Synthesis of novel thiazolidin-4-ones by reaction of malonthioamide derivatives with dimethyl acetylenedicarboxylate

Article abstract of DOI:10.1039/a803543a

Novel 2,5-dimethylenethiazolidin-4-one derivatives have been prepared by reaction of malonthioamide derivatives with dimethyl acetylenedicarboxylate. These compounds exist as separate (E,Z)- and (Z,Z)-isomers or as a mixture. The (E,Z)-isomer is formed as the initial product which transforms to the (Z,Z)-isomer under mild conditions. The structures of the obtained compounds have been confirmed by IR and NMR spectroscopy.

Full text of DOI:10.1039/a803543a

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Synthesis of novel thiazolidin-4-ones by reaction of malonthioamide
derivatives with dimethyl acetylenedicarboxylate
a
b
a
,c
Vera S. Berseneva, Alexey V. Tkachev, Yury Yu. Morzherin, Wim Dehaen,*
c
c
,a
Ingrid Luyten, Suzanne Toppet and Vasiliy A. Bakulev*
a
Department of Technology and Organic Synthesis, Ural State Technical University, 620002,
Ekaterinburg, Russia
Novosibirsk’s Institute of Organic Chemistry, 630090, Novosibirsk, Russia
b
c
Department of Chemistry, University of Leuven, Celestijnenlaan 200F,
3
001 Leuven (Heverlee), Belgium
Novel 2,5-dimethylenethiazolidin-4-one derivatives have been prepared by reaction of malonthioamide
derivatives with dimethyl acetylenedicarboxylate. These compounds exist as separate (E,Z)- and (Z,Z)-
isomers or as a mixture. The (E,Z)-isomer is formed as the initial product which transforms to the (Z,Z)-
isomer under mild conditions. The structures of the obtained compounds have been confirmed by IR and
NMR spectroscopy.
Introduction
MeO2C
H
CO2Me
CO2Me
Reactions of acetylene derivatives with compounds containing
a thiocarbamoyl group are known to follow various routes to
O
S
+
S
1–7
6–9
10
R
NH
form thiazole, thiazine
and pyridine rings, as well as
NH2
7
vinylmercapto heterocycles. The outcome of the reaction has
been shown to depend on both the structure of the thioamide
H
R
4,6,7,9
and the nature of the acetylene component.
Despite the
1
a–h
2a–h
fact that the condensation of thioureas with dimethyl acetyl-
enedicarboxylate (DMAD) is known to be a convenient
method to prepare 2-imino-5-methoxycarbonylthiazolidin-4-
Me
MeO
1–3,5,11,12
ones,
the malonthioamide derivatives, which are the
a R = CO Et
d R = CONH
e R = CONH
f R = CONH
g R = CO
h R = CO
2
carbon analogs of thioureas, have not been subjected to this
reaction yet.
Thus, as a means to prepare novel 2,5-dimethylenethiazol-
idin-4-one derivatives, we have studied the cyclizations of
malonthioamide derivatives with DMAD.
Cl
b R = CONMe2
c R = CN
N
N
Cl
O
Results and discussion
Scheme 1
Both the acetylene and thioamide compounds possess a
number of possible electrophilic and nucleophilic centers and
one could expect the potential formation of at least six five-
membered and six six-membered heterocycles along with a
number of macrocycles and polymers.
7
MeO C
2
6
H
7
CO2Me
S 1 5
2
O
S 1
2
6
4
5
4
The reaction of 2-(ethoxycarbonyl)thioacetamide 1a with
3
NH
R
8
3
dimethyl acetylenedicarboxylate affords only one product
N
H
O
H
1
13
(
Scheme 1), which was identified by IR, H and C NMR spec-
8
H
R
troscopy as the thiazolidine 2a.
1
13
2
3
On the basis of the H and C NMR data, shown in Tables 1
and 2, the correct structure could be assigned to compounds 2.
Structures having an exocyclic sulfur can be excluded because
To determine which of the signals could be associated either
with H6 or H8 we prepared the model compounds 5a,b via the
reaction of DMAD with hydrazono acyl thioacetamides 4a,b
(Scheme 2) and examined their H NMR spectra. In the thiazo-
lidines 5a,b, the methylene group at C2 is absent, allowing us to
13
of the absence of signals in the C NMR spectrum at 170–190
ppm which are typical for the thiocarbonyl and thiolactone
carbon. The thiazinone structure 3 could be rejected on the
1
2
3
basis of the J
and J
coupling constants. This method
C–H
C–H
was successfully employed to determine the structures of com-
pounds obtained in the reaction of thioureas with acetylene
assign the methylene proton at C6 more easily.
The hydrazones 4 were obtained by a diazo coupling reaction
of the corresponding thioacetamides with a 4-methylphenyl-
diazonium salt. The treatment of thioamides 4a,b with DMAD
11
derivatives. The signal for C7 in the spectra of 2a appears as a
3
doublet of quartets and exhibits a J
coupling of 4.2 Hz with
C–H
1
the protons of the methyl ester group and a small C–H coupling
in absolute alcohol then afforded thiazolidines 5a,b. The H
2
of 1.1 Hz. The magnitude of the latter corresponds to a J
NMR spectra of these compounds contain a singlet corres-
ponding to the H6 methine proton at 6.73 ppm. This allows us,
by analogy, to assign the signal at 5.7 ppm in the spectra of
compound 2a to H8.
C7–H6
coupling constant (over two bonds) and is in agreement with
the presence of an exocyclic double bond, which corresponds to
the thiazolidine structure 2a.
J. Chem. Soc., Perkin Trans. 1, 1998
2133

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1
Table 1 H NMR Chemical shifts (δ/ppm) of 2a–h and 2aЈ–hЈ
1
Compound
Solvent
H Chemical shifts
2
2
2
2
2
2
2
a
aЈ
b
bЈ
c
cЈ
d
CDCl3
CDCl3
10.8 (1H, s, NH), 6.89 (1H, s, H6), 5.35 (1H, s, H8), 4.22 (2H, q, OCH ), 3.86 (3H, s, OMe), 1.30 (3H, t, CH )
2 3
9.2 (1H, br s, NH), 6.82 (1H, s, H6), 5.75 (1H, s, H8), 4.25 (2H, q, OCH ), 3.86 (3H, s, OMe), 1.31 (3H, t, CH )
2
3
CDCl
11.92 (1H, s, NH), 6.85 (1H, s, H6), 5.61 (1H, s, H8), 3.85 (3H, s, OMe), 3.09 (3H, s, NCH ), 3.02 (3H, s, NCH )
3 3
3
2
[ H ]DMSO
12.2 (1H, br s, NH), 6.52 (1H, s, H6), 6.18 (1H, s, H8), 3.77 (3H, s, OMe), 3.01 (3H, s, CH ), 2.90 (3H, s, NCH )
6
3
3
2
[ H ]DMSO
13.8–11.2 (1H, br s, NH), 6.66 (1H, s, H6), 5.43 (1H, s, H8), 3.78 (3H, s, OMe)
13.8–11.2 (1H, br s, NH), 6.72 (1H, s, H6), 5.38 (1H, s, H8), 3.80 (3H, s, OMe)
6
2
[ H ]DMSO
6
2
[ H ]DMSO
12.39 (1H, s, NH), 9.47 (1H, s, NH), 8.0–8.2 (1H, m, ArH), 8.0–7.2 (3H, m, 3 ArH), 6.56 (1H, s, H6), 6.20 (1H,
s, H8), 3.77 (3H, s, OCH ), 2.22 (3H, s, ArCH )
6
3
3
2
2
2
2
2
2
2
e
[ H ]DMSO
11.63 (1H, s, NH), 10.10 (1H, s, NH), 7.56 (2H, d, ArH), 7.37 (1H, t, ArH), 6.71 (1H, s, H6), 5.83 (1H, s, H8),
.79 (3H, s, OCH3)
12.41 (1H, s, NH), 10.06 (1H, s, NH), 7.55 (2H, d, ArH), 7.35 (1H, t, ArH), 6.55 (1H, s, H6), 6.14 (1H, s, H8),
.76 (3H, s, OCH3)
6
3
2
eЈ
f
[ H ]DMSO
6
3
2
[ H ]DMSO
11.73 (1H, s, NH), 9.41 (1H, s, NH), 7.12–6.89 (4H, m, ArH), 6.91 (1H, s, H6), 6.08 (1H, s, H8), 3.84 (3H, s,
OCH ), 3.77 (3H, s, OCH )
6
3
3
2
fЈ
g
[ H ]DMSO
12.42 (1H, s, NH), 9.52 (1H, s, NH), 8.01 (1H, d, ArH), 7.08–7.03 (3H, m, ArH), 6.93–6.89 (1H, m, ArH), 6.54
1H, s, C H), 6.38 (1H, s, H8), 3.84 (3H, s, OCH ), 3.77 (3H, s, OCH )
6
(
6
3
3
CDCl3
11.9 (1H, s, NH), 6.85 (1H, s, H6), 5.65 (1H, s, H8), 3.85 (3H, s, OMe), 3.60 (3H, br s, NCH ), 3.49 (3H, br s,
3
NCH ), 1.4–1.7 (6H, m, 3 CH )
3
2
gЈ
CDCl3
9.83 (1H, br s, NH), 6.74 (1H, s, H6), 5.18 (1H, s, H8), 3.83 (3H, s, OMe), 3.60 (3H, br s, NCH ), 3.49 (3H, br s,
3
NCH ), 1.4–1.7 (6H, m, 3 CH )
3
2
2
2
2
5
h
[ H ]DMSO
11.92 (1H, s, NH), 6.68 (1H, s, H6), 6.22 (1H, s, H8), 3.78 (3H, s, OCH ), 3.4–3.6 (8H, m, 4 CH )
6
3
2
2
hЈ
a
[ H ]DMSO
12.2 (1H, s, NH), 6.53 (1H, s, H6), 6.18 (1H, s, H8), 3.77 (3H, s, OCH ), 3.3–3.7 (8H, m, 4 CH )
3 2
6
2
[ H ]DMSO
7.92 (1H, d, NH), 7.31 and 7.52 (4H, AB, J 8.4, C H ), 6.73 (1H, s, H6), 3.81 (3H, s, OCH ), 2.88 (3H, s, CH ),
6
6
4
3
3
2
.35 (3H, s, CH3)
2
5
b
[ H ]DMSO
7.90 (1H, d, NH), 7.33 and 7.55 (4H, AB, J 8.4, C H ), 6.73 (1H, s, H6), 3.81 (3H, s, OCH ), 3.1–3.6 (8H, m,
6
6
4
3
4
CH ), 2.37 (3H, s, CH )
2
3
1
13
13
O
N
S
detail with H and C NMR spectroscopy. The C NMR
2 3
MeO2C
S
H
chemical shifts and coupling constants ( J
Hz) of 2a–h and 2aЈ–hЈ indicate that for both isomers
2a–h and 2aЈ–hЈ the C5᎐C6 double bond exists in the (Z)-
configuration and therefore the formation of the second isomer
of 2a–h can be associated only with rotation about the C2᎐C8
bond (Table 2). The configuration of the C2᎐C8 bond was
determined by 1D NOE experiments. In the case of the (Z,Z)-
isomer we expected that saturation of the NH-proton would
give an NOE enhancement of the H8-proton but instead we
~ 1 Hz; J
~
C4–H6
C7–H6
R
H
NH2
+
5
CO2Me
CO2Me
O
N
᎐
CH3
NH
N
R
N
᎐
᎐
O
CH3
4a,b
5a,b
performed an excitation on the H O-signal because the N-H
signal was broad and in some cases even not observed. Because
2
a R = NMe2 b R = N
O
of chemical exchange between the labile N-H proton with H O
2
Scheme 2
the transfer of saturation from H O to the N-H proton leads to
2
an NOE enhancement of the H8-proton. These experiments
have proved that the compounds 2aЈ–hЈ can be assigned the
The presence of two exocyclic double bonds in the structure
of 2a allows for several geometric configurations. Indeed the
heating of thiazolidine 2a in ethanol or DMSO leads to the
formation of the isomeric product 2aЈ (Scheme 3). This process
(
Z,Z)-isomeric form. The proton chemical shifts of the com-
pounds 2a–h and 2aЈ–hЈ are shown in Table 1.
We have also studied the conversion of 2a–h [the (E,Z)-
2
1
isomer] to 2aЈ–hЈ [the (Z,Z)-isomer] in [ H ]DMSO by
H
6
MeO2C
H
MeO2C
H
NMR spectroscopy at 298 K. The compounds 2b,e,f convert in
1
00% yield to their (Z,Z)-isomer, compound 2c in 82% and
O
H
O
compound 2h in 80%. In CDCl , 2a only converts in 10% yield
to 2aЈ. Clearly, the (E,Z)-isomers 2 are stabilized in non-polar
solvents by the formation of an intramolecular hydrogen bond.
In a polar solvent, such as [ H
S
S
3
N
O
NH
O
H
2
EtO
H
]DMSO, intermolecular hydro-
6
gen bonding with the solvent allows the formation of the (Z,Z)-
isomers, which now may be stabilized by a close S ؒ ؒ ؒ O con-
tact. This also explains the formation of the two isomers in
the case of 2c–cЈ, where the cyano function will not interact
either with the sulfur or the NH-group of the thiazolidine ring.
EtO
2
a
2a′
13
Scheme 3
proceeded in 20% conversion after 7 days when chloroform was
used as a solvent. A number of thioamides 1b–h were reacted
analogously with DMAD to afford the thiazolidine products
b–h (Scheme 1). The N,N-dimethylcarbamoyl derivative 1b
gave a mixture, from which both 2b and an isomeric compound
bЈ were isolated. Cyanothioacetamide 1c gave an inseparable
mixture of thiazolidines 2c,cЈ, whereas the other thioamides
d–h only yielded the isomer 2d–h. The formation of the second
Conclusions
2
Thus, reaction of malonthioamide derivatives with dimethyl
acetylenedicarboxylate leads to new thiazole derivatives, and
to the previously unknown 2,5-dimethylenethiazolidin-4-one
system. It is worth noting that compounds 1, in contrast to
2
1
7
6
isomers for the products 2d–h were monitored by TLC and
NMR spectroscopy; these isomers were not isolated. The
geometric configuration of 2a–h and 2aЈ–hЈ was studied in
thiocarbamoylazomethine ylide and enamino thioamides, do
not enter into the reaction with methyl propiolate, which reveals
their relatively low nucleophilicity.
2
134
J. Chem. Soc., Perkin Trans. 1, 1998

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13
a
Table 2
C NMR Chemical shifts (δ/ppm) and coupling constants for 2a–h and 2aЈ–hЈ
13
C Chemical shifts δ
C᎐O
(R )
᎐
1
3
2
2
1
1
Solvent
CDCl3
C2
C4
C5
C6
C7
C8
JC4–H6 JC7–H6 JC5–H6 JC8–H8 JC6–H6
2
2
2
2
a
150.5 (dd)
150.1 (dd)
148.4 (dd)
164.6 (dd)
165.9 (dd)
164.6 (d)
165.0 (d)
140.6 (dd)
115.8 (d) 166.6 (dq) 92.8 (d) 167.0
t)
116.4 (d) 166.1 (dq) 94.9 (d) 166.5
t)
141.2 (br d) 114.7 (d) 166.8 (dq) 91.4 (d) 165.7
qqd)
145.5 (br s) 113.0 (d) 166.0 (dq) 93.0 (d) 165.6
qqd)
5.1
5.4
5.1
5.5
1.1
1.4
1.1
1.4
1.8
1.2
170.2 173.0
166.2 173.0
163.5 172.6
161.8 171.0
(
aЈ CDCl3
142.4 (dd)
(
b
CDCl3
(
2
bЈ [ H ]DMSO 148.4 (s)
6
(
2
2
2
2
c
[ H ]DMSO 153.6
165.8 (d)
165.3 (d)
164.4 (d)
142.7 (d)
141.8 (dd)
114.5 (d) 166.1
114.5 (d) 166.0 (dq) 72.1 (d)
70.0 (d)
1.8
1.0
181.0 173.0
180.6 180.6
6
2
cЈ [ H ]DMSO 154.9 (d)
5.0
1.0
6
2
eЈ [ H ]DMSO 148.4 (s)
144.9 (br s) 113.5 (d) 166.1 (dq) 95.7 (d) 165.3
qqd)
6
(
2
2
2
2
2
fЈ [ H ]DMSO 147.2 (br s) 164.5 (d)
145.2
141.6
145.3
141.4 (dd)
112.9
113.2
113.2
166.0 (dq) 97.6
166.2 (dq) 92.2
166.0 (dq) 92.2
165.2
164.4
164.6
6
2
h
[ H ]DMSO 147.1 (br s) 164.2 (d)
5.0
5.0
5.8
6
2
hЈ [ H ]DMSO 149.6 (br s) 165.0 (d)
1.8
1.1
6
g
CDCl3
148.4 (br s) 164.6 (dd)
114.6 (d) 166.9 (dq) 91.3 (d) 164.7
m)
115.6 (d) 165.9 (dq) 93.3 (d) 165.9
m)
2.1
163.0 173.0
159.9 172.0
(
2
gЈ CDCl3
148.9 (s)
166.1 (br d) 143.3 (s)
5.8
1.4
(
a
J Values are given in Hz.
Experimental
H and C NMR spectra were recorded at 400 and 100 MHz,
respectively, on a Bruker AMX 400 with SiMe as internal ref-
(E)-2-[N-(2-Methylphenyl)carbamoylmethylene]-(Z)-5-
methoxycarbonylmethylene)thiazolidin-4-one 2d
Following the method for the preparation of 2a, compound 2d
(
1
13
4
was obtained as yellow needles, yield 66%, mp 222–225 ЊC
2
erence in either [ H ]DMSO or CDCl solutions. IR Spectra
6
3
(
from ethanol) (Found: N, 9.1; S, 10.5. Calc. for C H N O S:
15 14 2 4
were obtained on a Specord IR spectrometer as KBr pellets.
Products were analyzed by TLC on DC-Plastikfolen Kieselgel
N, 8.8; S, 10.1%).
6
0 F 254 plates. The melting points are uncorrected. The
(
E)-2-[N-(2,6-Dichlorophenyl)carbamoylmethylene]-(Z)-5-
methoxycarbonylmethylene)thiazolidin-4-one 2e
monothioamides (1a–h) were prepared by the reaction of the
corresponding nitriles with hydrogen sulfide, as reported.
(
14
Following the method for the preparation of 2a, compound 2e
was obtained as yellow crystals, yield 54%, mp 237–240 ЊC
(
E)-2-(Ethoxycarbonylmethylene)-(Z)-5-(methoxycarbonyl-
(
from ethanol) (Found: N, 7.2; S, 8.3. Calc. for
methylene)thiazolidin-4-one 2a
DMAD (0.002 mol) Was added to a solution of thioacetamide
C H Cl N O S: N, 7.5; S, 8.6%).
14
10
2
2
4
1
a (0.002 mol) in chloroform. The mixture was stirred at room
(
(
E)-2-[N-(2-Methoxyphenyl)carbamoylmethylene]-(Z)-5-
methoxycarbonylmethylene)thiazolidin-4-one 2f
temperature for 2 h. Filtration gave compound 2a as yellow
crystals, mp 175–178 ЊC (from ethanol). Yield 64% (Found: C,
Following the method for the preparation of 2a, compound 2f
was obtained as yellow crystals, yield 54%, mp 216–218 ЊC
(from ethanol) (Found: N, 8.6; S, 9.4. Calc. for C H N O S: N,
4
6.36; H, 3.98; N, 5.80; S, 12.9. Calc. for C H NO S: C, 46.70;
10 11 5
Ϫ1
H, 4.28; N, 5.40; S, 12.45%); νmax/cm 3190, 3050, 1730, 1690.
15
14
2
5
8
.4; S, 9.6%).
2
-(N,N-Dimethylcarbamoylmethylene)-5-(methoxycarbonyl-
methylene)thiazolidin-4-one 2b
(E)-2-(2-Oxo-2-piperidinoethylidene)-(Z)-5-(methoxycarbonyl-
methylene)thiazolidin-4-one 2g
DMAD (0.002 mol) Was added to a stirred solution of 1b
(
(
0.002 mol) in chloroform. After 30 min a precipitate of (Z)-2-
N,N-dimethylcarbamoylmethylene)-(Z)-5-(methoxycarbonyl-
Following the method for the preparation of 2a, compound 2g
was obtained as yellow needles, yield 74%, mp 143–145 ЊC
(from ethanol) (Found: N, 9.63; S, 11.30. Calc. for
methylene)thiazolidin-4-one 2bЈ was collected as yellow
crystals, mp 224–227 ЊC (from ethanol). Yield 17% (Found:
C, 47.26; H, 4.87; N, 10.93; S, 12.88. Calc. for C H N O S:
Ϫ1
C H N O S: N, 9.46; S, 10.81%); νmax/cm 3200, 3060, 1720,
13
16
2
4
10
12
2
4
1680.
Ϫ1
C, 46.87; H, 4.72; N, 10.93; S, 12.51%); νmax/cm 3050, 1730,
630.
Evaporation of the filtrate gave yellow needles of (E)-2-
N,N-dimethylcarbamoylmethylene)-(Z)-5-(methoxycarbonyl-
1
(
E)-2-[2-Oxo-2-(morpholin-4-yl)ethylidene]-(Z)-5-(methoxy-
carbonylmethylene)thiazolidin-4-one 2h
Following the method for the preparation of 2a, compound 2h
was obtained as yellow needles, yield 76%, mp 168–172 ЊC
(
methylene)thiazolidin-4-one 2b, mp 178–180 ЊC (from ethanol).
Yield 66% (Found: C, 47.12; H, 5.12; N, 11.10; S, 13.0. Calc. for
(
from ethanol) (Found: C, 48.57; H, 4.87; N, 9.14; S, 11.22.
Ϫ1
C H N O S: C, 46.87; H, 4.72; N, 10.93; S, 12.51%); νmax/cm
10
12
2
4
Calc. for C H N O S: C, 48.32; H, 4.73; N, 9.39; S, 10.75%);
1
2
14
2
5
3
160, 3040, 1730, 1680.
Ϫ1
νmax/cm 3160, 3020, 1720, 1690.
(
E,Z)-2-Cyanomethylene-(Z)-5-(methoxycarbonylmethylene)-
2-(N,N-Dimethylcarbamoyl)-2-(p-tolylhydrazono)thioacetamide
4a
thiazolidin-4-one 2c
Following the method for the preparation of 2a, compound 2c
was obtained as a mixture of yellow needles, yield 46%, mp
A solution of NaNO (0.0027 mol) in water (5 ml) was added
2
to an ice-cooled solution of p-toluidine (0.0027 mol) in 7%
hydrochloric acid. This diazonium salt solution was added to a
stirred solution of thioacetamide 1b (0.0027 mol) in ethanol at
2
31–233 ЊC (from ethanol) (Found: N, 13.33; S, 15.28. Calc.
for C H N O S: N, 13.45; S, 15.27%).
8
6
2
3
J. Chem. Soc., Perkin Trans. 1, 1998
2135

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5
–10 ЊC. The pH of the reaction mixture was kept at 6–7 by
financial support. W. D. also thanks the Ministerie voor
addition of solid sodium acetate. The reaction mixture was left
overnight in the refrigerator. Filtration gave the yellow aryl
hydrazone 4a, mp 218–220 ЊC (from ethanol). Yield 64%
Wetenschapsbeleid and the University of Leuven for their sup-
port. I. L. is a Postdoctoral Fellow of the FWO-Vlaanderen.
(
1
Found: N, 20.78; S, 12.53. Calc. for C H N OS: N, 21.19; S,
2.13%).
12 16 4
References
1
J. B. Hendrickson, P. Reeds and J. F. Templeton, J. Am. Chem. Soc.,
1
964, 86, 107.
2
-(Morpholin-4-ylcarbonyl)-2-(p-tolylhydrazono)thioacetamide
b
2
3
H. Nagase, Chem. Pharm. Bull., 1973, 21, 270.
4
L. I. Giannola, S. Palazzo, P. Agozzino, L. Lamatrina and
L. Caraulo, J. Chem. Soc., Perkin Trans. 1, 1978, 1428.
L. I. Giannola, G. Giammona, S. Palazzo and L. Lamatrina,
J. Chem. Soc., Perkin Trans. 1, 1984, 2707.
Following the method for the preparation of 4a, compound 4b
was obtained as yellow crystals, yield 60%, mp 223–225 ЊC
4
(
from ethanol) (Found: C, 55.27; H, 5.97; N, 18.73. Calc. for
C H N O S: C, 54.90; H, 5.88; N, 18.30%).
5 V. Ya. Causs, E. E. Liepinsh, I. Ya. Calvinish and E. Ya. Lucevic,
Khim. Geterotsikl. Soedin., 1990, 120.
14
18
4
2
6
7
S. Coen, B. Ragonnet, C. Vieillescazes and J. P. Roggero,
Heterocycles, 1985, 23, 1225.
V. S. Berseneva, N. Yu. Biryucheva and V. A. Bakulev, Khim.
Geterotsikl. Soedin., 1993, 1688.
2
-[p-Tolylhydrazono(N,N-dimethylcarbamoyl)methylene]-
methoxycarbonylmethylene-4,5-dihydrothiazol-4-one 5a
DMAD (0.0025 mol) Was added to a solution of hydrazone 4a
(
0.002 mol) in absolute ethanol. The mixture was stirred at
room temperature for 2 h. Filtration gave the compound 5a
66%) as red crystals, mp 238–240 ЊC (from ethanol) (Found: N,
8 J. W. Lown and J. C. N. Ma, Can. J. Chem., 1967, 45, 939, 953.
9 G. Giammona, M. Neri, B. Carlisi, A. Pazzo and C. La Rosa,
J. Heterocycl. Chem., 1991, 28, 325.
(
1
0 L. A. Rodinovskaya, Yu. A. Sharanin, A. M. Shestopalov, V. K.
Promonenkov, B. M. Zolotarev and V. Yu. Mortikov, Zh. Org.
Khim., 1986, 22, 223.
1 U. Vojeli, W. Von. Philipsborn, K. Nagarajan and M. D. Nair,
Helv. Chim. Acta, 1978, 61, 607.
1
4.54; S, 8.56. Calc. for C H N O S: N, 14.96; S, 8.56%).
17 18 4 4
2
-[p-Tolylhydrazono(morpholin-4-ylcarbonyl)methylene]-5-
1
(
methoxycarbonylmethylene)thiazolidin-4-one 5b
Following the method for the preparation of 5a, compound 5b
was obtained (68%) as red crystals, yield 68%, mp 223–225 ЊC
12 R. M. Achenson and J. D. Wallis, J. Chem. Soc., Perkin Trans. 1,
981, 415.
1
1
1
3 B. D’hooge and W. Dehaen, Bull. Soc. Chim. Belg., 1997, 106, 729.
4 V. A. Bakulev, E. F. Dankova, A. T. Lebeev, V. S. Mokrushin and
V. S. Petrosyan, Tetrahedron, 1989, 45, 7329.
(
from ethanol) (Found: N, 13.86; S, 8.12. Calc. for
C H N O S: N, 13.45; S, 7.70%).
19
20
4
5
Acknowledgements
The Ekaterinburg group (V. A. B.) is grateful to the Russian
Foundation for Basic Research (Grant 97.03.32941a) for
Paper 8/03543A
Received 12th May 1998
Accepted 22nd May 1998
2
136
J. Chem. Soc., Perkin Trans. 1, 1998