Intramolecular heterocyclization of α,β-unsaturated ketone thiosemicarbazones

Article abstract of DOI:10.1134/S1070428009010205

Intramolecular heterocyclization of thiosemicarbazones derived from α,β-enones under acid activation of one nucleophilic center afforded previously unknown 2-(2-arylethenyl)-2,3-dihydro-1,3,4-thiadiazoles. The transformation involves the thiol tautomer of

Full text of DOI:10.1134/S1070428009010205

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2009, Vol. 45, No. 1, pp. 146–150. © Pleiades Publishing, Ltd., 2009.
Original Russian Text © I.N. Klochkova, A.A. Anis’kov, 2009, published in Zhurnal Organicheskoi Khimii, 2009, Vol. 45, No. 1, pp. 148–152.
Intramolecular Heterocyclization of α,β-Unsaturated
Ketone Thiosemicarbazones
I. N. Klochkova and A. A. Anis’kov
Chernyshevskii Saratov State University, ul. Astrakhanskaya 83, Saratov, 410012 Russia
e-mail: aniskovaa@mail.ru
Received February 20, 2008
Abstract—Intramolecular heterocyclization of thiosemicarbazones derived from α,β-enones under acid activa-
tion of one nucleophilic center afforded previously unknown 2-(2-arylethenyl)-2,3-dihydro-1,3,4-thiadiazoles.
The transformation involves the thiol tautomer of thiosemicarbazone without participation of the conjugated
carbon–carbon double bond.
DOI: 10.1134/S1070428009010205
Dihydro-1,3,4-thiadiazoles exhibit a broad spec-
trum of biological activity, including antimicrobial,
antiviral, and fungistatic [1]. Convenient starting com-
pounds for the synthesis of dihydro-1,3,4-thiadiazoles
are aldehyde and ketone thiosemicarbazones. How-
ever, published data on heterocyclizations of thiosemi-
carbazones are fairly scanty and are concerned mainly
with thiosemicarbazones derived from aromatic, fatty–
aromatic, and saturated acyclic carbonyl compounds
[2, 3]. We previously described the synthesis of thio-
urea derivatives of carbo- and heterocyclic carbonyl
compounds [4, 5]. Nether the use of multicenter con-
jugated substrates nor mechanistic or preparative
aspects of heterocyclization of thiosemicarbazones
were reported.
In the present work we examined intramolecular
heterocyclization of multicenter α,β-enone thiosemi-
carbazones with a view to extend preparative potential
of this reaction and obtain previously unknown dihy-
dro-1,3,4-thiadiazoles which may be promising from
the viewpoint of their antibiotic activity.
As substrates we used arylmethylidene(furfuryli-
dene)methyl ketone thiosemicarbazones IIIa–IIIh
which were prepared from the corresponding α,β-unsa-
turated ketones Ia–Ig and thiosemicarbazides IIa and
IIb (Scheme 1). Heterocyclization of thiosemicarba-
Scheme 1.
Ac
R3
R4
R2
S
N
N
R4
R3
N
NH
Ac2O, pyridine
R1
R3
H2N
R4
R2
R2
HN
+
N
S
N
N
H
H
Ac
S
O
R1
R1
Ia–Ig
IIa, IIb
R1
IIIa–IIIh
IVa–IVh
R3
R4
Ac
S
N
N
Ac
R2
R3
N
R2
N
R4
N
Ac
S
N
R1
Ac
A
B
I, R1 = 2-furyl: R2 = H, R3 = Me (a); R2R3 = (CH2)4 (b), (CH2)3 (c), (CH2)5 (d); R2R3 = (CH2)4, R1 = Ph (e), o-ClC6H4 (f),
p-MeOC6H4 (g); II, R4 = H (a), Ph (b); III, IV, R1 = 2-furyl, R2 = R4 = H, R3 = Me (a); R4 = H, R2R3 = (CH2)4 (b), (CH2)3 (c),
(CH2)5 (d); R4 = H, R2R3 = (CH2)4, R1 = Ph (e), o-ClC6H4 (f), p-MeOC6H4 (g); R1 = 2-furyl, R2 = H, R3 = Me, R4 = Ph (h).
146

INTRAMOLECULAR HETEROCYCLIZATION OF α,β-UNSATURATED
147
Scheme 2.
Ac
N
R3
R4
R3
R4
R1
S
R4
N
NH
N
NH
Pyridine
Ac2O, pyridine
–AcOH
R2
HN
R2
N
R2
N
S
SH
N
R1
R1
R3
III
C
D
Ac
Ac
Ac
R3
R3
R3
R2
R2
R2
H+
S
S
S
Ac2O
–AcOH
N
N
N
R4
R4
R4
N
N
HN
N
N
N
R1
R1
R1
Ac
E
F
IV
zones IIIa–IIIh was performed in pyridine in the
presence of acetic anhydride as acylating agent. Under
these conditions, several alternative reaction pathways
are possible: (1) cyclocondensation to give five-mem-
bered dihydro-1,3,4-thiadiazole derivatives IVa–IVh,
(2) heterocyclization involving the conjugated C=C
bond with formation of 1,3,4-thiadiazepine system
(structure A), and (3) acylation of the NH groups in III
with formation of N,N′-diacetyl derivatives like B.
therefore, alternative linear thiosemicarbazone struc-
ture B may be ruled out.
A probable reaction mechanism is illustrated by
Scheme 2. It involves tautomeric transformation of the
thionic form of thiosemicarbazone III into thiol C
which undergoes acylation at the primary amino group
to give intermediate D having activated nucleophilic
sulfur center and two electrophilic centers: C=N car-
bon atom and β-carbon atom at the conjugated double
bond. Attack by the sulfur atom on the C=N carbon
atom gives structure E which is stabilized by addition
of proton, and the subsequent acylation yields final di-
hydrothiazole IV.
Analysis of the spectral parameters of the isolated
products showed that they have the structure of
2-(2-arylethenyl)-2,3-dihydro-1,3,4-thiadiazoles IVa–
IVh. The reaction involves regioselective intramolec-
ular attack by the nucleophilic sulfur atom on the car-
bon atom in the azomethine fragment, while the double
C=C bond remains intact. Compounds IVa–IVh were
formed in up to 82% yield. The IR spectra of thiadi-
azoles IVa–IVh contained absorption bands in the
region 1610–1600 cm–1 due to stretching vibrations of
the double C=C bond conjugated with the aromatic
ring. Analogous absorption band is present in the spec-
To conclude, we were the first to effect heterocy-
clization of α,β-unsaturated ketone thiosemicarba-
zones. The cyclization is regioselective, and the prod-
ucts are substituted dihydro-1,3,4-thiadiazole deriva-
tives (including those spiro-fused to a carbocycle)
having unsaturated substituents.
EXPERIMENTAL
1
tra of the initial ketones. In the H NMR spectra of
1
The H and 13C NMR spectra were recorded from
thiadiazoles IVa–IVh we observed singlets at δ 5.75–
5.79 ppm from the vinylic protons (compound IVa dis-
played two doublets from the vinylic protons at δ 6.18
and 6.24 ppm, J = 6.55 Hz), which excludes formation
of seven-membered heterocyclic system A. In the 13C
NMR spectra of IVa–IVh, the C2 atom in the thiadi-
azole ring resonated at δC 60.0–85.5 ppm, signals from
the acetyl carbonyl carbon atoms were located at
δC 168.1–170.4 ppm, the C5 signal appeared at
δC 135.8–142.1 ppm, and double-bonded carbon atoms
in the substituent on C2 had chemical shifts in the δC
ranges 112.0–113.1 and 150.1–153 ppm. The 13C NMR
spectra of IVa–IVh lacked downfield signal at about
δC 190 ppm, which is typical of thiocarbonyl group;
solutions in DMSO-d6 on a Bruker MSL-400 spec-
trometer (400 and 100 MHz, respectively); the chem-
ical shifts were measured relative to tetramethylsilane
as internal reference. The IR spectra were recorded in
KBr on a Specord M-80 instrument. The progress of
reactions and the purity of products were monitored
by TLC on Silufol UV-254 plates using hexane–ethyl
acetate–chloroform (2:2:1) as eluent; spots were visu-
alized by treatment with iodine vapor.
Thiosemicarbazones IIIa–IIIh (general proce-
dure). A solution of 0.05 mol of the corresponding
ketone and 0.06 mol of thiosemicarbazide in 60 ml of
isopropyl alcohol was heated for 4 h under reflux.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 1 2009

KLOCHKOVA, ANIS’KOV
148
When the reaction was complete (TLC), the mixture
was cooled to room temperature and kept for 30 min,
and the precipitate was filtered off, washed with iso-
propyl alcohol, and recrystallized from the same
solvent.
H 6.74; N 15.95. C13H17N3OS. Calculated, %: C 59.29;
H 6.51; N 15.96.
2-Benzylidenecyclohexan-1-one thiosemicarba-
zone (IIIe). Yield 65%, mp 154–156°C. IR spectrum,
ν, cm–1: 3250, 3145 (NH2); 3210 (NH); 3180–3050
(=C–H); 3090–3010 (C–Harom); 2935–2870 (CH2);
4-(2-Furyl)but-3-en-2-one thiosemicarbazone
(IIIa). Yield 87%, mp 143–145°C. IR spectrum, ν,
cm–1: 3362, 3340 (NH2), 3220 (NH), 3150–3100
(=CH), 3180–3140 (C–H, Fu), 2980–2860 (CH3), 1605
(C=C), 1200 (C=S). 1H NMR spectrum, δ, ppm: 1.89 s
(1H, NH), 2.12 s (3H, CH3), 6.19 d (1H, 3-H, J =
6.55 Hz), 6.74 d (4-H, J = 6.55 Hz), 6.79–6.83 m (2H,
3′-H, 4′-H), 7.29 s (1H, 5′-H), 10.53 s (2H, NH2).
Found, %: C 51.55; H 5.28; N 20.35. C9H11N3OS. Cal-
culated, %: C 51.65; H 5.30; N 20.08.
1
1691 (C=C), 1205 (C=S). H NMR spectrum, δ, ppm:
1.67 s (1H, NH), 2.32–2.52 m (8H, CH2), 6.21 s (1H,
=CH), 7.03–7.49 m (5H, Harom), 10.06 s (2H, NH2).
13C NMR spectrum, δC, ppm: 22.3, 22.7, 23.3, 40.5
(CH2); 127.8 (=CH); 121.2, 123.5, 123.7, 123.9, 124.5,
125.1 (Carom); 149.5 (=C); 153.5 (C=N); 183.1 (C=S).
Found, %: C 64.51; H 6.64; N 16.52. C14H17N3S. Cal-
culated, %: C 64.83; H 6.61; N 16.20.
2-(2-Chlorobenzylidene)cyclohexan-1-one thio-
semicarbazone (IIIf). Yield 69%, mp 158–159°C. IR
spectrum, ν, cm–1: 3310, 3150 (NH2); 3215 (NH);
3070–3045 (=C–H); 3095–3005 (C–Harom); 2940–2825
(CH2); 1690 (C=C); 1195 (C=S). 1H NMR spectrum, δ,
ppm: 1.69 s (1H, NH), 2.31–2.55 m (8H, CH2), 6.15 s
(1H, =CH), 7.12–7.51 m (4H, Harom), 10.16 s (2H,
NH2). 13C NMR spectrum, δC, ppm: 25.1, 27.7,
28.3, 39.6 (CH2); 127.5 (=CH); 121.1, 122.9, 123.1,
123.8, 124.8, 135.2 (Carom); 147.5 (=C); 154.1 (C=N);
185.8 (C=S). Found, %: C 57.61; H 5.61; N 14.52.
C14H16ClN3OS. Calculated, %: C 57.23; H 5.49;
N 14.30.
2-Furfurylidenecyclohexan-1-one thiosemicarba-
zone (IIIb). Yield 75%, mp 173–175°C. IR spectrum,
ν, cm–1: 3330, 3150 (NH2); 3400 (NH); 3100–3100
(=C–H); 3170–3150 (C–H, Fu); 2940–2860 (CH2);
1
1600 (C=C); 1200 (C=S). H NMR spectrum, δ, ppm:
1.55 s (1H, NH), 2.12–2.42 m (8H, CH2), 6.18 s (1H,
=CH), 6.79–6.86 m (2H, 3′-H, 4′-H), 7.31 s (1H, 5′-H),
9.56 s (2H, NH2). 13C NMR spectrum, δC, ppm: 22.7,
22.9, 23.1, 41.1 (CH2); 129.5 (=CH); 128.0 (C4′); 134.4
(C3′); 142.8 (C2′); 148.4 (C5′); 142.8 (=C); 154.8 (C=N);
184.5 (C=S). Found, %: C 57.57; H 6.23; N 19.97.
C12H15N3OS. Calculated, %: C 57.81; H 6.06; N 19.85.
2-Furfurylidenecyclopentan-1-one thiosemicar-
bazone (IIIc). Yield 68%, mp 190–191°C. IR spec-
trum, ν, cm–1: 3200, 3110 (NH2); 3390 (NH); 3120–
3000 (=C–H); 3165–3140 (C–H, Fu); 2945–2864
(CH2); 1665 (C=C); 1193 (C=S). 1H NMR spectrum, δ,
ppm: 1.85 s (1H, NH), 2.10–2.31 m (6H, CH2), 6.33 s
(1H, =CH), 6.78–6.86 m (2H, 3′-H, 4′-H), 7.35 s (1H,
5′-H), 9.67 s (2H, NH2). 13C NMR spectrum, δC, ppm:
24.6, 25.1, 46.8 (CH2); 129.7 (=CH); 128.4 (C4′); 135.1
(C3′); 141.6 (C2′); 149.1 (C5′); 151.3 (=C); 149.5 (C=N);
181.7 (C=S). Found, %: C 57.57; H 6.23; N 19.97.
C11H13N3OS. Calculated, %: C 57.81; H 6.06; N 19.85.
2-(4-Methoxybenzylidene)cyclohexan-1-one
thiosemicarbazone (IIIg). Yield 73%, mp 161–163°C.
IR spectrum, ν, cm–1: 3321, 3148 (NH2); 3217 (NH);
3095–3053 (=C–H); 3091–3011 (C–Harom); 2960–2820
1
(CH2); 1685 (C=C); 1204 (C=S). H NMR spectrum,
δ, ppm: 1.71 s (1H, NH), 1.91–2.45 m (8H, CH2),
3.75 s (3H, CH3O), 6.21 s (1H, =CH), 6.98–7.19 m
(4H, Harom), 10.12 s (2H, NH2). 13C NMR spectrum, δC,
ppm: 25.4, 27.9, 28.4, 38.1 (CH2); 60.3 (CH3O); 121.3,
123.2, 123.4, 123.5, 124.8, 135.2 (Carom); 131.4 (=CH);
139.6 (=C); 149.1 (C=N); 183.9 (C=S). Found, %:
C 57.61; H 5.61; N 14.52. C15H19N3OS. Calculated, %:
C 57.23; H 5.49; N 14.30.
2-Furfurylidenecycloheptan-1-one thiosemicar-
bazone (IIId). Yield 55%, mp 175–177°C. IR spec-
trum, ν, cm–1: 3240, 3150 (NH2); 3350 (NH); 3100–
3012 (=C–H); 3195–3130 (C–H, Fu); 2935–2856
(CH2); 1671 (C=C); 1195 (C=S). 1H NMR spectrum, δ,
ppm: 1.75 s (1H, NH), 2.05–2.41 m (10H, CH2), 6.31 s
(1H, =CH), 6.79–6.87 m (2H, 3′-H, 4′-H), 7.41 s (1H,
5′-H), 10.17 s (2H, NH2). 13C NMR spectrum, δC, ppm:
23.2, 24.9, 25.9, 26.4, 49.1 (CH2); 129.9 (=CH); 128.3
(C4′); 136.2 (C3′); 141.1 (C2′); 148.2 (C5′); 156.4 (=C);
150.9 (C=N); 184.3 (C=S). Found, %: C 58.97;
4-(2-Furyl)but-3-en-2-one 4-phenylthiosemicar-
bazone (IIIh). Yield 51%, mp 191–193°C. IR spec-
trum, ν, cm–1: 3320 (NH), 3227 (NH), 3096–3061
(=C–H), 3090–3006 (C–Harom), 2965–2819 (CH3),
1
1693 (C=C), 1203 (C=S). H NMR spectrum, δ, ppm:
1.73 s (1H, NH), 1.31 s (3H, CH3), 6.21 d (1H, 3-H,
J
= 6.55 Hz), 6.25 d (1H, 4-H, J = 6.55 Hz), 6.71–
6.82 m (2H, 3′-H, 4′-H), 6.98–7.19 m (5H, Harom),
7.3 d (1H, 5′-H), 10.19 s (2H, NH2). Found, %:
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INTRAMOLECULAR HETEROCYCLIZATION OF α,β-UNSATURATED
149
C 63.59; H 5.15; N 14.69. C15H15N3OS. Calculated, %:
C 63.13; H 5.30; N 14.73.
mp 152–155°C. IR spectrum, ν, cm–1: 3480 (NH),
1685 (amide I), 1600 (C=N), 1490 (amide II), 3200–
1
3150 (C–H, Fu), 1630–1625 (C=C). H NMR spec-
1,3,4-Thiadiazoles IVa–IVh (general procedure).
A solution of 0.015 mol of thiosemicarbazone IIIa–
IIIh and 0.03 mol of acetic anhydride in 30 ml of
pyridine was stirred for 4 h at 50°C. The mixture was
cooled and concentrated under reduced pressure, and
the precipitate was filtered off, washed with ethanol,
and recrystallized from ethanol.
trum, δ, ppm: 1.32–2.22 m (10H, CH2), 1.75 s and
2.25 s (3H each, COCH3), 5.9 s (1H, =CH), 6.77–
6.85 m (2H, 3′-H, 4′-H), 7.3 s (1H, 5′-H), 8.9 s (1H,
NH). 13C NMR spectrum, δC, ppm: 26.8, 28.7, 28.6,
31.4, 56.2 (CH2); 84.7 (Cspiro); 38.1, 45.4 (CH3); 127.2
(=CH); 128.6 (C4′); 133.9 (C3′); 142.1 (C2′); 148.9 (C5′);
139.9 (C=N); 145.9 (CH=C); 175.9, 177.1 (C=O).
Found, %: C 58.34; N 6.01; N 12.01. C18H21N3O3S.
Calculated, %: C 58.77; N 6.09; N 12.09.
3-Acetyl-5-acetylamino-2-methyl-2-[2-(2-furyl)-
ethenyl)]-2,3-dihydro-1,3,4-thiadiazole (IVa). Yield
63%, mp 160–162°C. IR spectrum, ν, cm–1: 3150
(NH), 1690 (amide I), 1610 (C=N), 1520 (amide II),
1-Acetyl-3-acetylamino-6-benzylidene-4-thia-1,2-
diazaspiro[4.5]dec-2-ene (IVe). Yield 64%, mp 170–
171°C. IR spectrum, ν, cm–1: 3350 ( NH), 1650
(amide I), 1600 (C=N), 1500 (amide II), 3180–3140
1
3180–3140 (C–H, Fu), 1650–1625 (C=C). H NMR
spectrum, δ, ppm: 1.52 s and 2.15 s (3H each,
COCH3), 2.21 s (3H, CH3), 6.20 d (1H, 2-CH, J =
6.55 Hz), 6.63 d (1H, =CH, J = 6.55 Hz), 6.67–6.89 m
(2H, 3′-H, 4′-H), 7.32 s (1H, 5′-H ), 9.6 s (1H, NH).
Found, %: C 54.10; H 5.50; N 13.96. C13H15N3O3S.
Calculated, %: C 53.61; H 5.15; N 14.34.
1
(C–Harom), 1640–1635 (C=C). H NMR spectrum, δ,
ppm: 1.23–2.38 m (8H, CH2), 1.32 s and 1.95 s (3H
each, COCH3), 6.2 s (1H, =CH), 7.25–7.89 m (5H,
H
arom), 8.9 s (1H NH). 13C NMR spectrum, δC, ppm:
26.9, 28.6, 32.1, 57.8 (CH2); 87.3 (Cspiro); 35.2, 39.1
(CH3); 126.7 (=CH); 122.1, 123.4, 123.9, 124.1, 125.1,
126.4 (Carom); 140.5 (C=N); 143.9 (CH=C); 175.3,
177.6 (C=O). Found, %: C 62.34; H 6.16; N 12.21.
C18H21N3O2S. Calculated, %: C 62.95; H 6.16; N 12.23.
1-Acetyl-3-acetylamino-6-furfurylidene-4-thia-
1,2-diazaspiro[4.5]dec-2-ene (IVb). Yield 62%,
mp 187–190°C. IR spectrum, ν, cm–1: 3140 (NH),
1680 (amide I), 1615 (C=N), 1540 (amide II), 3180–
3140 (C–H, Fu), 1660–1630 (C=C), 740–710 (δCH).
1H NMR spectrum, δ, ppm: 1.22–2.32 m (8H, CH2),
1.92 s and 2.45 s (3H each, COCH3), 5.8 s (1H, C=C),
6.71–6.82 m (2H, 3′-H, 4′-H), 7.32 s (1H, 5′-H), 8.29 s
(1H, NH). 13C NMR spectrum, δC, ppm: 26.8, 28.7,
31.4, 56.2 (CH2); 85.1 (Cspiro); 36.3, 38.2 (COCH3);
129.5 (=CH); 128.1 (C4′); 134.5 (C3′); 141.5 (C2′);
149.1 (C5′); 142.1 (C=N); 144.1 (CH=C); 178.9,
179.8 (C=O). Found, %: C 57.35; H 5.63; N 12.60.
C16H19N3O3S. Calculated, %: C 57.69; H 5.74; N 12.60.
1-Acetyl-3-acetylamino-6-(2-chlorobenzylidene)-
4-thia-1,2-diazaspiro[4.5]dec-2-ene (IVf). Yield 51%,
mp 167–169°C. IR spectrum, ν, cm–1: 3410 (NH),
1690 (amide I), 1600 (C=N), 1500 (amide II), 3180–
1
3140 (C–Harom), 1650–1645 (C=C). H NMR spec-
trum, δ, ppm: 1.25–1.78 m (8H, CH2), 1.42 s and
1.85 s (3H each, COCH3), 6.3 s (1H, =CH), 7.15–
7.49 m (4H, Harom), 9.1 s (1H, NH). 13C NMR spec-
trum, δC, ppm: 26.8, 28.5, 32.4, 58.5 (CH2); 80.6
(Cspiro); 31.6, 35.8 (CH3); 127.1 (=CH); 122.3, 123.6,
124.1, 125.1, 125.8, 129.3 (Carom); 136.2 (C=N); 137.6
(CH=C); 174.9, 178.1 (C=O). Found, %: C 57.34;
H 5.49; N 11.21. C18H20ClN3O2S. Calculated, %:
C 57.21; H 5.33; N 11.12.
1-Acetyl-3-acetylamino-6-furfurylidene-4-thia-
1,2-diazaspiro[4.4]non-2-ene (IVc). Yield 59%,
mp 167–169°C. IR spectrum, ν, cm–1: 3390 ( NH),
1680 (amide I), 1600 (C=N), 1500 (amide II), 3180–
1
3140 (=C–H), 1664–1633 (C=C). H NMR spectrum,
δ, ppm: 1.22–1.72 m (6H, CH2), 1.52 s and 2.15 s
(3H each, COCH3), 6.1 s (1H, =CH), 6.72–6.82 m (2H,
3′-H, 4′-H), 7.29 s (1H, 5′-H ), 8.8 s (1H, NH).
13C NMR spectrum, δC, ppm: 27.9, 30.3, 59.2 (CH2);
83.2 (Cspiro); 39.3, 44.2 (COCH3); 129.1 (=CH); 128.3
(C4′); 134.9 (C3′); 141.2 (C2′); 149.7 (C5′); 141.9
(C=N); 150.6 (CH=C); 173.9, 179.1 (C=O). Found, %:
C 56.44; H 5.37; N 13.96. C15H17N3O3S. Calculated,
%: C 56.41; H 5.37; N 13.16.
1-Acetyl-3-acetylamino-6-(4-methoxybenzyli-
dene)-4-thia-1,2-diazaspiro[4.5]dec-2-ene (IVg).
Yield 56%, mp 170–172°C. IR spectrum, ν, cm–1: 3380
(NH), 1685 (amide I), 1600 (C=N), 1480 (amide II),
1
3190–3110 (C–Harom), 1650–1645 (C=C). H NMR
spectrum, δ, ppm: 1.23–2.39 m (8H, CH2), 1.42 s and
2.14 s (3H each, COCH3), 6.5 s (1H, =CH), 7.15–
7.69 m (4H, Harom), 9.2 s (1H, NH). 13C NMR spec-
trum, δC, ppm: 25.9, 29.1, 32.5, 57.9 (CH2); 86.3
(Cspiro); 37.4, 39.6 (CH3); 60.3 (CH3O); 125.3 (=CH);
122.4, 122.7, 123.3, 123.7, 124.9, 134.2 (Carom); 135.8
1-Acetyl-3-acetylamino-6-furfurylidene-4-thia-
1,2-diazaspiro[4.6]undec-2-ene (IVd). Yield 56%,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 1 2009

KLOCHKOVA, ANIS’KOV
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REFERENCES
(C=N); 138.1 (CH=C); 174.8, 177.4 (C=O). Found, %:
C 61.34; H 6.31; N 11.21. C19H23N3O4S. Calculated,
%: C 61.10; H 6.21; N 11.25.
1. Martins Alho, M.A., Moglioni, A.G., Brousse, B., Moltra-
sio, G.Y., and D’Accorso, N.B., Arkivoc, 2000, part (iv),
p. 627.
3-Acetyl-5-[acetyl(phenyl)amino]-2-[2-(2-furyl)-
ethenyl]-2-methyl-2,3-dihydro-1,3,4-thiadiazole
(IVh). Yield 49%, mp 160–162°C. IR spectrum, ν,
cm–1: 3380 (NH), 1685 (amide I), 1600 (C=N), 1480
(amide II), 3190–3110 (C–Harom), 1650–1645 (C=C).
1H NMR spectrum, δ, ppm: 1.71 s and 2.09 s (3H each,
COCH3), 2.07 s (3H, NCH3), 6.05 d (1H, 2-CH, J =
6.55 Hz), 6.12 d (1H, 2-CH=CH, J = 6.55 Hz), 6.75–
6.83 m (2H, 3′-H, 4′-H), 7.32 s (1H, 5′-H), 7.2–7.6 m
(5H, Harom), 9.4 s (1H NH). Found, %: C 62.27;
H 5.05; N 10.94. C19H19N3O3S. Calculated, %:
C 61.77; H 5.18; N 11.37.
2. Ueda, Y., Toyooka, F., Kazuichi, F., Kouhei, T., and
Shibuya, M., J. Org. Chem., 1980, vol. 45, p. 1476.
3. Andreae, S., Schmitz, E., and Seeboth, H., J. Prakt.
Chem., 1986, vol. 328, p. 205.
4. Sazonov, A.A., Frantsuzov, A.A., and Klochkova, I.N.,
Izv. Vyssh. Uchebn. Zaved., Ser. Khim. Khim. Tekhnol.,
2005, vol. 48, p. 127.
5. Klochkova, I.N., Sazonov, A.A., Anis’kov, A.A., Voro-
nov, I.I., and Frantsuzov, A.A., Izv. Saratov. Univ., Ser.
Khim. Biol. Ekol., 2006, no. 6, p. 35.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 1 2009