A new method for the synthesis of CF3-containing aminovinyl ketones

Article abstract of DOI:10.1023/A:1012728922156

A new method for the synthesis of aminovinyl trifluoroinethyl ketones was developed. The method is based on the reactions of 4-sulfonyl-1,1,1-trifluorobut-3-ene-2,2-diols with various alkyl-, aryl-, dialkyl-, and alkylarylamines. The stereochemistry of the compounds obtained was studied.

Full text of DOI:10.1023/A:1012728922156

Russian Chemical Bulletin, International Edition, Vol. 50, No. 8, pp. 1395—1400, August, 2001
1395
Organic Chemistry
A new method for the synthesis of CF -containing aminovinyl ketones
3
«
A. L. Krasovsky, V. G. Nenajdenko, and E. S. Balenkova
Department of Chemistry, M. V. Lomonosov Moscow State University,
Leninskie Gory, 119899 Moscow, Russian Federation.
Fax: +7 (095) 932 8846. E-mail: nen@acylium.chem.msu.ru
A new method for the synthesis of aminovinyl trifluoromethyl ketones was developed. The
method is based on the reactions of 4-sulfonyl-1,1,1-trifluorobut-3-ene-2,2-diols with various
alkyl-, aryl-, dialkyl-, and alkylarylamines. The stereochemistry of the compounds obtained
was studied.
Key words: β-sulfonylvinyl(trifluoromethyl)methanediols, amines, β-trifluoroacetylvinyl-
amines, enamines, stereochemistry, nucleophilic substitution.
Earlier, sulfones 1a 1 and 1b 2 were obtained for the
first time by the oxidation of the corresponding easily
accessible sulfides with 30% hydrogen peroxide in
trifluoroacetic acid. They were found to react with
various electron-enriched heteroaromatic compounds to
Scheme 1
F C
OH
OH
3
1
2
+
R R NH
–H2O
give CF -containing β-hetarylalkenyl ketones.1
3
RSO2
In the present paper, the reactions of easily available
and stable sulfones 1a,b with various amines were stud-
ied. Under mild conditions, they readily afford a variety
R = Ph, E/Z = 7/2 (ꢀ=);
Me, E (ꢀ>)
F C
of CF -containing enaminoketones 2—5 in virtually
3
3
O
quantitative yields (Scheme 1).
+
RSO H
2
1
2
R R N
Results and Discussion
—
#
The reaction can involve aliphatic, aromatic, and
heteroaromatic amines with a primary or secondary
amino group; both pure amines and their aqueous solu-
tions may be used, which is especially important from
the preparative viewpoint. The results of the reactions of
sulfones 1a,b with amines are given in Table 1. The
reaction course is insignificantly influenced either by
the presence of the OH group in products 2d and 3d or
by the presence of electron-withdrawing groups in the
starting amines, so that both 3-aminopyridine and
p-nitroaniline are involved in the reaction. Of particular
interest is that the complete conversion of sulfone 1 is
reached even with one equivalent of the amine, though
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1329—1333, August, 2001.
066-5285/01/5008-1395 $25.00 ©ꢀ2001 Plenum Publishing Corporation
1

1
396
Russ.Chem.Bull., Int.Ed., Vol. 50, No. 8, August, 2001
Krasovsky et al.
Table 1. Products in the reactions of amines with sulfones 1a,b
starting sulfones 1a,b. Thus, ammonia and primary ali-
phatic amines react with sulfones 1a,b to give only
Z isomers 2a—e owing to the formation of intramolecu-
lar hydrogen bond,3 while the reactions of secondary
amines afford E isomers.4
The stereochemistry of enamines was determined
from their 1H NMR spectra. The formation of the
Z isomer is proved by the coupling constants of the H
atoms at the double bond (J = 7.0—7.8 Hz) and by a
distinct splitting of the H(1) atom on the amino group
H(3) atom (J = 12.9—14.1 Hz) fixed via an intramo-
lecular hydrogen bond.3 In the case of the E isomer,
J = 12.0—12.5 Hz.
Com-
R1
R2
E/Z
Yield
pound(%)
2à
2b
2c
2d
2e
3a
H
H
H
H
H
Me
H
Bu
Z
Z
Z
Z
Z
E
95
96
93
90
96
95
n
Allyl
HOCH CH
Bu
Me
2
2
t
3
b
O
E
92
3c
3d
3e
4a
4b
5a
Et
Et
E
E
E
Z
E
E
95
90
94
88
93
95
HOCH CH
HOCH CH
Pri
2-NH Ph
3-Py
Ph
2
2
2
2
Pri
H
H
Me
3JH,H = 7.0—7.8 Hz
3JH,H = 12.0—12.5 Hz
2
F3C
5
b
E
98
H(1)
N
H(2)
H(1)
O
R
CF3
R
N
R
H(2)
H(3)
O
the reaction produces sulfinic acid also capable of bind-
ing the starting amino compound. Apparently, this
is explained by extremely high reactivity of com-
pounds 1a,b.
o-Phenylenediamine reacts with one equivalent of
diol 1a or 1b to give unknown monosubstituted enamine
3JH,H = 12.9—14.1 Hz
We studied the influence of the ring substituents in
enamines 4c—g on the ratio of the E and Z isomers
Table 2). The presence of electron-releasing substitu-
ents stabilizes the Z form owing to the formation of an
intramolecular hydrogen bond which is more thermody-
namically preferred than that with electron-withdrawing
substituents. In solvents that are less polar than
(
4
a in high yield, whereas its reactions with β-alkoxyvinyl
3
trifluoromethyl ketones previously afforded an addition
product with both amino group involved (Scheme 2).
DMSO-d6 (e.g., in CDCl ), the equilibrium between
Scheme 2
3
the E and Z isomers is completely shifted to the
Z isomers, which is in full agreement with the litera-
F C
OH
OH
ture data.3,5
3
NH2
NH2
–
RSO H
2
+
Thus, the study of the reactions of β-sulfonylvinyl
trifluoromethyl ketones with various amines showed that
they proceed under mild conditions in virtually quanti-
tative yields and allow one to develop a convenient
–
H O
2
RSO2
ꢀ
=,>
method for the preparation of a variety of CF -contain-
CF3
3
ing enamines, which are promising reagents for the
synthesis of new biologically active heterocycles. The
stereochemistry of the compounds obtained was investi-
N
H
O
NH2
Table 2. Products in the reactions of anilines with sulfones 1a,b
"
=
Aniline
Conditions*
4
E/Z **
Yield
%)
Sulfone 1a is more reactive in this reaction than 1b,
which is probably due to the fact that the phenylsulfonyl
substituent is better leaving group than the methylsulfonyl
one. However, the reactions of amines with sulfone 1b
give higher yields because the resulting weak methyl-
sulfinic acid binds the starting amine less strongly.
The stereochemistry of the enamines obtained de-
pends on the structure of the starting amine, being
independent of the ratio of the E/Z isomers in the
(
2,4-(MeO)2Ñ6H3NH2 0 °C, 15 s
ñ
d
e
f
1/2.5
2/1
2.5/1
2.5/1
4/1
95
95
97
96
90
4
-EtOÑ H NH
0 °C, 15 s
6
4
2
4
-MeÑ H NH
2
20 °C, 1 min
20 °C, 1 min
80 °C, 1 h
6
4
Ñ H NH
2
6
5
4
-NO Ñ H NH
2
g
2
6
4
* MeCN.
** DMSO-d6.

CF -containing aminovinylketones
Russ.Chem.Bull., Int.Ed., Vol. 50, No. 8, August, 2001
1397
3
Table 3. Characteristics of synthesized aminovinyl ketones 2—5
Com-
poundCalculated
Found
Molecular
formula
IR,
ν/cm
1H NMR,
δ, J/Hz
13C NMR,
δ, J/Hz
(
%)
–
1
C
H
—
2
2
à*
b*
—
—
—
—
179.0 (q, ÑÎ, J = 33.8);
1
55.7,117.1 (q, ÑF3,
J = 288.6); 88.8
178.0 (q, ÑÎ, J = 33.7);
157.9, 117.2 (q, ÑF3,
J = 288.5);
49.23
6.20
6.16
C H F NO 1590 (Ñ=Ñ);
10.26 (br.s, 1 Í, NH);
7.10 (dd, 1 Í, =Ñ͗N,
J1 = 7.0, J2 = 14.1);
8
12 3
4
9.28
1655 (Ñ=Î)
5
.32 (d, 1 Í, =Ñ͗C,
86.8, 49.6, 32.5, 19.5, 13.5
J = 7.0); 3.34 (m, 2 Í,
ÑÍ —N); 1.60 (m, 2 Í,
2
ÑÍ ); 1.40 (m, 2 H, CH );
2
2
0
.94 (m, 3 H, Me)
2
ñ*
46.83
6.93
4.45
4.50
C H F NO
1592 (Ñ=Ñ);
1653 (Ñ=Î)
10.20 (br.s, 1 Í, NH);
7.08 (dd, 1 Í, =Ñ͗N,
J1 = 7.1, J2 = 13.5);
178.5 (q, ÑÎ, J = 34.5);
157.8, 117.3 (q, ÑF3,
J = 288.5);
7
8 3
4
5
5
.85 (m, 1 Í, =ÑÍ);
.38 (d, 1 Í, =Ñ͗C,
132.7, 118.4, 87.5, 51.5
J = 7.1); 5.25 (m, 2 Í,
ÑÍ ); 3.92 (m, 2 H, CH )
=
2
2
2
2
3
d**
å*
39.30
9.35
4.41
4.40
C H F NO
2
1596 (Ñ=Ñ);
1655 (Ñ=Î)
7.18 (dd, 1 Í, =Ñ͗N,
J1 = 7.0, J2 = 13.2); 5.38
178.5 (q, ÑÎ, J = 34.6);
157.8, 117.4 (q, ÑF3,
J = 288.6);
6
8
3
3
(
d, 1 Í, =Ñ͗C, J = 7.0);
3
3
.79 (m, 2 Í, ÑÍ );
.48 (m, 2 H, CH2)
84.5, 58.7, 51.3
2
49.10
9.23
6.12
6.20
C H F NO 1590 (Ñ=Ñ);
10.65 (br.s, 1 Í, NH);
7.25 (dd, 1 Í, =Ñ͗N,
J1 = 7.1, J2 = 14.0); 5.36
177.2 (q, ÑÎ, J = 32.9);
153.6, 117.3 (q, ÑF3,
J = 288.5); 86.7, 53.6, 29.7
8
12 3
4
1655 (Ñ=Î)
(
1
d, 1 Í, =Ñ͗C, J = 7.1);
.35 (s, 9 H, 3 Me)
b*
45.80
5.94
4.79
4.82
C H F NO2 1600 (Ñ=Ñ);
7.83 (d, 1 Í, =Ñ͗N,
J = 12.5); 5.48 (d, 1 Í,
177.6 (q, ÑÎ, J = 32.1);
155.0, 117.9 (q, ÑF3,
J = 291.1);
8
10 3
4
1670 (Ñ=Î)
=
Ñ͗C, J = 12.5);
3
3
3
.67 (m, 4 Í, 2 ÑÍ —O);
87.3, 66.7, 65.5, 53.7, 46.1
2
.45 (m, 2 Í, 2 ÑÍ —N);
2
.22 (m, 2 Í, ÑÍ —N)
2
3
3
4
d**
42.10
2.29
5.21
5.32
C H F NO3 1610 (Ñ=Ñ);
7.90 (d, 1 Í, =Ñ͗N,
J = 12.3); 5.41 (d, 1 Í,
174.9 (q, ÑÎ, J = 31.1);
157.7, 117.8 (q, ÑF3,
J = 291.8);
8
12 3
4
1677 (Ñ=Î)
=
Ñ͗C, J = 12.3);
4
3
3
.59 (m, 2 Í, ÑÍ —N);
.55 (m, 8 H,
CH2 + 2 OH)
86.2, 59.1, 58.7, 57.4, 51.3
2
f*
53.69
3.80
7.11
7.22
Ñ10H16F NO 1607 (Ñ=Ñ);
7.98 (d, 1 Í, =Ñ͗N,
J = 12.4); 5.45 (d, 1 Í,
176.9 (q, ÑÎ, J = 32.1);
151.7, 117.9 (q, ÑF3,
J = 291.2);
3
5
1677 (Ñ=Î)
=
Ñ͗C, J = 12.4);
3
3
1
.98 (m, 1 Í, ÑÍ);
.69 (m, 1 Í, ÑÍ);
.27 (m, 12 H, 4 Me)
87.1, 50.4, 49.1, 23.5, 19.5
a*
52.06
2.18
3.86
3.94
Ñ10H F N O 1598 (Ñ=Ñ);
11.78 (br.s, 1 Í, NH);
7.58 (dd, 1 Í, =Ñ͗N,
J1 = 7.2, J2 = 12.9);
179.1 (q, ÑÎ, J = 32.7);
152.1 (=CH—N);
137.7, 127.2, 126.9, 120.1,
118.0, 117.7, 117.2
9
3
2
5
1660 (Ñ=Î)
7
6
5
.08 (m, 2 Í, ÑÍ arom.);
.82 (m, 2 Í, ÑÍ arom.);
.68 (d, 1 Í, =Ñ͗C,
(q, ÑF , J = 290.0); 90.1
3
J = 7.2); 3.71 (br.s,
Í, NH2)
2
(
to be continued)

1
398
Russ.Chem.Bull., Int.Ed., Vol. 50, No. 8, August, 2001
Krasovsky et al.
Table 3 (continue)
Com- Found
Molecular
formula
IR,
ν/cm
1H NMR,
δ, J/Hz
13C NMR,
δ, J/Hz
(
%)
–
1
poundCalculated
C
H
4
b*
49.96
0.01
3.21
3.26
C H F N O 1595 (Ñ=Ñ);
11.65 (br.s, 1 Í, NH);
8.45 (m, 2 Í, ÑÍ arom.);
180.1 (q, ÑÎ, J = 33.7);
149.4, 146.7, 139.7, 135.5,
124.2, 124.2, 117.0 (q, ÑF3,
J = 288.6); 91.3
9
7
3
2
5
1656 (Ñ=Î)
7
.61 (dd, 1 Í, =Ñ͗N,
J1 = 7.6, J2 = 12.9);
7
6
5
.44 (m, 1 Í, ÑÍ arom.);
.31 (m, 1 Í, ÑÍ arom.);
.71 (d, 1 Í, =Ñ͗C,
J = 7.6)
4
c**
52.29
2.37
4.36
4.39
C12H12F NO3 1598 (Ñ=Ñ);
12.05 (d, 1 Í, NH,
J = 13.7, Z); 10.55 (br.s,
1 Í, NH, E); 8.21 (br.d,
1 Í, =Ñ͗N, J = 12.0, E);
175.6 (q, ÑÎ); 175.5 (q, ÑÎ);
156.5, 155.8, 152.2, 149.8,
132.7, 132.1, 119.5, 118.4,
3
5
1607 (Ñ=Ñ);
1
1
660 (Ñ=Î);
677 (Ñ=Î)
117.2 (q, ÑF ); 117.1
3
8
.20 (dd, 1 Í, =Ñ͗N,
J1 = 7.1, J2 = 13.7, Z); 7.50
d, 1 Í, ÑÍ arom., Z);
(q, ÑF );
115.4, 115.3, 90.9, 88.1,
63.3, 14.6
3
(
7
6
6
6
6
6
.29 (d, 1 Í, ÑÍ arom., E);
.72 (d, 1 Í, ÑÍ arom., Z);
.68 (d, 1 Í, ÑÍ arom., E);
.59 (dd, 1 Í, ÑÍ arom., Z);
.53 (dd, 1 Í, ÑÍ arom., E);
.02 (d, 1 Í, =Ñ͗C,
J = 12.0, E); 5.61 (d, 1 Í,
Ñ͗C, J = 7.1, Z);
=
3
3
3
3
.93 (s, 3 Í, Me, Z);
.88 (s, 3 Í, Me, Å);
.78 (s, 3 Í, Me, Z);
.76 (s, 3 Í, Me, Å)
4
d**
55.51
5.60
4.61
4.67
C12H12F NO2 1595 (Ñ=Ñ);
11.75 (d, 1 Í, NH, J = 13.4, Z); 175.6 (q, ÑÎ); 175.5 (q, ÑÎ);
3
5
1610 (Ñ=Ñ);
10.95 (br.s, 1 Í, NH, E);
8.30 (br.d, 1 Í, =Ñ͗N,
J = 12.1, E);
156.5, 155.8, 152.2, 149.8,
132.7, 132.1, 119.5, 118.4,
1
1
660 (Ñ=Î);
675 (Ñ=Î)
117.2 (q, ÑF ); 117.1
3
8
.08 (dd, 1 Í, =Ñ͗N,
(q, ÑF ); 115.4, 115.3,
3
J1 = 7.3, J2 = 13.4, Z);
90.9, 88.1, 63.3, 14.6
7
7
6
7
5
.38 (d, 2 Í, ÑÍ arom., Z);
.22 (d, 2 Í, ÑÍ arom., E);
.94 (d, 2 Í, ÑÍ arom., Z);
.91 (d, 2 Í, ÑÍ arom., E);
.80 (d, 1 Í, =Ñ͗C,
J = 12.1, E); 5.54 (d, 1 Í,
Ñ͗C, J = 7.3, Z);
=
3
1
.97 (m, 2 Í, ÑÍ , Z and Å);
.30 (m, 3 Í, Me, Z and E)
2
4
d*
—
—
C12H12F NO2
—
7.53 (dd, 1 Í, =Ñ͗N,
J1 = 7.3, J2 = 13.2);
178.6 (q, ÑÎ, J = 36.0);
157.1, 150.2, 131.9, 118.9,
115.6, 117.0 (q, ÑF3,
3
7
6
5
.04 (d, 2 Í, ÑÍ arom.);
.88 (d, 2 Í, ÑÍ arom.);
.58 (d, 1 Í, =Ñ͗C,
J = 290.0); 89.2, 63.8, 14.7
J = 7.3); 3.99 (q, 2 Í, ÑÍ );
2
1
.39 (t, 3 Í, Me)
(
to be continued)

CF -containing aminovinylketones
Russ.Chem.Bull., Int.Ed., Vol. 50, No. 8, August, 2001
1399
3
Table 3 (continue)
Com-
poundCalculated
Found
Molecular
formula
IR,
ν/cm
1H NMR,
δ, J/Hz
13C NMR,
δ, J/Hz
(
%)
–
1
C
H
4
e*
57.51
7.64
4.34
4.40
C11H10F NO 1596 (Ñ=Ñ);
11.69 (br.d, 1 Í, NH,
J = 13.4, Z); 10.99 (br.d,
1 Í, NH, J = 14.0, E);
8.36 (dd, 1 Í, =Ñ͗N,
J1 = 12.1, J2 = 14.0,
170.1 (q, ÑÎ); 170.0 (q, ÑÎ);
150.8, 148.2, 135.6, 135.1,
133.6, 132.4, 128.8, 128.4,
3
5
1607 (Ñ=Ñ);
1
1
662 (Ñ=Î);
676 (Ñ=Î)
116.5, 115.4, 117.0 (q, ÑF );
3
116.9 (q, ÑF ); 89.9, 87.0
3
J3 = 12.1, E); 8.17 (dd,
1
Í, =Ñ͗N, J1 = 7.4,
J2 = 13.4, Z); 7.30 (m, 4 Í,
ÑÍ arom., Z and E); 5.81
(
d, 1 Í, =Ñ͗C, J = 12.1,
E); 5.57 (d, 1 Í, =Ñ͗C,
J = 7.4, Z); 2.28 (s, 3 Í,
Me, Z); 2.27 (s, 3 Í, Me, E)
11.68 (br.s, 1 Í, NH, Z);
10.98 (br.s, 1 Í, NH, E);
8.40 (d, 1 Í, =Ñ͗N,
4
f*
55.65
5.82
3.76
3.75
C H F NO
1596 (Ñ=Ñ);
1610 (Ñ=Ñ);
170.1 (q, ÑÎ); 170.0 (q, ÑÎ);
150.9, 148.6, 145.4, 145.0,
142.8, 142.6, 125.7, 125.4,
7
8 3
5
1
1
658 (Ñ=Î);
674 (Ñ=Î)
J = 12.4, E); 8.23 (dd, 1 Í,
118.1, 116.8, 117.0 (q, ÑF );
3
=
Ñ͗N, J1 = 7.6, J2 = 12.9,
116.9 (q, ÑF ); 94.9, 91.0
3
Z); 7.30 (m, 5 Í, ÑÍ arom.,
E and Z); 5.87 (d, 1 Í,=Ñ͗C,
J = 12.4, E); 5.61 (d, 1 Í,
=
Ñ͗C, J = 7.8, Z)
4
g**
46.02
6.16
2.60
2.71
C H F NO
1600 (Ñ=Ñ);
1613 (Ñ=Ñ);
11.55 (br.s, 1 Í, NH, Z);
11.55 (br.s, 1 Í, NH, E);
8.49 (d, 1 Í, =Ñ͗N,
J = 12.4, E); 8.25 (d, 2 Í,
ÑÍ arom., Z); 8.23 (m, 1 Í,
170.1 (q, ÑÎ); 170.0 (q, ÑÎ);
150.9, 148.6, 145.4, 145.0,
142.8, 142.6, 125.7, 125.4,
7
8 3
4
1
1
665 (Ñ=Î);
679 (Ñ=Î)
118.1, 116.8, 117.0 (q, ÑF );
3
116.9 (q, ÑF ); 94.9, 91.0
3
=
Ñ͗N, Z); 8.22 (d, 2 Í,
ÑÍ arom., E); 7.71 (d, 2 Í,
ÑÍ arom., Z); 7.49 (d, 2 Í,
ÑÍ arom., E); 6.02 (d, 1 Í,
=
Ñ͗C, J = 12.4, E);
5
.75 (d, 1 Í, =Ñ͗C,
J = 7.8, Z)
5
5
a**
b*
57.55
7.64
4.34
4.40
C11H10F NO 1585 (Ñ=Ñ);
8.12 (d, 1 Í, =Ñ͗N,
J = 12.4); 7.38 (m, 5 Í,
ÑÍ arom.); 5.78 (d, 1 Í,
174.7 (q, ÑÎ, J = 32.1);
152.0, 144.2, 130.2, 125.0,
119.7, 117.4 (q, ÑF3,
3
5
1655 (Ñ=Î)
=
Ñ͗C, J = 12.4);
J = 290.9); 89.3, 36.3
3
.42 (c, 3 Í, Me)
59.63
9.75
4.09
4.18
C12H10F NO 1586 (Ñ=Ñ);
8.41 (d, 1 Í, =Ñ͗N,
J = 12.5); 7.17 (m, 4 Í,
ÑÍ arom.); 5.51 (d, 1 Í,
178.0 (q, ÑÎ, J = 32.0);
144.0, 142.4, 131.9, 128.3,
126.0, 125.0, 117.5
3
5
1655 (Ñ=Î)
=
Ñ͗C, J = 12.5);
(q, ÑF , J = 290.8);
3
3
3
.92 (m, 2 Í, ÑÍ —N);
.28 (m, 2 Í, ÑÍ2 arom.)
109.0, 91.3, 48.5, 27.5
2
Note. The IR and 1H NMR spectra of compound 2a correlate with the published data.6 The spectral data for compounds 3a and 3c
are identical to those in Refs. 6 and 7, respectively.
*
*
CDCl3.
* DMSO-d6.

1
400
Russ.Chem.Bull., Int.Ed., Vol. 50, No. 8, August, 2001
Krasovsky et al.
gated to find out how the electronic structure of ring
substituents in amines and the polarity of the solvent
influence the ratio of the resulting E and Z isomers.
References
1
. V. G. Nenajdenko, A. L. Krasovsky, M. L. Lebedev, and
E. S. Balenkova, Synlett., 1997, 12, 1349.
Experimental
2. A. L. Krasovsky, V. G. Nenajdenko, and E. S. Balenkova,
Tetrahedron, 2001, 57, 201.
1H and 13C NMR were recorded on a Varian VXR-400
spectrometer (400 and 100 MHz, respectively) in CDCl3 and
3. I. I. Gerus, M. G. Gorbunova, S. I. Vdovenko, Yu. L.
Yagupol´skii, and V. P. Kukhar´, Zh. Org. Khim., 1990, 26,
1877 [J. Org. Chem. USSR, 1990, 26 (Engl. Transl.)].
4. S. V. Pazenok, I. I. Gerus, E. A. Chaika, and L. M.
Yagupol´skii, Zh. Org. Khim., 1989, 25, 379 [J. Org. Chem.
USSR, 1989, 25 (Engl. Transl.)].
5. S. I. Vdovenko, I. I. Gerus, and M. G. Gorbunova, J. Chem.
Soc., Perkin Trans. 2, 1993, 559.
6. M. Hojo, R. Masuda, and E. Okada, Tetrahedron Lett.,
1989, 30, 6173.
(
CD ) SO with Me Si as the internal standard. IR spectra were
3 2 4
recorded on a UR-20 spectrometer (Vaseline oil). TLC analysis
was carried out on Silufol UV-254 plates; the spots were
visualized with an acidified solution of KMnO4 and in iodine
vapors.
Synthesis of aminovinyl ketones 2—5 (general procedure).
The corresponding amine (2 mmol) was added at ∼20 °C to a
solution of sulfone 1a,b (1 mmol) in 5 mL of MeCN. The
reaction course was monitored by TLC. β-Aminovinyl ketones
7. A. M. Platoshkin, Yu. A. Cheburkov, and I. I. Knunyants,
Izv. Akad. Nauk SSSR, Ser. Khim., 1969, 112 [Bull. Acad.
Sci. USSR, Div. Chem. Sci., 1969, 1 (Engl. Transl.).
1
were isolated by column chromatography on silica gel. The
and 1 C NMR and IR data are given in Table 3.
H
3
This work was financially supported by the Russian
Foundation for Basic Research (Project No. 00-03-
Received February 12, 2001;
in revised form April 10, 2001
3
2760a).