ISSN 1070-3632, Russian Journal of General Chemistry, 2011, Vol. 81, No. 9, pp. 1886–1888. © Pleiades Publishing, Ltd., 2011.
Original Russian Text © Sun Minyan, S.M. Ramsh, V.N. Plotkin, S.Yu. Solov’eva, 2011, published in Zhurnal Obshchei Khimii, 2011, Vol. 81, No. 9,
pp. 1549–1551.
Condensation of Pseudothiohydantoin
with Substituted Isatins
Sun Minyan, S. M. Ramsh, V. N. Plotkin, and S. Yu. Solov’eva
St. Petersburg State Technological Institute, Moskovskii pr. 26, St. Petersburg, 119013 Russia
e-mail: gsramsh@mail.wplus.net
Received February 24, 2011
Abstract—Pseudothiohydantoin С5-mono(hydroxymethyl) derivatives were obtained by the reaction of
unsubstituted pseudothiohydantoin with substituted isatins.
DOI: 10.1134/S1070363211090246
Typically, the reaction of pseudothiohydantoin I or
its derivatives with carbonyl compounds proceeds as a
crotonic condensation in the 5 position of the hetero-
cycle to form the products of 5-ylide nature [1, 2].
the reaction of pseudothiohydantoin I with the
substituted isatins IIa–IIj. The condensation was
carried out by the method described for the reaction of
isatin derivatives with CH-acids [3]. A mixture of
equimolar amounts of pseudothiohydantoin I and the
corresponding isatin IIa–IIj [4] in 1 ml of ethanol with
diethylamine as a catalyst was kept at room tempera-
ture for 1–10 days under stirring. The reaction com-
pletion was monitored by TLC. The resulting solid was
filtered off, washed on the filter 2–3 times with ethanol
and once with diethyl ether, and dried in a vacuum at
70–80°C. Typically, compounds IIIa–IIIj were ob-
tained in a pure form in high yields (Table 1). Their
O
O
H
N
N
R
O
HN
H2N
R
S
S
I
It was interesting to determine whether it is
possible to stop this process at the stage of the
formation of the aldol condensation product and to
obtain a C5-mono(hydroxymethyl)-substituted derivatives
of pseudothiohydantoin. For this purpose we examined
1
structures were established by H NMR spectroscopy
and confirmed by the mass spectrometry and elemental
analysis.
O
N
O
HO
O
R1
NH2
R1
HNEt2
S
O
N
+
O
H2N
N
N
S
R2
R2
I
IIIа−IIIj
IIа−IIj
а, R1 = R2 = H; b, R1 = CН3, R2 = Н; c, R1 = Н, R2 = СН3; d, R1 = Н, R2 = СН2С(О)NH2; e, R1 = Cl, R2 = СН2-1-naphthyl;
f, R1 = Н, R2 = СН2С(=СН2)СН3; g, R1 = OСН3, R2 = Н; h, R1 = СН2СН3, R2 =Н; i, R1 = Н, R2 = СН2СН=СНС6Н5; j, R1 =
Н, R2 = СН2СН2О-(2-СН3ОС6Н4).
1
Indeed, the characteristic feature of the H NMR
spectrum of the compounds IIIa–IIIj is a clear signal
of hydroxy proton of indole fragment at 6.5–7.1 ppm
and a singlet signal of CH-proton of thiazolidine
fragment at 4.8–5.0 ppm (Table 2).
The fact that the dehydration of the aldol condensa-
tion product III does not occur in the reaction can be
attributed to the considerable conjugation in the
dihydropyrrole ring of a hypothetical product of cro-
tonic condensation.
1886
Minyan, Sun
