Study on the reactions of 3-bromo-4-ethoxy-1,1,1-trifluoro-3-buten-2-one with benzenethiols promoted by InCl3?4H2O

Article abstract of DOI:10.1002/cjoc.201090275

In the presence of InCl₃?4H₂O, the reaction of 3-bromo-4-ethoxy-1,1,1-trifluoro-3-buten-2-one 2 with a series of benzenethiols proceeds readily and gave both the addition-elimination product 3-bromo-1,1,1-trifluoro-4-thiophenyl-but-3-en-2-one and substitution product 1,1,1-trifluoro-3,4-bis-thiophenyl-but-3-en-2-one. The reactivity of benzenethiols is discussed in terms of their substituted group.

Full text of DOI:10.1002/cjoc.201090275

FULL PAPER
Study on the Reactions of 3-Bromo-4-ethoxy-1,1,1-trifluoro-
3-buten-2-one with Benzenethiols Promoted by InCl3•4H2O†
Zhao, Jingweia,b(赵经纬)
Song, Taoa,b(宋涛)
Jiang, Huilingb(蒋慧玲)
Xu, Liangzhong*,a(许良忠)
Zhu, Shizheng*,b(朱仕正)
a Key Laboratory of Eco-chemical Engineering, Ministry of Education, Qingdao University of Science and
Technology, Qingdao, Shandong 266042, China
b Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of
Sciences, 345 Lingling Road, Shanghai 200032, China
In the presence of InCl3•4H2O, the reaction of 3-bromo-4-ethoxy-1,1,1-trifluoro-3-buten-2-one 2 with a series
of benzenethiols proceeds readily and gave both the addition-elimination product 3-bromo-1,1,1-trifluoro-4-thio-
phenyl-but-3-en-2-one and substitution product 1,1,1-trifluoro-3,4-bis-thiophenyl-but-3-en-2-one. The reactivity of
benzenethiols is discussed in terms of their substituted group.
Keywords 3-bromo-4-ethoxy-1,1,1-trifluoro-3-buten-2-one, benzenethiols, coupling, addition-elimination, sub-
stitution, AdNESN mechanism
Introduction
Trifluoromethyl substituted α,β-unsaturated ketones
are of great importance, and are useful synthons to in-
troduce trifluoromethyl group into molecules.1,2 The
methods for the synthesis of trifluoromethylated com-
pounds have drawn considerable attention.3,4 We have
continued studying on the chemical transformation of
(E)-4-ethoxy-1,1,1-trifluoro-3-buten-2-one 1.5 Recently,
Gerus et al. reported a modified α,β-unsaturated ketone
2 with a CF3 group, which was obtained from bromina-
tion of enone 1.6,7 The presence of bromine atom at the
α-position, however, allows some new reactions of 2,
such as substitution of the bromine atom that is obvi-
ously different from enone 1. However, to our best
knowledge, very little is known about the reaction of
α-bromo vinylic compound 2 with nucleophiles. The
only reported examples are the reaction of 2 with nitro-
gen nucleophiles6,8,9 and the reaction with sulfur nu-
cleophiles has not been reported till now. Rosnati et al.
have reported the reactions of phenol and benzenethiol
with a number of vinyl bromides.10 In their experiments,
adducts and substituted products were obtained in the
system K2CO3-acetone. However, the replacement of
hydrogen atom by fluorine atom influenced profoundly
the chemical property of 2, when it reacted with thiols
there were no adducts obtained. In this paper, we report
the results of the reactions of 2 with a series of ben-
zenethiols and discuss the possible reaction mechanism.
Results and discussion
In the presence of InCl3•4H2O (10 mol%), we found
that the reaction of α-bromo Michael acceptor 2 (2
mmol) with thiophenol 3 (2 mmol) proceeds readily at
room temperature to afford three products 3a (9%), 3b
(16%) and 3c (15%), respectively. Among them 3a is
the direct coupling product of thiophenol; 3b is the
product without the substitution of the vinylic bromine
through addition of the thiophenol, followed by the
elimination of an ethanol. On the basis of the formation
of 3b, 3c might have been formed through nucleophilic
substitution of the Michael substrates (Table 1, Entry 1).
How about the reaction under other conditions?
During our careful investigations, we found that this
type of reaction was extremely sensitive to reaction
conditions. Firstly, we found if there was no catalyst in
this system, the coupling reaction proceeded and the
yield of 3a was up to 64% (Table 1, Entry 2) and little
products of 3b and 3c were isolated. Secondly, if we
reduced the reaction temperature down to 0 ℃, the re-
action time was prolonged obviously and the yield of 3a
was also increased, but no remarkable improving of
*
E-mail: zhusz@sioc.ac.cn; Tel.: 0086-021-54925185; Fax: 0086-021-64166128
Received April 28, 2010; revised July 20, 2010; accepted August 18, 2010.
Project supported by the National Natural Science Foundation of China (No. 20972178, 21032006).
†
Dedicated to the 60th Anniversary of Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences.
Chin. J. Chem. 2010, 28, 1623— 1629
© 2010 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
1623

Zhao et al.
FULL PAPER
halogen was introduced into thiophenol, the reactivity
changed correspondingly. As a weak electron-donor
fluorine atom influenced the nucleophilic reactivity
hardly, the ratio of the products was the same as the
thiophenol. On the other hand, when chlorine atom was
introduced into the thiophenol molecular, the ratio of
coupling products raised and reaction time was pro-
longed. Especially, the stronger electron-withdrawing
nitryl weakened extremely the reactivity of the sulfur so
that 12 appeared to have completely no reactivity in the
reaction. It was worth to notice that phenol or sodium
phenolate was unable to react with 2 under the same
conditions. The reason must be the lower nucleophilic
reactivity of the oxygen atom. All these results were
summarized in the Figure 1, which showed clearly the
whole current of the yields.
other products. Furthermore, it was unsuccessful that
increasing the concentration of thiophenol in the solvent
to increase the yield of 3b and 3c, and it only led to the
raising yield of the coupling product (Table 1, Entry 4).
Interestingly, when these two reagents were introduced
into Rosnati’s K2CO3-actone system, only the coupling
product 3a was isolated (Table 1, Entry 5). Clearly, in
this reaction, the presence of catalyst InCl3•4H2O is
necessary and reducing or increasing the reaction tem-
perature is unable to increase the yield of addition-
elimination or substitution product.
Table 1 Reaction results of 2 with thiophenol under different
conditions
Yield/%
Figure 1 Results of the reaction of 2 with substituted ben-
zenethiols.
Entry Catalyst
Temp. Time/h
3a 3b 3c
9c 16c 15c
64c 9c 6c
69c 14c 8c
80d 4d 6d
96d 0d 0d
1a
2a
3a
4b
5b
InCl3•4H2O
r.t.
12
21
48
24
2
Naturely, we were interested in elucidating the
mechanism of this InCl3•4H2O-mediated reaction of 2
with thiophenols. Despite some apparent difference, we
thought that Rosnati’s reaction of α-bromo Michael ac-
ceptors with phenol or benzenethiol in the system
K2CO3-acetone10 could serve as a prototype for our
InCl3•4H2O-promoted reaction. The results obtained in
the reaction of 2 with thiophenols clearly indicated that
there are two competition-reactions in this system. One
is the simple coupling-reaction, which occurred between
the thiophenols and gave the coupling products. The
other occurred through a reaction sequence initiated by
the conjugate additon of the reagent, followed by the
elimination of ethanol on the newly generated sp3 car-
bon atom and completed by nucleophilic substitution of
the bromine (AdNESN mechanism).
The following facts support the proposed mechanism:
(a) Coupling products a were isolated in all the reac-
tions under different conditions. And we found the yield
of a changed with the reaction time; the yield increased
with the prolonged time. (b) The expected Michael-
type adducts A have not been isolated, which could be
accounted for the easy leaving of ethanol to produce the
β-phenylsulfanyl vinylic bromides b. (c) Diphenylthio
derivatives c were isolated from the reaction through
formal substitution of the vinylic bromine. (d) Putting
addition-elimination product 3b with equivalent amount
no
r.t.
InCl3•4H2O
InCl3•4H2O
K2CO3-Acetone
0 ℃
r.t.
r.t.
a Molar ratio of 2∶3＝1∶1. b Molar ratio of 2∶3＝1∶4.c Iso-
lated yield according to thiophenol. d Isolated yield according to
3-bromo-4-ethoxy-1,1,1-trifluoro-3-buten-2-one 2.
Further experiments demonstrated that other thio-
phenols could also react with 2 under the same condi-
tion. The most significant results were summarized in
Table 2. These showed that the substrate 2 reacted
readily with thiophenols, however, the groups on the
benzene influenced greatly the reactivities of these
thiophenols. Thus the reactions of the two reagents af-
forded a different ratio of the three products.
Thiophenols 4—6 bearing electro-donor groups such
as methyl or methoxyl, accounting for the stronger nu-
cleophilic reactivity than thiophenol 3, could react
readily with α-bromo vinyl compound 2. In their prod-
ucts, the ratio of coupling products decreased, while the
adding-elimination and substitution products became
the major products. This phenomenon was obviously
demonstrated that when 11 were applied in the reaction,
there was almost no coupling product obtained. When
1624
www.cjc.wiley-vch.de
© 2010 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chin. J. Chem. 2010, 28, 1623— 1629

Reactions of 3-Bromo-4-ethoxy-1,1,1-trifluoro-3-buten-2-one with Benzenethiols
Table 2 InCl3•4H2O-mediated reaction results of 2 with thiophenolsa
Entry
1
Thiophenols
Time
Products & yields/%
12
3a (18)
4a (12)
3b (27)
3c (39)
4c (41)
3
4
2
3
12
12
4b (29)
5b (17)
5a (16)
5c (43)
5
4
5
6
7
8
12
36
24
48
48
6a (14)
7a (20)
8a (28)
9a (50)
10a (44)
6b (21)
7b (20)
8b (21)
9b (17)
10b (16)
6c (42)
7c (48)
8c (44)
9c (22)
10c (18)
6
7
8
9
10
11
12
13
14
9
12
48
48
48
trace
—
11b (17)
11c (75)
—
10
11
12
—
—
—
—
—
—
—
a Reactions were carried out in 3 mL ethanol with 2 mmol thiophenol, 2 mmol 2 and 0.15 mg InCl3•4H2O under nitrogen atmosphere.
b Isolated yields according to thiophenol.
Chin. J. Chem. 2010, 28, 1623— 1629
© 2010 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.cjc.wiley-vch.de
1625

Zhao et al.
FULL PAPER
benzenethiol, some substitution product 3c could be
isolated.
were obtained on a Finnigan GC-MS 4021 or a Finnigan
MAT-8430 instrument using the electron impact ioni-
zation technique (70 eV), respectively. Elemental analy-
sis was performed by this institute. The material 2 was
prepared according to the reference.6,7
The following observations also point to the
AdNESN mechanism. The reactivity of benzenethiol can
be explained in terms of the nature of the substituent
group on the benzene, which appears to be the main
factor to affect the addition-elimination and the nucleo-
philic displacement of the bromine. Thus, all substrates
with electron-donating groups which increase the nu-
cleophilic activity could react readily with Michael-
acceptor 2 and the yield of addition-elimination and
substitution products was higher than the yield of cou-
pling products (Table 1, Entries 2—4). By contrast,
when benzene was substituted by strongly elec-
tron-drawing groups such as nitryl, which seriously
weaken the reactivity of sulfur, there was no reaction
occurred (Table 1, Entry 10). However, if halogen was
introduced into benzene, due to the different electron-
attracting power, the reaction results were different ei-
ther (Table 1, Entries 5—9). Fluorine atom could be
regarded as a weak electron-donor, so it enhanced the
reactivity of sulfur. On the other hand, chlorine atom
was a weak electron-drawer, which slightly decreased
sulfur’s reactivity, so the reaction time was prolonged,
ultimately responsible for more benzenethiol under-
taking the coupling reaction.
General procedure
2 (2 mmol) was added into a 10 mL flask containing
benzenethiosl (2 mmol) and 3 mL EtOH. Then
InCl3•4H2O (0.15 mg) was added into the mixture,
which was stirred at r.t. TLC analysis was used to
monitor the process. After the reaction finished, evapo-
rating the solvent, the residue was purified by column
chromatography on silica gel to give the products,
respectively.
Diphenyl disulfide (3a) White solid, yield 18%.
1H NMR (CDCl3) δ: 7.50 (dd, J＝1.5, 8.4 Hz, 4H, Ph),
7.26—7.29 (m, 6H, Ph).
(Z)-3-Bromo-1,1,1-trifluoro-4-phenylsulfanyl-but-
3-en-2-one (3b) Yellow solid (m.p. 36—38 ℃), yield
29%. 1H NMR (CDCl3) δ: 8.55 (s, 1H, CH), 7.56—7.53
(m, 2H, Ph), 7.51—7.48 (m, 3H, Ph). 19F NMR (CDCl3)
δ: －68.93 (s, CF3). 13C NMR (CDCl3) δ: 171.3 (q, 2JCF
＝28 Hz, C＝O), 157.6 (＝CH), 131.4 (C6H5), 131.2
(C6H5), 130.0 (C6H5), 129.8 (C6H5), 115.8 (q, 1JCF＝232
－1
Hz, CF3), 112.4 (C＝). IR ν: 1703, 1532, 1125, 707 cm .
MS m/z (%): 312 (M＋,＋100), 310 (M＋, 100), 243＋(M＋－
CF3, 79.71), 241 (M －CF3, 75.09), 231 (M －Br,
6.57), 123 (CF3COC＝CH＋ , 4.99), 69 (CF3, 2.79).
HRMS calcd for C10H6BrF3OS 310.116, found 309.930.
(Z)-1,1,1-Trifluoro-3,4-bis-phenylsulfanyl-but-3-
en-2-one (3c) Yellow solid (m.p. 71—72 ℃), yield
37%. 1H NMR (CDCl3) δ: 8.69 (s, 1H, CH), 7.56—7.46
(m, 5H, Ph), 7.33—7.19 (m, 5H, Ph). 19F NMR (CDCl3)
δ: －69.84 (s, CF3). 13C NMR (CDCl3) δ: 174.8 (q, 2JCF
＝27 Hz, C＝O), 165.8 (＝CH), 131.2 (C6H5), 129.9
(C6H5), 129.3 (C6H5), 128.8 (C6H5), 127.1 (C＝), 118.0
Conclusion
In summary, we have the first reported the reaction
of 3-bromo-4-ethoxy-1,1,1-trifluoro-3-buten-2-one with
a series of benzenethiols in the presence of InCl3•4H2O.
There are two-competition reactions in these system and
three products are isolated, accounting for the proposed
AdNESN mechanism.
Experimental
1
Materials and instruments
(q, JCF＝232 Hz, CF3). IR ν: 1693, 1532, 1317, 1145,
＋
－1
1129, 883 cm . MS m/z (%): 246 (M －Ph-H2O, 9.61),
177 (M＋－Ph-H2O－CF3, 92.27), 123 (CF3COC＝CH＋,
100), 109 (PhS＋, 1.58), 97 (CF3CO, 8.54), 69 (CF3,
76.08).
Melting points were measured on a Temp-Melt ap-
paratus and were uncorrected. 1H, 13C and 19F NMR spec-
tra were recorded on Bruker AM-300 instruments with
Me4Si and CFCl3 as the internal and external standards,
respectively. FT-IR spectra were obtained with a Nicolet
AV-360 spectrophotometer. Low-resolution mass spec-
tra (LRMS) or high-resolution mass spectra (HRMS)
Di-p-tolyl-disulfide (4a) White solid, yield 12%.
1H NMR (CDCl3) δ: 7.41 (d, J＝8.4 Hz, 4H, Ph), 7.13
(d, J＝8.1 Hz, 4H, Ph), 2.35 (s, 6H, Me).
Scheme 3 Proposed AdNESN mechanism
1626
www.cjc.wiley-vch.de
© 2010 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chin. J. Chem. 2010, 28, 1623— 1629

Reactions of 3-Bromo-4-ethoxy-1,1,1-trifluoro-3-buten-2-one with Benzenethiols
2
(Z)-3-Bromo-1,1,1-trifluoro-4-p-tolylsulfanyl-but-
3-en-2-one (4b) Yellow solid (m.p. 55—57 ℃), yield
29%. 1H NMR (CDCl3) δ: 8.50 (s, 1H, CH), 7.41 (d, J＝
8.1 Hz, 2H, Ph), 7.21 (d, J＝5.4 Hz, 2H, Ph), 2.41 (s,
3H, Me). 19F NMR (CDCl3) δ: －68.63 (s, CF3). IR ν:
－68.91 (s, CF3). 13C NMR (CDCl3) δ: 174.7 (q, JCF＝
28 Hz, C＝O), 165.9 (＝CH), 134.2 (C6H4), 130.8
1
(C6H4), 123.2 (C6H4), 120.7(C6H4), 117.8 (q, JCF＝232
Hz, CF3), 116.2 (C6H4), 114.0 (C6H4), 112.7 (C＝), 55.4
－1
(CH3). IR ν: 1779, 1698, 1593, 1126, 705 cm . MS m/z
－1
1694, 1＋532, 1376, 1148, 1127, 887 cm . MS m/z (%):
(%): 342 (M＋, 23.19), 340 (M＋, 21.63), 273 (M＋－CF3,
10.22), 271 (M＋－CF3, 9.67), 261 (M＋－Br, 12.66),
164 (M＋ －Br－CF3CO, 100), 139 (M＋ －SphOMe,
11.57), 69 (CF3, 13.59). HRMS calcd for C11H8BrF3O2S
339.141; found 339.947.
326 (M , 100), 324 (M＋, 98.72), 257 (M＋－CF3, 79.77),
255 (M＋ －CF3, 77.82), 246 (M＋ －Br, 17.42), 123
(CF3COC＝CH＋, 49.79), 69 (CF3, 13.59). Anal. calcd
for C11H8BrF3OS: C 40.63, H 2.48; found C 40.21, H
2.67.
(Z)-1,1,1-Trifluoro-3,4-bis-(3-methoxy-phenyl-
sulfanyl)-but-3-en-2-one (6c) Yellow oil, yield 42%.
1H NMR (CDCl3) δ: 8.70 (s, 1H, CH), 7.7 (t, J＝8.1 Hz,
1H, Ph), 7.22 (t, J＝7.8 Hz, 1H, Ph), 7.10—7.07 (m, 1H,
Ph), 7.03—6.96 (m, 2H, Ph), 6.90—6.85 (m, 2H, Ph),
6.9—6.76 (m, 1H, Ph), 3.85 (s, 3H, Me), 3.80 (s, 3H,
Me). 19F NMR (CDCl3) δ: －69.86 (s, CF3). 13C NMR
(Z)-1,1,1-Trifluoro-3,4-bis-p-tolylsulfanyl-but-3-
en-2-one (4c) Yellow solid (m.p. 55—57 ℃), yield
41%. 1H NMR (CDCl3) δ: 8.57 (s, 1H, CH), 7.40 (d, J＝
3.8 Hz, 2H, Ph), 7.28—7.24 (m, 4H, Ph), 7.11 (d, J＝
7.5 Hz, 2H, Ph), 2.41 (s, 3H, Me), 2.33 (s, 3H, Me). 19
F
NMR (CDCl3) δ: －69.82 (s, CF3). IR ν: 1691, 1510,
－1
2
1322, 1126, 896, 808 cm . MS (ESI) m/z (%): 369.2
(CDCl3) δ: 176.8 (q, JC-F＝28 Hz, C＝O), 157.5
(M＋＋H). Anal. calcd for C18H15F3OS2: C 58.68, H 4.10;
(＝CH), 132.2 (C6H4), 130.9 (C6H4), 123.2 (C6H4),
116.9 (C6H4), 116.8 (C6H4), 115.6 (C6H4), 114.6 (q,
1JC-F＝232 Hz, CF3), 112.4 (C＝), 55.5 (CH3). IR ν:
found C 58.92, H 4.16.
Di-o-tolyl disulfide (5a) White solid, yield 16%.
1H NMR (CDCl3) δ: 7.50—7.56 (m, 2H, Ph), 7.15—
7.20 (m, 6H, Ph), 2.45 (s, 6H, Ph).
－1
1696, 1591, 1480, 11＋23, 713 cm . MS m/z (%): 400
(M＋, 11.11), 261 (M －SPhOMe, 17.46), 191 (M＋－
SphOMe－CF3, 15.67), 140 (HSPhOMe, 30.84), 124
(CF3COCCH2, 8.62), 69 (CF3, 11.69). HRMS calcd for
C18H15F3O3S2 400.429, found 400.043.
(Z)-3-Bromo-1,1,1-trifluoro-4-o-tolylsulfanyl-but-
3-en-2-one (5b) Yellow solid (m.p. 75—76 ℃), yield
17%. 1H NMR (CDCl3) δ: 8.42 (s, 1H, CH), 7.52—7.49
(m, 1H, Ph), 7.38—7.33 (m, 3H, Ph), 2.48 (s, 3H, Me).
19F NMR (CDCl3) δ: －68.90 (s, CF3). 13C NMR
(CDCl3) δ: 171.7 (q, 2JCF＝27 Hz, C＝O), 158.0 (＝CH),
133.0 (C6H4), 131.4 (C6H4), 130.4 (C6H4), 127.6 (C6H4),
Bis-(4-fluoro-phenyl)-disulfide (7a) White solid,
yield 20%. 1H NMR (CDCl3) δ: 7.62 (d, J＝8.7 Hz, 4H),
7.21 (d, J＝8.7 Hz, 4H). 19F NMR (CDCl3) δ:
－110.18 (s).
1
115.6 (q, JCF＝232 Hz, CF3), 112.6 (C＝), 20.8 (CH3).
(Z)-3-Bromo-1,1,1-trifluoro-4-(4-fluoro-phenyl-
sulfanyl)-but-3-en-2-one (7b) Yellow solid (m.p. 30
＋
－1
IR ν: 1705, 1533, 1316, 885 cm＋ . MS m/z (%): 326 (M ＋,
100), 344 (M＋, 97.72), 257 (M －CF3, 79.58), 255 (M
－CF3, 77.20), 245 (M＋－Br, 18.61), 123 (CF3COCCH,
14.01), 69 (CF3, 11.74). HRMS calcd for C11H8BrF3OS
323.142, found 323.944.
1
—32 ℃), yield 20%. H NMR (CDCl3) δ: 8.44 (s, 1H,
CH), 7.57—7.52 (m, 2H, Ph), 7.20—7.15 (m, 2H, Ph).
19F NMR (CDCl3) δ: －69.02 (s, CF3), －110.08 (1F,
s). 13C NMR (CDCl3) δ: 181.6 (q, JCF＝29 Hz, C＝O),
2
(Z)-1,1,1-Trifluoro-3,4-bis-o-tolylsulfanyl-but-3-
en-2-one (5c) Yellow solid (m.p. 75—76 ℃), yield
43%. 1H NMR (CDCl3) δ: 8.49 (s, 1H, CH), 7.48 (d, J＝
7.5 Hz, 1H, Ph), 7.36—7.26 (m, 3H, Ph), 7.19—7.11 (m,
4H, Ph), 2.50 (s, 3H, Me), 2.42 (s, 3H, Me). 19F NMR
(CDCl3) δ: －69.46 (s, CF3). IR ν: 3057, 1690, 1511,
163.6 (＝CH), 137.7 (C6H41), 136.2 (C6H4), 131.3 (C6H4),
129.8 (C6H4), 119.1 (q, JCF＝232 Hz, CF3), 115.9
－1
(C＝). IR ν: 1693, 1592, 1492, 1318, 1152 cm . MS
m/z (%): 330 (M＋, 43.80), 328 (M＋, 50.37), 261 (M＋－
CF3, 56.65), 259 (M ＋ － CF3, 57.51), 152 (M ＋ －
CF3COCBr, 80.37), 127 (FPhS＋, 91.14), 83 (CF3CH,
100), 69 (CF3, 60.33). HRMS calcd for C10H5BrF4OS
328.106, found 328.925.
＋
－1
1195, 1119, 756 cm . MS＋m/z (%): 368 (M , 100), 29＋9
(M＋－CF3, 4.06), 245 (M －SPhMe, 16.90), 188 (M
－2PhMe, 4.23), 124 (CF3COCCH2, 23.21), 69 (CF3,
9.54). Anal. calcd for C18H15F3OS2: C 58.68, H 4.10;
found C 58.76, H 4.18.
(Z)-1,1,1-Trifluoro-3,4-bis-(4-fluoro-phenylsul-
fanyl)-but-3-en-2-one (7c) Yellow solid (m.p. 71—73
1
℃), yield 48%. H NMR (CDCl3) δ: 8.47 (s, 1H, CH),
Bis-(3-methoxy-phenyl)-disulfide (6a)
White
7.52 (dd, J＝6.9, 1.8 Hz, 2H, Ph), 7.39 (dd, J＝9.0, 5.1
Hz, 2H, Ph), 7.17 (t, J＝8.4 Hz, 2H, Ph), 7.02 (t, J＝8.7
Hz, 2H, Ph). 19F NMR (CDCl3) δ: －69.91 (s, CF3),
－110.18 (1F, s), －113.88 (1F, s). IR ν: 1694, 1591,
1
solid, yield 14%. H NMR (CDCl3) δ: 7.23—7.27 (m,
2H, Ph), 7.05—7.09 (m, 4H, Ph), 6.76—6.80 (m, 2H,
Ph), 3.78 (s, 6H, Me).
＋
－1
(Z)-3-Bromo-1,1,1-trifluoro-4-(3-methoxy-phenyl-
sulfanyl)-but-3-en-2-one (6b) Yellow liquid, yield
21%. 1H NMR (CDCl3) δ: 8.57 (s, 1H, CH), 7.40—7.36
(m, 1H, Ph), 7.12—7.11 (m, 1H, Ph), 7.05—7.03 (m,
2H, Ph), 3.85 (s, 3H, Me). 19F NMR (CDCl3) δ:
1490, 1233, 830 cm . MS m/z (%): 376 (M , 68.69),
307 (M＋－CF3, 2.15), 201 (M＋－CF3CO－FPh＋H,
1.80), 152 (CH＝CHSPhF, 100), 69 (CF3, 29.92). Anal.
calcd for C16H9F5OS2: C 51.06, H 2.41; found C 51.20,
H 2.43.
Chin. J. Chem. 2010, 28, 1623— 1629
© 2010 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.cjc.wiley-vch.de
1627

Zhao et al.
FULL PAPER
1
Bis-(2-fluoro-phenyl)-disulfide (8a) White solid,
yield 28%.1H NMR (CDCl3) δ: 7.60 (t, J＝7.8 Hz, 2H,
Ph), 7.25—7.29 (m, 2H, Ph), 7.07—7.13 (m, 4H, Ph).
19F NMR (CDCl3) δ: －110.23 (s).
—46 ℃, yield 16%. H NMR (CDCl3) δ: 8.44 (s, 1H,
CH), 7.61—7.54 (m, 2H, Ph), 7.46—7.37 (m, 2H, Ph).
19F NMR (CDCl3) δ: －69.12 (s, CF3). 13C NMR
(CDCl3) δ: 171.2 (q, 2JCF＝27 Hz, C＝O), 155.7 (＝CH),
134.5 (C6H4), 133.7 (C6H4), 130.6 (C6H4), 130.2 (C6H4),
(Z)-3-Bromo-1,1,1-trifluoro-4-(2-fluoro-phenyl-
sulfanyl)-but-3-en-2-one (8b) Yellow solid (m.p. 39
1
129.5 (C6H4), 115.1 (q, JCF＝232 Hz, CF3), 113.2
1
－1
—40 ℃), yield 21%. H NMR (CDCl3) δ: 8.45 (s, 1H,
(C＝). IR ν: 1706, 1534, 1123, 701 cm . MS m/z (%):
CH), 7.57—7.47 (m, 2H, Ph), 7.27—7.23 (m, 2H, Ph).
19F NMR (CDCl3) δ: －69.02 (s, CF3). IR ν: 1699, 1534,
346 (M＋, 71.31), 344 (M＋, 54.64), 277 (M＋－CF3, 100),
275 (M＋ －CF3, 75.81), 265 (M＋ －Br, 5.27), 143
(o-ClPhS, 25.60), 123 (CF3COCCH, 3.51), 69 (CF3,
34.04). HRMS calcd for C10H5BrClF3OS 343.8885,
found 343.8853.
＋
－1
1492, 1149, 1129, 878 cm . MS＋m/z (%): 330 (M ,
64.23), 328 (M＋, 60.83), 261 (M －CF3, 66.73), 259
(M＋－CF3, 61.68), 152 (M＋－CF3COCBr, 100), 127
(FPhS ＋ , 46.64), 69 (CF3, 42.66). Anal. calcd for
C10H5BrF4OS: C 36.49, H 1.53; found C 37.01, H 1.67.
(Z)-1,1,1-Trifluoro-3,4-bis-(2-fluoro-phenylsul-
fanyl)-but-3-en-2-one (8c) Yellow solid (m.p. 55—56
(Z)-3,4-Bis-(2-chloro-phenylsulfanyl)-1,1,1-tri-
fluoro-but-3-en-2-one (10c) Yellow solid, m.p. 53—
55 ℃, yield 18%. 1H NMR (CDCl3) δ: 8.60 (s, 1H, CH),
7.60—7.53 (m, 2H, Ph), 7.44—7.36 (m, 3H, Ph), 7.20—
7 . 1 6 ( m , 3 H , P h ) . 1 9 F N M R ( C D C l 3 ) δ :
1
℃), yield 44 %. H NMR (CDCl3) δ: 8.51 (s, 1H, CH),
－1
7.53—7.49 (m, 2H, Ph), 7.31—7.20 (m, 4H, Ph), 7.13—
7.09 (m, 2H, Ph). 19F NMR (CDCl3) δ: －70.06 (s, CF3),
－108.59 (s, 1F), －109.82 (s, 1F). IR ν: 1698, 1516,
－70.07 (s, CF3). IR ν: 1697, 1513, 1452, 1121, 749 cm .
MS m/z (%): 409 (M＋, 11.00), 339 (M＋－CF3, 4.01),
265 (M ＋ － o-ClPhS, 8.23), 168 (M ＋ － o-ClPhS －
CF3CO, 100), 143 (o-ClPhS, 36.68), 123 (CF3COCCH,
2.39), 69 (CF3, 16.90). Anal. calcd for C16H9Cl2F3OS2:
C 46.96, H 2.22; found C 47.07, H 2.33.
＋
－1
1474, 1＋200, 1120 cm . MS m/z (%): 376 (M , 100),
307 (M －CF3, 6.82), 200 (M＋－CF3CO－FPh, 0.31),
155 (CF3COCH＝CHS＋, 0.72), 120 (COCSHCHSH,
1.93), 69 (CF3, 19.29). Anal. calcd for C16H9F5OS2: C
51.06, H 2.41; found C 51.39, H 2.63.
Bis-(4-chloro-benzyl)-disulfide (11a) White solid
(trace); 1H NMR (CDCl3) δ: 7.30 (d, J＝8.1 Hz, 4H, Ph),
7.16 (d, J＝8.7 Hz, 4H, Ph), 3.60 (s, 4H, CH2).
Bis-(4-chloro-phenyl)-disulfide (9a) White solid,
yield 50%. 1H NMR (CDCl3) δ: 7.42 (d, J＝8.7 Hz, 4H,
Ph), 7.29 (d, J＝6.9 Hz, 4H).
(Z)-3-Bromo-4-(4-chloro-benzylsulfanyl)-1,1,1-
trifluoro-but-3-en-2-one (11b) Yellow solid, m.p. 24
1
(Z)-3-Bromo-4-(4-chloro-phenylsulfanyl)-1,1,1-
trifluoro-but-3-en-2-one (9b) Yellow solid, m.p. 35
—26 ℃, yield 17%. H NMR (CDCl3) δ: 8.34 (s, 1H,
CH), 7.54 (d, 3JHH＝8 Hz, 2H, Ph), 7.27 (d, 3JHH＝8 Hz,
2H, Ph), 4.18 (s, 2H, CH2). 19F NMR (CDCl3) δ:
1
—37 ℃, yield 17%. H NMR (CDCl3) δ: 8.44 (s, 1H,
2
CH), 7.57—7.50 (m, 2H, Ph), 7.16—7.15 (m, 2H, Ph).
19F NMR (CDCl3) δ: －69.02 (s, CF3). 13C NMR
(CDCl3) δ: 177.2 (q, 2JCF＝27 Hz, C＝O), 165.9 (＝CH),
131.3 (C6H4), 130.6 (C6H4), 129.9 (C6H4), 129.5 (C6H4),
122.3 (C＝), 117.1 (q, 1JCF＝232 Hz, CF3). MS m/z (%):
346 or 344 (M＋＋H, 15.14 or 12.31), 277 or 275 (M＋－
CF3, 19.45 or 25.71), 143 (o-ClPhS － , 9.62), 123
(CF3COCCH, 5.25), 69 (CF3, 46.84). HRMS calcd for
C10H5BrClF3OS 343.8885, found 343.8887.
－69.01 (s, CF3). 13C NMR (CDCl3) δ: 174.6 (q, JCF＝
27 Hz, C＝O), 165.9 (＝CH), 131.3 (C6H4), 130.5
(C6H4), 129.9 (C6H4), 128.9 (C6H4), 122.3 (C＝), 116.2
1
(q, JCF＝232 Hz, CF3), 21.2 (CH2). IR ν: 1697, 1533,
＋
－1
1491, 1＋317, 1016 cm .＋MS m/z (%): 360 (M , 6.99),
CH
358 (M , 6.30), 281 (M －Br, 1.63), 123 (CF3COC＝
＋
, 100), 69 (CF3, 5.37). Anal. calcd for
C11H7BrClF3OS: C 36.74, H 1.96; found C 37.46, H
2.19.
(Z)-3,4-Bis-(4-chloro-phenylsulfanyl)-1,1,1-tri-
fluoro-but-3-en-2-one (9c) Yellow solid (m.p. 62—
(Z)-3,4-Bis-(4-chloro-benzylsulfanyl)-1,1,1-tri-
fluoro-but-3-en-2-one (11c) Yellow solid, m.p. 46—
48 ℃, yield 75%. 1H NMR (CDCl3) δ: 8.16 (s, 1H, CH),
1
64 ℃), yield 22%. H NMR (CDCl3) δ: 8.54 (s, 1H,
3
CH), 7.43—7.47 (m, 4H, Ph), 7.25—7.29 (m, 4H, Ph).
19F NMR (CDCl3) δ: －69.95 (s, CF3). IR ν: 1697, 1475,
7.36 (d, JHH＝9 Hz, 3H, Ph), 7.21—7.08 (m, 5H, Ph),
4.00 (s, 2H, CH2), 3.90 (s, 2H, CH2). 19F NMR (CDCl3)
＋
＋
－1
1487, 1092 cm . MS＋m/z (%): 409 (M , 38.86), 374 (M
δ: －69.47 (s, CF3). IR ν: 1685, 1513, 1491, 1201, 1128
－Cl, 13.66), 340 (M －CF3, 1.99), 265 (M＋－o-ClPhS,
1.09), 167 (M＋ －o-ClPhS－CF3CO－H, 100), 143
(o-ClPhS, 26.66), 69 (CF3, 28.21). Anal. calcd for
C16H9Cl2F3OS2: C 46.96, H 2.22; found C 47.36, H 2.22.
Bis-(2-chloro-phenyl)-disulfide (10a) White solid,
yield 44%. 1H NMR (CDCl3) δ: 7.56 (dd, J＝1.8, 7.8 Hz,
2H, Ph), 7.37 (dd, J＝1.5, 7.8 Hz, 2H, Ph), 7.21—7.19
(m, 4H, Ph).
cm . MS m/z (%): 311 (M －CH2PhCl, 9.45), 243 (M
＋
＋
－1
－CH2PhCl－CF3, 0.62), 125 (CF3COC＝CH, 100), 69
(CF3, 3.79). Anal. calcd for C18H13Cl2F3OS2: C 49.44, H
3.00; found C 49.59, H 3.30.
References
1
Nenajdenko, V. G.; Sanin, A. V.; Balenkova, E. S. Mole-
cules 1997, 2, 186.
(Z)-3-Bromo-4-(2-chloro-phenylsulfanyl)-1,1,1-
trifluoro-but-3-en-2-one (10b) Yellow solid, m.p. 45
2
Plenkiewicz, H.; Dmowskiand, W.; Lipínski, M. J. Fluorine
1628
www.cjc.wiley-vch.de
© 2010 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chin. J. Chem. 2010, 28, 1623— 1629

Reactions of 3-Bromo-4-ethoxy-1,1,1-trifluoro-3-buten-2-one with Benzenethiols
Chem. 2001, 111, 227.
Chem. 2001, 111, 29.
3
4
5
Singh, R. P.; Shreeve, J. M. Tetrahedron 2000, 56, 7613.
Uneyama, K. J. Fluorine Chem. 1999, 97, 11.
Zhu, S. Z.; Wang, Y. L.; Peng, W. M.; Song, L. P.; Jin, G. F.
Curr. Org. Chem. 2002, 6, 1057.
8
9
Kacharova, L. M.; Gerus, I. I.; Kacharov, A. D. J. Fluorine
Chem. 2002, 117, 193.
Schlosser, M.; Volle, J. N.; Leroux, F.; Schenk, K. Eur. J.
Org. Chem. 2002, 17, 2913.
6
7
Gerus, I. I.; Kacharova, L. M.; Vdovenko, S. I. Synthesis
2001, 431.
10 Rosnati, V.; Saba, A.; Salimbeni, A.; Vettori, U. Gazzetta
Chimica Iraliata 1981, 111, 249.
Kacharova, L. M.; Kacharov, A. D.; Gerus, I. I. J. Fluorine
(E1004282 Cheng, F.)
Chin. J. Chem. 2010, 28, 1623— 1629
© 2010 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.cjc.wiley-vch.de
1629