An ionic liquid as reaction medium for the synthesis of halo-containing β-enaminones at room temperature

Article abstract of DOI:10.1007/s00706-008-0923-3

A series of twenty halomethylated β-enaminones [RC(O)CH=C(R ¹)NR ³ R ⁴, where R = CF₃,CCl ₃, CHCl₂; R ¹ = H, Me, Ph; R ³ = H, Me, Bu, Et; R ⁴ = Me, Et, Bu, allyl, tert-amyl, CH₂CH ₂OH, Bn, Ph] were synthesized using the ionic liquid [bmim]BF ₄ at room temperature. It is demonstrated that this ionic liquid is a reaction medium suitable for the amination of β-alkoxyvinyl halomethyl ketones. The advantages of this method are the absence of solvents, short reaction times, and good yields.

Full text of DOI:10.1007/s00706-008-0923-3

Monatsh Chem 139, 1321–1327 (2008)
DOI 10.1007/s00706-008-0923-3
Printed in The Netherlands
An ionic liquid as reaction medium for the synthesis of halo-containing
b-enaminones at room temperature
Marcos A. P. Martins, Emerson A. Guarda, Clarissa P. Frizzo, Mara R. B. Marzari,
Dayse N. Moreira, Nilo Zanatta, Helio G. Bonacorso
´
´
Nucleo de Quımica de Heterociclos – NUQUIMHE, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
Received 13 February 2008; Accepted 6 March 2008; Published online 19 June 2008
# Springer-Verlag 2008
Abstract A series of twenty halomethylated ꢀ-en-
aminones [RC(O)CH¼C(R1)NR3R4, where R ¼ CF3,
CCl3, CHCl2; R1 ¼ H, Me, Ph; R3 ¼ H, Me, Bu,
Et; R4 ¼ Me, Et, Bu, allyl, tert-amyl, CH2CH2OH,
Bn, Ph] were synthesized using the ionic liquid
[bmim]BF4 at room temperature. It is demonstrated
that this ionic liquid is a reaction medium suitable for
the amination of ꢀ-alkoxyvinyl halomethyl ketones.
The advantages of this method are the absence of
solvents, short reaction times, and good yields.
halomethylated ꢀ-enaminones, which may be ex-
pected to be a useful building block for the synthesis
of fluorine[chlorine]-containing heterocycles, has
scarcely been reported so far [5, 6]. One of the most
effective methods used to synthesize enaminones
containing a halomethyl group is the amination of
ꢀ-alkoxyvinyl halomethyl ketones [6]. Unfortunate-
ly, in general, many of these processes suffer major
or minor limitations, such as long reactions times,
tedious work-up, unsatisfactory yields, and hazard-
ous or expensive solvents and catalysts [5a].
Keywords Amines; ꢀ-Enaminones; ꢀ-Alkoxyvinyl halo-
methylated ketones; Homogeneous catalysis; Ionic liquids.
Our research group has studied exhaustively the
chemistry of trihalomethyl enaminones, and we have
described methods to faster synthesize trihalomethyl
enaminones with good yields, under solvent-free
conditions [7]. On the other hand, recently, our re-
search group has explored the effect of ionic liquids
in organic reactions involving trihalomethylated
compounds. We have reported a practical and effi-
cient procedure for the acylation of enol ethers with
trifluoroacetic anhydride and trichloroacetyl chloride
in the ionic liquids 1-buthyl-3-methylimidazolium
tetrafluoroborate ([bmim]BF4) and hexafluorophos-
phate ([bmim]PF6) [8]. We have also demonstrated
that ionic liquids are an excellent medium for con-
densation reactions between ꢀ-alkoxyvinyl halo-
methyl ketones and cyanoacethydrazide to pyrazoles
[9]. In recent years, ionic liquids have attracted a
great deal of interest as a possible replacement of
traditional solvents for organic reactions, particularly
Introduction
Recently, much attention has been paid to the devel-
opment of new methodologies for the synthesis of
many kinds of fluorine[chlorine]-containing hetero-
cycles [1]. These compounds are now widely recog-
nized as important materials, having interesting
functionalities for use in medicinal and agricultural
science [2, 3]. The chemistry and potential utility of
ꢀ-enaminones in organic synthesis are widely de-
scribed and several synthesis methods have been
reported in literature [4]. However, the synthesis of
´
´
Correspondence: Marcos A. P. Martins, Nucleo de Quımica
de Heterociclos – NUQUIMHE, Universidade Federal de
Santa Maria, Santa Maria, RS, Brazil. E-mail: mmartins@
base.ufsm.br

1322
M. A. P. Martins et al.
in the area of green chemistry, due to their advanta-
geous properties, including negligible vapor pressure
and high thermal and chemical stability. In addition,
ionic liquids have been related to allow chemoselec-
tivety to some organic reactions [10].
Thus, as part of our ongoing studies aimed to ex-
plore the utility and the effect of ionic liquids in the
chemoselectivety of important reactions, we decided
to investigate the use of [bmim]BF4 as a medium to
prepare of halomethylated ꢀ-enaminones by amina-
tion of ꢀ-alkoxyvinyl halomethyl ketones.
group of six ꢀ-alkoxyvinyl halomethyl ketones
(Scheme 1). The results are recorded in Table 1. In
all the cases, the reactants and products were solu-
ble in [bmim]BF4 All the isolated products were
well characterized by their melting points, H and
13C NMR, and GC=MS data.
1
The reaction was carried out at room temperature
for 30 min using commercially available amines 7
(1 mmol) and ꢀ-alkoxyvinyl halomethyl ketones
1–6 (1 mmol) in presence of [bmim]BF4 as the reac-
tion medium (1 mmol). After the reaction time, the
ionic liquid was separated from the products by add-
ing water and chloroform. The desired products 8–
13 were obtained after evaporation of chloroform.
The ionic liquid was recuperated after the evapora-
tion of water. The results are summarized in Table 1
and show that primary and secondary amines, both
aromatic and aliphatic, with linear and branched N-
substituents react without any significant difference
to give the corresponding halomethylated ꢀ-enami-
nones in good yields. The stereochemistry of halo-
methylated ꢀ-enaminones was determined from their
1H NMR spectra. The formation of the (Z)-isomer is
proved by the coupling constants of the hydrogen
Results and discussion
A variety of amines, including aliphatic and aro-
matic amines, were used to substitute the alkoxyde
Scheme 1
Table 1 [bmim]BF4 catalyzed formation of ꢀ-enaminones
Reagent
(enone)
R
R1
R2
Reagent
(amine)
R3
R4
Product
(enaminone)
Reaction
time=min
Yield=
%
a
1
1
1
1
1
1
1
1
1
1
2
2
3
4
4
4
4
5
5
5
6
6
6
CF3
CF3
CF3
CF3
CF3
CF3
CF3
CF3
CF3
CF3
CF3
CF3
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
H
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Et
7a
7b
7c
7d
7e
7f
7g
7h
7i
H
H
Me
Me
Bu
H
H
H
H
H
Bn
Ph
Bu
Ph
Bu
Me
8a
8b
8c
8d
8e
8f
8g
8h
8i
8j
9b
20
10
20
30
20
30
20
20
30
10
20
20
30
30
20
20
20
30
30
20
20
20
30
80
92
70
70
95
70
68
55
67
70
76
70
70
>99
91
75
79
92
95
88
88
91
81
tert-amyl
allyl
CH2CH2OH
7j
Et
Ph
Et
7b
7k
7k
7a
7b
7k
7i
7a
7b
7c
7a
7c
7m
H
H
Et
Et
Et
H
H
Et
9k
CF3
Ph
Me
Me
Me
Me
H
H
H
Me
Me
Me
Me
Me
Me
Me
Me
Et
Et
Et
Me
Me
Me
Et
10k
11a
11b
11k
11l
12a
12b
12c
13a
13c
13m
CCl3
CCl3
CCl3
CCl3
CCl3
CCl3
CCl3
CHCl2
CHCl2
CHCl2
Bn
Ph
Et
–(CH2)4–
H
H
Me
H
Bn
Ph
Bu
Bn
Bu
Me
–(CH2)2–O–(CH2)2–
a
Yields of isolated products

An ionic liquid as reaction medium
1323
ꢀ-alkoxyvinyl halomethyl ketones do not undergo
substitution with amines, such as diphenylamine.
Although the ionic liquids did not provide higher
yields than when the reaction was carried out under
solvent-free conditions, it was demonstrated that
they are better than other molecular solvents for ami-
nation (nucleophilic substitution). The effect of the
ionic liquid on the nucleophilic substitution reaction
has been investigated and, currently, the authors
agree that ‘‘the data on the properties such as dielec-
tric constants and polarity are not sufficient to ex-
plain the solvent=catalyst effect of ionic liquids in
organic transformations’’. For example, some studies
indicate that ionic liquids have polarities similar to
those of short-chain alcohols and other polar, aprotic
solvents (DMSO or DMF) and their polarity is inter-
mediate between water and chlorinated organic sol-
vents, varying in accordance with the nature of the
ionic liquid components [13, 14]. Contrarily, others
report that they exhibit solvent strengths as great as
or greater than the most polar aprotic solvent (aceto-
nitrile) [15]. Moreover, attempts have been made to
develop empirical solvent polarity scales as a means
to help explain differences in solvent-mediated re-
action pathways, reaction yields, synthesis product
ratios, chromatographic retention, and extraction co-
efficients. Clearly, a single parameter of ‘‘polarity’’=
‘‘solvent strength’’=‘‘interaction’’ is not sufficient to
explain the variation in experimental results in many
solvent-mediated processes. Ionic liquids are among
the most complex solvents. Given their structure and
diversity of functionality, they are capable of most
types of interactions (e.g., dispersive, ꢁ-ꢁ, n-ꢁ, hy-
drogen bonding, dipolar, and ionic=charge–charge).
In every solution, there may be a number of different
(in terms of type and strength) and often simultaneous
solute–solvent interactions. Also, the well-established
scenarios for describing dipolar interactions in molec-
ular liquids are not easily transferred to ionic liquids
Fig. 1 Coupling constants of the hydrogen atoms at the double
bond of (Z)- and (E)-isomers
atoms at the double bond (J ¼ 7.0–7.8 Hz) and by a
distinct splitting of the H(1) atom (Fig. 1) on the
amino group H(3) atom (J ¼ 12.9–14.1 Hz) (Fig. 1)
fixed via an intramolecular hydrogen bond. In the
case of the (E)-isomer, J ¼ 12.0–12.5 Hz (Fig. 1).
Moreover, the stereochemistry of the enaminones
obtained depends on the structure of the starting
amine, regardless of the ratio of the (E)=(Z)-isomers
in the starting ꢀ-alkoxyvinyl halomethyl ketones.
The proposed structures were confirmed by X-ray
diffraction for 13a and 13m (Fig. 2).
Furthermore, it is proposed that the ionic liquid
does not interfere with the stereochemistry of the
ꢀ-enaminones obtained. This fact is reasonably
based on data related to literature, where primary
aliphatic amines are described to react with ꢀ-alkoxy-
vinyl halomethyl ketones to give only (Z)-isomers,
due to the formation of an intramolecular hydrogen
bond [11], while the reactions of secondary amines
afford (E)-isomers [12].
Finally, to demonstrate the generality of this meth-
od we investigated the scope of this reaction under
optimized conditions and the results are summarized
in Table 1. Thus, a variety of ꢀ-alkoxyvinyl halo-
methyl ketones, including 4-H, 4-methyl, and 4-aryl
substituted ones, reacted with aliphatic amines, and
all the ꢀ-alkoxyvinyl halomethyl ketones gave good
yields. These reactions were very clean and free
from side reactions. However, the 4-aryl substituted
Fig. 2 ORTEP plof of (E)-1,1-dichloro-4-morpholin-4-yl-3-penten-2-one (13m) and (Z)-4-benzylamino-1,1-dichloro-3-pen-
ten-2-one (13a)

1324
M. A. P. Martins et al.
ried out with the SHELXL-97 [18] package. The ORTEP [19]
diagram of the molecules indicating atom numbering scheme
with thermal ellipsoids at 50% probability is illustrated in
Fig. 2. The ionic liquid [bmim]BF4 was synthesized according
to Ref. [20].
because the net charges of the ions create a funda-
mentally different environment with partial charge-
ordering and screening of dipole–dipole interactions
by the sea of surrounding ions. The presence of
charged species adds new degrees of freedom in
the mix of interactions. In this case, the concept of
polarity may even require a careful rethinking of the
fundamental nature of solvation [16]. A probable
effect of the ionic liquids on activated complexes
is that they could become more stable and long-lived
in these media [10]. A comparison of the results of
this paper with the results described for molecular
solvents [6] show that this method allows a relatively
short reaction time. All the reactions proceeded to
completion under ambient conditions at room tem-
perature in ionic liquid without any other catalyst.
For every reaction, the ionic liquid was recovered by
the evaporation of water and washed successively
with dichloromethane, dried with Na2SO4, and then
the solvent was evaporated. Recycled, the ionic liq-
uid could be reused several times without any loss of
activity.
In conclusion, we disclosed an easy and environ-
mentally sound method for the synthesis of halo-
methylated ꢀ-enaminones starting from differently
substituted ꢀ-alkoxyvinyl halomethyl ketones with
a variety of substituents and amines in the ionic liq-
uid [bmim]BF4. The simple work-up procedure,
mild reaction conditions, short reaction times, and
good yields make our methodology a valid contribu-
tion to the existing process in the field of ꢀ-enami-
none synthesis.
Synthesis of ꢀ-enaminones
A mixture of 1 mmol 1–6 and 225 mg [bmim]BF4 (1 mmol)
was stirred until a homogeneous mixture was formed. Then,
1 mmol 7 was added slowly to this mixture. After this, the
mixture was stirred at room temperature for 10–30min. Water
(3cm3) was added, and the crude products 8–13 were
extracted with 3ꢁ20cm3 CHCl3. The organic phases were
dried (Na2SO4) and the solvent was evaporated. The ꢀ-enam-
inone products were obtained in a pure form, without further
purification.
(Z)-4-Benzylamino-1,1,1-trifluoro-3-pent-2-one
(8a, C12H12F3NO)
Mp 59–61ꢂC; 1H NMR (CDCl3, 400 MHz): ꢂ ¼ 2.02 (s, CH3),
4.56 (d, CH2), 5.40 (s, CH) 7.26–7.35 (m, 5H, arom), 11.61
(s, NH) ppm; 13C NMR (CDCl3, 100MHz): ꢂ ¼ 19.4 (CH3),
47.5 (CH2), 89.7 (CH), 117.2 (q, CF3, J ¼ 288 Hz), 126.9
(CH), 128.0 (2CH), 129.0 (2CH), 135.9 (CH), 169.6 (C), 175.5
(q, C¼O, J ¼ 32 Hz) ppm; MS: m=z (%) ¼ 243 (Mþ, 45), 91
(100), 174 (81), 65 (52), 146 (13); IR (KBr): ꢃꢀ¼ 1585, 1302,
1225, 887, 835, 738, 724 cmꢃ1
.
(Z)-1,1,1-Trifluoro-4-phenylamino-3-penten-2-one
(8b, C11H10F3NO)
Mp 55–57ꢂC; 1H NMR (CDCl3, 400 MHz): ꢂ ¼ 2.11 (s, CH3),
5.54 (s, CH), 7.15–7.42 (m, 5H, arom), 10.89 (s, NH) ppm;
13C NMR (CDCl3, 100MHz): ꢂ ¼ 20.1 (CH3), 90.7 (CH),
117.4 (q, CF3, J ¼ 288 Hz), 125.1 (C), 127.3 (2CH), 129.4
(2CH), 136.8, (CH), 167.9 (C), 176.4 (q, C¼O, J ¼ 32Hz)
ppm; MS: m=z (%) ¼ 229 (Mþ, 18), 160 (100), 77 (35), 51
(20), 117 (17); IR (KBr): ꢃꢀ¼ 3448, 1578, 1253, 1126, 756,
728 cmꢃ1
.
(E)-4-(Butylmethylamino)-1,1,1-trifluoro-3-penten-2-one
(8c, C10H16F3NO)
Experimental
Unless indicated otherwise, all common reagents and solvents
were used as obtained from commercial supplies without
further purifications. H and 13C NMR spectra were recorded
Oil; 1H NMR (CDCl3, 400MHz): ꢂ ¼ 0.97 (t, CH3), 1.34 (sex,
CH2), 1.58 (qui, CH2), 2.61 (s, CH3), 3.03 (s, CH3), 3.40
(t, CH2), 5.19 (s, CH) ppm; 13C NMR (CDCl3, 100 MHz):
ꢂ ¼ 13.7 (CH3), 16.7 (CH2), 19.8 (CH3), 30.3 (CH2), 39.0
(N–CH2), 52.21 (N–CH3), 86.9 (CH), 117.0 (q, CF3, J ¼
288 Hz), 167.7 (CH), 175.1 (q, C¼O, J ¼ 32 Hz) ppm; MS:
m=z (%) ¼ 223 (Mþ, 13), 56 (100), 154 (57), 112 (46), 126
(26), 180 (20); IR (KBr): ꢃꢀ¼ 1645, 1552, 1358, 1281, 1111,
1
on a Bruker DPX 400 (1H at 400.13 MHz and 13C at
100.62 MHz) in 5 mm sample tubes at 298 K (digital resolu-
tion ꢀ0.01 ppm) in CDCl3=TMS solutions. Mass spectra were
registered in a HP 5973 MSD connected to a HP 6890 GC and
interfaced by a Pentium PC. The CG was equipped with a
split–splitless injector, autosampler, cross-linked to a HP-5
capillary column (30 m length, 0.32 mm internal diameter),
and He was used as the carrier gas. All melting points were
determined on a Reichert Thermovar apparatus. X-Ray data
were collected on a Bruker SMART CCD diffractometer. The
866, 777 cmꢃ1
.
(E)-1,1,1-Trifluoro-4-(methylphenylamino)-3-penten-2-one
(8d, C12H12F3NO)
Oil; 1H NMR (CDCl3, 400 MHz): ꢂ ¼ 2.83 (s, CH3), 3.36 (s,
CH3), 5.42 (s, CH), 7.14–7.46 (5H arom) ppm; 13C NMR
(CDCl3, 100 MHz): ꢂ ¼ 30.8 (CH3), 41.7 (CH3), 88.6 (CH),
123.0 (q, CF3, J ¼ 292 Hz), 122.6 (C), 126.4 (CH), 128.2
˚
wavelength of diffractometer is 0.71073A and the crystals
sizes are 0.44ꢁ0.35ꢁ0.15mm3 for 13a and 0.51ꢁ0.39ꢁ
0.32mm3 for 13m. The crystallographic structure was solved
by direct methods (SHELXS-97) [17]. Refinements were car-

An ionic liquid as reaction medium
1325
(CH), 129.1(CH), 129.9 (CH), 144.5 (CH), 168.0 (C), 181.6
(q, C¼O, J ¼ 30 Hz) ppm; MS: m=z (%) ¼ 243 (Mþ, 45),
174 (100), 56 (96), 77 (80), 131 (62), 146 (47), 104 (17); IR
(KBr): ꢃꢀ¼ 1675, 1538, 1497, 1202, 1134, 835, 721, 695,
ꢂ ¼ 19.5 (CH3), 46.0 (CH2), 60.5 (CH2), 89.7 (CH), 117.7
(q, CF3, J ¼ 288 Hz), 170.4 (C), 174.8 (q, C¼O, J ¼ 33Hz)
ppm; MS: m=z (%) ¼ 197 (Mþ, 34), 128 (100), 154 (50), 166
(48), 69 (48), 81 (30), 54 (27), 96 (21); IR (KBr): ꢃꢀ¼ 3367,
565 cmꢃ1
.
1568, 1255, 1191, 1128, 851, 726 cmꢃ1
.
(E)-4-Dibutylamino-1,1,1-trifluoro-3-penten-2-one
(Z)-4-Ethylamino-1,1,1-trifluoro-3-penten-2-one
(8e, C13H22F3NO)
1
(8j, C7H10F3NO)
1
Oil; H NMR (CDCl3, 400 MHz): ꢂ ¼ 0.97 (t, 2CH3), 1.36
Oil; H NMR (CDCl3, 400MHz): ꢂ ¼ 1.30 (t, CH3), 2.08 (s,
(sex, 2CH2), 1.59 (qui, 2CH2), 2.60 (s, CH3), 3.32 (t, CH2),
5.25 (s, CH) ppm; 13C NMR (CDCl3, 100 MHz): ꢂ ¼ 13.5
(2CH3), 16.9 (CH3), 18.0 (2CH3), 19.9 (2CH2), 27.9 (CH2),
30.4 (CH2), 51.4 (2CH2) 86.4 (CH), 118.1 (q, CF3, J ¼
292 Hz), 167.2 (C), 174.7 (q, C ¼ O, J ¼ 32Hz) ppm; MS:
m=z (%) ¼ 265 (Mþ, 24), 98 (100), 154 (81), 196 (79), 222
(70), 168 (65), 57 (63), 126 (17); IR (KBr): ꢃꢀ¼ 2961, 2933,
CH3), 3.38 (qui, CH2), 5.31 (s, CH), 11.09 (s, NH) ppm; 13C
NMR (CDCl3, 100MHz): ꢂ ¼ 14.6 (CH3), 18.9 (CH3), 38.5
(CH2), 89.0 (CH), 117.6 (q, CF3, J ¼ 287 Hz), 169.3 (C),
172.2 (q, C¼O, J ¼ 32Hz) ppm; MS: m=z (%) ¼ 181 (Mþ,
49), 112 (100), 94 (50), 69 (27), 138 (8); IR (KBr): ꢃꢀ¼ 1614,
1441, 1298, 1242, 1189, 1117, 881, 741 cmꢃ1
.
1550, 1280, 1236, 1046, 960, 737 cmꢃ1
.
(E)-4-Diethylamino-1,1,1-trifluoro-3-buten-2-one
(9b, C8H12F3NO)
Oil; 1H NMR (CDCl3, 400 MHz): ꢂ ¼ 1.26 (t, 2CH3), 3.38 (q,
2CH2), 5.32 (d, J ¼ 12 Hz, CH), 7.88 (d, J ¼ 12 Hz, CH) ppm;
13C NMR (CDCl3, 100 MHz): ꢂ ¼ 11.4 (CH3), 14.4 (CH3),
43.3 (CH2), 51.1 (CH2), 86.8 (CH), 117.7 (q, CF3, J ¼
290 Hz), 154.8 (C), 176.9 (q, C¼O, J ¼ 32Hz) ppm; MS:
m=z (%) ¼ 195 (Mþ, 28), 126 (100), 56 (47), 69 (32), 195
(28), 108 (28), 82 (28); IR (KBr): ꢃꢀ¼ 2983, 1576, 1262, 1133,
(Z)-1,1,1-Trifluoro-4-methylamino-3-penten-2-one
(8f, C6H8F3NO)
Mp 49–52ꢂC; 1H NMR (CDCl3, 400 MHz): ꢂ ¼ 2.08 (s,
CH3), 3.06 (d, CH3), 5.35 (s, CH), 11.07 (s, CH), 11.08
(s, NH) ppm; 13C NMR (CDCl3, 100 MHz): ꢂ ¼ 19.1 (CH3),
30.1 (CH3), 19.9 (CH2), 89.2 (CH), 117.6 (q, CF3, J ¼
287 Hz), 170.5 (C), 175.1 (q, C¼O, J ¼ 31 Hz) ppm; MS:
m=z (%) ¼ 167 (Mþ, 20), 98 (100), 56 (72), 69 (23), 82 (13);
IR (KBr): ꢃꢀ¼ 1621, 1436, 1281, 1244, 1183, 1116, 884,
1083, 880, 709 cmꢃ1
.
737 cmꢃ1
.
(Z)-1,1,1-Trifluoro-4-Phenylamino-3-buten-2-one
(9k, C10H8F3NO)
Mp 90–92ꢂC; 1H NMR (CDCl3, 400 MHz): ꢂ ¼ 5.65 (d,
J ¼ 7 Hz, CH), 6.83 (d, J ¼ 7 Hz, CH), 7.12–7.11 (m, 5H,
arom), 11.48 (s, NH) ppm; 13C NMR (CDCl3, 100MHz):
ꢂ ¼ 89.9 (CH), 119.2 (q, CF3, J ¼ 288Hz), 117.3 (C), 125.7
(CH), 129.9 (2CH), 138.7 (2CH), 149.7 (CH), 179.3 (q, C¼O,
J ¼ 34 Hz) ppm; MS: m=z (%) ¼ 215 (Mþ, 30), 146 (100), 77
(30), 91 (20), 51 (20), 117 (14); IR (KBr): ꢃꢀ¼ 3250, 1601,
(Z)-4-(1,1-Dimethylpropylamino)-1,1,1-trifluoro-3-penten-2-
one (8g, C10H16F3NO)
1
Oil; H NMR (CDCl3, 400 MHz): ꢂ ¼ 0.97 (t, CH3), 1.41 (s,
2CH3), 1.73 (q, CH2), 2.19 (s, CH3), 5.26 (s, CH), 11.59 (s,
NH) ppm; 13C NMR (CDCl3, 100 MHz): ꢂ ¼ 8.1 (CH3), 20.7
(CH3), 27.8 (2CH3), 35.2 (2CH2), 56.7 (C), 90.4 (CH), 117.0
(q, CF3, J ¼ 287 Hz), 169.7 (C), 174.2 (q, C¼O, J ¼ 32 Hz)
ppm; MS: m=z (%) ¼ 223 (Mþ, 20), 84 (100), 154 (86), 71
(42), 194 (36), 55 (24); IR (KBr): ꢃꢀ¼ 2976, 1608, 1252, 1181,
1555, 1280, 894, 757cmꢃ1
.
1122, 871, 739 cmꢃ1
.
(E)-4-Diethylamino-1,1,1-trifluoro-4-phenyl-3-buten-2-one
(10k, C14H16F3NO)
Mp 87–89ꢂC; 1H NMR (CDCl3, 400 MHz): ꢂ ¼ 1.05 (t, CH3),
1.36 (t, CH3), 3.10 (q, CH2), 3.52 (q, CH2), 5.42 (s, CH),
7.17–7.43 (5H, arom) ppm; 13C NMR (CDCl3, 100MHz):
ꢂ ¼ 11.3 (CH3), 13.3 (CH3), 44.2 (CH2), 44.6 (CH2), 86.8
(CH), 109.6 (CH), 109.5 (C), 117.5 (q, CF3, J ¼ 288 Hz),
126.2 (2C), 127.2 (2C), 135.5 (C), 167.2 (C), 174.7 (q, C¼O,
J ¼ 32 Hz) ppm; MS: m=z (%) ¼ 270 (Mþ, 25), 202 (100), 104
(68), 77 (34), 149 (19), 56 (17); IR (KBr): ꢃꢀ¼ 2977, 1654,
(Z)-4-Allylamino-1,1,1-trifluoro-3-penten-2-one
(8h, C8H10F3NO)
Oil; 1H NMR (CDCl3, 400 MHz): ꢂ ¼ 2.08 (s, CH3), 3.98 (t,
CH2), 5.23 (d, CH), 5.31 (d, CH ), 5.36 (s, CH), 5.84 (m,
CH), 11.15 (s, NH) ppm; 13C NMR (CDCl3, 100 MHz):
ꢂ ¼ 19.1 (CH3), 45.7 (CH2), 89.6 (CH), 116.6 (CH2),
117.7 (q, CF3, J ¼ 288 Hz), 132 (CH), 169.7 (CH), 175.5
(q, C¼O, J ¼ 32 Hz) ppm; MS: m=z (%) ¼ 197 (Mþ, 34),
128 (100), 154 (50), 166 (48), 69 (48), 81 (30), 54 (27), 96
(21); IR (KBr): ꢃꢀ¼ 3367, 1568, 1255, 1191, 1128, 851,
1522, 1293, 1132, 900, 786 cmꢃ1
.
726 cmꢃ1
.
(Z)-4-Benzylamino-1,1,1-trichloro-3-penten-2-one
(11a, C11H10Cl3NO)
Mp 87–90ꢂC; 1H NMR (CDCl3, 400 MHz): ꢂ ¼ 4.51 (s, CH2),
7.14 (d, J ¼ 7 Hz, 1H), 7.26–7.39 (m, 5H, arom), 10.95 (s,
NH) ppm; 13C NMR (CDCl3, 100 MHz): ꢂ ¼ 19.8 (CH3),
86.9 (CH), 97.2 (CCl3), 126.9 (C), 128 (2CH), 128.9 (2CH),
136 (CH), 168.8 (C), 180.5 (C¼O) ppm; MS: m=z (%) ¼ 291
(Z)-1,1,1-Trifluoro-4-(2-hydroxyethylamino)-3-penten-2-one
(8i, C7H10F3NO2)
Mp 74–76ꢂC; 1H NMR (CDCl3, 400 MHz): ꢂ ¼ 2.11 (s,
2CH2), 2.90 (s, O–H), 3.52 (q, CH2), 3.83 (q, CH2), 5.34 (s,
CH), 11.26 (s, NH) ppm; 13C NMR (CDCl3, 100 MHz):

1326
M. A. P. Martins et al.
(Mþ, 8), 228 (30), 174 (100), 91 (96), 65 (60); IR (KBr):
3.35 (t, CH2), 5.59 (d, J ¼ 12 Hz, CH), 7.83 (d, J ¼ 12 Hz,
CH) ppm; 13C NMR (CDCl3, 100 MHz): ꢂ ¼ 13.5 (CH3),
19.5 (CH2), 27.8 (CH2), 35.7 (CH3), 58.5 (CH2), 84.7
(CH), 98.0 (CCl3), 156.8 (CH), 180.7 (C¼O) ppm; MS:
m=z (%) ¼ 257 (Mþ, 28), 140 (100), 84 (24), 55 (19), 194
(17); IR (KBr): ꢃꢀ¼ 2959, 2931, 2872, 1656, 1557, 1278,
ꢃꢀ¼ 1596, 1310, 1224, 885, 835, 741, 718 cmꢃ1
.
(Z)-1,1,1-Trichloro-4-phenylamino-3-penten-2-one
(11b, C11H10Cl3NO)
Mp 83–84ꢂC; 1H NMR (CDCl3, 400 MHz): ꢂ ¼ 2.15 (s, CH3),
5.88 (s, CH), 7.17–7.41 (m, 5H arom), 12.14 (s, NH) ppm; 13C
NMR (CDCl3, 100 MHz): ꢂ ¼ 20.6 (CH3), 88.3 (CH), 96.9
(CCl3), 125.1(C), 127.0 (2CH) 129.4 (2CH), 137.3 (CH),
167.0 (CH), 180.2 (C¼O) ppm; MS: m=z (%) ¼ 278 (Mþ, 5),
160 (100), 77 (26), 51 (16), 117 (11), 214 (10), 178 (8); IR
1117, 806, 764, 701, 665 cmꢃ1
.
(Z)-4-Benzylamino-1,1-dichloro-3-penten-2-one
(13a, C12H13Cl2NO)
Mp 74–77ꢂC; 1H NMR (CDCl3, 400 MHz): ꢂ ¼ 2.08 (s, CH3),
4.52 (s, CH2), 5.41 (s, CH), 5.85 (s, CH) 7.26–7.33 (m, 5H
arom), 11.11 (s, NH) ppm; 13C NMR (CDCl3, 100MHz):
ꢂ ¼ 19.4 (CH3), 47.3 (CH2), 89.7 (CH), 92.0 (CCl3), 126.9
(C), 127.8 (2CH), 128.9 (2CH), 136.3 (C), 168.2 (C), 184.0
(C¼O) ppm; MS: m=z (%) ¼ 257 (Mþ, 5), 91 (100), 174 (52),
65 (17); IR (KBr): ꢃꢀ¼ 1605, 1307, 1225, 888, 831, 737,
723 cmꢃ1. Crystallographic data for 13a were deposited at
the Cambridge Crystallographic Data Center (CCDC 649397).
Copies of the data can be obtained, free of charge, on appli-
cation to CCDC 12 Union Road, Cambridge CB2 1EZ, UK
(Fax: þ44-1223-336033 or e-mail: deposit@ccdc.cam.ac.uk).
(KBr): ꢃꢀ¼ 3196, 1616, 1320, 1259, 1200, 1154, 738, 556cmꢃ1
.
(E)-1,1,1-Trichloro-4-diethylamino-3-penten-2-one
(11k, C9H14Cl3NO)
Oil; 1H NMR (CDCl3, 400 MHz): ꢂ ¼ 1.25 (t, 2CH3), 2.58 (s,
CH3), 3.42 (qua, 2CH2), 5.69 (s, CH) ppm; 13C NMR (CDCl3,
100 MHz): ꢂ ¼ 16.3 (2CH3), 45.2 (2CH2), 84.1 (CH), 99.9
(CCl3), 166.5 (C), 178.5 (C¼O) ppm; MS: m=z (%) ¼ 258
(Mþ, 2), 140 (100), 194 (19), 122 (15); IR (KBr): ꢃꢀ¼ 2977,
1652, 1542, 1354, 1129, 1043, 804, 774, 682, 661 cmꢃ1
.
(E)-1,1,1-Trichloro-4-pyrrolidin-1-yl-3-penten-2-one
(E)-4-(Butylmethylamino)-1,1-dichloro-3-penten-2-one
(13c, C10H17Cl2NO)
(11l, C9H12Cl3NO)
1
Mp 108–110ꢂC; H NMR (CDCl3, 400 MHz): ꢂ ¼ 2.02 (qui,
2CH2), 2.59 (s, CH3), 3.42 (t, CH2), 3.56 (t, CH2), 5.58 (s, CH)
ppm; 13C NMR (CDCl3, 100 MHz): ꢂ ¼ 18.2 (CH3), 24.7
(CH2), 25.1 (CH2), 48.8 (CH2), 49.0 (CH2), 85.0 (CH), 99.7
(CCl3), 165.8 (C), 178.6 (C¼O) ppm; MS: m=z (%) ¼ 256
(Mþ, 3), 138 (100), 192 (14), 120 (9); IR (KBr): ꢃꢀ¼ 1642,
Oil; 1H NMR (CDCl3, 400MHz): ꢂ ¼ 0.97 (t, CH3), 1.35 (sex,
CH2), 1.59 (qui, CH2), 2.57 (s, CH3), 3.04 (s, CH3), 3.36 (t,
CH2), 5.42 (s, CH), 5.80 (s, CH) ppm; 13C NMR (CDCl3,
100 MHz): ꢂ ¼ 13.7 (CH3), 19.83 (CH3), 19.86 (CH2), 30.4
(CH2), 38.7 (CH3), 51.9 (CH2), 72.7 (C), 87.5 (CH), 166.4
(CH), 183.3 (C¼O) ppm; MS: m=z (%) ¼ 237 (Mþ, 3), 154
(100), 56 (72), 112 (17), 82 (17), 136 (11), 174 (10); IR (KBr):
ꢃꢀ¼ 2977, 1652, 1542, 1354, 1129, 1043, 804, 774, 682,
1544, 1302, 1162, 1028, 817, 801, 660 cmꢃ1
.
(Z)-4-Benzylamino-1,1,1-trichloro-3-buten-2-one
(12a, C11H10Cl3N)
661 cmꢃ1
.
1
Oil; H NMR (CDCl3, 400 MHz): ꢂ ¼ 4.50 (s, CH2), 5.73 (d,
(E)-1,1-Dichloro-4-morpholin-4-yl-3-penten-2-one
(13m, C9H13Cl2NO2)
J ¼ 7 Hz, CH), 7.02 (d, J ¼ 7 Hz, CH), 7.14–7.39 (m, 5H
arom), 10.97 (s, NH) ppm; 13C NMR (CDCl3, 100 MHz):
ꢂ ¼ 53.1 (CH2), 85.1 (C), 96.6 (CCl3), 127.4 (C), 128.2
(2CH), 129.0 (2CH), 136.1 (CH), 157.2 (CH), 182.2 (C¼O)
ppm; MS: m=z (%) ¼ 277 (Mþ, 4), 91 (100), 160 (53), 65 (18);
Mp 96–98ꢂC; 1H NMR (CDCl3, 400 MHz): ꢂ ¼ 2.56 (s, CH3),
3.51 (qua, 2CH2), 3.76 (qua, 2CH2), 5.53 (s, CH), 5.79 (s, CH)
ppm; 13C NMR (CDCl3, 100 MHz): ꢂ ¼ 16.1 (CH3), 46.5
(CH2), 66.1 (CH2), 72.4 (C), 88.7 (CH), 165.9 (CH), 184.4
(C¼O) ppm; MS: m=z (%) ¼ 237 (Mþ, 6), 154 (100), 55 (33),
96 (22), 174 (12), 126 (7), 202 (5); IR (KBr): ꢃꢀ¼ 3012, 2866,
1633, 1260, 1114, 1002, 782, 690cmꢃ1. Crystallographic data
for 13m were deposited at the Cambridge Crystallographic
Data Center (CCDC 649396). Copies of the data can be ob-
tained, free of charge, on application to CCDC 12 Union
Road, Cambridge CB2 1EZ, UK (Fax: þ44-1223-336033 or
e-mail: deposit@ccdc.cam.ac.uk).
IR (KBr): ꢃꢀ¼ 2927, 1646, 1580, 1292, 813, 738 cmꢃ1
.
(Z)-1,1,1-Trichloro-4-phenylamino-3-buten-2-one
(12b, C10H8Cl3NO)
1
Mp 102–104ꢂC; H NMR (CDCl3, 400 MHz): ꢂ ¼ 5.97 (d,
J ¼ 7 Hz, CH), 7.11 (d, J ¼ 7 Hz, CH), 7.17–7.68 (m, 5H
arom), 11.35 (s, NH) ppm; 13C NMR (CDCl3, 100 MHz):
ꢂ ¼ 88.0 (CH), 116.9 (CCl3), 125.1 (2CH), 129.8 (2CH), 138.9
(CH), 148.9 (CH), 182.8 (C¼O) ppm; MS: m=z (%) ¼ 263
(Mþ, 5), 146 (100), 77 (29), 51 (20), 117 (18), 200 (14),
91 (13); IR (KBr): ꢃꢀ¼ 1667, 1539, 1480, 1302, 818, 759,
718 cmꢃ1
.
Acknowledgements
The authors thank the Conselho Nacional de Desenvolvimento
(E)-4-(Butylmethylamino)-1,1,1-trichloro-3-buten-2-one
(12c, C9H14Cl3NO)
´
Cientıfico e Tecnologico (CNPq=PADCT) and the Fundac
de Amparo a Pesquisa do Estado do Rio Grande do Sul
(FAPERGS) for financial support. The fellowships from
CNPq, CAPES and FAPERGS are also acknowledged.
´
°
a˜o
`
Mp 55–57ꢂC; 1H NMR (CDCl3, 400 MHz): ꢂ ¼ 0.95 (t,
CH3), 1.33 (sex, CH2), 1.61 (qui, 2CH2), 2.94 (s, CH3),

An ionic liquid as reaction medium
1327
S, Peres RL, Zimmermann N, Rosa FA, Fiss GF, Zanatta
N, Bonacorso HG (2006) Synthesis 9:1485; d) Martins
MAP, Frizzo CP, Moreira DN, Rosa FA, Marzari MRB,
Zanatta N, Bonacorso HG (2007) Catal Commun, doi:
10.1016=j.catcom.2007.11.037
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