3),
Di-tert-butyl 2-(1H-pyrrole-1-yl)-3-(triphenylphosphoranylidene)
butanedioate (5c): White powder Yield 0.53 g yield 96%, m.p. 161–
163°C; IR (KBr) νmax 1737 and 1725 (C=O), 1620 (C=C) cm-1. MS
(m/z,%): 555 (M, 5), 489 (100), 454 (62), 262 (45), 183 (72), 108
(21), 77(19), 66 (49). Anal. Calcd for C34H38NO4P (555.64) C, 73.50;
H, 6.89; N, 2.52%, Found: C, 73.66; H, 6.61; N, 2.36%.
3
3.67 (1H, d, JHP = 17.8 Hz, P–C–CH), 5.19 (1H, br s, C4H4N),
5.91 (1H, dd, J1 = 5.6, J2 = 2.7 Hz, C4H4N), 6.69 (1H, d, J = 2.1
Hz, C4H4N), 7.41–7.71 (15H, m, 3 C6H5), 10.28 (1H, s, NH). 13C
NMR (125.8 MHz, CDCl3): δC 28.24 and 28.38 (2 s, 2OCMe3),
Major isomer: (E)-5c, 1H NMR (500.1 MHz, CDCl3): δH 1.03 and
3
1.59 (18 H, 2 s, 2CCH3), 4.36 (1H, d, JHP = 19.8 Hz, P–C–CH),
2
1
5.96–6.80 (4Harom, C4H4N), 7.49–7.71 (15H, m, 3C6H5). 13C NMR
43.77 (d, JCP = 13.5 Hz, P-C-CH), 44.26 (d, JCP = 125.8 Hz, P–
CH), 77.04 and 79.68 (2 s, 2 OCMe3), 104.0, 105.6 and 116.4 (3C,
C4H4N), 127.75 (d, 1JCP = 91.7 Hz, Cipso), 128.47 (d, 3JCP = 11.8 Hz,
1
(125.8 MHz, CDCl3): δC 28.28 and 28.46 (2CMe3), 43.62 (d, JCP
2
= 128.3 Hz, P =C), 62.49 (d, JCP = 16.0 Hz, P–C–CH), 77.33 and
4
2
Cmeta), 131.90 (d, JCP = 2.4 Hz, Cpara), 132.04 (d, JCP = 10.2 Hz,
80.56 (2 s, 2 OCMe3), 106.91 and 120.56 (2C, C4H4N), 127.54 (d,
Cortho), 135.03 (d, 3JCP = 3.0 Hz, Cα, C4H4N), 170.48 (d, 2JCP = 12.6
3
1JCP = 91.8 Hz, Cipso), 128.41 (1C, C4H4N), 128.62 (d, JCP = 11.7
Hz, C=O), 173.72 (d, JCP = 9.6 Hz, C=O). 31P NMR (202.4 MHz,
3
4
Hz, Cmeta), 134.00 (1C, C4H4N), 132.02 (d, JCP = 2.0 Hz, Cpara),
CDCl3): δP 22.83 (s, Ph3P+-C).
2
2
133.84 (d, JCP = 9.3 Hz, Cortho), 168.65 (d, JCP = 12.3 Hz, C=O),
3
171.33 (d, JCP = 13.6 Hz, P-C=C). 31P NMR (202.4 MHz, CDCl3):
δP 23.79 (Ph3P+-C).
General procedures (exemplified by 5a)
To a magnetically stirred solution of triphenylphosphine (0.26 or
1 mmol) and pyrrole (0.66 g or 1 mmol) in 10 ml of dry ethyl acetate
was added, dropwise, a mixture of dimethyl acetylendicarboxylate
(0.14 g or 1 mmol) in 3 ml of ethyl acetate at –5°C over 10 min.
After 8 hour stirring at room temperature, the product was filtered
and recrystallised from ethyl acetate.
We gratefully acknowledge financial support from the
Research Council of University of Sistan and Balouchestan.
Received 5 September 2007; accepted 22 October 2007
Paper 07/4825
doi: 10.3184/030823407X255560
Dimethyl
2-(1H-pyrrole-1-yl)-3-(triphenylphosphoranylidene)
butanedioate (5a): Colourless crystals, 0.45 g, yield 95%, m.p.147–
149°C; IR (KBr) νmax 1750 and 1715 (C=O), 1625 (C=C) cm-1.
MS (m/z,%): 471 (M, 7), 412 (45), 405 (100), 262 (56), 183 (100),
108(46), 77(4). Anal. Calcd for C28H26NO4P (471.50) C, 71.33;
H, 5.56; N, 2.97%, Found: C, 71.08; H, 5.38; N, 2.74%.
References
1
(a) A. Hall, R.A. Bit, S.H. Brown, H.M. Chaignot, I.P. Chessel,
T. Coleman, G.M.P. Giblin, D.N. Hurst, I.R. Kilford, X.Q. Lewell,
A.D. Michel, S. Mohamed, A. Naylor, R. Novelli, L. Skinner,
D.J. Spalding, S.P. Tang and R.J. Wilson, Bioorg. Med. Lett., 2006,
16, 2666; (b) A. Lansiaux, L. Dassonneville, M. Facompre, A. Kumar,
C.E. Stephens, M. Bajic, F. Tanious, W.D. Wilson, D.W. Boykin and
C. Bailly, J. Med. Chem., 2002, 45, 1994; (c) K. Kikuchi, K. Tagami,
S. Hibi, H. Yoshimura, N. Tokuhara, K. Tai, T. Hida, T. Yamauchi and
M. Nagai, Bioorg. Med. Chem. Lett., 2001, 11, 1215; (d) M. Biava,
G.C. Portea, D. Deidda, R. Pompei, A. Tafi and F. Marinetti, Bioorg. Med.
Chem., 2003, 11, 515; (e) B. Jolicoeur, E.E. Chapman, A. Thompson and
W.D. Lubell, Tetrahedron., 2006, 62, 11531.
Major isomer: (E)-5a (%68), 1H NMR (500.1 MHz, CDCl3):
3
δH 3.20 and 3.78 (6H, 2 s, 2OCH3), 4.53 (1H, d, JHP = 16.0 Hz,
P–C–CH), 6.01–6.73 (4Harom, C4H4N), 7.43–7.70 (15H, m, 3 C6H5);
13C NMR (125.8 MHz, CDCl3): δC 44.86 (d, 1JCP = 136.2 Hz, P =C),
49.25 and 52.67 (2 s, 2 OCH3), 62.05 (d, 2JCP = 15.6 Hz, P–C–CH),
1
107.18 and 120.64 (2C, C4H4N), 126.08 (d, JCP = 92.5 Hz, Cipso),
3
128.67 (1C, C4H4N), 128.86 (d, JCP = 12.3 Hz, Cmeta), 132.05 (1C,
4
2
C4H4N), 132.23 (d, JCP = 2.5 Hz, Cpara), 133.72 (d, JCP = 9.8 Hz,
3
2
Cortho), 169.67 (d, JCP = 12.6 Hz, C=O), 173.15 (d, JCP = 14.7 Hz,
P-C=C). 31P NMR (202.4 MHz, CDCl3): δP 24.31 (Ph3P+ -C).
Minor isomer: (Z)-5a (%32), 1H NMR (500.1 MHz, CDCl3):
2
H.R. Hudson, The Chemistry of Organophosphorus Compounds, Vol.
1. Primary, Secondary and Tertiary Phosphines and Heterocyclic
Organophosphorus III Compounds; F.R. Hartley (ed.), Wiley, New York:
1990, pp. 382-472.
3
δH 3.64 and 3.75 (6H, 2 s, 2OCH3), 4.60 (1H, d, JHP = 17.7 Hz,
P–C–CH),6.03–6.75 (4Harom, C4H4N), 7.43–7.70 (15H, m, 3C6H5);
3
4
5
6
R. Engel, Synthesis of Carbon–phosphorus bonds; CRC Press, Boca
Raton, FL, 1988.
J.I.G. Cadogan, Organophosphorus Reagents in Organic Synthesis,
Academic Press, New York: 1979.
M.T. Maghsoodlou, N. Hazeri, S.M. Habibi-Khorassani, L. Saghatforoush,
M.K. Rofouei and M. Rezaei, Arkivoc., 2006, xiii, 117.
M.T. Maghsoodlou, S.M. Habibi-Khorassani, M.K. Rofouei,
S.R. Adhamdoust and M. Nassiri, Arkivoc., 2006, xii, 145.
G. Wittig, Science, 1980, 210, 600.
13C NMR (125.8 MHz, CDCl3): δC 44.97 (d, 1JCP = 126.2 Hz, P =C),
3
50.29 and 52.49 (2 s, 2 OCH3), 61.40 (d, JCP1 = 15.4 Hz, P-C-CH),
107.33 and 120.40 (2C, C4H4N), 127.11 (d, JCP = 92.2 Hz, Cipso),
2
128.52 (1C, C4H4N), 128.91 (d, JCP = 12.2 Hz, Cmeta), 132.10 (1C,
4
2
C4H4N), 132.20 (d, JCP = 2.5 Hz, Cpara), 133.78 (d, JCP = 8.3 Hz,
3
2
Cortho), 170.40 (d, JCP = 18.4 Hz, C=O), 175.31(d, JCP = 13.6 Hz,
P-C=C). 31P NMR (202.4 MHz, CDCl3): δP 25.17 (Ph3P+-C).
7
8
9
Diethyl
2-(1H-pyrrole-1-yl)-3-(triphenylphosphoranylidene)
B.E. Maryanoff and A.B. Rietz, Chem. Rev., 1989, 89, 863.
R.A. Cherkasov and M.A. Pudovik, Russ. Chem. Rev., 1994, 63, 1019.
butanedioate (5b): White solid, 0.46 g, yield 93%, m.p. 129–131°C;
IR (KBr) νmax 1756 and 1725 (C=O), 1620 (C=C) cm-1. MS (m/z,%):
499 (M, 3), 454 (18), 426 (87), 437 (63), 262 (37), 183 (66) 108(17).
Anal. Calcd for C30H30NO4P (499.54) C, 72.13; H, 6.05; N, 2.80%,
Found: C, 71.39; H, 5.93; N, 2.93%.
10 A.J. Arduago and C.A. Stewant, Chem. Rev., 1994, 94, 1215.
11 K.M. Pietrusiewiz and M. Zabloka, Chem. Rev., 1994, 94, 1375.
12 H.J. Bestmann and O. Vostrowsky, Topics Curr. Chem., 1983, 109, 86.
13 M.V. George, S.K. Khetan and R.K. Gupta, Adu. Heterocycl. Chem.,
1976, 19, 354.
14 R. Burgada, Y. Leroux and Y.U. Khoshnieh, Tetrahedron Lett., 1981, 22,
3533.
15 M.T. Maghsoodlou, S.M. Habibi-Khorassani, N. Hazeri, M. Nassiri,
R. Kakaie and G. Marandi, Phosphorus, Sulfur Silicon, 2006, 181, 553.
16 M.T. Maghsoodlou, N. Hazeri, S.M. Habibi-Khorassani, A.G. Shahzadeh
and M. Nassiri, Phosphorus, Sulfur Silicon, 2006, 181, 913.
17 M.T. Maghsoodlou, N. Hazeri, S.M. Habibi-Khorassani, R. Kakaie and
M. Nassiri, Phosphorus, Sulfur Silicon, 2006, 181, 25.
18 S.M. Habibi-Khorassani, M.T. Maghsoodlou, N. Hazeri, M. Nassiri,
G. Marandi and A.G. Shahzadeh, Phosphorus, Sulfur Silicon, 2006, 181,
567.
19 N. Hazeri, S.M. Habibi-Khorassani, M.T. Maghsoodlou, G. Marandi,
M. Nassiri and A.G. Shahzadeh, J. Chem. Res., 2006, 215.
20 M.T. Maghsoodlou, N. Hazeri, S.M. Habibi-Khorassani, R. Heydari,
M. Nassiri, G. Marandi, Z. Moeeni, U. Niromand and Z. Eskandari-
Torbagan, Phosphorus, Sulfur Silicon, 2006, 181, 865.
21 M.T. Maghsoodlou, N. Hazeri, S.M. Habibi-Khorassani, M. Nassiri,
G. Marandi, G. Afshari and U. Niroumand, J. Sulfur. Chem., 2005,
26, 261.
1
Major isomer: (E)-5b (%71), H NMR (500.1 MHz, CDCl3):
δH 0.52 and 1.31 (6H, 2t, 3JHH = 6.0 Hz, 2 OCH2CH3), 3.79 and 4.19
3
(4H, 2 ABX3 system, 2 OCH2CH3), 4.51 (1H, d, JHP = 16.4 Hz, P–
C–CH), 5.98–6.72 (4Harom, C4H4N), 7.41–7.70 (15H, m, 3C6H5). 13
C
NMR (125.8 MHz, CDCl3): δC 14.09 and 14.34 (2 s, 2 OCH2CH3),
44.09 (d, 1JCP = 127.5 Hz, P =C), 57.80 and 58.50 (2 s, 2 OCH2CH3),
61.31 (d, 2JCP = 15.8 Hz, P–C–CH), 107.06 and 120.68 (2C, C4H4N),
126.35 (d, 1JCP = 92.2 Hz, Cipso) 128.33 (1C, C4H4N), 128.76 (d, 3JCP
4
2
= 11.4 Hz, Cmeta), 132.18 (d, JCP = 2.2 Hz, Cpara), 133.78 (d, JCP
3
= 9.8 Hz, Cortho), 133.93 (1C, C4H4N), 169.17 (d, JCP = 12.7 Hz,
C=O), 172.44 (d, JCP = 13.7 Hz, P–C=C). 31P NMR (202.4 MHz,
2
CDCl3): δP 23.43 (s, Ph3P+-C).
Minor isomer: (Z)-5b (%29), 1H NMR (500.1 MHz, CDCl3):
δH 1.25 and 1.38 (6H, 2t, 3JHH = 7.0 Hz, 2OCH2CH3), 3.78 and 4.27
3
(4H, 2 ABX3 system, 2 OCH2CH3), 4.56 (1H, d, JHP = 18.2 Hz,
P–C–CH), 5.99- 6.75 (4Harom
, C4H4N), 7.41–7.70 (15H, m,
3C6H5). 13C NMR (125.8 MHz, CDCl3): δC 14.33 and 15.01 (2 s,
2 OCH2CH3), 44.64 (d, 1JCP = 135.3 Hz, P =C), 57.83 and 58.52 (2 s,
2 OCH2CH3), 62.01 (d, 2JCP = 15.1 Hz, P–C–CH), 107.18 and 120.48
22 M. Kalantari, M.R. Islami, Z. Hasani and K. Saidi, Arkivoc, 2006, x, 55.
23 M.R. Islami, F. Mollazehi, A. Badiei and H. Sheibani, Arkivoc, 2005, xv,
25.
24 Z. Hassani, M.R. Islami, H. Sheibani, M. Kalantari and K. Saidi, Arkivoc,
2006, i, 89.
25 T.L. Gilchrist, Heterocyclic Chemistry, Wiley, New York, 1985.
26 G.A. Pagani, Heterocycles. Rev., 1993, 35, 843.
1
(2C, C4H4N), 127.33 (d, JCP = 92.0 Hz, Cipso),128.24 (1C, C4H4N),
3
4
128.86 (d, JCP = 10.2 Hz, Cmeta), 132.20 (d, JCP = 2.2 Hz, Cpara),
2
133.80 (d, JCP = 10.0 Hz, Cortho), 134.28 (1C, C4H4N), 170.10 (d,
2JCP = 17.5 Hz, C=O), 170.88 (d, 3JCP = 13.5 Hz, P–C=C). 31P NMR
(202.4 MHz, CDCl3): δP 23.87 (s, Ph3P+–C).
PAPER: 07/4825