Triphenylphosphine-mediated chemoselective synthesis of functionalized thiazol-2(5H)-ones

Article abstract of DOI:10.1007/s00706-010-0434-x

Stabilized phosphoranes, obtained from three-component reaction between dialkyl acetylenedicarboxylates and thiazolidine-2,4-dione in the presence of triphenylphosphine, undergo a smooth intramolecular Wittig reaction in boiling toluene to produce functio

Full text of DOI:10.1007/s00706-010-0434-x

Monatsh Chem (2011) 142:177–182
DOI 10.1007/s00706-010-0434-x
ORIGINAL PAPER
Triphenylphosphine-mediated chemoselective synthesis
of functionalized thiazol-2(5H)-ones
•
Issa Yavari Leila Azad Tayebeh Sanaeishoar
•
Received: 16 August 2010 / Accepted: 23 November 2010 / Published online: 4 January 2011
Ó Springer-Verlag 2010
Abstract Stabilized phosphoranes, obtained from three-
component reaction between dialkyl acetylenedicarboxy-
lates and thiazolidine-2,4-dione in the presence of
triphenylphosphine, undergo a smooth intramolecular
Wittig reaction in boiling toluene to produce functionalized
thiazol-2(5H)-ones in good yields. When alkyl propiolates
were employed in these reactions, only the (E)-isomer of
alkyl 3-(2,4-dioxothiazolidin-3-yl)acrylates were isolated.
A dynamic effect was observed in the 1H nuclear magnetic
resonance (NMR) spectrum of ethyl (E)-3-(2,4-dioxo-
thiazolidin-3-yl)-3-phenylacrylate as a result of restricted
rotation (DG= = 77 kJ/mol) around the N–C bond
between the thiazolidine moiety and the vinyl group.
bioactivity [2], while others have found application as
liquid crystals [3] and cosmetic sunscreens [4]. Several
methods for synthesis of thiazole derivatives have been
developed [5–8], the most widely used method being
Hantzsch synthesis [9].
As part of our current studies on synthesis of sulfur-
containing organic compounds [10–12], herein we report
an efficient procedure for chemoselective synthesis of
functionalized thiazol-2(5H)-ones from reaction between
thiazolidine-2,4-diones and acetylenic esters in the pres-
ence of triphenylphosphine (Ph3P).
Results and discussion
Keywords Thiazol-2(5H)-one Á Thiazolidin-2,4-dione Á
Hindered rotation Á Intramolecular Wittig reaction Á
Triphenylphosphine
The reaction of dialkyl acetylenedicarboxylates 1 with
thiazolidine-2,4-dione (2) in the presence of Ph3P at r.t. in
ethyl acetate was completed within a few hours, and
phosphoranes 3 were produced in good yields [13–16]. The
1H NMR spectra of the reaction mixtures clearly showed
the formation of the phosphorane 3, and no other products
could be detected. These ylides were subjected to intra-
molecular Wittig reaction in boiling toluene, without
further purification, to produce dialkyl 2-(2,5-dihydro-2-
oxothiazol-4-yl)fumarates 4 in good yields (Scheme 1). To
establish the structure of the phosphoranes 3, the ylide 3a
Introduction
Thiazole and its derivatives play a prominent role in nature,
as they are found in numerous bioactive compounds. The
thiazolium core present in vitamin B1 and its coenzyme
complex plays an important role in the decarboxylation of
a-keto acids. A large number of thiazole derivatives
obtained from microbial and marine origins exhibit
important biological effects such as antitumor, antifungal,
antibiotic, and antiviral activities [1]. Synthetic thiazoles
have also been shown to exhibit a wide variety of
1
was isolated and characterized by infrared (IR), H NMR,
and 13C NMR spectral data (see ‘‘Experimental’’).
Although these phosphorus ylides are stable at ambient
temperature, they undergo a smooth reaction in boiling
toluene to produce dialkyl 2-(2,5-dihydro-2-oxothiazol-4-
yl)fumarates 4 in good yields (Scheme 1). Using 5-aryli-
denethiazolidine-2,4-diones 5 as the NH-acidic component
in this reaction afforded dialkyl (5Z)-2-(5-benzylidene-2,5-
dihydro-2-oxothiazol-4-yl)fumarates 7. Structures 4 and 7
I. Yavari (&) Á L. Azad Á T. Sanaeishoar
Department of Chemistry, Science and Research Branch,
Islamic Azad University, Ponak, Tehran, Iran
e-mail: yavarisa@modares.ac.ir
123

178
I. Yavari et al.
Scheme 1
RO2C
O
O
Ph3P
CO2R
Ph3PO
CO2R
+
CO2R
CO2R
N
+
NH
PPh3
+
S
N
S
S
O
CO2R
R
O
O
R
2
4a
Me
1a
1b
3
Me
Et
4b Et
RO2C
O
O
Ph3P
CO2R
+
CO2R
Ar
Ar
CO2R
CO2R
Ar
NH
N
PPh3
+
+ Ph3PO
N
S
S
S
CO2R
R
1a Me
1b Et
O
O
O
Ar
Ph
Ph
Ar
Ph
p-Tolyl
2-Thienyl
R
Ar
R
5a
5b
5c
6a Me
6b
Ph
Ph
7a
7b
Me
Et
Et
6c Me p-Tolyl
p-Tolyl
p-Tolyl
2-Thienyl
2-Thienyl
7c Me
6d Et
p-Tolyl
7d
7e
Et
Me
6e
Me 2-Thienyl
6f Et
2-Thienyl
7f Et
were assigned to the isolated products on the basis of their
1
presence of products 10a, 10b, and 11 (Scheme 3). These
products were separated by column chromatography and
IR, H NMR, 13C NMR, and mass spectral data. Thus, the
1H NMR spectrum of each of the isolated products
exhibited a C=CH proton signal at about 7.0–7.2 ppm,
which is in agreement with the (E) configuration [17] for
the vinylic moieties in compounds 4 and 7.
identified by their IR, H NMR, and 13C NMR spectral
1
data. The mass spectra of these compounds displayed
molecular ion peaks at appropriate m/z values. The 1H
NMR spectrum of 10a exhibited an AX system for the
3
Although we have not yet established the mechanism of
formation of 4 and 7 in an experimental manner, a plau-
sible explanation is proposed in Scheme 2. Ylides 3
undergo intramolecular Wittig reaction to produce the
fused bicyclic intermediates 8, which apparently isomerize
under the reaction conditions employed to produce 4 in
good yields. Compound 3 has two carbonyl groups, namely
the NCO and NCOS, available for intramolecular Wittig
reaction. However, only the NCO carbonyl group partici-
pates in the intramolecular Wittig reaction. This
chemoselectivity arises from higher electrophilic reactivity
of the NCO carbonyl group toward the ylenic carbon
compared with the carbonyl group of the NCOS moiety.
The reaction of thiazolidine-2,4-dione (2) or 5-benzyli-
dene-thiazolidine-2,4-dione (5a) with alkyl propiolates 9 in
the presence of Ph3P proceeded spontaneously at r.t. in
trans-olefinic protons with JHH = 14.0 Hz. On the basis
of the chemistry of trivalent phosphorus nucleophiles
[14–16], it is reasonable to assume that compound 10a
results from initial addition of Ph3P to ethyl propiolate 9a
and subsequent protonation of the 1:1 adduct by the NH-
acidic 2. Then, the positively charged ion 13 is attacked by
the nitrogen atom of the conjugate base 14 to produce the
zwitterionic intermediate 15, which is converted to 10a by
elimination of Ph3P (Scheme 4) [14, 16].
1
The H NMR spectrum of 10b exhibits a characteristic
AB quartet for the diastereotopic methylene protons in
1
CDCl3 at 25 °C. The H NMR of 10b in 1,2-dichloro-
benzene at 25 °C is similar to that measured in CDCl3.
Increasing the temperature results in coalescence of the
CH2 resonances. At 110 °C, a relatively broad singlet was
observed for the CH2 group. This dynamic effect is inter-
preted in terms of restricted rotation around the N–C bond
linking the vinyl group to thiazolidine ring. Although
1
toluene and was finished within 1–4 h. H and 13C NMR
spectra of the reaction mixtures clearly indicated the
Scheme 2
RO2C
CO2R
O
PPh3
CO2R
Electrocyclic
ring opening
Intramolecular
N
CO2R
N
CO2R
N
S
S
S
Wittig reaction
CO2R
_
O
Ph3PO
O
O
3
8
4
123

Triphenylphosphine-mediated chemoselective synthesis of functionalized thiazol-2(5H)-ones
179
O
Experimental
O
CO2Et
R
PPh3
N
+
NH
Chemicals were purchased from Merck and used without
further purification. Compounds 5 were prepared from 2 by a
known method [19]. Melting points were measured on an
Electrothermal 9100 apparatus. H and 13C NMR spectra
S
S
CO2Et
R
R
H
O
O
1
R
2
9a
H
10a H
(CDCl3) were measured with a Bruker Avance DRX-300
spectrometer at 300 and 75 MHz, respectively. IR spectra
were measured on a Shimadzu IR-460 spectrometer. Mass
spectra were recorded on a FINNIGAN-MAT 8430 spec-
trometer operating at ionization potential of 70 eV.
Chromatography columns were prepared from Merck silica
gel 70–230 mesh.
9b Ph
10b Ph
O
N
O
CO2Et
Ph
Ph
Ph
PPh3
+
S
NH
CO2Et
S
H
O
Ph
O
5a
9b
11
General procedure for the preparation of compounds
3 and 6
Scheme 3
O
To a stirred solution of the thiazolidine-2,4-dione 2 or 5
(1 mmol) and dialkyl acetylenedicarboxylate 1 (1 mmol)
in 5 cm3 EtOAc was added dropwise a solution of 0.26 g
Ph3P (1 mmol) in 2 cm3 EtOAc at 25 °C over 10 min.
After 3 h stirring at r.t., the product was filtered and
washed with cold EtOAc. Although products were usually
pure enough and could be directly used for the preparation
of compounds 4 (and 7), 3a was purified and spectroscopic
data are given below as an example.
NH
O
N
S
CO2Et
CO2Et
CHCO2Et
+
PPh3
H
O
2
PPh3
+
S
PPh3
12
O
9a
14
13
O
O
Conjugate
Addition
CO2Et
PPh3
_
Ph3P
N
N
S
Dimethyl 2-(2,4-dioxo-3-thiazolidinyl)-3-
(triphenylphosphoranylidene)butanedioate
(3a, C27H24NO6PS)
S
CO2Et
O
O
15
10a
Pink powder; m.p.: 137–139 °C; yield 0.42 g (80%); IR
ꢀ
(KBr): m = 1,619 (C=O), 1,691 (C=O), 1,745 (C=O), 1,434
Scheme 4
(C=C) cm-1; EI-MS: m/z = 521 (M?, 2), 275 (12), 262
(100), 200 (10), 184 (75), 140 (18), 115 (16), 59 (8).
Major isomer (Z)-3a (55%): 1H NMR (CDCl3): d = 3.12
(3H, s, MeO), 3.74 (3H, s, MeO), 3.82 (2H, s, CH2S), 4.76
extensive line-shape analysis in relation to the dynamic
NMR effect observed for 10b was not undertaken in
the present work, the variable temperature spectra are
sufficient to calculate the free energy of activation for
the restricted N–C bond rotation. From the coalescence
of the methylene protons and using the expression
k = HDm2 + 6JA2 B, the rate constant (k) was calculated to be
116 s-1 at 365 K. Application of the absolute rate theory
with a transmission coefficient of 1 gives a free energy
of activation (DG=) of 77 2 kJ/mol for 10b, where
all known sources of errors are estimated and included
[18].
3
(1H, d, JPC = 15.5 Hz, CH), 7.45–7.74 (15H, m,
3C6H5) ppm; 13C NMR (CDCl3): d = 33.3 (CH2S), 37.5
(d, JPC = 130.0 Hz, P–C), 49.4 (MeO), 50.9 (MeO), 59.1
1
2
(d, JPC = 17.1 Hz, CH), 126.5 (d, JPC = 91.0 Hz,
1
3
P–Cipso), 129.2 (d, JPC = 12.0 Hz, Cmeta), 132.4 (d,
2
4JPC = 2.0 Hz, Cpara), 134.0 (d, JPC = 11.1 Hz, Cortho),
2
166.7 (C=O), 167.2 (C=O), 170.5 (d, JPC = 14.0 Hz,
PC=C), 171.0 (C=O) ppm.
Minor isomer (E)-3a (45%): 1H NMR (CDCl3):
d = 3.60 (3H, s, MeO), 3.73 (3H, s, MeO), 3.99 (2H, s,
CH2S), 4,80 (1H, d, 3JPC = 17.5 Hz, CH), 7.45–7.74 (15H,
m, 3C6H5) ppm; 13C NMR (CDCl3): d = 35.9 (CH2S),
In conclusion, the present method features the advan-
tages that the reaction can be performed under neutral
conditions and that the starting materials and reagents can
be mixed without any modifications. The procedure
described herein provides an acceptable method for prep-
aration of highly functionalized thiazol-2(5H)-ones and
(5Z)-5-arylidenethiazol-2(5H)-ones.
1
41.5 (d, JPC = 140.0 Hz, P–C), 52.7 (MeO), 53.3 (MeO),
2
58.8 (d, JPC = 17.1 Hz, CH), 127.0 (d, JPC = 93.2 Hz,
1
3
P–Cipso), 128.9 (d, JPC = 12.0 Hz,
Cmeta), 132.3
(d, JPC = 2.0 Hz, Cpara), 133.8 (d, JPC = 11.2 Hz,
4
2
123

180
I. Yavari et al.
C
ortho), 163.1 (C=O), 164.2 (C=O), 168.8 (d,
Diethyl (E)-2-((5Z)-5-benzylidene-2,5-dihydro-
2-oxothiazol-4-yl)butenedioate (7b, C18H17NO5S)
2JPC = 14.2 Hz, PC=C), 172.2 (C=O) ppm.
Yellow crystals; m.p.: 98–100 °C; yield 0.52 g (73%); IR
General procedure for the preparation of compounds
4 and 7
(KBr):
ꢀm = 1,676 (C=O), 1,735 (C=O), 1,424 (C=C) cm-1
;
EI-MS: m/z = 359 (M?, 6), 294 (38), 269 (17), 161 (15),
134 (100), 98 (11), 90 (27), 77 (29), 69 (40), 57 (24), 43
(67); 1H NMR (CDCl3): d = 1.28 (3H, t, 3J = 7.1 Hz,
Me), 1.38 (3H, t, 3J = 7.1 Hz, Me), 4.23 (2H, q,
To a stirred solution of the thiazolidine-2,4-dione (2 or 5,
2 mmol) and dialkyl acetylenedicarboxylate (1, 2 mmol) in
10 cm3 toluene was added dropwise a solution of 0.52 g
Ph3P (2 mmol) in 5 cm3 toluene at r.t. over 10 min. After
1 h stirring at r.t., the reaction mixture was refluxed. After
completion of the reaction [1–4 h, thin-layer chromatog-
raphy (TLC): AcOEt/hexane 2:1], the solvent was removed
from reaction mixture at reduced pressure and the residue
was purified by column chromatography [silica gel
230–240 mesh (Merck), hexane/AcOEt 4:1].
3
3J = 7.1 Hz, CH2O), 4.35 (2H, q, J = 7.1 Hz, CH2O),
7.23 (1H, s, CH), 7.46–7.58 (5H, m, CH), 7.95 (1H, s,
CH) ppm; 13C NMR (CDCl3): d = 14.3 (Me), 14.4 (Me),
62.2 (CH2O), 63.4 (CH2O), 121.4 (CH), 121.8 (CH), 130.4
(2CH), 130.8 (2CH), 132.8 (CH), 133.5 (C), 135.3 (C),
143.5 (C), 161.3, 162.6, 170.3 (3C=O), 170.6 (C=N) ppm.
Dimethyl (E)-2-((5Z)-5-(4-methylbenzylidene)-
2,5-dihydro-2-oxothiazol-4-yl)butenedioate
(7c, C17H15NO5S)
Dimethyl (E)-2-(2,5-dihydro-2-oxothiazol-4-yl)-
butenedioate (4a, C9H9NO5S)
Colorless crystals; m.p.: 109–111 °C; yield 0.52 g (74%);
ꢀ
IR (KBr): m = 1,681 (C=O), 1,749 (C=O), 1,429
Yellow crystals; m.p.: 107–109 °C; yield 0.34 g (67%); IR
(C=C) cm-1; EI-MS: m/z = 345 (M?, 7), 267 (22), 241
(34), 227 (11), 176 (12), 148 (100), 104 (24), 91 (34), 84
-1
ꢀ
(KBr): m = 1,693 (C=O), 1,741 (C=O), 1,436 (C=C) cm
;
EI-MS: m/z = 243 (M?, 10), 125 (14), 77 (25), 74 (10), 69
(42), 57 (33), 43 (100); 1H NMR (CDCl3): d = 3.80 (3H, s,
MeO), 3.89 (3H, s, MeO), 4.14 (2H, s, CH2S), 7.20 (1H, s,
CH) ppm; 13C NMR (CDCl3): d = 35.9 (CH2S), 53.1
(MeO), 54.0 (MeO), 132.1 (C), 143.4 (CH), 161.3, 162.6,
170.1 (3C=O), 170.4 (C=N) ppm.
1
(8), 77 (19), 69 (30), 57 (28), 43 (65); H NMR (CDCl3):
d = 2.38 (3H, s, Me), 3.79 (3H, s, Me), 3.90 (3H, s, Me),
7.24 (1H, s, CH), 7.31 (2H, d, J = 7.5 Hz, 2CH), 7.44
3
3
(2H, d, J = 7.5 Hz, 2CH), 7.93 (1H, s, CH) ppm; 13C
NMR (CDCl3): d = 22.0 (Me), 53.1 (MeO), 54.0 (MeO),
121.6 (CH), 129.9 (CH), 130.8 (2CH), 130.9 (2CH), 131.5
(C), 133.3 (C), 133.5 (C), 135.3 (C), 161.3, 162.8, 170.2
(3C=O), 170.6 (C=N) ppm.
Diethyl (E)-2-(2,5-dihydro-2-oxothiazol-4-yl)butenedioate
(4b, C11H13NO5S)
Yellow crystals; m.p.: 108–111 °C; yield 0.36 g (65%); IR
Diethyl (E)-2-((5Z)-5-(4-methylbenzylidene)-2,5-dihydro-
2-oxothiazol-4-yl)butenedioate (7d, C19H19NO5S)
-1
;
ꢀ
(KBr) m = 1,691 (C=O), 1,739 (C=O), 1,435 (C=C) cm
EI-MS: m/z = 271 (M?, 8), 125 (15), 77 (27), 74 (11), 69
(45), 57 (36), 43 (100); 1H NMR (CDCl3): d = 1.30 (3H, t,
3J = 7.1 Hz, Me), 1.35 (3H, t, 3J = 7.1 Hz, Me), 4.14 (2H,
Colorless crystals; m.p.: 110–112 °C; yield 0.54 g (72%);
ꢀ
IR (KBr): m = 1,671 (C=O), 1,737 (C=O), 1,428
(C=C) cm-1; EI-MS: m/z = 373 (M?, 10), 294 (26), 269
(38), 227 (13), 176 (15), 148 (100), 104 (21), 98 (10), 91
(35), 77 (18), 69 (35), 57 (31), 43 (60); 1H NMR (CDCl3):
d = 1.28 (3H, t, 3J = 7.1 Hz, Me), 1.33 (3H, t,
3J = 7.1 Hz, Me), 2.43 (3H, s, Me), 4.23 (2H, q,
3
s, CH2S), 4.27 (2H, q, J = 7.1 Hz, CH2O), 4.33 (2H, q,
3J = 7.1 Hz, CH2O), 7.05 (1H, s, CH) ppm; 13C NMR
(CDCl3): d = 14.3 (Me), 14.4 (Me), 35.9 (CH2S), 62.2
(CH2O), 63.4 (CH2O), 132.0 (C), 143.3 (CH), 161.2, 162.6,
170.1, (3C=O), 170.3 (C=N) ppm.
3
3J = 7.1 Hz, CH2O), 4.33 (2H, q, J = 7.1 Hz, CH2O),
3
7.23 (1H, s, CH), 7.31 (2H, d, J = 7.5 Hz, 2CH), 7.44
Dimethyl (E)-2-((5Z)-5-benzylidene-2,5-dihydro-
2-oxothiazol-4-yl)butenedioate (7a, C16H13NO5S)
3
(2H, d, J = 7.5 Hz, 2CH), 7.93 (1H, s, CH) ppm; 13C
NMR (CDCl3): d = 14.3 (Me), 14.4 (Me), 22.0 (Me), 62.3
(CH2O), 63.4 (CH2O), 121.6 (CH), 129.9 (CH), 130.8
(2CH), 130.9 (2CH), 131.5 (C), 133.3 (C), 133.5 (C), 135.3
(C), 161.3, 162.8, 170.2 (3C=O), 170.6 (C=N) ppm.
Yellow crystals; m.p.: 99–101 °C; yield 0.44 g (64%); IR
-1
ꢀ
(KBr): m = 1,628 (C=O), 1,749 (C=O), 1,424 (C=C) cm
;
EI-MS: m/z = 331 (M?, 7), 267 (24), 241 (33), 227 (15), 161
(16), 134 (100), 90 (23), 84 (9), 77 (21), 69 (33), 57 (20), 43
(61); 1H NMR (CDCl3): d = 3.80 (3H, s, MeO), 3.91 (3H, s,
MeO), 7.25 (1H, s, CH), 7.47–7.58 (5H, m, 5 CH), 7.95 (1H,
s, CH) ppm; 13C NMR (CDCl3): d = 53.3 (MeO), 54.0
(MeO), 121.4 (CH), 129.7 (CH), 130.7 (2CH), 130.9 (2CH),
131.2 (C), 133.1 (CH), 133.4 (C), 135.3 (C), 161.3, 162.7,
170.2 (3C=O), 170.6 (C=N) ppm.
Dimethyl (E)-2-((5Z)-5-(thiophen-2-ylmethylene)-2,5-
dihydro-2-oxothiazol-4-yl)butenedioate
(7e, C14H11NO5S2)
Yellow crystals; m.p.: 87–89 °C; yield 0.46 g (70%); IR
-1
ꢀ
(KBr): m = 1,689 (C=O), 1,735 (C=O), 1,431 (C=C) cm
;
EI-MS: m/z = 337 (M?, 5), 241 (36), 219 (17), 167 (16),
123

Triphenylphosphine-mediated chemoselective synthesis of functionalized thiazol-2(5H)-ones
181
140 (100), 96 (30), 84 (7), 83 (39), 77 (21), 69 (32), 57
1
Ethyl (E)-3-(2,4-dioxothiazolidin-3-yl)-3-phenyl-2-pro-
penoate (10b, C14H13NO4S)
(25), 43 (62); H NMR (CDCl3): d = 3.80 (3H, s, MeO),
3.89 (3H, s, MeO), 7.18 (1H, dd, 3J = 4.5 Hz, 3J =
Yellow crystals; m.p.: 97–99 °C; yield 0.46 g (78%); IR
(KBr): ꢀm = 1,631 (C=O), 1,695 (C=O), 1,747 (C=O), 1,430
(C=C) cm-1; EI-MS: m/z = 291 (M?, 14), 263 (30), 218 (79),
77 (11), 73 (27), 69 (85), 57 (98), 43 (100); 1H NMR (CDCl3):
d = 1.33 (3H, t, 3J = 7.1 Hz, Me), 4.05 (2H, ABq,
JAB = 17.5 Hz, DmAB = 30 Hz, CH2S), 4.27 (2H, q,
3J = 7.1 Hz, CH2O), 7.35–7.47 (5H, m, CH), 8.10 (1H, s,
CH) ppm; 13C NMR (CDCl3): d = 14.4 (Me), 34.5 (CH2S),
62.7 (CH2O), 122.0 (CH), 129.2 (2CH), 129.4 (2CH), 131.3
(CH), 132.1 (C), 143.4 (C), 162.8, 170.1, 170.4 (3C=O) ppm.
3
3.6 Hz, CH), 7.24 (1H, s, CH), 7.44 (1H, d, J = 3.6 Hz,
CH), 7.71 (1H, d, 3J = 4.5 Hz, CH), 8.11 (1H, s,
CH) ppm; 13C NMR (CDCl3): d = 53.1 (MeO), 54.0
(MeO), 119.0 (C), 128.0 (CH), 129.1 (CH), 130.5 (CH),
132.9 (CH), 133.3 (C), 134.3 (CH), 137.8 (C), 161.4,
162.9, 170.3 (3C=O), 170.6 (C=N) ppm.
Diethyl (E)-2-((5Z)-5-(thiophen-2-ylmethylene)-2,5-
dihydro-2-oxothiazol-4-yl)butenedioate
(7f, C16H15NO5S2)
Yellow crystals; m.p.: 90–92 °C; yield 0.76 g (69%); IR
Ethyl (E)-3-((Z)-5-benzylidene-2,4-dioxothiazolidin-
3-yl)-3-phenyl-2-propenoate (11, C21H17NO4S)
-1
ꢀ
(KBr): m = 1,683 (C=O), 1,737 (C=O), 1,426 (C=C) cm
;
EI-MS: m/z = 365 (M?, 7), 269 (40), 219 (18), 167 (19),
140 (100), 98 (8), 96 (29), 83 (37), 77 (23), 69 (38), 57
(26), 43 (67); 1H NMR (CDCl3): d = 1.28 (3H, t,
3J = 7.1 Hz, Me), 1.34 (3H, t, 3J = 7.1 Hz, Me), 4.22
Yellow crystals; m.p.: 90–92 °C; yield 0.56 g (73%); IR
ꢀ
(KBr): m = 1,637 (C=O), 1,696 (C=O), 1,740 (C=O), 1,435
(C=C) cm-1; EI-MS: m/z = 379 (M?, 15), 351 (28), 315
(13), 306 (70), 289 (35), 90 (25), 77 (34), 73 (26), 69 (87), 57
(97), 43 (100); 1H NMR (CDCl3): d = 1.35 (3H, t,
3J = 7.1 Hz, Me), 4.34 (2H, q, 3J = 7.1 Hz, CH2O), 7.33-
7.44 (5H, m, CH), 7.46–7.63 (5H, m, CH), 7.95 (1H, s, CH),
8.12 (1H, s, CH) ppm; 13C NMR (CDCl3): d = 14.6 (Me),
62.7 (CH2O), 121.5 (CH), 121.8 (CH), 129.5 (CH), 129.6
(2CH), 129.7 (2CH), 130.8 (2CH), 131.2 (CH), 131.3 (CH),
132.2 (C), 133.4 (C), 135.3 (C), 143.4 (C), 162.6, 165.4,
166.6 (3C=O) ppm.
3
3
(2H, q, J = 7.1 Hz, CH2O), 4.34 (2H, q, J = 7.1 Hz,
CH2O), 7.18 (1H, dd, 3J = 4.9 Hz, 3J = 3.5 Hz, CH), 7.24
3
(1H, s, CH), 7.44 (1H, d, J = 3.5 Hz, CH), 7.71 (1H, d,
3J = 4.9 Hz, CH), 8.11 (1H, s, CH) ppm; 13C NMR
(CDCl3): d = 14.3 (Me), 14.4 (Me), 62.2 (CH2O), 63.4
(CH2O), 119.0 (C), 127.8 (CH), 129.1 (CH), 130.7 (CH),
132.8 (CH), 133.3 (C), 134.3 (CH), 137.8 (C), 161.4,
162.7, 170.5 (3C=O), 170.8 (C=N) ppm.
General procedure for the preparation of compounds
10 and 11
References
1. Lewis JR (1996) Nat Prod Rep 13:435
2. Metzger JV (1979) Thiazole and its Derivatives. Wiley, New
York
3. Kiryanov AA, Sampson P, Seed AJ (2001) J Org Chem 66:7925
4. Bach T, Heuser S (2000) Tetrahedron Lett 41:1707
5. Potewar TM, Ingale SA, Srinivasan KV (2007) Tetrahedron
63:11066
6. Zambon A, Borsato G, Brussolo S, Frascella P, Lucchini V
(2008) Tetrahedron Lett 49:66
7. Franklin PX, Pillai AD, Rathod PD, Yerande S, Nivsarkar M,
Padh H, Vasu KK, Sudarsanam V (2008) Eur J Med Chem
43:129
8. Karegoudar P, Karthikeyan MS, Prasad DJ, Mahalinga M, Holla
BS, Kumari NS (2008) Eur J Med Chem 43:261
9. Ochiai M, Nishi Y, Hashimoto S, Tsuchimoto Y, Chen DW
(2003) J Org Chem 68:7887
10. Yavari I, Hajinasiri R, Sayyed-Alangi SZ, Iravani N (2008)
Monatsh Chem 139:1029
To a stirred solution of the thiazolidine-2,4-dione (2 or
5a, 2 mmol) and 0.52 g Ph3P (2 mmol) in 10 cm3 toluene
was added dropwise a solution of the propiolate (2 mmol)
in 5 cm3 toluene at r.t. After completion of the reaction
(1–4 h, TLC: AcOEt/hexane 2:1), the solvent was
removed from the reaction mixture at reduced pressure
and the residue was purified by column chromatography
[silica gel 230–240 mesh (Merck), hexane/AcOEt 4:1].
Ethyl (E)-3-(2,4-dioxothiazolidin-3-yl)-2-propenoate
(10a, C8H9NO4S)
Yellow crystals; m.p.: 88–91 °C; yield 0.32 g (75%); IR
ꢀ
(KBr): m = 1,625 (C=O), 1,696 (C=O), 1,743 (C=O), 1,428
(C=C) cm-1; EI-MS: m/z = 215 (M?, 11), 187 (26), 142
1
(68), 77 (10), 73 (24), 69 (88), 57 (99), 43 (100) ppm; H
11. Yavari I, Nematpour M, Hossaini Z (2010) Monatsh Chem
141:229
3
NMR (CDCl3): d = 1.33 (3H, t, J = 7.1 Hz, Me), 4.05
(2H, s, CH2S), 4.27 (2H, q, 3J = 7.1 Hz, CH2O), 6.99 (1H,
d, 3J = 14.0 Hz, CH), 7.78 (1H, d, 3J = 14.0 Hz,
CH) ppm; 13C NMR (CDCl3): d = 14.4 (Me), 34.5
(CH2S), 62.7 (CH2O), 132 (CH), 145 (CH), 162.6, 170.1,
170.5 (3C=O) ppm.
12. Yavari I, Sanaeishoar T, Ghazvini M, Iravani N (2010) J Sulfur
Chem 31:169
13. Ramazani A, Kazemizadeh AR, Ahmadi E, Noshiranzadeh N,
Souldozi A (2008) Curr Org Chem 12:59
14. Yavari I, Zabarjad-Shiraz N, Maghsoodlou MT, Hazeri N (2002)
Phosphorus Sulfur Silicon Relat Elem 177:759
123

182
I. Yavari et al.
15. Yavari I, Zabarjad-Shiraz N (2004) Phosphorus. Sulfur Silicon
Relat Elem 179:1477
18. Gu¨nther H (1995) NMR Spectroscopy, 2nd ed, Wiley, New York,
Chapter 9
16. Yavari I, Zabarjad-Shiraz N (2003) Monatsh Chem 134:445
17. Eliel EL, Wilen SH (1994) Stereochemistry of Organic Com-
pounds. Wiley, New York, p 569
19. Bruno G, Costantino L, Curinga C, Maccari R, Monforte F, Ni-
colo F, Ottana R, Vigorita MG (2002) Bioorg Med Chem 10:1077
123