One-step three-component and solvent-free synthesis of thiazoles from tertiary thioamides

Article abstract of DOI:10.1007/s13738-016-0873-3

Abstract: A novel one-pot three-component reaction has been developed for construction of thiazole derivatives under solvent-free conditions. Hence, tertiary thioamides, α-haloketones, and NH₄OAc were grinded together and allowed to react thermally at 110?°C and/or under microwave irradiation to produce the corresponding thiazole derivatives in very good yields. Graphical Abstract: [Figure not available: see fulltext.]

Full text of DOI:10.1007/s13738-016-0873-3

J IRAN CHEM SOC
DOI 10.1007/s13738-016-0873-3
ORIGINAL PAPER
One-step three-component and solvent-free synthesis of thiazoles
from tertiary thioamides
Hassan Zali-Boeini1 · Seyed Gholamhossein Mansouri1
Received: 1 February 2016 / Accepted: 25 April 2016
© Iranian Chemical Society 2016
Abstract A novel one-pot three-component reaction has
been developed for construction of thiazole derivatives
under solvent-free conditions. Hence, tertiary thioamides,
α-haloketones, and NH4OAc were grinded together and
allowed to react thermally at 110 °C and/or under micro-
wave irradiation to produce the corresponding thiazole
derivatives in very good yields.
Introduction
It is well known that thiazoles are among the most impor-
tant heterocycles that are frequently found in natural prod-
ucts [1, 2], pharmaceuticals [3–8], and agricultural chem-
istry [9]. They also have gained wide applications in the
areas of organic electronics as electroluminescence and
electron transport materials [10–12], electro-optic [13, 14]
Graphical Abstract
and photonic devices [15–18]. The thiazole ring as a latent
formyl group has been frequently used as a useful build-
ing block in new synthetic transformations [19]. The most
known approach to the synthesis of thiazole ring is the
Hantzsch synthesis in which primary thioamides react with
α-halocarbonyls to produce thiazole derivatives in a sin-
gle step [20]. Also, α-halogenation of β-keto esters with
N-bromosuccinimide, followed by cyclization with thio-
urea or selenourea produce 2-amino-4-alkyl- and 2-amino-
4-arylthiazole-5-carboxylates and the corresponding selena-
zole analogues, respectively [21]. Thiazoles also could be
easily accessed by the reaction of α-acylaminoketones and
Keywords Synthetic methods · Sulfur heterocycles ·
Thiazole · Green chemistry
Electronic supplementary material The online version of this
article (doi:10.1007/s13738-016-0873-3) contains supplementary
material, which is available to authorized users.
* Hassan Zali-Boeini
h.zali@chem.ui.ac.ir
1
Department of Chemistry, Faculty of Science, University
of Isfahan, 81746-73441 Isfahan, Iran
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J IRAN CHEM SOC
Scheme 1 Synthesis of thiazole
derivatives by reaction of ter-
tiary thioamides, α-haloketones,
and NH4OAc
P2S5 (Gabriel synthesis) [22]. They can be also obtained in
good yields via the reaction of 1H-1-(1′-alkynyl)-5-methyl-
1,2,3-benziodoxathiole 3,3-dioxides with primary thioam-
ides [23]. Reaction of dithiooxamide (rubeanic acid) with
aromatic aldehydes has been utilized for the synthesis of
thiazolothiazole derivatives [24]. Reaction of mercaptoac-
etaldehyde dimer, ammonia, and aldehydes is leading to
2,5-dihydro-1,3-thiazoles [25]. It has been shown that, when
S-alkylated thioamides or thioureas are reacted with cer-
tain acid derivatives, various types of substituted thiazoles
are prepared in low to moderate yields [26]. Direct one-
step reaction of thiocarboxylic acids, α-haloketones, and
NH4OAc in refluxing AcOH has been used for the prepa-
ration of thiazole derivatives [27]. 2-Aminothiazole deriva-
tives have been prepared by the reaction of 2-N-acylglyci-
namides with a thionating reagent followed by subsequent
cyclization mediated by triflouroacetic anhydride (TFAA)
[28]. Recently 5-aminothiazoles have been prepared based
on cyclization of their diamide adducts, prepared by the Ugi
reaction, in the presence of Lawesson’s reagent [29]. More
recently a new approach for the construction of thiazole
ring has been developed using the cyclocondensation reac-
tion of primary thioamides and alkynyl(aryl)iodonium rea-
gent [30]. Direct conversion of alkenes to the corresponding
2-aminothiazoles is possible via reaction with thiourea in
the presence of 2-iodoxybenzoic acid (IBX) as oxidant [31,
32]. Dimethyl cyanodithioimidocarbonates as starting mate-
rial have been successfully employed for the synthesis of
1,3-thiazoles and 1,3-selenazoles [33]. Another method ben-
efits from base-induced cyclization reaction of isocyanides
bearing an active methylene with methyl arenecarbodithio-
ates for the synthesis of 4,5-disubstituted thiazoles [34].
Following our studies on exploration of new synthetic
methods for the construction of sulfur containing rings
[35–40], herein we wish to report for the first time an effi-
cient one-step method for the synthesis of disubstituted
thiazoles via the three-component reaction of tertiary thio-
amides, α-haloketones, and NH4OAc under solvent-free
condition (Scheme 1).
Experimental
The chemicals used in this work were purchased from
Fluka and Merck chemical companies. The progress of the
reaction was monitored by TLC using 0.25-μm pre-coated
silica gel plates. Melting points were determined using
1
Stuart Scientific SMP2 apparatus and are uncorrected. H
NMR (400 MHz) and 13C NMR (100 MHz) spectra were
recorded on Bruker-Avance 400.
General procedure for the one-pot three-component
preparation of thiazoles 3a–3i
In
a
25-mL round-bottom flask, finely grinded
morpholino(aryl)methanethione (1 mmol), α-bromoketone
(1.15 mmol), ammonium acetate (1.6 mmol, 125 mg), and
tetraethylammonium iodide (TEAI, 0.1 mmol, 26 mg) were
heated at melting point (110 °C) and (or subjected to MW
heating in a domestic microwave oven at medium power
for 5 min) heating was continued for 2 h. After cooling, the
reaction mixture was triturated with hexane–EtOAc (4:1,
10 mL). Then, the crude precipitated product was filtered
and recrystallized from a suitable solvent (EtOH). In some
cases (3d and 3h) after work-up of the reaction a crude oily
product was obtained. In these cases, the crude product was
purified by column chromatography on silica gel using a
mixture of hexane–EtOAc (4:1) as eluent.
General procedure for the one-pot three-component
preparation of thiazoles 3j–3 l
In a 25-mL round-bottom flask, 1,3-phenylenebis(morph
olinomethanethione) (1 mmol, 336 mg), α-bromoketone
(2.3 mmol), ammonium acetate (3.2 mmol, 250 mg), and
TEAI (0.1 mmol, 26 mg) were heated at 110 °C to make
a melted reaction mixture and heating was continued for
a further 2 h. Thereafter, the reaction mixture was boiled
with MeOH (10 ml) and cooled. Then, the crude precipi-
tated product was filtered and recrystallized from EtOH to
1 3

J IRAN CHEM SOC
obtain 1,3-bis(4-arylthiazol-2-yl)benzene derivatives as off-
white or light yellow powders.
Compound 3f: 1H NMR (500 MHz, CDCl3): δ 8.04–7.99
(m, 2H), 7.95–7.91 (m, 2H), 7.45 (s, 1H), 7.44–7.40 (m,
2H), 7.19–7.13 (m, 2H); 13C NMR (125 MHz, CDCl3): δ
166.9 (C-2 thiazole), 165.0 (C-4 thiazole), 163.0, 155.2,
134.1, 132.9, 130.0, 128.9, 128.6, 128.5, 127.7, 116.1,
115.9, 112.8 (C-5 thiazole); Anal. Calcd. for C15H9ClFNS:
C, 62.18; H, 3.13; Cl, 12.24; F, 6.56; N, 4.83; S, 11.07
Found: C, 62.24; H, 3.17; Cl, 12.18; F, 6.51; N, 4.78; S,
11.11.
Spectral data of compounds 3a–3l
1
Compound 3a: H NMR (500 MHz, CDCl3): δ 8.42 (m,
4H), 8.07 (m, 4H), 7.52 (m, 6H); 13C NMR (125 MHz,
CDCl3): δ 164.9 (C-2 thiazole), 162.9 (C-4 thiazole), 134.4,
130.2, 128.8, 128.5, 128.2, 126.5, 116.1, 115.9, 112.5 (C-5
thiazole); Anal. Calcd. for C15H11NS: C, 75.91; H, 4.67; N,
5.90; S, 13.51 Found: C, 75.84; H, 4.71; N, 5.79; S, 13.57.
1
Compound 3g: H NMR (500 MHz, CDCl3): δ 8.05–
8.00 (m, 2H), 7.87 (d, j = 8.5 Hz, 2H), 7.58 (d, j = 8.5 Hz,
2H), 7.49 (s, 1H), 7.19–7.14 (m, 2H); 13C NMR (125 MHz,
CDCl3): δ 166.9 (C-2 thiazole), 165.0 (C-4 thiazole),
163.0, 155.2, 133.3, 131.9, 130.0, 128.6, 128.5, 128.0,
122.2, 116.1, 115.9, 112.9 (C-5 thiazole); Anal. Calcd.
for C15H9BrFNS: C, 53.91; H, 2.71; Br, 23.91; F, 5.68; N,
4.19; S, 9.59 Found: C, 53.85; H, 2.66; Br, 23.97; F, 5.74;
N, 4.14; S, 9.52.
1
Compound 3b: H NMR (500 MHz, CDCl3): δ 8.07–
8.05 (m, 2H), 7.91 (d, j = 8.0 Hz, 2H), 7.50–7.44 (m, 3H),
7.43 (s, 1H), 7.27 (d, j = 8.0 Hz, 2H), 2.41 (s, 3H); 13C
NMR (125 MHz, CDCl3): δ 166.7 (C-2 thiazole), 162.3
(C-4 thiazole), 156.7, 138.3, 131.6, 130.8, 129.3, 128.6,
128.2, 126.2, 116.7, 111.8 (C-5 thiazole), 20.7; Anal.
Calcd. for C16H13NS: C, 76.46; H, 5.21; N, 5.57; S, 12.76
Found: C, 76.34; H, 5.31; N, 5.70; S, 12.59.
1
Compound 3h: H NMR (500 MHz, CDCl3): δ 7.95
Compound 3c: 1H NMR (500 MHz, CDCl3): δ 8.06–8.03
(m, 2H), 7.96–7.93 (m, 2H), 7.50–7.40 (m, 6H); 13C NMR
(125 MHz, CDCl3): δ 168.1 (C-2 thiazole), 155.1 (C-4 thi-
azole), 134.0, 133.6, 133.0, 130.2, 128.94, 128.89, 127.7,
126.6, 112.8 (C-5 thiazole); Anal. Calcd. for C15H10ClNS:
C, 66.29; H, 3.71; Cl, 13.05; N, 5.15; S, 11.80 Found: C,
66.34; H, 3.61; Cl, 13.13; N, 5.10; S, 11.69.
(d, j = 8.7 Hz, 2H), 7.87 (d, j = 8.4 Hz, 2H), 7.57 (d,
j = 8.4 Hz, 2H), 7.40 (s, 1H), 6.98 (d, j = 8.7 Hz, 2H),
3.88 (s, 3H);13C NMR (125 MHz, CDCl3): δ 168.0 (C-2
thiazole), 161.3 (C-4 thiazole), 154.9, 133.6, 131.8, 128.1,
128.0, 126.6, 122.0, 114.3, 112.1 (C-5 thiazole), 55.4;
Anal. Calcd. for C16H12BrNOS: C, 55.50; H, 3.49; Br,
23.08; N, 4.05; S, 9.26 Found: C, 55.56; H, 3.45; Br, 23.13;
N, 3.99; S, 9.21.
Compound 3d: 1H NMR (500 MHz, CDCl3): δ
8.01–7.98 (m, 4H), 7.47–7.43 (m, 2H), 7.41 (s, 1H),
7.38–7.34 (m, 1H), 7.01–6.97 (m, 2H), 3.88 (s, 3H); 13C
NMR (125 MHz, CDCl3): δ 168.8 (C-2 thiazole), 161.3
(C-4 thiazole), 154.7, 133.5, 131.3, 128.3, 127.2, 126.5,
122.2, 114.6, 112.1 (C-5 thiazole), 54.4; Anal. Calcd. for
C16H13NOS: C, 71.88; H, 4.90; N, 5.24; S, 11.99 Found: C,
71.74; H, 4.97; N, 5.18; S, 12.04.
Compound 3i: 1H NMR (500 MHz, CDCl3): δ 8.06–8.02
(m, 2H), 7.89 (d, j = 8.1 Hz, 2H), 7.41 (s, 1H), 7.26 (d,
j = 7.9 Hz, 2H), 7.19–7.13 (m, 2H), 2.41 (s, 3H); 13C NMR
(125 MHz, CDCl3): δ 166.5 (C-2 thiazole), 164.9 (C-4
thiazole), 162.9, 156.5, 138.1, 131.8, 130.2, 129.4, 128.53,
128.47, 126.4, 116.0, 115.8, 111.7 (C-5 thiazole), 21.3;
Anal. Calcd. for C16H12FNS: C, 71.35; H, 4.49; F, 7.05; N,
5.20; S, 11.91 Found: C, 71.28; H, 4.46; F, 7.11; N, 5.16;
S, 11.94.
1
Compound 3e: H NMR (500 MHz, CDCl3): δ 8.07–
8.02 (m, 2H), 8.01–7.98 (m, 2H), 7.47 (s, 1H), 7.45 (d,
j = 7.8 Hz, 2H), 7.37 (t, j = 7.4 Hz, 1H), 7.19–7.13 (m,
2H); 13C NMR (125 MHz, CDCl3): δ 164.9 (C-2 thiazole),
162.9 (C-4 thiazole), 156.4, 134.4, 130.2, 128.7, 128.6,
128.5, 128.2, 126.5, 116.1, 115.9, 112.5 (C-5 thiazole); Anal.
Calcd. for C15H10FNS: C, 70.57; H, 3.95; F, 7.44; N, 5.49; S,
12.56 Found: C, 70.49; H, 3.90; F, 7.49; N, 5.42; S, 12.49.
1
Compound 3j: H NMR (500 MHz, CDCl3): δ 8.68 (s,
1H), 8.14 (d, j = 7.8 Hz, 1H), 8.13 (d, j = 7.8 Hz, 1H), 8.05
(d, j = 7.7 Hz, 4H), 7.58 (t, j = 7.7 Hz, 1H), 7.54 (s, 2H),
7.49 (t, j = 7.6 Hz, 4H), 7.39 (t, j = 7.5 Hz, 2H); 13C NMR
(125 MHz, CDCl3): δ 167.0 (C-2 thiazole), 156.6 (C-4
thiazole), 134.6, 134.5, 129.5, 128.8, 128.3, 128.1, 126.5,
Scheme 2 Application of bisthioamides for the synthesis of 1,3-bis(4-arylthiazol-2-yl)benzene derivatives
1 3

J IRAN CHEM SOC
Table 1 A novel solvent-free approach for the synthesis of thiazole derivativesa, b
Entry
1
Thioamide
α
-haloketones
Product
2
3
4
5
6
7
8
9
10
11
12
a
Reaction conditions: morpholino(aryl)methanethione (1 mmol), α-bromoketone (1.2 mmol), NH4OAc (2 mmol, 154 mg), and TEAI
(0.1 mmol, 26 mg) and heated at 110 °C for 2 h
b
Yields refer to pure isolated products
1 3

J IRAN CHEM SOC
Scheme 3 A proposed mecha-
nism for the construction of
thiazole ring
124.6, 113.0 (C-5 thiazole); Anal. Calcd. for C24H16N2S2:
C, 72.70; H, 4.07; N, 7.06; S, 16.17 Found: C, 72.76; H,
4.11; N, 7.01; S, 16.21.
Anal. Calcd. for C26H20N2S2: C, 73.55; H, 4.75; N, 6.60; S,
15.10 Found: C, 73.49; H, 4.71; N, 6.66; S, 15.04.
1
Compound 3l: H NMR (500 MHz, CDCl3): δ 8.64 (s,
Compound 3k: 1H NMR (500 MHz, CDCl3): δ 8.66 (s, 1H),
8.13 (d, j = 7.7 Hz, 1H), 8.12 (d, j = 7.7 Hz, 1H), 7.93 (d,
j = 8.0 Hz, 4H), 7.57 (t, j = 7.7 Hz, 1H), 7.48 (s, 2H), 7.29 (d,
j = 8.0 Hz, 4H), 2.42 (s, 6H);13C NMR (125 MHz, CDCl3): δ
166.9 (C-2 thiazole), 156.7 (C-4 thiazole), 138.1, 134.6, 131.8,
129.5, 129.4, 128.0, 126.4, 124.6, 112.2 (C-5 thiazole), 21.3;
1H), 8.12–8.10 (m, 2H), 7.91 (d, j = 8.3 Hz, 4H), 7.62–
7.53 (m, 7H); 13C NMR (125 MHz, CDCl3): δ 167.2 (C-2
thiazole), 155.4 (C-4 thiazole), 134.4, 133.3, 131.9, 129.6,
128.2, 128.1, 124.6, 122.3, 113.4 (C-5 thiazole); Anal.
Calcd. for C24H14Br2N2S2: C, 52.00; H, 2.55; Br, 28.83; N,
5.05; S, 11.57 Found: C, 51.96; H, 2.52; Br, 28.88; N, 5.09;
S, 11.53.
Results and discussion
At the beginning of our investigation, thioamide 1a (1 mmol)
as a test substrate was mixed with α-bromoacetophenone 2a
(1.2 mmol) and NH4OAc (1.2 mmol). Then, the mixture
was grinded and heated at melting point (100–110 °C) for
2 h. The reaction mixture was proceeded smoothly, and the
product 3a was obtained in moderate yield (56 %). We found
that with increasing the amount of NH4OAc to 2 molar
equivalents the product yield of the reaction was meaning-
fully raised up to 77 %. Surprisingly, it was found that the
product yield of the reaction was significantly improved
with addition of small amounts of tetraethylammonium
iodide (TEAI, 0.1 mmol) to the reaction media. We assume
that, this is due to catalytic role of iodide ion in activating
α-bromoketone 2 and partial increasing of polarity of the
reaction mixture. Therefore, when the reaction was carried
out using thioamide 1a (1 mmol), α-bromoacetophenone
2a (1.2 mmol) and NH4OAc (2 mmol) in the presence of
TEAI (0.1 mmol) at 110 °C, the product 3a was produced
in a very good yield (90 %). Unfortunately, further increase
in the reaction temperature resulted in diminishing the yield
of 3a accompanied with the formation of some dark tarry
Scheme 4 Simplicity and immediacy of our approach in comparison
with a previously reported method
1 3

J IRAN CHEM SOC
materials. The necessary thioamides 1a–1c are readily pre-
pared by Willgerodt–Kindler reaction of the corresponding
aldehydes with morpholine and sulfur and/or with thiona-
tion of the corresponding amides [41–44]. In order to show
the generality of the reaction, other types of tertiary thioam-
ides such as bisthioamide 1d were chosen and reacted at the
same reaction conditions to produce compounds 3j–3l as
1,3-bis(4-arylthiazol-2-yl)benzene derivatives (Scheme 2) in
good yields (69–74 %) and the results are given in Table 1.
A plausible mechanism is also proposed for the
course of reaction and shown in scheme 3. First,
α-bromoacetophenone 2 is activated by the aid of TEAI
and undergone a nucleophilic attack by thioamide 1 to pro-
duce S-alkylated thioamide intermediate 4. Then NH4OAc
as a source of NH3 makes a nucleophilic attack on this
intermediate and cyclizes to intermediate 5. Eventually, this
intermediate transforms to thiazole 3 thru elimination of a
morpholine and water molecules.
The simplicity and the immediacy of the presented
approach are demonstrated in scheme 4 by comparison
with the method with one of the previously reported meth-
ods. In one of the reported methods, thiazole derivatives
have been prepared by the reaction of thiocarboxylic acids
and α-haloketones with NH4OAc in refluxing AcOH [27].
Although this method is rather effective, but investiga-
tion of a narrow substituent’s scope (only five examples),
exploiting thiocarboxylic acids which are unpleasant and
noxious materials and performing the reaction in reflux-
ing acetic acid which is a corrosive and irritating solvent
are major drawbacks of the method. We found that replac-
ing thiocarboxylic acids with tertiary thioamides which are
safe and odorless materials and performing the reaction
course under solvent-free conditions avoids the environ-
mental issues associated with using of a solvent media.
References
1. A.K. Todorova, F. Jüttner, A. Linden, T. Plüss, W. von Philips-
born, J. Org. Chem. 60, 7891 (1996)
2. S.-L. You, J.W. Kelly, J. Org. Chem. 68, 9506 (2003)
3. K. Matsumoto, P.P.K. Ho, U.S. Patent 4,322,428; 30 Mar 1982
4. D.J. Carini, R.R. Wexler, U.S. Patent 4,632,930; 30 Dec 1986
5. T. Rosen, T.F. Seeger, S. McLean, A.A. Nagel, J.L. Ives, K.J.
Guarino, D. Bryce, J. Furman, R.W. Roth, P.M. Chalabi, J.H.
Windels, J. Med. Chem. 33, 3020 (1990)
6. Y. Kumar, R. Green, D.S. Wise, L.L. Wotring, L.B. Townsend, J.
Med. Chem. 36, 3849 (1993)
7. J.E. van Muijlwijk-Koezen, H. Timmerman, R.C. Vollinga, J.F.
von Drabbe Künzel, M. de Groote, S. Visser, A.P. IJzerman, J.
Med. Chem. 44, 749 (2001)
8. T. Rosen, A.A. Nagel, J.P. Rizzi, J.L. Ives, J.B. Daffeh, A.H.
Ganong, K. Guarino, J. Heym, S. McLean, J.T. Nowakowski,
A.W. Schmidt, T.F. Seeger, C.J. Siok, L.A. Vincent, J. Med.
Chem. 33, 2715 (1990)
9. R.E. Manning, U.S. Patent 3,542,801; 24 Nov 1970
10. M. Mamada, J.-I. Nishida, D. Kumaki, S. Tokito, Y. Yamashita,
Chem. Mater. 19, 5404 (2007)
11. S. Ando, R. Murakami, J.-I. Nishida, H. Tada, Y. Inoue, S. Tok-
ito, Y. Yamashita, J. Am. Chem. Soc. 127, 14996 (2005)
12. X.M. Hong, H.E. Katz, A.J. Lovinger, B.-C. Wang, K.
Raghavachari, Chem. Mater. 13, 4686 (2001)
13. M. He, Y. Zhou, J. Miao, C. Liu, Y. Cui, T. Zhang, Dyes Pig-
ments 86, 107 (2010)
14. K. Schmidt, A. Leclercq, E. Zojer, P.V. Lawson, S.-H. Jang, S.
Barlow, A.K.-Y. Jen, S.R. Marder, J.-L. Brédas, Adv. Funct.
Mater. 18, 794 (2008)
15. S. Kawai, T. Nakashima, K. Atsumi, T. Sakai, M. Harigai, Y.
Imamoto, H. Kamikubo, M. Kataoka, T. Kawai, Chem. Mater.
19, 3479 (2007)
16. E.M. Breitung, C.-F. Shu, R.J. McMahon, J. Am. Chem. Soc.
122, 1154 (2000)
17. F. Menacher, M. Rubner, S. Berndl, H.-A. Wagenknecht, J. Org.
Chem. 73, 4263 (2008)
18. C.W. Dirk, H.E. Katz, M.L. Schilling, L.A. King, Chem. Mater.
2, 700 (1990)
19. A. Dondoni, A. Marra, Chem. Rev. 104, 2557 (2004)
20. S.E. Bramley, V. Dupplin, D.G.C. Goberdhan, G.D. Meakins, J.
Chem. Soc., Perkin Trans. 1, 639 (1987)
21. M. Narender, M.S. Reddy, V.P. Kumar, B. Srinivas, R. Srid-
har, Y.V.D. Nageswar, K.R. Rao, Synthesis (2007). doi:10.105
5/s-2007-990849
Conclusion
22. P. W. Sheldrake, M. Matteucci, E. McDonald, Synlett (2006). doi
:10.1055/s-2006-926243
23. Y. Ishiwata, H. Togo, Synlett (2008). doi:10.1055/s-0028-1083439
24. J.R. Johnson, R. Ketcham, J. Am. Chem. Soc. 82, 2719 (1960)
25. P. Dubs, M. Pesaro, Synthesis, 294 (1974)
26. J. Liebscher, E. Mitzner, Synthesis, 414 (1985)
27. P. Dubs, R. Stuessi, Synthesis, 696 (1976)
28. M.J. Thompson, W. Heal, B. Chen, Tetrahedron Lett. 47, 2361
(2006)
29. M.J. Thompson, B. Chen, Tetrahedron Lett. 49, 5324 (2008)
30. P. Wipf, S. Venkatraman, J. Org. Chem. 61, 8004 (1996)
31. T.J. Donohoe, M.A. Kabeshov, A.H. Rathi, I.E.D. Smit, Org.
Biomol. Chem. 10, 1093 (2012)
To sum up, a new one-step three-component and solvent-
free approach for the synthesis of diverse thiazole deriva-
tives has been developed. Construction of thiazoles using
cheap and readily available starting materials, solvent-free
synthesis, microwave acceleration of the reaction, using
a nontoxic and odorless sulfur source, simple work-up of
the reaction mixture, and easy isolation and purification of
final product are some advantages of the presented method.
These benefits promote the method as a favorable alter-
native to the synthesis of thiazole derivatives, which are
important chemicals in drug development and industrial
chemistry.
32. T.J. Donohoe, M.A. Kabeshov, A.H. Rathi, I.E.D. Smith, Synlett
19, 2956 (2010)
33. D. Thomae, E. Perspicace, Z. Xu, D. Henryon, S. Schneider, S.
Hesse, G. Kirsch, P. Seck, Tetrahedron 65, 2982 (2009)
34. G.S. Lingaraju, T.R. Swaroop, A.C. Vinayaka, K.S.S. Kumar,
M.P. Sadashiva, K.S. Ragappa, Synthesis 44, 1373 (2012)
Acknowledgments Providing the facilities for this research from
University of Isfahan research council is warmly acknowledged.
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J IRAN CHEM SOC
35. H. Zali-Boeini, N. Fadaei, Synlett 26, 1819 (2015)
36. K. Hajibabae, H. Zali-Boeini, Synlett 26, 108 (2015)
37. H. Zali-Boeini, S.G. Mansouri, Synth. Commun. 45, 1681
(2015)
41. E. Schwenk, D. Papa, J. Org. Chem. 11, 798 (1946)
42. B.S. Pedersen, S.O. Lawesson, Tetrahedron 35, 2433 (1979)
43. I. Thomsen, K. Clausen, S. Scheibye, S.O. Lawesson, Org.
Synth. 62, 158 (1984)
38. H. Zali-Boeini, K. Hajibabaei Najafabadi, Eur. J. Org. Chem. 29,
4926 (2009)
44. B. Yde, N.M. Yousif, U. Pedersen, I. Thomsen, S.O. Lawesson,
Tetrahedron 40, 2047 (1984)
39. H. Zali-Boeini, Helv. Chim. Acta 92, 1268 (2009)
40. F.M. Moghaddam, H.Z. Boeini, Synlett, 1612 (2005)
1 3