Reaction of 5-aryl-3-furan-2-ones and their 3-arylmethylidene derivatives with thiosemicarbazide

Full text of DOI:10.1134/S1070428012050235

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2012, Vol. 48, No. 5, pp. 750−752. © Pleiades Publishing, Ltd., 2012.
Original Russian Text © O.V. Burukhina, T.V. Anis’kova, A.Yu. Egorova, 2012, published in Zhurnal Organicheskoi Khimii, 2012, Vol. 48, No. 5, pp. 749−750.
SHORT
COMMUNICATIONS
Reaction of 5-Aryl-3Н-furan-2-ones and Their
3-Arylmethylidene Derivatives with Thiosemicarbazide
O. V. Burukhina, T. V. Anis’kova, and A. Yu. Egorova
Chernyshevskii Saratov State University, Saratov, 410012 Russia
е-mail: dioksanochka@mail.ru
Received December 30, 2011
DOI: 10.1134/S1070428012050235
The interest to 3Н-furan-2—ones and their
arylmethylidene derivatives is due to the structural
features. The presence of several electrophilic sites, the
reciprocal position of groups makes these compounds
valuable substrates for the synthesis of versatile hetero-
cyclic systems [1].
triazole structures by the reactions of 5-aryl-3Н-
furan-2-ones and their 3-arylmethylidene derivatives
with thiosemicarbazide under the conditions of basic
catalysis.
Reactions of 5-aryl-3Н-furan-2-ones Ia, Ib with
thiosemicarbazide were carried out in ethanol solution
in the presence of a catalytic quantity of triethylamine.
The goal of this study was obtaining substituted
SH
S
N
S
N
O
N
NH
NH2NHCNH2
O
O
N
N
R
H
H
R
O
O
NHNHCNH2
S
R
IIа, IIb
R
Iа, Ib
A
O
R = Tol (а), Ph (b).
1
IR and Н NMR spectra confirm the fact of hetero-
cyclization and the formatiom of products which we
have identified as 3-(5-mercapto-2Н-1,2,4-triazol-3-
yl)-1-arylpropan-1-ones IIа, IIb. IR spectra contain the
absorption bands of carbonyl group (1672–1666 cm–1),
methylene groups (818–815 cm–1), NH group (2928–2922
cm–1). In the 1Н NMR spectra of compounds IIа, IIb the
following signals were observed: triplets of methylene
groups (2.73–2.74, 3.29 ppm), singlets of protons of
NH groups (7.87– 7.89 ppm), proton signals of mercapto
groups (2.17– 2.29 ppm).
reaction conditions undergo the cyclization into triazoles
derivatives IIа, IIb. Compounds IIа, IIb exist in diverse
tautomeric forms due to the lability of proton in their
structures. The presence in the 1Н NMR spectra of proton
signals from groups SH, NH, and CH2 and the lack in the
IR spectra of the absorption band belonging to the C=S
bond prove the formation of mercaptotriazoles IIа, IIb.
Beside 3Н-furan-2-ones Ia, Ib we used as initial com-
pounds 5-aryl-3-(2-chlorophenylmethylidene)-3Н-furan-
2-ones IIIа, IIIb. The reaction was carried out under the
same conditions but at longer heating.
The attack of the NH2 group of the thiosemicarbazide
is directed to the electron-deficient carbon atom of the
furanone ring causing the ring opening with the forma-
tion of thiosemicarbazones of 4-oxoacids А, which in the
We characterized compounds obtained as 5-(2-chloro-
phenyl)-4-(2-oxo-2-arylethyl)-2,5-dihydro-1Н-pyrazole-
1-carbothioamides IVa, IVb. Their spectral characteris-
tics confirm the cyclic structure.
750

REACTION OF 5-ARYL-3Н-FURAN-2-ONES
751
Cl
Cl
S
NH2NHCNH2
Cl
O
S
O
N
O
R
O
O
R
R
NH2
NH
IIIа, IIIb
NHNHCNH2
S
IVа, IVb
B
R = Tol (а), Ph (b).
IR spectra of compounds IVa, IVb contain absorption
bands of the bond C=S (1282–1262 cm–1), amino group
(3200–3400 cm–1), С=О group (1684–1678 cm–1), СН
IR spectrum, ν, cm–1: 2928 (NH), 1672 (С=О), 818
(СН2). 1Н NMR spectrum, δ, ppm: 2.29 s (1Н, SH),
2.73 t (2Н, СОСН2СН2, J 8 Hz), 3.29 t (2Н, СОСН2СН2,
J 8 Hz), 7.13–7.42 m (4Н, Ar), 7.89 s (1Н, NH). Found,
%: С 57.46; Н 4.93; N 17.16; S 12.57. C11H11N3OS.
Calculated, %: C 56.63; H 4.75; N 18.01; S 13.74.
1
bond of the heteroring (762–758 cm–1). In the Н NMR
spectra singlets appear of the protons of NH (8.03 ppm)
and NH2 (2.02–2.17 ppm) groups, of the protons at the
tertiary carnon atom (4.22–4.28 ppm), at the vinyl carbon
atom (7.18–7.19 ppm) and of the methylene group (4.04–
4.09 ppm). The reaction apparently proceeds analogously
involving the carbonyl fragment of the substrate leading
primarily to the opening of the ring and the formation of the
thiosemicarbazone of 4-oxoacid B, which further under-
goes heterocyclization involving the methylidene fragment.
Compounds (IVа, IVb). General procedure.
In 30 ml of ethanol 3 mmol of aryl-3-(2-chloro-
phenylmethylidene)-3Н-furan-2-one IIIа, IIIb and 4.5
mmol of thiosemicarbazide was heated for 18 h in the
presence of 0.1 ml of triethylamine. The reaction mixture
was poured into cold water, neutralized and left stand-
ing for 24 h, then it was extracted with chloroform, and
the solvent was distilled off. The obtained crystals were
recrystallized from 2-propanol.
Thus we studied the reactions of 5-aryl-3Н-furan-2-
one and its arylmethylidene derivatives with thiosemi-
carbazide. The reaction did nt stop at the stage of the
formation of a linear product but underwent a heterocy-
clization providing substituted pyrazoles and triazoles.
5-(2-Chlorophenyl)-4-[2-oxo-2-(4-methylphenyl)
ethyl]-2,5-dihydro-1Н-pyrazole-1-carbothioamide
(IVа). Yield 0.81 g (73%), mp 103–104°С. IR spectrum,
ν, cm–1: 3400–3200 [νas and νs (NH2)], 1684 (ArCOR),
1262 (=S), 815 (СН2), 758 (СН of heterocycle). 1Н NMR
spectrum, δ, ppm: 2.02 s (2Н, NH2), 2.41 s (3Н, СН3),
4.04 s (2Н, СН2), 4.22 s (1Н, СН), 7.18 s (1Н, =СН),
7.16–7.88 m (8Н, Ar), 8.03 s (1Н, NH). Found, %:
С 61.04; Н 4.86; Cl 9.52; N 11.30; S 7.70. C19H18ClN3SO.
Calculated, %: С 61.36; Н 4.33; Cl 9.61; N 11.37; S 8.66.
Compounds IIа, IIb. General procedure. In 30 ml
of ethanol 6 mmol of 5-aryl-3Н-furan-2-one Ia, Ib and
9 mmol of thiosemicarbazide was heated for 10 h in the
presence of 0.1 ml of triethylamine. The reaction mixture
was poured into cold water, neutralized and left stand-
ing for 24 h, then it was extracted with chloroform, and
the solvent was distilled off. The obtained crystals were
recrystallized from 2-propanol.
5-(2-Chlorophenyl)-4-(2-oxo-2-phenylethyl)-2,5-
dihydro-1Н-pyrazole-1-carbothioamide (IVb). Yield
0.72 g (67%), mp 103–104°С. IR spectrum, ν, cm–1:
3400–3200 [νas and νs(NH2)], 1678 (ArCOR), 1282 (=S),
3-(5-Mercapto-2Н-1,2,4-triazole-3-yl)-1-(4-methyl-
phenyl)propan-1-one (IIа). Yield 0.97 g (65%), mp
73–75°С. IR spectrum, ν, cm–1: 2922 (NH), 1666 (С=О),
1
1
815 (СН2). Н NMR spectrum, δ, ppm: 2.17 s (1Н, SH),
815 (СН2), 762 (СН of heterocycle). Н NMR spectrum,
2.55 s (3Н, СН3), 2.74 t (2Н, СОСН2СН2, J 8 Hz), 3.29 t
(2 Н, СОСН2СН2, J 8 Hz), 7.00–7.31 m (4Н, Ar), 7.87 s
(1Н, NH). Found, %: С 58.56; Н 5.63; N 16.16; S 13.57.
C12H13N3OS. Calculated, %: C 58.28; H 5.30; N 16.99;
S 12.97.
δ, ppm: 2.17 s (2Н, NH2), 4.09 s (2Н, СН2), 4.28 s (1Н,
СН), 7.19 s (1Н, =СН), 7.18–7.69 m (8Н, Ar), 8.03 s
(1Н, NH). Found, %: С 61.01; Н 4.72; Cl 9.52; N 11.02;
S 10.34. C18H16ClN3SO.Calculated, %: С 60.41; Н 4.51;
Cl 9.91; N 11.74; S 8.96.
3-(5-Mercapto-2Н-1,2,4-triazole-3-yl)-1-phenyl-
propan-1-one (IIb). Yield 0.96 g (71%), mp 69–70°С.
IR spectra were recorded on an IR Fourier spectrom-
eter FSM 1201 from pellets with KBr, 1Н NMR spectra,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 48 No. 5 2012

BURUKHINA et al.
752
on a spectrometer Bruker MSL-400 (operating frequency
400 MHz) in CDCl3, internal reference TMS. The purity
of compounds was checked by TLC on Silufol plates,
eluent ethyl acetate–hexane–chloroform, 2 : 2 : 1, devel-
opment in iodine vapor.
of the Russian Foundation for Basic Research (grant no.
10-03-00640-а) and of the grant from the President of the
Russian Federation for the state support of young Russian
scientists (grant MK-2054.2011.3).
REFERENCES
ACKNOWLEDGMENTS
1. Grinev, V.S., Amal’chieva, O.A., Egorova, A.Yu., and
Lyubun’, E.V., Zh. Org. Khim., 2010, vol. 46, p. 1376.
The study was carried out under the financial support
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 48 No. 5 2012