Synthesis of oxazolidinones, dioxazolidinone and polyoxazolidinone (a new polyurethane) via a multi component-coupling of aldehyde, diamine dihydrochloride, terminal alkyne and CO2

Article abstract of DOI:10.2174/157017812802850221

In the present paper, the coupling reaction of aldehyde, terminal alkyne, amine salt and CO₂ was investigated. Copper iodide was found to be an efficient catalyst for the coupling reaction in ethyl acetate at 80 °C and under an atmospheric pres

Full text of DOI:10.2174/157017812802850221

Letters in Organic Chemistry, 2012, 9, 585-593
585
Synthesis of Oxazolidinones, Dioxazolidinone and Polyoxazolidinone
(A New Polyurethane) Via A Multi Component-Coupling of Aldehyde,
Diamine Dihydrochloride, Terminal Alkyne and CO2
Djamila Teffahi,1, 2 Smain Hocine1 and Chao-Jun Li*2
1Laboratoire de Génie Chimique et Chimie Appliquée, Hasnaoua Université, Mouloud Mammeri, 15000 Tizi-Ouzou,
Algérie
2Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal QC H3A 2K6, Canada
Received January 23, 2012: Revised July 01, 2012: Accepted July 01, 2012
Abstract: In the present paper, the coupling reaction of aldehyde, terminal alkyne, amine salt and CO2 was investigated.
Copper iodide was found to be an efficient catalyst for the coupling reaction in ethyl acetate at 80 °C and under an atmos-
pheric pressure of CO2. A diverse range of oxazolidinones was prepared by this method. Subsequently, a copper-catalyzed
coupling of aldehyde, terminal alkyne, diamine salt and CO2 was developed to generate a dioxazolidinone. Finally, under
the optimised conditions, we report for the first time a facile synthetic route for the synthesis of polyoxazolidinone, a new
polyurethane, via a multi-component coupling of benzaldehyde, 1, 4-diethynylbenzene, 1, 6-hexadiamine and CO2.
Keywords: Carbon dioxide fixation, copper catalysis, multicomponent reactions, oxazolidinone, polyurethane.
1. INTRODUCTION
pounds containing active hydroxyl groups, such as polyols.
Usually, both isocyanates and polyols for polyurethane pro-
ductions are petroleum based.
While the increased atmospheric carbon dioxide level [1]
has caused major concerns, [2] opportunity arises for the
development of commercially viable routes to basic chemi-
cals that employ carbon dioxide as the starting material [3].
Fixation of CO2 by transition-metal catalysts has made sig-
nificant progress recently. One of the successes is the utiliza-
tion of propargylic alcohol derivatives and carbon dioxide as
the starting materials to prepare cyclic carbonates in the
presence of a metal catalyst such as ruthenium, [4] cobalt,
[5] palladium [6], and copper [7] or phosphine compounds
[8]. Another protocol in which CO2 has been utilized as a
substrate is through the carboxylative cyclization of propar-
gylic amines to generate oxazolidinones bearing exocyclic
alkenes. For example, propargylic amines have been reacted
with CO2 in the presence of organometallic complexes of
ruthenium [9] and palladium [10]. Catalyst-free versions of
the carboxylative cyclization of propargylamines with CO2
have also been achieved using strong bases, [11] in super-
critical CO2 [12] and under electrochemical conditions [13].
However, these cyclisation protocols of propargylic alcohols
and propargylic amines are often carried out under a high
pressure of CO2.
Renewable resources are recently gaining considerable
attention as petroleum substitute in producing polymers [15].
In this context, there have been a large number of publica-
tions on the use of vegetable oil as a starting material for
polymers, which offers numerous advantages such as low
toxicity, inherent biodegradability, and high purity [16]. The
development of new routes to (functional) polymers com-
prising urethane groups without using isocyanates was also
investigated. An isocyanate-free preparation of polyurethane
was reported by reacting diamines with a cyclic carbonate
(EC or PC), or from the reaction of diphenyl carbonate, and
a glycol (ethylene glycol or 1, 2-propanediol) [17]. Because
polyurethanes offer extraordinary versatility and are used in
many applications, more considerable attention has been
paid to the synthesis of such polymers based on the devel-
opment of simpler routes with the use of easily accessible
and cheap reagents.
After successfully developed a wide range of catalyzed
three-component coupling reactions between aldehydes,
amines, and alkynes (A3-coupling) to generate propargylic
amines, [18] our group reported a tandem five-component
double A3-coupling [19] and a tandem six-component double
A3-coupling followed by a [2+2+2] cycloaddition reaction
catalyzed by copper [20]. More recently, we also reported an
efficient copper-catalyzed four-component, tandem A3- cou-
pling/carboxylative cyclization between aldehydes, amines,
terminal alkynes and CO2 in which CO2 serves as both a
promoter and a reagent for the facile synthesis of syntheti-
cally important oxazolidinone products [21].
Polyurethanes (PUs) are among the most important and
versatile classes of polymers and can vary from thermoplas-
tic to thermosetting materials [14]. The industrial production
of PUs is normally accomplished through the co-poly-
merization reaction between organic isocyanates and com-
*Address correspondence to this author at the Department of Chemistry,
McGill University, 801 Sherbrooke Street West, Montreal QC H3A 2K6,
Canada; Fax: (+1)-514-398-3797; E-mail: cj.li@mcgill.ca
1875-6255/12 $58.00+.00
© 2012 Bentham Science Publishers

586 Letters in Organic Chemistry, 2012, Vol. 9, No. 8
Teffahi et al.
O
N
O
CHO
CO2 (1 atm)
NH3+Cl-
+
+
CuI (20 mol%)
NaOH, 80 oC
EtOAc
1a
2b
3a
4a
Scheme 1. Oxazolidinone synthesis from aldehyde, alyne, amine salt and CO2.
CHO
CO2 (1 atm)
NH3+Cl-
+
+
Cl-NH3
+
CuI (20 mol%)
NaOH, 80 oC
EtOAc
1a
5
2b
O
O
O
N
N
O
6
Scheme 2. Dioxazolidinone synthesis from aldehyde, alkyne, amine salt and CO2.
CHO
CO2 (1 atm)
NH3+Cl-
+
+
Cl-NH3
+
CuI (20 mol%)
NaOH, 80 oC
EtOAc
O
1a
5
7
O
*
N
N
O
*
n
O
8
Scheme 3. Polyoxazolidinone (polyurethane) synthesis from aldehyde, alkyne, amine salt and CO2.
As part of our ongoing research on the utilization of A3-
coupling, we conceived a new route to polyurethane under
mild conditions directly from CO2, an alkyldiamine (ideally
renewable amino acid salts), a diyne and an aldehyde. Be-
cause of the wide availability and high stability of amines in
salt forms (such as amino acids), we focused our investiga-
tion with the study of the feasibility of simple oxazolidinone
synthesis via a multi-component coupling of aldehyde,
amine salt (amine hydrochloride), alkyne and CO2 at atmos-
pheric pressure in the present of a base. Herein we wish to
report a copper-catalyzed synthesis of oxazolidinone, a diox-
azolidinone, and a polyoxazolidinone (a form of polyure-
thane) via a multi-component coupling of an aldehyde, an
amine salt, and an alkyne under an atmospheric pressure of
CO2 under basic conditions.
2. RESULTS AND DISCUSSION
2.1. Oxazolidinone Synthesis
In an optimization study, we began with the oxazolidi-
none synthesis by coupling benzaldehyde, phenylacetylene
and propylamine hydrochloride using copper iodide as cata-
lyst under an atmospheric pressure of CO2 (Table 1). The
cyclization reaction was carried out using different solvents
under various reaction conditions. We also examined various
transition metal salts to catalyze this coupling reaction. Un-
fortunately, almost all metals including silver that was ex-
pected to catalyze both the A3-coupling reaction to generate
propargyle amines and CO2 fixation on the propargylamines
or propargyl alcohols to generate oxazolidinone or cyclic
carbonates, [22] was inert in this reaction. CuI, the catalyst

Synthesis of Oxazolidinones, Dioxazolidinone and Polyoxazolidinone
Letters in Organic Chemistry, 2012, Vol. 9, No. 8
587
Table 1. Optimization of the Four-component Coupling between Alkyne, Aldehyde, Amine Salt and CO2.
O
R
CO2 (1 atm)
N
O
R
NH3+Cl-
+
Ph
Ph-CHO +
cat (20 mol%)
80 oC
1a
2b
3a
4a
Entry
Catalyst
Solvent
Base
Yield (%)
1
2
CuI
CuI
Neat
Neat
NaOH Aq
NaOH s
KOH s
<5
34
20
<5
<5
<5
36
71
34
12
trace
43
5
3
CuI
Neat
s
4
CuI
Neat
Ba(OH)2
Li(OH)
NaOHS
NaOH s
NaOHs
NaOHs
NaOHs
NaOHs
NaOHs
NaOHs
NaOHs
NaOHs
NaOHs
NaOHs
NaOHs
NaOHs
NaOHs
NaOHs
5
CuI
Neat
6
CuI
EtOH
H2O
7
CuI
8
CuI
EtOAc
Toluene
THF
9
CuI
10
11
12
13
14
15
16
17
18
19
20
21
CuI
CuI
DMSO
CH3CN
DMFA
DMAc
DCE
CuI
CuI
CuI
5
CuI
37
23
7
CuI
DCM
EtOAc
EtOAc
EtOAc
EtOAc
EtOAc
CuBr
CuBr2
Cu(0)
AgCl
AgBr
13
<5
trace
0
Conditions: all reactions were carried out on a 0.25 mmol scale with phenylacetylene (1.5 equiv), benzaldehyde (1.0 equiv), propyl amine hydrochloride (1.0 equiv), and copper
catalyst (20 mol %) in solvent (0.2 mL) under CO2 (1 atm). Reported yields based on 1a and determined by 1H-NMR using an internal standard.
that we used for the oxazolidinone synthesis with amine,
[21] was found to be also suitable with amine salt in combi-
nation with a base with the modification of reaction condi-
tions.
12, 15 and 16). Using ethyl acetate as solvent, compound 4a
was obtained in 71% yield in the presence of 2 equiv of a
strong base such as NaOH (solid form) (Table 1, entry 8).
Bases other than NaOH were tested. KOH could be used and
lead to 20% yield in neat conditions (entry 2) but Ba(OH)2,
K2CO3, LiOH afforded 4a in only 0~5 % yield. It is clear
that not only the basicity but also the kind of cation affects
the reaction (Table 1, entries 2-5).
The screening of a range of solvents showed that the sol-
vent had a strong effect on the reaction (Table 1, entry 5): in
the same solvent (ethanol) used previously for oxazolidinone
synthesis with free amine, [21] only a trace amount of the
desired product was obtained (Table 1, entry 6). Table 1
shows that THF, DMSO, DMFA, DMAc were less suitable
solvents for this coupling reaction (Entries 10, 12, 13 and
14), and the desired product was obtained in very low yields
(yield < 5) at 80°C even after stirring for 24 h. The tandem
reaction proceeded smoothly under neat conditions as well as
in water, toluene, dichloroethane or dichloromethane to offer
the oxazolidinone in moderate yields (Table 1, entries 2, 7, 9,
The optimized catalytic system was successfully applied
to various combinations of alkynes, aldehydes and amine
salts (Table 2). In the presence of 20 mol % of CuI under an
atmospheric pressure of CO2 at 80 °C, the benzaldehyde,
phenylacetylene together with propylamine hydrochloride, 2-
phenylethylamine hydrochloride or 2-hydroxylethylamine
hydrochloride were converted into the corresponding oxa-
zolidinone in 71%, 70% and 71% yields, respectively (En-

588 Letters in Organic Chemistry, 2012, Vol. 9, No. 8
Teffahi et al.
Table 2. Copper-catalyzed four Coupling between Alkyne, Aldehyde, Amine Salt and CO2.
O
"R
CO2 (1 atm)
N
O
"R NH3+Cl-
+
R'
R-CHO +
cat (20 mol%)
80 oC
R'
R
1
2
3
4
Entry
R
R’
R’’
Product
Yield (%)
1
2
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Pr
Ph-CH2-CH2-
4a
4b
4c
4d
4e
4f
71
70
71
10
44
60
64
40
20
20
45
44
30
3
HO-CH2-CH2-
4
Br-(CH2)2-CH2-
5
4-MeC6H4-
Pr
Pr
Pr
Pr
Pr
Pr
Pr
Pr
Pr
6
4-BrC6H4-
4-HOC6H4-
4-MeOC6H4-
4-CNC6H4-
C6H11-
7
4g
4h
4i
8
9
10
11
12
13
4j
Ph
3-HOC6H4-
3-FC6H4-
4k
4l
Ph
Ph
4-ButylC6H4-
4m
Conditions: All reactions were performed at 0.25 mmol scale with alkyne (1.0 equiv), aldehyde (1.0 equiv), amine salt (1.0 equiv) and CuI (20 mol%) in EtOH (0.2 mL) under CO2
(1 atm). Isolated yields based on the aldehyde.
tries 1-3). However, the use of bromopropylamine hydro-
bromide resulted in a low yield of the corresponding product
(Table 2, entry 4).
1a (1 equiv) and phenylacetylene 2a (1 equiv), under atmos-
pheric pressure of CO2 lead to the formation of dioxazolidi-
none 6 in a low yield of 20 and 27%, respectively. Also a
moderate yield of 36% was obtained with the use of 1 equiv
of diamine salt 5 with 1 equiv of NaOH; whereas a good
yield (71%) of the dioxazolidinone product was obtained by
using 1 equiv of diamine salt 5 and 2 equiv of NaOH. It is
interesting to note that the mono-oxazolidinone was not de-
tected, possibly due to the increased solubility of the inter-
mediate (compared to the starting di-salt form) in the reac-
tion solvent. We then contemplated the possibility to synthe-
size new polyoxazolidinone by using the tandem method.
Next, we examined the effect of varying the aldehyde
component of the tandem reaction (Table 2, entries 5-9). In
general, it appears that the four-component reaction is very
sensitive to the electronic properties of the aldehyde. Devia-
tion from the benzaldehyde to either a more electron-rich or
electron-poor aromatic aldehyde decreased the yield (Table
2, entries 5-9). An aliphatic aldehyde such as cyclohexanal
was also a viable substrate and provided the desired oxa-
zolidinone in a moderate yield (Table 2, entry 10). Finally,
the alkyne component of the tandem reaction was examined
(Table 2, entries 9-11): the oxazolidinones were also ob-
tained in moderate yields when aromatic alkynes bearing
fluoro, hydroxyl and tert-butyl were used as substrates (Ta-
ble 2, entries 11-13).
Under the same reaction conditions, a good isolated yield
(87%) of polyoxazolidinone 8 was obtained by the coupling
of 1, 4-diethynylbenzene (7), benzaldehyde (1a), 1,6-
hexadiamine dihydrochloride (5) and 2 equiv of sodium hy-
droxide under an atmospheric pressure of CO2 at 80°C in
ethyl acetate (Scheme 3). The 1H-NMR spectrum of the
dioxazolidinone 6 is shown in Fig. (1). The proton bonded to
the double bond appeared at 5.35 ppm and the characteristic
protons of the oxazolidinone ring appeared at 5.25 ppm. The
13C-NMR spectrum of the dioxazolidinone 6 and polyoxa-
zolidinone 8 are shown in Figs. (2 and 3) respectively. In the
dioxazolidinone spectrum, the carbonyl characteristic of the
oxazolidinone ring appeared at 155 ppm (see ref 21). For the
symmetric carbons of the hexyl bridge showed two peaks at
26.73, 25.93 and a peak at 41.63 corresponding to the carbon
bonded to the nitrogen. In order to characterize the polyoxa-
zolidinone 8, various attempts were made to dissolve the
2.2. Synthesis and Characterizations of Dioxazolidinone
and Polyoxazolidinone
With the optimized conditions in hand and with the goal
to prepare a polymeric oxazolidinone, as a model study, we
first investigated the reactivity of 1, 6-hexadiamine salt in
the coupling reaction with benzaldehyde, phenyl acetylene
and CO2 to prepare the corresponding dioxazolidinone 6
(Scheme 2). Initially, we felt that 0.5 of diamine salt 5 is
sufficient to generate the desired oxazolidinone in good
yield. However, using 0.5 equiv of 1, 6-hexadiamine hydro-
chloride salt (5) with 0.5 or 1 equiv of NaOH, benzaldehyde

Synthesis of Oxazolidinones, Dioxazolidinone and Polyoxazolidinone
Letters in Organic Chemistry, 2012, Vol. 9, No. 8
589
Fig. (1). 1H-NMR of the dioxazolidinone (6).
Fig. (2). 13C-NM of the dioxazolidinone (6).
Fig. (3). 13C-NMR of the polyoxazolidinone (8) at 25°C.
solid polymer with various solvents such as CH2Cl2, DMF,
ether, THF, DMSO, CHCl3, benzene, toluene and ethanol
without any success. Subsequently, a solid state 13C-NMR
measurement was performed on the insoluble materials. Be-
cause of the symmetrical nature of the molecule we observed
four peaks of the hexyl bridge at 1.15 ppm (4H), 1.40 ppm
(4H), 2.80 polyoxazolidinone 8. In the obtained 13C-NMR
spectrum there was overlap of the peaks of the carbons of the
hexyl bridge and showed a large peak at around 41 ppm. The
specific carbonyl signal of the oxazolidinone ring was also
visible at 154.7 ppm. Additional peaks at 47.6, 54.8, 61.0,
84.9, 92.1, 168.3, 173.4, and 184.2 were visible and were
attributed to the rest of unreacted benzaldehyde and its de-
rivatives generated by Cannizzaro reaction.

590 Letters in Organic Chemistry, 2012, Vol. 9, No. 8
Teffahi et al.
1781.05
%T
3024.01
2852.71
2932.65
800
600 500.0
3503.7
3
2
2
00
2800
2400
2000
1800
1600
1400
1200
1000
cm-1
Fig. (4). FT-IR spectra of the polyoxazolidinone 8: (-) fresh, (-) after heating at 130 °C.
Fig. (5). DSC curve of the polyoxazolidinone 8 in N2 at heating rate 20°C/min.
Fig. (6). TGA and DTG curves of the polyoxazolidinone 8 measured in N2 at heating rate of 10°C/min.
The FT-IR spectrum of the polyoxazolidinone 8 is shown
in Fig. (4). Another evidence of the formation of the polyox-
azolidinone is the peak at 1781 cm-1 which was due to the
the carbonyl group stretching of the oxazolidinone ring (see
ref 16). The hexyl bridge showed peaks corresponding to the
C-H bonds stretching at 2920 cm-1. The phenyl groups
showed peaks corresponding to the C-H bond stretching and
bending at 3020 cm-1 and 697 cm-1 respectively. A visible
small peak at 1730 cm-1 can be attributed to carbonyl of the
unreacted benzaldehyde. It was noted that there was no char-
acteristic peak of the free amine around 3300 cm-1. The
thermal properties of the polymeric oxazolidinone were in-
vestigated by Differential Scanning Calorimetry (DSC) (Fig.
5) and Thermogravimetric Analysis (TGA) under nitrogen.
In the DSC curve, a weak endothermic peak appeared at
around 100°C with a small weight loss in the TGA curve. In
an effort to determine just what may be the nature of this
weight loss, a FT-IR analysis was carried out on dried
polyoxazolidinone at 130°C. The resulting spectra (Fig. 4)
did not show any change in the characteristic peaks demon-
strating that the lost weight was due to the rest of residue
product such as water or solvent. The glass transition (Tg)
was observed with a weak endothermic peak around 135°C
in the DSC curve.

Synthesis of Oxazolidinones, Dioxazolidinone and Polyoxazolidinone
Letters in Organic Chemistry, 2012, Vol. 9, No. 8
591
An exothermic peak was observed from 145°C with a
weight loss in TGA curve. A FT- IR analysis was carried out
for the polyoxazolidinone heated to the 232°C in order to
check the nature of this lost weight. The peak characteristic
to the carbonyl ring of the oxazolidinone (1781 cm-1) disap-
peared in the FT-IR spectra demonstrating the decomposi-
tion of the polyoxazolidnone 8.
663.96, 625.74, 575.84cm-1; 1H-NMR (400MHz, CDCl3,
ppm): ꢀ= 7.93-7.7.59 (m, 4H), 7.45-7.40 (m, 6H), 7.37-7.29
(m, 8H), 7.25-7.16 (m, 2H), 5.38-5.33 (S, 2H), 5.28-5.23 (S,
2H), 3.48-3.42(m, 2H), 2.86-2.77 (m, 2H), 1.47-1.32(m, 4H),
1.31-1.17(m, 4H); 13C-NMR (75MHz, CDCl3, ppm):
ꢀ=155.1, 147.6, 137.2, 133.4, 129.4, 129.4, 128.4, 128.3,
128.0, 127.8, 127.0, 104.6, 63.9, 63.2, 41.6, 26.7, 25.9.
4.2.3. Synthesis of the Polymeric Oxazolidinone (8)
3. CONCLUSION
The polymeric oxazolidinone 8 was prepared by the same
method as the preparation of the dimer 6. With using benzal-
dehyde (1a) (0.025 mL, 0.25 mmol), 1, 6-hexanediamine
dihydrochloride (5) (47 mg, 0.25 mmol), NaOH (20 mg, 0.5
mmol) and 1,4-diethynylbenzene (32 mg, 0.25 mmol) in
ethyl acetate under an atmospheric pressure of CO2 at 80°C
(Scheme 3). The product 8 was isolated as a colorless solid
by filtration and then washed with water and dichloro-
methane. The product 8 was obtained in 87% yield. The
polymer is insoluble in water and various organic solvents
such as DMSO, benzene, THF, DMF, toluene, ethanol and
CH2Cl2.
In summary, we reported the use of carbon dioxide for
the preparation of oxazolidinones, a dioxazolidinone and a
polyoxazolidinone (polyurethane) via a copper-catalyzed
multi-component coupling between aldehydes, amine salts,
alkynes, and under atmospheric pressure of CO2. Further
studies on the scope of this novel method as well as efforts to
increase the quality and to tune the properties of the polyure-
thanes are under further investigation.
4. EXPERIMENTAL
4.1. Materials and Measurements
CHARACTERIZATION OF OTHER COMPOUNDS
All reagents were commercially available materials and
were used without further purification.1H NMR and 13C-
NMR spectra were recorded on Varian 400MHz, 300 MHz
and 500MHz spectrometers. IR spectra were measured on a
PerkinElmer FTIR. TGA and DSC were recorded on TGA
Q500 and DSC Q2000 instrument.
•
(Z)-5-benzylidene-3-phenylethyl-4-
phenyloxazolidin-2-one (4b): white solid; Rf=0.27
1
(EtOAc/hexane: 1/9); HNMR (400MHz, CDCl3): ꢀ= 7. 45-
7.55 (m, 2H), 7.38-7.45 (m, 3H), 7.22-7.38 (m, 6H), 7.18-
7.24 (m, 3H), 7.8-7.16 (m, 2H). 5.17-5.16 (S, 1H); 5.06-5.05
(S, 1H); 3.79-3.72 (m, 1H); 3.11-2.19(m, 1H); 2.89-2.87 (m,
1H); 2.77-2.38 (m, 1H); 13C-NMR (75MHz, CDCl3): ꢀ=
147.6, 138.1, 129.4, 129.3, 128.7, 128.7, 128.4, 128.31,
127.9, 126.9, 126.8, 104.5, 64.4, 43.2, 33.7. GC-MS: m/z=
4.2.1. Synthesis of the Mono-oxazolidinone (4a)
The oxazolidinone (4a) was prepared as following
(Scheme 1). A sealable test-tube equipped with a magnetic
stir bar was charged with CuI (10.0 mg, 0.052 mmol), propy-
lamine hydrochloride (3a) (24 mg, 0.25 mmol) and NaOH
(10 mg, 0.25 mmol). The reaction vessel was sealed and
flushed with CO2. The tube was attached with a balloon of
CO2 and charged with EtOAc (0.2 mL), aldehyde 1a (0.025
mL, 0.25 mmol), and then phenylacetylene (2a) (0.025 mL,
0.25 mmol). The reaction mixture was allowed to stir slowly
at room temperature for approximately 30 sec (caution: reac-
tion is slightly exothermic and will increase CO2 pressure).
The test tube was placed in an oil bath set at 80°C and was
allowed to stir overnight. The reaction mixture was allowed
to cool to room temperature and was passed through a plug
of silica gel. The crude reaction mixture was further purified
by silica gel column chromatography (hexane/EtOAc= 7:1)
to provide the desired oxazolidinone 4a as a yellow oil
(51.21 mg, 71% yield). The 1H-NMR and 13C-NMR data are
consistent with our previous report [21].
1
355. The H-NMR, 13C-NMR data are consistent with our
previous report [21].
•
(Z)-5-benzylidene-3-(2-hydroxyethyl)-4-
phenyloxazolidin-2-one (4c): Yellow liquid; Yield=71%;
1
Rf= 0.27 (hexane/EtOAc: 7/1); H-NMR (400MHz, CDCl3):
ꢀ= 7.51-7.42 (m, 2H), 7.41-7.40 (m, 3H), 7.37-7.35 (m,
4H),7.33-7.29(m, 4H), 7.26-7.15 (m,1H), 5.58-5.56 (m, 1H),
3.81-3.66 (m, 2H), 3.62-3.53(m, 1H), 3.07-2.76 (m,1H); 13C-
NMR (75MHz, CDCl3): ꢀ= 155.8, 147.7, 137.2, 133.4,
129.4, 129.4, 128.5, 128.0, 128.0, 127.9, 127.0, 104.7, 65.0,
60.3, 44.4; GC-MS: m/z = 295.
•
(Z)-5-benzylidene)-3-propyl-4-(p-
tolyl)oxazolidin-2-one (4e): pale yellow oil; Rf=0.27
(EtOAc/hexane: 1/9); 1H-NMR (400MHz, CDCl3): ꢀ= 7. 45-
7.55 (m, 2H), 7.38-7.45 (m, 3H), 7.22-7.38 (m, 6H), 7.18-
7.24 (m, 3H), 7.8-7.16 (m, 2H). 5.38-5.33 (S, 2H), 5.28-5.23
(S, 2H), 3.50-3.39 (m, 1H), 2.88-2.75 (m, 1H), 2.42-2.33 (s,
3H), 1.61-1.41 (m, 2H), 0.95-0.85 (m, 3H). 13C-NMR
(75MHz, CDCl3): ꢀ= 11.1; 20.3; 21.5, 43.5; 63.9; 104.5;
126.9; 127.8; 128.3; 128.4; 129.3; 129.4; 133.45; 137.3;
147.7; 155.1.
4.2.2. Synthesis of the Dioxazolidinone (6)
The dioxazolidinone was prepared similarly as described
above by using 1, 6-hexadiamine dihydrochloride (5) (47
mg, 0.25 mmol) in place of propylamine hydrochloride and
NaOH (20 mg, 0.5 mmol). The desired product 6 was ob-
tained as a white solid in 71% yield, soluble in EtOAc,
CH2Cl2 and CHCl3. Rf=0.27 (EtOAc/Hexane: 1/9). FT-IR:
2924.51, 1761.06, 1690.26, 1598.07, 1492.60, 1448.99,
1418.71, 1346.64, 1275.87, 1259.56, 1203.99, 1182.88,
1157.51, 1094.00, 1071.31, 1037.92, 999.79, 946.25, 913.05,
863.67, 808.53, 775.78, 751.61, 726.11, 715.51, 690.45,
•
(Z)-5-benzylidene-4-(4-bromoyphenyl)-3-
propyloxazolidin-2-one (4f): yield=60%, yellow oil,
1
Rf =0.48 (hexane/EtOAc: 3/2), H-NMR (400MHz, CDCl3):
ꢀ= 7.53-7.45 (m, 2H), 7.31-7.30 (m, 2H), 7.29-7.7.23 (m,
2H), 7.119-7.16 (m, 1H), 6.95-6.89 (m, 2H), 5.34-533
(S,1H), 5.24-5.23 (S, 1H), 3.43-3.37 (m,1H), 2.85-2.78

592 Letters in Organic Chemistry, 2012, Vol. 9, No. 8
Teffahi et al.
(m,1H), 1.53-1.46 (m, 2H), 0.89-0.85 (m, 3H); 13C-NMR
(75MHz, CDCl3): ꢀ= 157.3, 147.9, 133.4, 131.6, 129.4,
128.5, 128.3, 128.0, 127.0, 116.3, 104.7, 63.6, 43.4, 20.3,
11.1.
CONFLICT OF INTEREST
The author(s) confirm that this article has no conflicts of
interest.
•
(Z)-5-benzylidene-4-(4-methoxyphenyl)-3-
ACKNOWLEDGEMENTS
propyloxazolidin-2-one (4h): yellow liquid, Yield=40%;
Rf= 0.33 (hexane/EtOAc= 3/2); 1H-NMR (400MHz; CDCl3):
ꢀ= 7.55-7.54 (m, 3H); 7.51-7.18 (m, 4H); 6.96-6.88 (m, 2H),
5.35-5.34 (S, 1H), 5.25-5.24 (S, 1H), 3.85-3.80 (m, 3H),
3.45-3.34 (m, 1H), 2.86-2.75 (m, 1H), 1.55-1.43 (m, 2H),
0.95-0.83 (m, 3H); 13C- NMR (75 MHz, CDCl3): ꢀ= 160.3,
155.0, 148.1, 133,5, 131.7, 129.2, 129.2, 128.8, 128.4, 128.3,
128.3, 126.9 114.6, 140.3, 63.4, 55.4, 43.1, 20.3, 11.1.
DT thanks the Algerian MESRS for a fellowship for
visiting McGill University. We are grateful to the Canada
Research Chair (Tier I) foundation (to C.-J. Li.), the CFI,
NSERC, and McGill University for support of our research.
We also thank NMR Facilities Manager Department of
Chemistry McGill University (to Dr. F. Morrin) for NMR
analysis and Prof. R. B. Lennox for facilitating the FT-IR,
TGA and DSC measurements.
•
(Z)-4-(5-benzylidene-2-oxo-3-propyloxazolidin-4-
yl)benzonitrile (4i): yellow oil, yield=20%, Rf=0.47 (hex-
ane/EtOAc=7/1), H-NMR (400MHz, CDCl3): 7.53-50 (m,
1
REFERENCES
2H), 7.45-7.40 (m, 2H), 7.34-7.25 (m, 4H), 7.21-7.15 (m,
1H), 5.39-5.38 (S, 1H), 5.25-5.24 (M, 1H), 3.48-3.40 (m,
1H), 2.86-2.77 (m, 1H), 1.55-1.45 (m, 2H), 0.89-0.85 (M,
3H); 13C-NMR (75MHz, CDCl3): 147.70; 137.3; 133.4;
129.4; 129.3; 128.4; 128.3; 127.8; 126.9; 104.5; 63.8; 43.5;
20.3; 11.1.
[1]
Yamada, W.; Sugawara, Y.; Cheng, H.M.; Ikeno, T.; Yamada, T.,
Silver-catalyzed incorporation of carbon dioxide into propargylic
alcohols. Eur. J. Org. Chem., 2007, 2604-2607.
Sakakura, T.; Choi J.-C.; Yasuda, H. Transformation of carbon
dioxide. Chem. Rev., 2007, 107, 2365-2387.
[2]
[3]
a) Aresta, M.; Dibenedetto, A. The contribution of the utilization
option to reducing the CO2 atmospheric loading: research needed to
overcome existing barriers for a full exploitation of the potential of
the CO2 use. Catal. Today, 2004, 98, 455-462; b) Aresta, M.;
Dibenedetto, A. Utilisation of CO2 as a chemical feedstock: oppor-
tunities and challenges. Dalton Trans., 2007, 2975-2992; c) Omae,
I. Aspects of carbon dioxide utilization. Catal. Today, 2006, 115,
33-52.
Sasaki, Y. Reaction of carbon dioxide with propargyl alcohol cata-
lyzed by a combination of Ru3(CO)12 and Et3N. Tetrahedron Lett.,
1986, 27, 1573-1574.
Inoue, Y.; Ishikawa, J.; Taniguchi, M.; Hashimoto, H. Cobalto-
cene-catalyzed reaction of carbon dioxide with propargyl alcohols.
Bull. Chem. Soc. Jpn., 1987, 60, 1204-1206.
a) Iritani, K.; Yanagihara, N.; Utimoto, K. Carboxylative coupling
of propargylic alcohols with allyl chloride. J. Org. Chem., 1986,
51, 5499-5501; b) Inoue, Y.; Itoh, Y.; Yen, I.-F.; Imaizumi, S. Pal-
ladium(0)-catalyzed carboxylative cyclized coupling of propargylic
alcohol with aryl halides. J. Mol. Catal., 1990, 60, L1-L3; c) Ue-
mura, K.; Shiraishi, D.; Nozori, M. Inoue, Y. Preparation of cyclic
carbonates from alkadienols, CO2 and aryl or vinylic halides cata-
lyzed by a palladium complex. Bull. Chem. Soc. Jpn., 1999, 72,
1063-1070.
a) Laas, H.; Nissen, A.; Nurrenbach, A. A simple synthesis of 3 H-
indoles starting from acetylenic alcohols. Synthesis, 1981, 958-959;
b) Dimroth, P.; Pasedach, H. Ger., 1961, 1098953; c) Dimroth, P.;
Schefczik, E.; Pasedach, H. Ger., 1963, 1145632.
Joumier, J.M.; Fournier, J.; Bruneau, C.; Dixneuf, P.H. Functional
carbonates: cyclic ꢁ-methylene and ꢂ-oxopropyl carbonates from
prop-2-ynyl alcohol derivatives and CO2. J. Chem. Soc., Perkin
Trans., 1991, 1, 3271-3274.
Mitsudo, T.; Hori, Y.; Yamakawa, Y.; Watanabe, Y. Ruthenium
catalyzed selective synthesis of enol carbamates by fixation of car-
bon dioxide. Tetrahedron Lett., 1987, 28, 4417-4418.
b) Shi, M.; Shen, Y.-M. Transition-metal-catalyzed reactions of
propargylamine with carbon dioxide and carbon disulfide. J. Org.
Chem., 2002, 67,16-21.
a) Costa, M.; Chiusoli, G.P.; Rizzardi, M. Base-catalysed direct
introduction of carbon dioxide into acetylenic amines. Chem.
Commun., 1996, 1699-1700; b) Costa, M.; Chiusoli, G.P.; Taffurel-
li, D.; Dalmonego, G.J. Superbase catalysis of oxazolidin-2-one
ring formation from carbon dioxide and prop-2-yn-1-amines under
homogeneous or heterogenous conditions. J. Chem. Soc. Perkin
Trans. 1, 1998, 1541-1546.
Kayaki, Y.; Yamamoto, M.; Suzuki, T.; Ikariya, T. Carboxylative
cyclization of propargylamines with supercritical carbon dioxide,
Green Chem., 2006, 8, 1019-1021.
Feroci, M.; Orsini, M.; Sotgiu, G.; Rossi, L.; Inesi, A. Electro-
chemically promoted C-N bond formation from acetylenic amines
•
(Z)-5-benzylidene-4-cyclohexyl-3-
propyloxazolidin-2-one [4j]: yellow oil, yield=20%,
1
Rf=0.32 (hexane/EtOAc: 7/1); H-NMR (400MHz, CDCl3):
7.61-7.59 (m, 1H), 7.44-7.30 (m, 2H), 7.27-7.18 (m, 2H),
5.49-5.40 (S, 1H), 4.25-4.23 (S, 1H), 3.41-3.39 (m, 1H),
3.08-2.3.00 (m, 1H), 2.93-2.84 (m, 2H) , 2.65-57 (m,1H),
1.89-1.52 (m, 10H), 1.37-1.20 (m, 2H), 0.98-0.93 (m, 3H).
[4]
[5]
[6]
•
(Z)-5-(4-hydroxybenzylidene)-4-phenyl-3-
propyloxazolidin-2-one (4k): yellow oil, yield= 45%,
1
Rf=0.32 (hexane/EtOAc: 7/1); H-NMR (400MHz, CDCl3):
7.58-7.55 (m, 1H), 7.42-7.38 (m, 1H) 7.37-7.21 (m, 3H)
7.20-7.15 (m, 3H) 6.99-7.85 (m, 2H) 5.35-5.33 (S, 1H)
5.11-5.09 (S, 1H) 3.48-3.40 (m, 1H), 2.86-2.77 (m, 1H),
1.55-1.45 (m, 2H), 0.89-0.85(M, 3H); 13C-NMR (75MHz,
CDCl3): ꢀ= 156.2, 147.7, 137.1, 134.6, 129.7, 129.5, 129.4,
129.3, 128.7, 128.0, 127.8, 127.7, 104.6, 63.9, 43.6, 31.0,
20.3, 11.1.
[7]
[8]
•
(Z)-5-(3-fluorobenzylidene)-4-phenyl-3-
1
propyloxazolidin-2-one (4l): yellow oil, yield= 44%, H-
NMR (400MHz, CDCl3): ꢀ= 7.46-7.42 (m, 3H), 7.33-7.29
(m, 2H), 7.27-7.22 (m, 2H), 6.90-6.84 (m, 1H), 5.39-5.36
(S,1H), 5.23-5.21 (S, 1H), 350-3.40 (m, 1H), 2.86-2.77 (m,
1H), 1.54-1.45 (m, 2H), 0.89-0.84 (m, 3H); 13C-NMR
(75MHz, CDCl3): ꢀ= 164.4, 161.2, 154.8, 148.8, 137.0,
129.8, 129.7, 129.4, 127.7, 124.1, 124.0, 115.1, 114.8, 113.9,
113.6, 103.5, 63.8, 20.3, 11.1.
[9]
[10]
[11]
•
(Z)-5-(4-(tert-butyl)benzylidene)-4-phenyl-3-
propyloxazolidin-2-one (4m): yellow oil, yield=30% ,
Rf=0.27 (hexane/EtOAc; 6/1); 1H-NMR (400 MHz, CDCl3):
ꢀ= 7.60-7.48 (m, 2H), 7.47-7.45 (m, 3H), 7.45-7.43 (m,3H),
7.26-7.25 (S, 1H), 5.38-5.37 (S,1H), 5.23-5.22 (S, 1H), 3.49-
3.39 (m, 1H), 2.85-2.76 (m, 1H), 1.34-1.29 (m, 9H), 0.96-
0.87 (m, 3H); 13C-NMR (75MHz, CDCl3): ꢀ= 155.2, 150.0,
148.0, 130.6, 129.3, 129.3, 128.1, 127.8, 125.3, 104.4, 63.8,
43.5, 34.5, 31.2, 31.2, 20.3, 11.1.
[12]
[13]

Synthesis of Oxazolidinones, Dioxazolidinone and Polyoxazolidinone
Letters in Organic Chemistry, 2012, Vol. 9, No. 8
593
and CO2. Synthesis of 5-methylene-1,3-oxazolidin-2-ones. J. Org.
Chem., 2005, 70, 7795-7798.
Lligadas, G.; Ronda, J.C.; Galià, M.; Cádiz, V. Oleic and unde-
cylenic acids as renewable feedstocks in the synthesis of polyols
and polyurethanes. Polymers, 2010, 2, 440-453.
Gandini, A. Polymers from renewable resources: A challenge for
the future of macromolecular materials. Macromolecules 2008, 41,
9491-9504.
a) Baumann, H.; Bühler, M.; Fochem, H.; Hisrsinger, F.; Zoeblein,
H.; Falbe, J. Renewable raw materials for the chemical industry.
Angew. Chem. Int. Ed. Engl., 1988, 27, 41-62. b) Biermann, U.;
Friedt, W.; Lang, S.; Lühs, W.; Machmüller, G.; Metzger, J.O.;
Klaas, M.R.; Schäfer, H.J.; Shneiderüsch, M.P. New syntheses with
oils and fats as renewable raw materials for the chemical industry.
Angew. Chem. Int. Ed., 2000, 39, 2206-2224.
a) Güner, F.S.; Yagci, Y.; Erciyes, T. Polymers from triglyceride
oils. Prog. Polym. Sci., 2006, 31, 633-670; b) Sharma, V.; Kundu,
P. P. Polymers from natural oils—A review, Prog. Polym. Sci.,
2006, 31, 983-1008; c) Meier, M.A.R.; Metzger, J.O.; Schubert,
U.S. Plant oil renewable resources as green alternatives in polymer
science. Chem. Soc. Rev. 2007, 36, 1778-1802; d) Y. Lu and R. C.
Larock, Novel polymeric materials from vegetable oils and vinyl
monomers: preparation, properties, and applications. Chem. Sus.
Chem., 2009, 2, 136-147.
ment of A3-coupling (aldehyde-alkyne-amine) and AA3-coupling
(asymmetric aldehyde-alkyne-amine. Synlett 2004, 1472-1483; d)
W.-J. Yoo, L. Zhao, C.-J. Li, The A3-coupling (aldehyde-alkyne-
amine) reaction: A versatile method for the preparation of propar-
gylamines. Aldrichemi. Acta, 2011, 44, 43-51.
Bonfield, E. R.; Li, C.-J. Efficient ruthenium and copper cocatal-
zyed five-component coupling to form dipropargyl amines under
mild conditions in water. Org. Biomol. Chem., 2007, 5, 435-437.
Bonfield, E. R.; Li, C.-J. Efficient preparation of the isoindoline
framework via a six component, tandem double A3 coupling and
[2+2+2] cycloaddition reaction, Adv. Synth. Catal. 2008, 350, 370-
374.
[14]
[15]
[16]
[19]
[20]
[21]
[22]
a) Yoo, W.-J.; Li, C.-J. Copper-catalyzed four-component coupling
between aldehydes, amines, alkynes, and carbon dioxide, Adv.
Synth. Catal. 2008, 350, 1503-1506.
[17]
[21] a) Huang, B.; Yao, X.; Li, C.-J. Diastereoselective aldehyde-
alkyne-amine coupling of ꢀ-hydroxylated compounds, Adv. Synth.
Catal. 2006, 348, 1528-1532; b) Wang, S.; He, X.; Song, L.;
Wang, Z., Silver nanoparticles supported by novel nickel metal-
organic frameworks: an efficient heterogeneous catalyst for an A3
coupling reaction, Synlett 2009, 447-450; c) Yoshida, S.; Fukui,
K.; Kikuchi, S.; Yamada, T. Silver-catalyzed enantioselective car-
bon dioxide incorporation into bispropargylic alcohols. J. Am.
Chem. Soc., 2010, 132, 4072-4073.
[18]
a) Li, C.-J. The development of catalytic nucleophilic additions of
terminal alkynes in water. Acc. Chem. Res., 2010, 43, 581-590; b)
Chen, L.; Li, C.-J. Reaction of alkynes in water. Adv. Synth. Catal.,
2006, 348, 1459-1484; c) Wei, C.; Li, Z.; Li, C.-J. The develop-
[23]
Yoshida, S.; Fukui, K.; Kikuchi, S.; Yamada, T. Silver-catalyzed
preparation of oxazolidinones from carbon dioxide and propargylic
amines. Chem. Lett. 2009, 38, 786-787.