Reaction of 3-aryl-2-cyanothioacrylamides with dimethyl acetylenecarboxylate, methyl propiolate, and N-phenylmaleimide

Article abstract of DOI:10.1007/s11172-006-0204-4

The reaction of cyanothioacrylamides with dimethyl acetylenedicarboxylate, methyl propiolate, and N-phenylmaleimide was studied. The reaction follows a cycloaddition pathway to give thiopyrans, irrespective of the electronic or spatial effects of the substituents in the thioamide group and in position 3 of the 1-thiabuta-1,3-diene system. The reaction is regio-and stereoselective.

Full text of DOI:10.1007/s11172-006-0204-4

2880
Russian Chemical Bulletin, International Edition, Vol. 54, No. 12, pp. 2880—2889, December, 2005
Reaction of 3ꢀarylꢀ2ꢀcyanothioacrylamides with dimethyl
acetylenecarboxylate, methyl propiolate, and Nꢀphenylmaleimide
T. G. Deryabina, M. A. Demina, N. P. Belskaya,ꢀ and V. A. Bakulev
Ural State Technical University,
19 ul. Mira, 620002 Ekaterinburg, Russian Federation.
Fax: +7 (343) 374 5483. Eꢀmail: belska@htf.ustu.ru
The reaction of cyanothioacrylamides with dimethyl acetylenedicarboxylate, methyl
propiolate, and Nꢀphenylmaleimide was studied. The reaction follows a cycloaddition pathway
to give thiopyrans, irrespective of the electronic or spatial effects of the substituents in the
thioamide group and in position 3 of the 1ꢀthiabutaꢀ1,3ꢀdiene system. The reaction is regioꢀ
and stereoselective.
Key words: cyanothioacrylamides, cycloaddition, dimethyl acetylenedicarboxylate,
methylpropiolate, Nꢀphenylmaleimide, thiopyrans.
Scheme 1
The reaction of thioamides with acetylenes has long
attracted keen attention of chemists.1—8 This is due, first
of all, to the diversity of possible reaction routes. The
structures of the reactants and the reaction conditions
have a pronounced effect on the reaction outcome. The
electronic effects of substituents, both proximate to and
remote from the thioamide fragment,1—3 and the use of
catalysts and solvents are also important factors. Some
thioamides are able to undergo [4π+2π]ꢀcycloaddition
both as dienes (due to the electronꢀdeficient C=S bond4)
and as dienophiles.5 It was shown6,7 that the thioamide
group can be incorporated in the 1ꢀthiabutaꢀ1,3ꢀdiene
fragment of a thioacrylamide and, in this case, the amide
is involved in the Diels—Alder reaction as a diene but
only after preꢀactivation by acylation. Cyanothioacrylꢀ
amides react with dimethyl acetylenedicarboxylate and
methyl propiolate to give arylꢀ4Hꢀthiopyrancarbonitriles
without preliminary acylation.8
1: R1 = NH2 (a), NHMe (b), cycloꢀC5H9NH (c), cycloꢀC6H11NH (d),
cycloꢀC7H13NH (e),
(f),
(g)
2: R2 = 4ꢀClC6H4 (a), 4ꢀMeC6H4 (b), 4ꢀMeOC6H4 (c), 2ꢀthienyl (d)
3, 4: R2 = 4ꢀClC6H4, R1 = NHMe (a), cycloꢀC5H9NH (b),
The purpose of this work was to study the effect of the
structural fragments in the thiocarbamoyl group and the
substituent in position 3 on the reactivity of cyanothioꢀ
acrylamides toward cycloaddition with acetylenes and
olefins.
cycloꢀC6H11NH (c), cycloꢀC7H13NH (d),
2 = 4ꢀMeC6H4, R1 = NHMe (f), cycloꢀC6H11NH (g);
(e);
R
R2
=
, R1 = cycloꢀC6H11NH (h),
(i);
R2 = 4ꢀMeOC6H4, R1 = NHMe (j),
The reaction of cyanoacetamides 1a—g with aromatic
aldehydes 2a—d gave 3ꢀarylꢀ2ꢀcyanoacrylamides 3a—l.
By treatment with the Lawesson´s reagent, compounds
3a—k were converted into 3ꢀarylꢀ2ꢀcyanoacrylthioamides
4a—k, containing different substituents at the nitrogen
atom of the thioamide group and in the aromatic ring
(Scheme 1, Table 1). NꢀUnsubstituted thioamide 4l was
obtained by the reaction of cyanothioacetamide with
thiopheneꢀ2ꢀcarbaldehyde (2d).
cycloꢀC6H11NH (k); R2 = 2ꢀthienyl, R1 = NH2 (l)
i. Lawesson´s reagent.
routes, which may yield either cycloaddition products, or
the products of addition at the triple bond, or cycloꢀ
condensation products.
The reactions of 2ꢀcyanothioacrylamides 4 with dienoꢀ
philes were carried out under various conditions (room
temperature or refluxing in solvents) using various solꢀ
vents (dichloromethane, benzene, toluene, xylene) and
In principle, the reaction of 2ꢀcyanoacrylthioamides 4
with alkyl acetylenedicarboxylates can proceed by several
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2784—2792, December, 2005.
1066ꢀ5285/05/5412ꢀ2880 © 2005 Springer Science+Business Media, Inc.

2ꢀCyanoꢀ3ꢀarylthioacrylamides
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 12, December, 2005 2881
Table 1. Yields, melting points, and elemental analysis data of 3ꢀarylꢀ2ꢀcyanoacrylamides 3 and 3ꢀarylꢀ2ꢀcyanothioacrylamides 4
Compound
Procedure
Yield
(%)
M.p.
/°С
Found
Calculated
Molecular
formula
(%), N
3ꢀ(4ꢀChlorophenyl)ꢀ2ꢀcyanoꢀNꢀmethylacrylamide (3a)
A
A
B
A
A
A
B
B
A
A
B
B
C
C
C
C
C
C
C
C
C
C
C
D
75
83
70
83
90
72
86
88
53
79
65
62
75
43
66
70
45
81
65
93
87
60
72
80
157—159
161—162
160—161
123—125
83—85
12.06
11.84
10.31
10.20
9.82
9.70
9.25
9.20
10.75
10.70
13.80
13.99
10.20
10.44
9.48
C11H9ClN2O
C15H15ClN2O
C16H17ClN2O
C17H17ClN2O
C14H13ClN2O
C12H12N2
3ꢀ(4ꢀChlorophenyl)ꢀ2ꢀcyanoꢀNꢀcyclopentylꢀ
acrylamide (3b)
3ꢀ(4ꢀChlorophenyl)ꢀ2ꢀcyanoꢀNꢀcyclohexylꢀ
acrylamide (3c)
3ꢀ(4ꢀChlorophenyl)ꢀ2ꢀcyanoꢀNꢀcycloheptylꢀ
acrylamide (3d)
3ꢀ(4ꢀChlorophenyl)ꢀ2ꢀ(pyrrolidinocarbonyl)acrylоꢀ
nitrile (3e)
2ꢀCyanoꢀNꢀmethylꢀ3ꢀ(pꢀtolyl)acrylamide (3f)
136—138
125—127
169—170
163—164
145—147
138—139
168—170
156—158
129—131
158—160
88—90
2ꢀCyanoꢀNꢀcyclohexylꢀ3ꢀ(pꢀtolyl)acrylamide (3g)
C17H20N2O
C17H18N2O3
C22H21N3O4
C12H12N2O2
C17H20N2O2
C10H7ClN2S
C11H9ClN2S
C15H15ClN2S
C16H17ClN2S
C17H19ClN2S
C14H13ClN2S
C12H12N2S
3ꢀBenzo[1,3]dioxolꢀ5ꢀylꢀ2ꢀcyanoꢀNꢀcyclohexylꢀ
acrylamide (3h)
3ꢀBenzo[1,3]dioxolꢀ5ꢀylꢀ2ꢀ[4ꢀ(4ꢀmethoxyphenyl)ꢀ
piperazinoꢀ1ꢀylcarbonyl]acrylonitrile (3i)
2ꢀCyanoꢀ3ꢀ(4ꢀmethoxyphenyl)ꢀNꢀmethylꢀ
acrylamide (3j)
2ꢀCyanoꢀNꢀcyclohexylꢀ3ꢀ(4ꢀmethoxyphenyl)ꢀ
acrylamide (3k)
2ꢀCyanoꢀ3ꢀthiophenꢀ2ꢀylacrylamide (3l)
9.40
10.67
10.27
12.80
12.95
9.70
9.85
12.51
12.58
12.06
11.84
10.02
9.64
9.34
9.20
8.94
8.73
9.34
9.20
12.80
12.95
9.65
9.85
8.57
8.92
10.40
10.32
12.00
12.06
9.46
9.32
14.30
14.42
3ꢀ(4ꢀChlorophenyl)ꢀ2ꢀcyanoꢀNꢀmethylthioꢀ
acrylamide (4a)
3ꢀ(4ꢀChlorophenyl)ꢀ2ꢀcyanoꢀNꢀcyclopentylꢀ
thioacrylamide (4b)
3ꢀ(4ꢀChlorophenyl)ꢀ2ꢀcyanoꢀNꢀcyclohexylꢀ
thioacrylamide (4c)
3ꢀ(4ꢀChlorophenyl)ꢀ2ꢀcyanoꢀNꢀcycloheptylꢀ
thioacrylamide (4d)
3ꢀ(4ꢀChlorophenyl)ꢀ2ꢀ(pyrrolidinocarbothioyl)ꢀ
acrylоnitrile (4e)
2ꢀCyanoꢀNꢀmethylꢀ3ꢀ(pꢀtolyl)thioacrylamide (4f)
158—160
142—144
137—138
161—163
127—129
129—131
154—156
141—142
2ꢀCyanoꢀNꢀcyclohexylꢀ3ꢀ(pꢀtolyl)thioꢀ
acrylamide (4g)
3ꢀBenzo[1,3]dioxolꢀ5ꢀylꢀ2ꢀ(cyclohexylaminoꢀ
carbothioyl)acrylonitrile (4h)
3ꢀBenzo[1,3]dioxolꢀ5ꢀylꢀ2ꢀ[4ꢀ(4ꢀmethoxyphenyl)ꢀ
piperazinoꢀ1ꢀylcarbonylthio]acrylonitrile (4i)
2ꢀCyanoꢀ3ꢀ(4ꢀmethoxyphenyl)ꢀNꢀmethylthioꢀ
acrylamide (4j)
2ꢀCyanoꢀNꢀcyclohexylꢀ3ꢀ(4ꢀmethoxyphenyl)ꢀ
thioacrylamide (4k)
C17H20N2S
C17H18N2O2S
C22H21N3O3S
C12H12N2OS
C17H20N2OS
C8H6N2S2
2ꢀCyanoꢀ3ꢀ(thiophenꢀ2ꢀyl)thioacrylamide (4l)
reactant ratios. The formation of products was detected
even at room temperature, but in this case, the process
was very slow; even after 1—3 months the reaction mixꢀ
ture still contained substantial amounts of the reactants.
The conditions of choice are refluxing in an inert solvent
(xylene, toluene, benzene) using a threeꢀ to fiveꢀfold exꢀ
cess of dienophile.
1
On the basis of the IR, mass, and H and 13C NMR
spectra (Table 2—4), and elemental analysis data (see
Table 1), it was found that the reactions of 2ꢀcyanoacrylꢀ

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Russ.Chem.Bull., Int.Ed., Vol. 54, No. 12, December, 2005
Deryabina et al.
Table 2. Yields, melting points, and mass spectrometry and elemental analysis data for 6ꢀaminoꢀ4ꢀaryl(hetaryl)ꢀ5ꢀcyanoꢀ4Hꢀthiopyrans
5—9 and hexahydrothiopyranо[2,3ꢀc]pyrrolecarbonitrile derivatives 10
Compound
Yield M.p.
(%) /°С
Found
Calculated
Molecular
formula
Mass
spectrum,
m/z (I (%))
(%)
C
H
N
Dimethyl 6ꢀaminoꢀ4ꢀ(4ꢀchlorophenyl)ꢀ5ꢀcyanoꢀ
4Hꢀthiopyranꢀ2,3ꢀdicarboxylate (5a)
Methyl 6ꢀaminoꢀ4ꢀ(4ꢀchlorophenyl)ꢀ5ꢀcyanoꢀ
4Hꢀthiopyranꢀ3ꢀcarboxylate (5b)
46 98—100 52.59 3.41 7.82 C16H13ClN2O4S
52.68 3.59 7.68
63 200—201 54.78 3.55 9.72 C14H11ClN2O2S
54.81 3.61 9.84
61 118—120 59.06 5.02 6.05 C22H23ClN2O4S
59.12 5.19 6.27
45 90—91 61.79 5.33 7.35 C20H21ClN2O2S
61.77 5.44 7.21
54 111—112 58.22 4.80 6.08 C21H21ClN2O4S
58.26 4.89 6.47
45 109—110 59.89 5.39 5.59 C23H25ClN2O4S
59.93 5.47 6.05
83 123—124 53.97 3.84 7.13 C17H15ClN2O4S
53.99 3.99 7.40
35 118—120 56.13 4.01 8.90 C15H13ClN2O2S
56.16 4.08 8.74
52 148—150 57.30 4.49 6.88 C20H19ClN2O4S
57.35 4.57 6.70
73 141—143 64.71 6.10 6.40 C23H26N2O4S
64.77 6.14 6.57
36 136—137 68.44 6.51 7.72 C21H24N2O2S
68.45 6.56 7.60
57 151—153 60.33 4.99 7.75 C18H18N2O4S
60.32 5.06 7.82
53 145—146 63.95 5.33 9.20 C16H18N2O2S
63.98 5.37 9.26
67 136—138 57.71 4.80 7.40 C18H18N2O5S
57.74 4.85 7.48
51 125—126 60.75 5.07 8.71 C16H16N2O3S
60.74 5.10 8.85
58 113—114 62.40 5.89 6.51 C23H26N2O5S
62.43 5.92 6.33
364
(12.6)
306
(25.8)
446
(17.4)
388
(44.7)
432
(23.9)
462
(13.9)
378
(12.3)
320
(25.0)
418
(18.7)
426
(12.2)
368
(35.0)
358
(11.2)
300
(32.2)
374
(5.3)
316
(56.7)
442
(42.1)
549
Dimethyl 4ꢀ(4ꢀchlorophenyl)ꢀ5ꢀcyanoꢀ6ꢀcyclohexylꢀ
aminoꢀ4Hꢀthiopyranꢀ2,3ꢀdicarboxylate (5c)
Methyl 4ꢀ(4ꢀchlorophenyl)ꢀ5ꢀcyanoꢀ6ꢀcyclohexylꢀ
aminoꢀ4Hꢀthiopyranꢀ3ꢀcarboxylate (5d)
Dimethyl 4ꢀ(4ꢀchlorophenyl)ꢀ5ꢀcyanoꢀ6ꢀcyclopentylꢀ
aminoꢀ4Hꢀthiopyranꢀ2,3ꢀdicarboxylate (5e)
Dimethyl 4ꢀ(4ꢀchlorophenyl)ꢀ5ꢀcyanoꢀ6ꢀcycloheptylꢀ
aminoꢀ4Hꢀthiopyranꢀ2,3ꢀdicarboxylate (5f)
Dimethyl 4ꢀ(4ꢀchlorophenyl)ꢀ5ꢀcyanoꢀ6ꢀmethylaminoꢀ
4Hꢀthiopyranꢀ2,3ꢀdicarboxylate (5g)
Methyl 4ꢀ(4ꢀchlorophenyl)ꢀ5ꢀcyanoꢀ6ꢀmethylaminoꢀ
4Hꢀthiopyranꢀ3ꢀcarboxylate (5h)
Dimethyl 4ꢀ(4ꢀchlorophenyl)ꢀ5ꢀcyanoꢀ6ꢀpiperazineꢀ
4Hꢀthiopyranꢀ2,3ꢀdicarboxylate (5i)
Dimethyl 5ꢀcyanoꢀ6ꢀcyclohexylaminoꢀ4ꢀ(pꢀtolyl)ꢀ
4Hꢀthiopyranꢀ2,3ꢀdicarboxylate (6a)
Methyl 5ꢀcyanoꢀ6ꢀcyclohexylaminoꢀ4ꢀ(pꢀtolyl)ꢀ
4Hꢀthiopyranꢀ3ꢀcarboxylate (6b)
Dimethyl 5ꢀcyanoꢀ6ꢀmethylaminoꢀ4ꢀ(pꢀtolyl)ꢀ
4Hꢀthiopyranꢀ2,3ꢀdicarboxylate (6c)
Methyl 5ꢀcyanoꢀ6ꢀmethylaminoꢀ4ꢀ(pꢀtolyl)ꢀ
4Hꢀthiopyranꢀ3ꢀcarboxylate (6d)
Dimethyl 4ꢀ(4ꢀmethoxyphenyl)ꢀ5ꢀcyanoꢀ6ꢀmethylaminoꢀ
4Hꢀthiopyranꢀ2,3ꢀdicarboxylate (7a)
Methyl 4ꢀ(4ꢀmethoxyphenyl)ꢀ5ꢀcyanoꢀ6ꢀmethylaminoꢀ
4Hꢀthiopyranꢀ3ꢀcarboxylate (7b)
Dimethyl 4ꢀ(4ꢀmethoxyphenyl)ꢀ5ꢀcyanoꢀ6ꢀcyclohexylꢀ
aminoꢀ4Hꢀthiopyranꢀ2,3ꢀdicarboxylate (7c)
Dimethyl 4ꢀbenzo[1,3]dioxolꢀ5ꢀylꢀ5ꢀcyanoꢀ
6ꢀ[4ꢀ(4ꢀmethoxyphenyl)piperazino]ꢀ4Hꢀthiopyranꢀ
2,3ꢀdicarboxylate (8a)
52 123—124 61.15 4.91 5.94 C28H27N3O7S
61.19 4.95 6.14
(12.3)
Dimethyl 4ꢀbenzo[1,3]dioxolꢀ5ꢀylꢀ5ꢀcyanoꢀ6ꢀcycloꢀ
hexylaminoꢀ4Hꢀthiopyranꢀ2,3ꢀdicarboxylate (8b)
Methyl 6ꢀaminoꢀ5ꢀcyanoꢀ4ꢀthiophenꢀ2ꢀylꢀ4Hꢀthiopyranꢀ
3ꢀcarboxylate (9)
4ꢀ(4ꢀChlorophenyl)ꢀ2ꢀcyclohexylaminoꢀ5,7ꢀdioxoꢀ
6ꢀphenylꢀ4,4a,5,6,7,7aꢀhexahydrothioꢀ
66 119—120 60.45 5.39 6.06 C23H24ClN2O6S
60.51 5.30 6.14
55 213—215 51.77 3.60 10.71 C12H10N2O2S2
51.78 3.62 10.84
60 229—231 65.36 5.01 8.88 C26H23ClN3O2S
65.33 5.06 8.79
456
(13.1)
278
(41.9)
477
(9.5)
pyranо[2,3ꢀc]pyrrolꢀ3ꢀcarbonitrile (10a)
4ꢀ(4ꢀMethoxyphenyl)ꢀ2ꢀmethylaminoꢀ5,7ꢀdioxoꢀ
6ꢀphenylꢀ4,4a,5,6,7,7aꢀhexahydrothioꢀ
56 167—169 65.12 4.70 10.21 C22H19N3O3S
65.17 4.72 10.36
405
(15.1)
pyranо[2,3ꢀc]pyrroleꢀ3ꢀcarbonitrile (10b)
4ꢀBenzo[1,3]dioxolꢀ5ꢀylꢀ2ꢀ[4ꢀ(4ꢀmethoxyphenyl)ꢀ
piperazinꢀ1ꢀyl]ꢀ5,7ꢀdioxoꢀ6ꢀphenylꢀ4,4a,5,6,7,7aꢀ
hexahydrothiopyranо[2,3ꢀc]pyrroleꢀ3ꢀcarbonitrile (10c)
2ꢀAminoꢀ5,7ꢀdioxoꢀ6ꢀphenylꢀ4ꢀthiophenꢀ2ꢀylꢀ
4,4a,5,6,7,7aꢀhexahydrothiopyranо[2,3ꢀc]pyrroleꢀ
3ꢀcarbonitrile (10d)
58 190—192 66.18 4.88 9.74 C27H24N3O4S
66.19 4.86 9.65
580
(2.4)
62 155—157 58.80 3.50 9.63 C18H13N3O2S2
58.84 3.57 9.95
367
(2.4)

2ꢀCyanoꢀ3ꢀarylthioacrylamides
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 12, December, 2005 2883
Table 3. Spectroscopic characteristics of 6ꢀaminoꢀ4ꢀaryl(hetaryl)ꢀ5ꢀcyanoꢀ
4Hꢀthiopyrans 5—9 and hexahydrothiopyranо[2,3ꢀc]pyrrolecarbonitrile
derivatives 10 *
Comꢀ
pound
IR spectrum, ν/cm–1
CH NН C≡N C=O
2950, 3450 2190 1720, 7.20 (s, 2 H, NH2)
1H NMR (DMSOꢀd6), δ (J/Hz)
R1
R2
C(4)H
R3, R4
5a
5b
5c
7.44, 7.27 (4 H, Ar,
AA´BB´ system,
J = 8.8)
4.71
(s)
3.66, 3.79 (both s,
3 H each, OMe)
2930 1740
2950 3450 2180 1730, 6.97 (s, 2 H, NH2)
1740
7.39, 7.24 (4 H, Ar,
AA´BB´ system,
J = 8.5)
4.59
(s)
3.64 (s, 3 H, OMe);
7.80 (s, 1 H, C(3)H)
2930, 3430 2190 1720, 1.32—1.05, 1.90—1.51 7.43, 7.27 (4 H, Ar,
4.76
(s)
3.71, 3.79 (both s,
3 H each, OMe)
2850
1740 (both m, 5 H each,
СН2, Cy); 3.79—3.58
(m, 1 H, СH, Cy); 7.29
(s, 1 H, NH)
AA´BB´ system,
J = 8.5)
5d
5e
3010, 3450 2180 1710 1.33—1.05, 1.88—1.54 7.40, 7.24 (4 H, Ar,
4.64
(s)
3.67 (s, 3 H, OMe);
7.83 (s, 1 H, C(3)H)
2930
(both m, 5 H each,
AA´BB´ system,
J = 8.5)
СН2, Cy); 3.51—3.49
(m, 1 H, СH, Cy); 6.92
(d, 1 H, NH, J = 8.3)
2860, 3450 2190 1730, 1.71—1.57 (m, 6 H,
7.30, 7.24 (4 H, Ar,
AA´BB´ system,
J = 8.5)
4.69
(s)
3.73, 3.80 (both s,
3 H each, OMe)
2960
1740 СН2, Cy); 1.92—1.88
(m, 2 H, СН2, Cy);
4.11—4.08 (m, 1 H,
СН, Cy); 7.14 (d,
1 H, NH, J = 7.3)
5f
2930, 3450 2190 1730, 0.91—0.84 (m, 3 H,
7.31, 7.23 (4 H, Ar,
AA´BB´ system,
J = 8.5)
4.68
(s)
3.72, 3.81 (both s,
3 H each, OMe)
2850
1740 СН2, Cy); 1.27—1.21
(m, 8 H, СН2, Cy);
1.53—1.1.49 (m, 1 Н,
СН2, Cy); 6.82 (d,
1 H, NH, J = 7.4)
5g
5h
5i
2950, 3450 2180 1680, 2.96 (d, 3 H, Me,
7.30, 7.22 (4 H, Ar,
AA´BB´ system,
J = 8.6)
7.28, 7.23 (4 H, Ar,
AA´BB´ system,
J = 8.9)
4.69
(s)
3.71, 3.80 (both s,
3 H each, OMe)
2930
1720 J = 4.9); 7.30 (d,
1 H, NH, J = 8.4)
2950 3450 2180 1720, 2.92 (d, 3 H, Me,
1740 J = 4.9); 6.99 (q,
4.64
(s)
3.69 (s, 3 H, OMe);
7.68 (s, 1 H, C(3)H)
1 H, NH, J = 5.3)
2940,
2920
—
2190 1720, 2.06—1.87 (m, 4 H,
7.31, 7.24 (4 H, Ar,
4.77
(s)
3.76, 3.81 (both s,
3 H each, OMe)
1740 СН2, Pyr); 3.53—3.49, AA´BB´ system,
3.73—3.66 (both m,
2 H each, СН2, Pyr)
J = 8.2)
6a
6b
2930, 3290 2190 1720, 1.25—1.80 (m, 10 H,
2.30 (s, 3 H, Me);
7.10 (s, 4 H, Ar)
4.61
(s)
3.70, 3.80 (both s,
3 H each, OMe)
2950
1750 CH2); 3.60—3.41 (m,
1 H, CH); 6.78 (d,
1 H, NH, J = 8.6);
7.61 (s, 1 H, CH)
2940, 3370 2180 1720 1.21—1.88 (m, 10 H,
2.29 (s, 3 H, Me);
7.05, 7.11 (4 H, Ar,
AA´BB´ system,
J = 8.4)
4.59
(s)
3.68 (s, 3 H, OMe);
7.61 (s, 1 H, C(3)H)
3090
CH, Cy); 3.38—3.53
(m, 1 H, CH, Cy);
6.37 (d, 1 H,
NH, J = 8.1)
(to be continued)

2884
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 12, December, 2005
Deryabina et al.
Table 3 (continued)
Comꢀ
pound
IR spectrum, ν/cm–1
CH NН C≡N C=O
2930, 3330 2190 1720, 2.95 (d, 3 H, Me,
1H NMR (DMSOꢀd6), δ (J/Hz)
R1
R2
C(4)H
R3, R4
6c
6d
7a
7b
7c
2.30 (s, 3 H, Me);
7.09 (s, 4 H, Ar)
4.62
(s)
3.69, 3.80 (both s,
3 H each, OMe)
2960
1740 J = 4.9); 7.14 (d, 1 H,
NH, J = 4.8)
2960, 3300 2190 1720 2.91 (d, 3 H, Me,
2.29 (s, 3 H, Me);
4.59
(s)
3.68 (s, 3 H, OMe);
7.63 (s, 1 H, C(3)H)
3060
J = 4.9); 7.05 (q, 1 H,
NH, J = 0.02)
7.05, 7.11 (4 H, Ar,
AA´BB´ system, J = 8.2)
3.79 (s, 3 H, OMe);
2930, 3320 2180 1730, 2.95 (d, 3 H, Me,
4.60
(s)
3.69, 3.75 (both s,
3 H each, OMe)
2960,
2990
1750 J = 4.88); 7.15 (q, 1 H, 6.83, 7.14 (4 H, Ar,
NH, J = 0.2)
AA´BB´ system, J = 8.6)
3.73 (s, 3 H, OMe);
6.78, 7.13 (4 H, Ar,
2930, 3310 2190 1720 2.92 (d, 3 H, Me,
4.58
(s)
3.68 (s, 3 H, OMe);
7.60 (s, 1 H, C(3)H)
2950,
3000
J = 4.7); 6.86 (d, 1 H,
NH, J = 4.7)
AA´BB´ system, J = 8.4)
2930, 3320 2190 1720, 1.20—1.23, 1.53—1.91 3.78 (s, 3 H, OMe);
4.64
(s)
3.69, 3.73 (both s,
3 H each, OMe)
2950,
2990
1740 (both m, 5 H each,
CH, Cy); 3.51—3.61
(m, 1 H, CH, Cy);
6.91, 7.16 (4 H, Ar,
AA´BB´ system,
J = 8.6)
7.15 (s, 1 H, NH)
8a
2850, 3400 2180 1710, 3.16—3.03 (m, 4 H,
6.02 (s, 2 H, CH2);
6.74 (dd, 1 H, CH,
Ar, J1 = 8.1,
4.80
(s)
3.68, 3.74 (both s,
3 H each, OMe)
2930
1740 CH2); 3.54—3.47,
3.71—3.64 (both m,
2 H each, CH2);
3.80 (s, 3 H, OMe);
6.84, 6.92 (4 H, Ar,
AA´BB´ system,
J2 = 1.6); 6.80
(d, 1 H, CH, Ar,
J = 1.6); 6.89 (d, 1 H,
CH, Ar, J = 8.1)
J = 9.4)
8b
2840, 3420 2180 1710, 1.33—1.07 (m, 5 H,
6.01 (s, 2 H, CH2);
6.71 (dd, 1 H,
Ar, J1 = 2.4,
4.63
(s)
3.79, 3.81 (both s,
3 H each, OMe)
2920
1740 СН2); 1.55 (d, 1 H,
СН, J = 12.0);
1.72—1.66, 1.89—1.77 J2 = 1.8); 6.88 (d,
(both m, 2 H each,
СН2); 3.59—3.52 (m,
1 H, СН); 6.76 (d,
1 H, Ar, J = 1.8); 7.30,
7.24 (4 H, Ar, AA´BB´
system, J = 8.5)
1 H, Ar, J = 8.0);
7.16 (d, 1 H,
NH, J = 8.2)
9
2950, 3240, 2200 1700 6.77 (s, 2 H, NH2)
3080 3330,
3400
6.93—6.83 (m, 2 H,
CH, Ar); 7.21 (dd,
1 H, CH, Ar,
4.93
(s)
3.73 (s, 3 H, OMe);
7.59 (s, 1 H, C(3)H)
J1 = 5.0, J2 = 1.5)
7.74, 7.51 (4 H, Ar,
AA´BB´ system,
J = 8.6)
10a
—
3440 2180 1700, 1.31—1.06 (m, 10 H,
1680 СН); 3.67—3.59 (m,
1 H, СН); 7.18 (d,
4.09
(d,
J = 3.8)
4.18 (dd, 1 H, CH,
J1 = 9.2, J2 = 3.8);
4.86 (d, 1 H, CH,
1 H, NH, J = 8.3)
J = 9.2); 7.08—7.05
(m, 2 H, Ar); 7.44 (t,
1 H, Ar, J = 7.3);
7.51 (t, 2 H, Ar, J = 7.3)
4.71 (d, 1 H, CH,
10b
2930, 3380 2180 1720, 2.90 (d, 3 H, Me);
2990 1730 7.31 (s, 1 H, NH)
3.76 (s, 3 H, OMe);
6.93, 7.31 (4 H, Ar,
AA´BB´ system,
J = 8.7)
4.22
(d,
J = 2.6)
J = 9.4); 4.26 (dd, 1 H,
CH, J1 = 9.4; J2 = 2.8);
7.21—7.26 (m, 2 H, СН,
Ar); 7.48 (t, 1 H, Ar,
J = 7.4); 7.56 (t, 1 H,
Ar, J = 6.9)
(to be continued)

2ꢀCyanoꢀ3ꢀarylthioacrylamides
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 12, December, 2005 2885
Table 3 (continued)
Comꢀ
pound
IR spectrum, ν/cm–1
CH NН C≡N C=O
1H NMR (DMSOꢀd6), δ (J/Hz)
R1
R2
C(4)H
R3, R4
10c
—
—
2180 1720, 3.11—3.00 (m, 4 H,
1680 СН2); 3.54—3.50 (m,
2 H, СН2); 3.69 (s,
3 H, OMe);
6.02 (s, 2 H, CH2);
6.91 (d, 1 H, Ar, J = 8.8);
7.07 (dd, 1 H, Ar,
J1 = 8.8, J2 = 1.6);
7.20 (d, 1 H, Ar, J = 1.6)
4.13
(d,
J = 3.9)
4.93 (d, 1 H, CH,
J = 8.7); 4.23 (dd, 1 H,
CH, J1 = 8.7, J2 = 3.9);
7.11—7.15 (m, 2 H, СН,
Ar); 7.44 (t, 1 H,
Ar, J = 4.9); 7.51 (t, 1 H,
Ar, J = 7.2)
3.77—3.73 (m, 2 H,
СН2); 6.93, 6.83
(4 H, Ar,
AA´BB´ system,
J = 9.2)
10d
2920 3410 2190 1720, 7.08 (s, 2 H, NH2)
1730
6.97 (dd, 1 H, Ar,
J1 = 5.1, J2 = 3.4);
7.04 (d, 1 H, CH, Ar,
J = 3.4);
4.44
(d,
J = 5.5)
3.91 (dd, 1 H, CH,
J1 = 9.9, J2 = 5.5);
5.03 (d, 1 H, CH, J = 9);
6.83 (d, 2 H, CH,
7.39—7.42
Ar, J1 = 7.3);
(m, 1 H, Ar)
7.46—7.38 (m, 3 H, Ar)
* The following designations are used: Cy is cycloalkyl, Pyr pyrrolidino.
Table 4. Spectroscopic characteristics of 3ꢀarylꢀ2ꢀcyanothioacrylamides 4
Comꢀ Mass spectrum,
1H NMR (DMSOꢀd6), δ (J/Hz)
pound
m/z (I (%))
CH (s)
R1
R2
4a
4b
4c
236 (85.3)
290 (100.0)
304 (100.0)
7.97 3.11 (d, 3 H, Me, J1 = 4.6);
7.65, 7.93 (4 H, Ar, AA´BB´ system,
J = 8.6)
7.53, 7.92 (4 H, Ar, AA´BB´ system,
J = 8.6)
7.65, 7.93 (4 H, Ar,
AA´BB´ system,
J = 8.6)
10.58 (d, 1 H, NH, J = 4.6)
8.06 1.52—1.96 (m, 8 H, CH); 4.10—4.20 (m,
1 H, CH); 10.31—10.45 (m, 1 H, NH)
7.52 1.10—1.44 (m, 5 H, CH); 1.59—1.66 (m, 1 H,
CH); 1.73—1.80, 1.94—2.01 (both m, 2 H each,
CH); 4.17—4.27 (m, 1 H, CH);
10.37—10.42 (m, 1 H, NH)
4d
320 (84.2)
7.89 0.87—0.92 (m, 3 H, CH); 1.18—1.32 (m, 9 H, CH);
1.63—1.69 (m, 2 H, CH); 3.57—3.66 (m, 1 H, CH);
10.22—10.29 (m, 1 H, NH)
7.53, 7.90 (4 H, Ar,
AA´BB´ system,
J = 8.6)
4e
4f
276 (100.0)
216 (100.0)
284 (49.7)
314 (87.8)
7.60 1.82—2.07 (m, 4 H, CH); 3.07—3.46, 3.74—3.90
(both m, 2 H each, CH)
8.04 3.14 (d, 3 H, Me, J = 4.6);
7.49, 7.88 (4 H, Ar, AA´BB´ system,
J = 8.6)
2.41 (s, 3 H, Me); 7.32, 7.83 (4 H, Ar,
AA´BB´ system, J = 8.6)
2.41 (s, 3 H, Me); 7.31, 7.82 (4 H, Ar,
AA´BB´ system, J = 8.6)
6.14 (s, 2 H, CH2); 7.20 (d, 1 H, CH,
Ar, J = 8.6); 7.52 (dd, 1 H, CH, Ar,
J1 = 8.8, J2 = 1.4); 7.66 (d, 1 H,
CH, Ar, J = 1.6)
10.08—10.22 (m, 1 H, NH)
4g
4h
8.02 1.13—1.45, 1.58—1.89 (both m, 5 H each, CH);
3.61—3.78 (m, 1 H, CH); 7.71—7.78 (m, 1 H, NH)
7.51 1.10—1.48 (m, 5 H, CH); 1.54—1.62 (m, 1 H, CH);
1.64—1.80, 1.89—2.02 (both m, 2 H each, CH);
4.15—4.25 (m, 1 H, CH);
10.16 (d, 1 H, NH, J = 7.5)
4i
314 (56.2)
7.46 3.14—3.26 (m, 4 H, CH); 4.00—4.09, 4.29—4.37
(both m, 2 H each, CH); 3.69 (s, 3 H, OMe);
6.95, 6.52 (4 H, Ar, AA´BB´ system, J = 9.2)
8.07 3.14 (d, 3 H, Me, J1 = 4.6);
9.99—10.08 (m, 1 H, NH)
7.74 1.08—1.44 (m, 5 H, CH); 1.56—1.66 (m, 1 H, CH);
1.68—1.81, 1.90—2.01 (both m, 2 H each, CH);
6.16 (s, 2 H, CH2); 7.11 (d, 1 H, CH, Ar,
J = 8.7); 7.43 (dd, 1 H, CH, Ar, J1 = 8.7,
J2 = 1.7); 7.56 (d, 1 H, CH, Ar, J = 1.7)
3.87 (s, 3 H, OMe); 7.05, 7.94 (4 H,
Ar, AA´BB´ system, J = 8.6)
3.86 (s, 3 H, OMe); 7.13, 7.95
(4 H, Ar, AA´BB´ system,
4j
232 (100.0)
300 (52.3)
4k
4.18—4.30 (m, 1 H, CH); 10.20 (d, 1 H, NH, J = 7.5) J = 9.2)
8.41 9.18, 9.79 (both s, 1 H each, NH) 7.26 (dd, 1 H, CH, Ar, J1 = 5.0,
4l
194 (100.0)
J2 = 3.6); 7.85 (d, 1 H, CH, Ar,
J = 3.6); 7.99 (d, 1 H, CH, Ar, J = 5.0)

2886
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 12, December, 2005
Deryabina et al.
thioamides 4 with alkyl acetylenecarboxylates yield only
cycloaddition products 5—9. No cyclocondensation prodꢀ
ucts are formed (Scheme 2).
R4 = H) due to the methoxycarbonyl groups in positions 2
and 3 of the thiopyran ring. The singlet for the C(4)
proton shifts upfield compared to that for the starting
compounds, in particular, to δ 4.58—4.93. This is due to
the change in the hybridization of the carbon atom
from sp2 in cyanothioacrylamides 4 to sp3 in 4Hꢀthioꢀ
pyrans 5—9. In addition, the spectra contain signals for
the aromatic protons and aminoꢀgroup protons. The
13C NMR spectrum fully confirms the formation of the
4Hꢀthiopyran structure (Table 5).
Scheme 2
The IR spectra of compounds 5—9 exhibit an abꢀ
sorption band at 3290—3450 cm–1 corresponding to
the NH stretching vibrations, an absorption band at
2180—2200 cm–1 due to the CN vibrations, and strong
bands at 1710—1730 cm–1, typical of C=O bonds of
methoxycarbonyl groups.
Analysis of the mass spectra of thiopyrans 5a—i and 8b
(Scheme 3, see Table 5) revealed the following major
routes of fragmentation upon electron impact: abstracꢀ
tion of the substituent R2 (Φ2) and R4 (Φ3), ejection of
the isothiocyanate molecule (Φ4), and elimination of sulꢀ
fur from the ring to give fragments related to other types
of destruction of the thiopyran ring.
It is noteworthy that the 1H NMR spectrum of methyl
6ꢀaminoꢀ5ꢀcyanoꢀ4Hꢀthiopyranꢀ3ꢀcarboxylates (R4 = H;
compounds 5a,d,h, 6b,d, 7b, 9), resulting from the reacꢀ
tion of thioacrylamides 4 with an unsymmetrical dienoꢀ
phile, methyl propiolate, displays only one set of signals
for all protonꢀcontaining groups, the signals for the
thiopyran ring protons being represented by two separate
singlets. This indicates that the process is highly selective
and gives, of the two possible regiosomers 11 and 12, only
the former one.
5: R2 = 4ꢀClC6H4, R3 = MeOOC, R1 = NH2, R4 = MeOOC (a), H (b);
R
R
R
1 = cycloꢀC6H11NH, R4 = MeOOC (c), H (d);
1 = cycloꢀC5H9NH, R4 = MeOOC (e); R1 = cycloꢀC7H13NH,
4 = MeOOC (f); R1 = NHMe, R4 = MeOOC (g), H (h);
R1
=
, R4 = MeOOC (i)
6: R2 = 4ꢀMeC6H4, R3 = MeOOC, R1 = cycloꢀC6H11NH,
R
4 = MeOOC (a), H (b); R1 = NHMe, R4 = MeOOC (c), H (d)
7: R2 = 4ꢀMeOC6H4, R3 = MeOOC, R1 = NHMe, R4 = MeOOC (a),
H (b); R1 = cycloꢀC6H11NH, R4 = MeOOC (c)
8: R2
=
, R3 = MeOOC, R1
=
,
R4 = MeOOC (a); R1 = cycloꢀC6H11NH, R4 = MeOOC (b)
9: R2 = 2ꢀthienyl, R3 = MeOOC, R1 = NH2, R4 = H
10: R2 = 4ꢀClC6H4, R1 = cycloꢀC6H11NH (a);
R
2 = 4ꢀMeOC6H4, R1 = NHMe (b);
R2
=
, R1
=
(c);
R
2 = 2ꢀthienyl, R1 = NH2 (d)
The 1H NMR spectra of compounds 5—9 (see Table 3)
exhibit two singlets (or one singlet for compounds with
Table 5. Mass spectrometry data for 6ꢀaminoꢀ4ꢀarylꢀ5ꢀcyanoꢀ4Hꢀthiopyrans 5a—i and 8b
Compound
m/z (Irel (%))
Φ
Φ
Φ
Φ
Φ
Φ
Φ
7
1
2
3
4
5
6
5a
5b
5c
5d
5е
5f
5g
5h
5i
364 (12.6)
306 (25.8)
446 (17.4)
388 (44.7)
432 (23.9)
462 (13.9)
378 (12.3)
320 (25.0)
418 (18.7)
456 (13.1)
305 (100.0)
195 (100.0)
335 (100.0)
277 (88.9)
321 (29.6)
351 (31.9)
267 (41.2)
209 (100.0)
307 (20.0)
335 (2.9)
253 (34.9)
247 (30.8)
387 (78.5)
329 (19.0)
373 (100.0)
403 (100.0)
319 (100.0)
261 (22.1)
359 (100.0)
397 (100.0)
306 (17.6)
247 (30.8)
305 (47.1)
247 (17.2)
321 (29.6)
306 (0.0)
305 (2.6)
247 (1.4)
305 (49.3)
314 (0.0)
333 (7.2)
162 (0.0)
302 (0.0)
244 (0.0)
288 (0.0)
319 (5.9)
235 (8.1)
177 (10.8)
274 (0.0)
303 (2.1)
221 (5.1)
274 (0.0)
415 (4.4)
356 (0.0)
401 (7.5)
430 (0.0)
346 (6.6)
288 (5.2)
386 (0.0)
424 (0.0)
273 (0.0)
215 (0.0)
355 (1.9)
356 (0.0)
341 (4.1)
371 (2.6)
287 (4.8)
230 (0.0)
327 (5.0)
365 (1.2)
8b

2ꢀCyanoꢀ3ꢀarylthioacrylamides
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 12, December, 2005 2887
Scheme 3
The reaction of cyanothioacrylamides 4c,i,j,l with
phenylmaleimide was carried out under similar conditions
using a threefold excess of the dienophile. Hexahydroꢀ
thiopyranо[2,3ꢀd]pyrrolecarbonitriles 10 were formed
in 56 to 62% yields.
does not result in any substantial changes in the conforꢀ
mation of the reaction products. The characteristic sigꢀ
nals in the 13C NMR spectra correspond to the carbon
atoms in positions 2, 3, and 4 of the thiopyran fragment;
they occur at δ 44.6—47.5 and show appropriate splitting
(Table 6).
As a result of this study, we synthesized a series of new
monoꢀ and bicyclic thiopyrans. The variation of substituꢀ
ents having different electronic and steric effects in the
thiocabamoyl group and the substituent in position 3 of
the 1ꢀthiabutaꢀ1,3ꢀdiene system did not exert any subꢀ
stantial effect on the nature of the products, reaction
conditions, product yields or process duration. The presꢀ
ence of a cyano group in the α´ꢀposition of thioacrylamides
is the most important factor, resulting in cycloaddition
without additional activation by acylation or the use of
catalysts. Moreover, this structural modification of thioꢀ
acrylamides increases the regioselectivity and stereoꢀ
selectivity of the reaction.
The 1H NMR spectra of bicyclic compounds 10 differ
from the spectra of 4Hꢀthiopyrans 5—9 by the presence of
three groups of signals of coupled protons. Thus the
CH protons in the bridgehead positions of thiopyranоꢀ
pyrroles 10 are responsible for a doublet of doublets with
δ 3.91—4.26 and a doublet a δ 4.10—4.44. The couꢀ
pling constants of two pairs of protons (C(3)—C(2),
C(4)—C(3)) are substantially different, being equal to
8.7—9.9 and 2.6—5.5 Hz, respectively, which may imply
the axial positions of C(2)—C(3) protons and an equatoꢀ
rial position of the C(4) proton. The lack of additional
1
signals in the H NMR spectrum attests to the formation
of only one of four possible diastereomers and is a distincꢀ
tive feature of cyanothioacrylamides with respect to
thioacrylamides.6 For the latter compounds, the formaꢀ
tion of two diastereomeric adducts with different spatial
positions of substituents in the ring was detected in the
reaction with Nꢀphenylmaleimide. This high process
stereoselectivity can be due to additional spatial interacꢀ
tions in the transition state caused by the presence of the
cyano group,6 because variation of other structural factors
Experimental
1
H and 13C NMR spectra were recorded on a Bruker
WMꢀ250 instrument (1H, 250.13 MHz; 13C, 100.00 MHz) in a
CDCl3 solution using Me4Si as the internal standard. The reacꢀ
tions were monitored and the product purity was checked by

2888
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 12, December, 2005
Deryabina et al.
Table 6. 13C NMR data for 6ꢀaminoꢀ4ꢀaryl(hetaryl)ꢀ5ꢀcyanothiopyrans 5c,d and thiopyranоpyrrole 10a
Comꢀ
pound
δ (J/Hz)
R2
C(2)
C(3)
C(4)
C(5) C(6)
(m)
CN
cycloꢀC6H11
R4, R3
5c
154.2 (dt, J1 = 6.7,
J2 = 2.8); 132.3
(tt, J1 = 13.8,
J2 = 3.5); 128.8
(dd, J1 = 168.4,
J2 = 5.0); 128.5
(ddd, J1 = 162.0,
J2 = 7.1, J3 = 0.8)
151.9 (m); 131.8
(tt, J1 = 10.8,
J2 = 3.2);
138.6
(q,
J = 7.4)
130.0
(d,
J = 6.7) J1 = 134.7,
J2 = 3.9)
44.5
(dt,
69.3 132.7
(d,
119.7
(d,
J = 5.1)
54.1 (d,
164.8 (dq, J = 4.1);
163.1 (q, J = 3.3);
53.6, 52.0
J = 137.9);
33.1, 32.7,
24.8, 24.4,
24.3 (all t,
J = 130.3)
J = 8.2)
(both q, J1 = 149.9)
5d
130.8
(dd,
141.5
(dq,
41.7
(ddt,
70.5 131.0
(d,
120.2
(d,
53.8 (d,
163.5 (ddq,
J1 = 3.8, J2 = 3.5,
J3 = 1.9);
52.3 (q, J = 146.8);
41.7 (m)
J = 135.3);
33.1, 32.9,
24.8, 24.6,
24.4 (all t,
J = 130.3)
J1 = 182.7, J1 = 7.2, J1 = 134.3,
J2 = 5.8) J2 = 1.2) J2 = 6.7,
J3 = 3.8)
J1 = 5.9) J = 4.4)
128.7 (dd,
J1 = 166.9,
J2 = 5.4); 128.5
(ddd, J1 = 162.0,
J2 = 7.1, J3 = 0.8)
157.9, 131.8
(both m); 129.1
(dd,
J1 = 161.0;
J2 = 7.0);
128.7 (dd,
J1 = 166.0,
10a
45.8
(dd,
J1 =
47.5
(ddd,
J1 =
44.6
(d,
J = 131.4)
71.9 136.4
(dd,
118.9
(d,
53.8 (d,
174.3 (m); 173.8
(dd, J1 = 5.4,
J2 = 3.8);
J = 137.8);
33.1, 24.8,
24.6, 24.5
(all t,
J1 = 7.3, J = 4.8)
J2 = 8.0)
= 151.7) = 142.6,
J2 = 5.4) J2 = 6.3,
J3 = 2.5)
131.9 (ddd,
J1 = 162.7, J2 = 5.2,
J3 = 2.1); 131.6 (dt,
J1 = 161.1,
J = 130.3)
J2 = 5.2)
J2 = 7.7);
127.7 (d, J = 163.3);
126.6 (m)
TLC on Sorbfil UVꢀ254 plates in an ethyl—hexane (1 : 1) mixꢀ
ture. Mass spectra were run on a Varian MATT 311A instrument
with an ionizing voltage of 3 kV and an ionization energy of
70 eV. Melting points were not corrected.
Synthesis of 3ꢀaryl(hetaryl)ꢀ2ꢀcyanothioacrylamides 4 (genꢀ
eral procedure). Method C. 3ꢀAryl(hetaryl)ꢀ2ꢀcyanoacrylamide
(3.5 mmol) and the Lawesson´s reagent (0.707 g, 1.75 mmol)
were refluxed for 10 h in toluene (30 mL). Toluene was evapoꢀ
rated in vacuo. The residue was recrystallized from EtOH.
Method D. Aldehyde (6.0 mmol), 2ꢀcyanothioacetamide
(6.6 mmol), and Nꢀmethylmorpholine (0.242 g, 0.24 mmol)
were kept for 15 h in EtOH (30 mL) at room temperature. The
precipitate was filtered off.
Preparation of 6ꢀaminoꢀ4ꢀaryl(hetaryl)ꢀ5ꢀcyanothioꢀ
pyrans 5—9 and 2ꢀaminoꢀ4ꢀaryl(hetaryl)ꢀ5,7ꢀdioxoꢀ6ꢀphenylꢀ
4,4a,5,6,7,7aꢀhexahydrothiopyranо[2,3ꢀc]pyrroleꢀ3ꢀcarboꢀ
nitriles 10 (general procedure). 3ꢀAryl(hetaryl)ꢀ2ꢀcyanothioꢀ
acrylamide (0.48 mmol) and dienophile (2.4 mmol) were reꢀ
The yields and the physicochemical characteristics of the
synthesized compounds are presented in Tables 1—6.
Preparation of 3ꢀaryl(hetaryl)ꢀ2ꢀcyanoacrylamides 3 (genꢀ
eral procedure). Method A. Aldehyde (6.0 mmol), 2ꢀcyanoꢀ
acetamide (6.6 mmol), and piperidine (0.02 g, 0.24 mmol) were
refluxed for 15 h in toluene (30 mL). The reaction mixture was
cooled to room temperature. The precipitate was filtered off.
Method B. Aldehyde (6.0 mmol) and 2ꢀcyanoacetamide
(6.6 mmol) were fused together at 150 °C. The resulting material
was recrystallized from ethanol.

2ꢀCyanoꢀ3ꢀarylthioacrylamides
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 12, December, 2005 2889
fluxed for 2—5 h in mꢀxylene (10 mL). The solvent was evapoꢀ
rated in vacuo and the oily residue was recrystallized from MeOH.
3. V. S. Berseneva, Yu. Yu. Morzherin, W. Dehaen, I. Luyten,
and V. A. Bakulev, Tetrahedron, 2001, 57, 2179.
4. G. Seitz, R. Mohr, W. Overrheu, R. Allmann, and M. Nagel,
Angew. Chem., Int. Ed. Engl., 1984, 23, 890.
5. Ya. Vallee, P.ꢀY. Chavant, S. Pinet, N. PelouxꢀLeon,
R. Arnaud, and V. Barone, Phosphorus, Sulfur and Silicon,
1997, 120, 245.
This work was financially supported by the Russian
Foundation for Basic Research (Project No. 04ꢀ03ꢀ
32926a).
6. I. T. Barnish, C. W. G. Fishwick, D. R. Hill, and
C. Szantay, Jr., Tetrahedron, 1989, 45, 7879.
7. S. Bell, C. W. G. Fishwick, and J. E. Reed, Tetrahedron,
1998, 54, 3219.
8. J. Bloxham and C. P. Dell, J. Chem. Soc., Perkin Trans. 1,
1994, 989.
References
1. V. A. Bakulev, V. S. Berseneva, N. P. Belskaia, Yu. Yu.
Morzherin, A. Zaitsev, W. Dehaen, I. Luyten, and S. Toppet,
Org. Biomol. Chem., 2003, 1, 134.
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Received March 9, 2005;
in revised form January 18, 2006