Hetrocyclic thiones and their analogs in reactions of 1,3-dipolar addition: V. Reactions of 2,3,3-triphenyl-1-thioxophthalimidine with nitrile imines

Article abstract of DOI:10.1007/s11178-005-0240-9

2,3,3-Triphenyl-1-thioxophthalimidine reacted with nitrile imines along the pattern of [3+2]-cycloaddition affording 2,3,3,3′,5′- pentasubstituted benzo[c]pyrrolidine-1-spiro-2′-(2′,3′- dihydro-1′,3′,4′-thiadiazoles). The reaction is regioselective and in

Full text of DOI:10.1007/s11178-005-0240-9

Russian Journal of Organic Chemistry, Vol. 41, No. 5, 2005, pp. 758-760. Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 5, 2005,
pp. 772-775.
Original Russian Text Copyright Ó 2005 by Budarina, Labeish, Bel’skii, Galishev.
Hetrocyclic Thiones and Their Analogs in Reactions of 1,3-Dipolar
Addition: V.* Reactions of 2,3,3-Triphenyl-1-thioxophthalimidine
with Nitrile Imines
E.V. Budarina, N.N. Labeish, V.K. Bel’skii, and V.A. Galishev
1St. Petersburg State Technological Institute, St. Petersburg, 198013 Russia
å-mail: vlad@orgchem.spb.ru
2State Scientific Center of the Russian Federation“Karpov Physicochemical Research Institute”
ReceivedAugust 16, 2004
Abstract—2,3,3-Triphenyl-1-thioxophthalimidine reacted with nitrile imines along the pattern of [3+2]- cycloaddition
affording 2,3,3,3',5'-pentasubstituted benzo[c]pyrrolidine-1-spiro-2'-(2',3'-dihydro-1',3',4'-thiadiazoles). The reaction
is regioselective and involves the exocyclic C=S bond.
We formerly demonstrated [1–4] that thioketones
showed a high dipolarophile activity in the reactions of
1,3-dipolar cycloaddition. In the present study we continu-
ed to investigate the behavior of cyclic thioketones in
1,3-dipolar cycloaddition by an example of 2,3,3-triphenyl-
1-thioxophthalimidine.
regioselectively involving the exocyclic C=S bond fol-
lowing the mechanism of [3+2]-cycloaddition to yield
2,3,3,3',5'-pentasubstituted benzo[c]pyrrolidine-1-spiro-2'-
(2',3'-dihydro-1',3',4'-thiadiazoles) IIIa–IIIe.
This reaction scheme is confirmed by the lack in the
IR spectra of compounds obtained of the absorption
band belonging to the C=S bond in the region 1260–
Nitrile imines were generated in situ by treating with
triethylamine appropriate hydrazonoyl chlorides IIa–IIe.
The reaction of 1,3-dipolar cycloaddition was carried out
in boiling benzene applying equimolar quantities of 2,3,3-
triphenyl-1-thioxophthalimidine (I) and hydrazonoyl
chloride. The reaction progress was monitored by TLC.
As in the cases previously studied the reaction occurred
3K
–1
1270 cm and by appearance of absorption bands at
–1
1593–1596 and 1317–1364 cm corresponding to the
stretching vibrations of the C=N and C–N bonds of the
thiadiazole ring. In the spectra of compounds IIIb–IIId
the absorption bands of the stretching vibrations belong-
ing to C=O group of substituents attached to the position
5' of thiadiazoles are observed in the region 1634–
–1
1703 cm , and in the spectrum of compound IIIb the
3K
5&ꢀ&Oꢁ 1 1+3K
absorption bands of a nitro group appear at 1544,
1
3K
–1
1342 cm .
6
The UV absorption spectra of the isolated compounds
are characterized by a strong absorption maximum in the
UV region (~220 nm, lg e 4.4–4.5) (in the spectra of
compounds IIIb and IIId a shoulder additionally appears
on the absorption curve and a maximum at 264 and 253
nm respectively). Less strong absorption bands are also
observed in the visible region. The position on the
longwave maximum in the spectra depends on the
character of the substituent in the position 5' of the
thiadiazole ring.Ared shift of this band is observed in the
series of compounds IIIe » IIIa < IIIc < IIId < IIIb but
with a maximal change in the Dl value 75 vs. 64 nm.
,
,,D ,,H
3K
3K
(W 1
(W 1ꢂꢂ+&O
1
1
3K
3K
6
1
5
,,,D ,,,H
R = Ph (a), C6H4NO2-p (b), CH3C(O) (c), PhC(O) (d),
C2H5OC(O) (e).
1
The H NMR spectra of benzopyrrolidinespiro-
For communication IV, see [1].
thiadiazoles IIIa–IIIe contain the signals characteristic
1070-4280/05/4105-0758Ó2005 Pleiades Publishing, Inc.

HETROCYCLIC THIONES AND THEIR ANALOGS IN REACTIONS OF 1,3-DIPOLARADDITION: V.
759
°
of the substituents at the carbon and nitrogen of nitrile
imine, and also the signals from the aromatic protons of
the benzene rings.
Bond lengths d (A) and bond angles w (deg) in the molecule of
2,3,3,3',5'-pentaphenylbenzo[c]pyrrolidine-1-spiro-2'-(2',3'-
dihydro-1',3',4'-thiadiazole) (IIIa)
In the 13C NMR spectra of compounds obtained the
signals from the spiro carbons appeared in the region
109–119 ppm. Signals from the carbon in the position 5'
of the thiadiazole ring are observed in the range 142–144
ppm. The other spectral parameters are also consistent
with the assumed structure of compounds obtained.
%RQGꢀ
Gꢀ
%RQGꢀ
Gꢀ
6±& ꢀ
ꢁꢂꢃꢄꢄꢅꢆꢇꢀ
ꢁꢂꢈꢃꢉꢅꢉꢇꢀ
ꢁꢂꢋꢌꢍꢅꢉꢇꢀ
ꢁꢂꢋꢈꢉꢅꢉꢇꢀ
ꢁꢂꢋꢋꢆꢅꢃꢇꢀ
ꢁꢂꢈꢌꢆꢅꢄꢇꢀ
ꢁꢂꢈꢃꢁꢅꢄꢇꢀ
ꢁꢂꢈꢃꢃꢅꢃꢇꢀ
ꢁꢂꢈꢌꢁꢅꢃꢇꢀ
ꢁꢂꢆꢋꢄꢅꢃꢇꢀ
Zꢀ
6±& ꢀ
ꢁꢂꢄꢆꢈꢅꢉꢇꢀ
ꢁꢂꢊꢃꢄꢅꢄꢇꢀ
ꢁꢂꢋꢊꢉꢅꢃꢇꢀ
ꢁꢂꢋꢌꢄꢅꢉꢇꢀ
ꢁꢂꢈꢉꢄꢅꢄꢇꢀ
ꢁꢂꢆꢍꢈꢅꢄꢇꢀ
ꢁꢂꢆꢊꢃꢅꢄꢇꢀ
ꢁꢂꢈꢌꢃꢅꢌꢇꢀ
ꢁꢂꢆꢊꢌꢅꢃꢇꢀ
ꢁꢂꢋꢄꢈꢅꢃꢇꢀ
Zꢀ
1 ±1 ꢀ
1 ±& ꢀ
1 ±& ꢀ
1 ±& ꢀ
& ±& ꢀ
& ±& ꢀ
& ±& ꢀ
& ±& ꢀ
& ±& ꢀ
$QJOHꢀ
1 ±& ꢀ
1 ±& ꢀ
1 ±& ꢀ
& ±& ꢀ
& ±& ꢀ
& ±& ꢀ
& ±& ꢀ
& ±& ꢀ
& ±& ꢀ
$QJOHꢀ
The formation of benzopyrrolidinespirothiadiazoles
IIIa–IIIe was also confirmed by mass spectrometry.
The corresponding mass spectra contained both molecular
ion peaks and peaks from fragment ions.
The structure of 2,3,3,3',5'-pentaphenylbenzo[c]-
pyrrolidine-1-spiro-2'-(2',3'-dihydro-1',3',4'-thiadiazole)
(IIIa) was proved by X-ray diffraction analysis (see
figure).
& 6& ꢀ
ꢃꢌꢂꢄꢅꢈꢇꢀ
ꢁꢁꢆꢂꢋꢅꢋꢇꢀ
ꢁꢊꢁꢂꢋꢅꢋꢇꢀ
ꢁꢁꢃꢂꢆꢅꢋꢇꢀ
ꢁꢊꢁꢂꢈꢅꢆꢇꢀ
ꢁꢊꢃꢂꢍꢅꢆꢇꢀ
ꢁꢁꢍꢂꢆꢅꢋꢇꢀ
ꢁꢁꢄꢂꢌꢅꢆꢇꢀ
ꢁꢁꢌꢂꢌꢅꢆꢇꢀ
ꢌꢌꢂꢄꢅꢈꢇꢀ
1 1 & ꢀ
1 1 & ꢀ
& 1 & ꢀ
& 1 & ꢀ
& & & ꢀ
& & & ꢀ
& & & ꢀ
& & & ꢀ
& & & ꢀ
6& 1 ꢀ
ꢁꢁꢊꢂꢋꢅꢋꢇꢀ
ꢁꢁꢋꢂꢄꢅꢋꢇꢀ
ꢁꢁꢊꢂꢁꢅꢋꢇꢀ
ꢁꢊꢊꢂꢆꢅꢋꢇꢀ
ꢁꢁꢍꢂꢉꢅꢋꢇꢀ
ꢁꢊꢁꢂꢋꢅꢆꢇꢀ
ꢁꢊꢃꢂꢍꢅꢋꢇꢀ
ꢁꢊꢁꢂꢋꢅꢆꢇꢀ
ꢁꢁꢃꢂꢁꢅꢆꢇꢀ
ꢁꢁꢄꢂꢁꢅꢈꢇꢀ
ꢁꢍꢄꢂꢄꢅꢈꢇꢀ
ꢁꢍꢊꢂꢈꢅꢋꢇꢀ
ꢁꢁꢊꢂꢁꢅꢋꢇꢀ
ꢁꢁꢍꢂꢄꢅꢋꢇꢀ
ꢁꢁꢈꢂꢊꢅꢋꢇꢀ
ꢁꢊꢁꢂꢊꢅꢋꢇꢀ
ꢁꢊꢁꢂꢊꢅꢆꢇꢀ
ꢁꢁꢌꢂꢁꢅꢉꢇꢀ
ꢁꢁꢃꢂꢁꢅꢉꢇꢀ
ꢁꢊꢍꢂꢍꢅꢉꢇꢀ
ꢁꢁꢃꢂꢄꢅꢄꢇꢀ
ꢁꢊꢍꢂꢋꢅꢃꢇꢀ
ꢁꢊꢁꢂꢁꢅꢄꢇꢀ
ꢁꢊꢍꢂꢍꢅꢉꢇꢀ
ꢀ
1 1 & ꢀ
& 1 & ꢀ
& 1 & ꢀ
& & & ꢀ
& & & ꢀ
& & & ꢀ
& & & ꢀ
& & & ꢀ
6& 1 ꢀ
1 & 1 ꢀ
1 & & ꢀ
1 & & ꢀ
& & & ꢀ
& & & ꢀ
6& 1 ꢀ
1 & & ꢀ
& & & ꢀ
1 & & ꢀ
1 & & ꢀ
& & & ꢀ
& & & ꢀ
& & & ꢀ
& & & ꢀ
& & & ꢀ
The fused benzophthalimidine system is virtually planar.
The maximum deviation of atoms from the plane in
the benzene ring fused to the heterocycle amounts to
°
0.0543 A. The deviation of N3 atom from the plane in the
°
heterocycle N3C1C2C7C8 is –0.131 A, the deviation of
°
the N3 with respect to the plane C1–C8 is 0.181 A. The
angle between two components of the fused system is
4.3°. (In all descriptions of results obtained by X-ray
diffraction analysis the numbering of atoms is the same
as on the figure). The thiadiazole ring formed as a result
of the reaction is not planar, the average deviation of the
ꢁꢁꢈꢂꢄꢅꢋꢇꢀ
ꢁꢁꢉꢂꢌꢅꢋꢇꢀ
ꢌꢌꢂꢃꢅꢈꢇꢀ
6& & ꢀ
1 & & ꢀ
1 & & ꢀ
1 & & ꢀ
& & & ꢀ
6& & ꢀ
& & & ꢀ
1 & & ꢀ
1 & & ꢀ
& & & ꢀ
& & & ꢀ
& & & ꢀ
& & & ꢀ
& & & ꢀ
ꢀ
°
atoms from the plane SN1N2C7C9 reaches 0.117 A, and
ꢁꢍꢌꢂꢍꢅꢋꢇꢀ
ꢁꢁꢁꢂꢊꢅꢋꢇꢀ
ꢁꢁꢆꢂꢋꢅꢋꢇꢀ
ꢁꢊꢈꢂꢈꢅꢆꢇꢀ
ꢁꢁꢃꢂꢌꢅꢉꢇꢀ
ꢁꢊꢁꢂꢉꢅꢄꢇꢀ
ꢁꢊꢁꢂꢄꢅꢄꢇꢀ
ꢁꢊꢁꢂꢁꢅꢉꢇꢀ
ꢁꢊꢍꢂꢉꢅꢄꢇꢀ
ꢁꢁꢌꢂꢊꢅꢃꢇꢀ
ꢁꢁꢌꢂꢌꢅꢄꢇꢀ
ꢁꢊꢍꢂꢄꢅꢆꢇꢀ
this ring is orthogonal to the initial system (the angle
ꢀ
between the planes SN1N2C7C9 and N3C1C2C7C8 equals
to 89.1°). The bond lengths and bond angles are given in
the table.
&
EXPERIMENTAL
Structure of the molecule of 2,3,3,3',5'-pentaphenylbenzo-
[c]pyrrolidine-1-spiro-2'-(2',3'-dihydro-1',3',4'-thiadiazole)
(IIIa) according to X-ray diffraction analysis. Hydrogen atoms
are not shown.
IR spectra were recorded on a spectrophotometer
Specord 75IR from solutions of compounds IIIa–IIIe in
CHCl3 (cell thickness 0.97 mm). Electronic spectra were
RUSSIAN JOURNALOF ORGANIC CHEMISTRYVol. 41 No. 5 2005

BUDARINA et al.
760
taken on spectrometer Specord UV-Vis (l 1 cm) from
solutions in acetonitrile. NMR spectra were registered
on spectrometer BrukerAM-500 (500 MHz for 1H NMR,
125 MHz for 13C), 1H NMR spectra from 5% solutions
of compounds in DMSO-d6, and 13C spectra from 5%
solu-tions in CDCl3, internal reference HMDS. Mass
spectra were obtained on a MKh-1321 instrument,
vaporizer temperature 120°C, ionizing chamber
temperature 200°C, ionizing voltage 70 V.
2,3,3,3',5'-Pentaphenylbenzo[c]pyrrolidine-1-
spiro-2'-(2',3'-dihydro-1',3',4'-thiadiazole) (IIIa).
–1
Yield 90%, mp 223–224°C. IR spectrum, n, cm : 1596
(C=N), 1336, 1326 (C–N). Electronic spectrum (CH2Cl2),
max, nm (lg e): 349 (4.00). 1H NMR spectrum, d, ppm:
l
6.53–7.78 m (29 H, Harom). 13C NMR spectrum, d, ppm:
79.834 (C3), 109.765 (C1(2')), 119.486, 121.872, 124.987,
125.041, 126.160, 126.712, 127.211, 127.467, 127.575,
127.778, 128.196, 128.344, 128.452, 128.613, 129.085,
129.786, 130.204, 132.173, 132.253, 139.157, 139.723,
140.869, 142.878, 143.080, 143.822 (Carom), 144.376 (C5').
Mass spectrum, m/z (Irel, %): 571 (2) [C39H29N3S]+,
462 (30) [C33H24N3]+, 194 (55) [C13H10N2]+, 121 (30)
[C7H5S]+, 91 (100) [C6H5N]+, 77 (40) [C6H5]+. Found,
%: C 81.62; H 5.25; S 5.56. C39H29N3S. Calculated, %:
C 81.92; H 5.12; S 5.61.
X-ray diffraction study of a single crystal of 2,3,3,3',5'-
pentaphenylbenzo[c]pyrrolidine-1-spiro-2'-(2',3'-dihydro-
1',3',4'-thiadiazole) (IIIa) was performed on an automatic
diffractometer Syntex P-1 (MoKa-radiation, Nb-filter
q/2q-scanning, 2q£45°). Monoclinic crystals: C39H29N3S.
a 10.426(2), b 15.402(3), c 18.913 (3) A
° , b 97.19 (2)°,
°
V 3 0 1 3 . 2 ( 1 . 8 ) A3; space group P21/c, Z 4,
d
calc 1.260 g/cm3. The structure was solved by the direct
5'-(p-Nitrophenyl)-2,3,3,3'-tetraphenylbenzo[c]-
pyrrolidine-1-spiro-2'-(2',3'-dihydro-1',3',4'-thiadi-
azole) (IIIb). Yield 89%, mp 227–228°C. IR spectrum,
method [1960 reflections with I > 2s (I)] in full-matrix
approximation, anisotropic for atoms C, N, O, S, and
isotropic for hydrogen atoms, till R 0.045, Rw 0.050 (no
correction for extinction was done). The calculations were
performed along software SHELXTL on a minicomputer
NOVA-3. A perspective drawing of the molecule is
represented on the figure, the bond lengths and bond
angles are given in the table. The crystallographic
coordinates of nonhydrogen and hydrogen atoms and their
equivalent thermal factors are available from the authors.
–1
n, cm : 1593 (C=N), 1333, 1317 (C–N), 1544, 1342
(NO2). Electronic spectrum (CH3CN), lmax, nm (log e):
420 (4.09). 1H NMR spectrum, d, ppm: 6.52–8.17 m (28
H, Harom). 13C NMR spectrum, d, ppm: 79.807 (C3),
119.279 (C1(2')), 122.862, 123.919, 124.618, 124.904,
126.317, 126.802, 127.431, 127.787, 128.389, 128.544,
128.844, 129.258, 130.999, 138.180 (Carom), 142.448 (C5').
Mass spectrum, m/z (Irel, %): 507 (40) [C33H23N4O2]+,
377 (90) [C26H19NS]+, 376 (100) [C26H18NS]+, 300 (65)
[C20H13NS]+, 239 (35) [C13H9N3O2]+, 91 (95) [C6H5N]+,
77 (95) [C6H5]+. Found, %: C 75.65; H 4.73; S 5.00.
C39H28N4O2S. Calculated, %: C 75.94; H 4.58; S 5.20.
Preparation procedure for 2,3,3-triphenyl-1-
thioxophthalimidine. A mixture of 1.05 g of 2,3,3-
triphenylphthalimidine [5] and 0.75 g of P4S10 in 15 ml of
anhydrous o-xylene was boiled for 30 min, the hot solution
was filtered, the solvent was removed, and the residue
was recrystallized from ethanol. Yield 0.66 g (60%), mp
223–225°C.
5'-Acetyl-2,3,3,3'-tetraphenylbenzo[c]-pyrro-
lidine-1-spiro-2'-(2',3'-dihydro-1',3',4'-thiadiazole)
–1
(IIIc). Yield 83%, mp 188–189°C. IR spectrum, n, cm :
Nitrile imines were generated in situ by treating with
the triethylamine the corresponding hydrazonoyl chlorides
Ia–Ie [6].
1598 (C=N), 1364, 1314 (C–N), 1680 (C=O). Electronic
spectrum (CH2Cl2), lmax, nm (log e): 365 (4.07). 1H NMR
spectrum, d, ppm: 2.21 s (3H, CH3), 6.46–7.78 m (24H,
13
General procedure for reaction between 1-thioxo-
phthalimidine and C-aryl(acetyl, benzoyl, ethoxy-
carbonyl)-N-phenylnitrile imines IIa–IIe. To a soluti-
on of 2 mmol of 1-thioxophthalimidine in 30 ml of
anhydrous toluene was added in succession 2 mmol of
an appropriate hydrazonoyl chloride II and 4 mmol of
triethylamine. The reaction mixture was boiled for 1 h.
On cooling the precipitate of triethylamine hydrochloride
was filtered off, the filtrate was evaporated under reduced
pressure, and the residue was crystallized by grinding
with ether. The products obtained were recrystallized from
acetonitrile.
H
arom). C NMR spectrum, d, ppm: 25.001 (CH3), 80.482
(C3), 111.079 (C1(2')), 120.743, 123.574, 124.006, 125.125,
125.179, 126.716, 127.242, 127.323, 127.457, 127.619,
127.781, 127.848, 128.266, 128.442, 128.536, 128.711,
129.021, 129.601, 129.790, 130.127, 132.473, 132.635,
138.392, 138.540, 139.120, 141.857, 142.410, 142.572,
142.626 (Carom), 144.432 (C5'), 191.218 (C=O). Mass
spectrum, m/z (Irel, %): 537 (20) [C35H27N3OS]+, 428 (20)
[C29H19N3O]+, 377 (22) [C26H19NS]+, 376 (32)
[C26H18NS]+, 77 (100) [C6H5]+. Found, %: C 77.90;
H 5.20; S 5.86. C35H27N3OS. Calculated, %: C 76.15;
H 5.16; S 5.65.
RUSSIAN JOURNALOF ORGANIC CHEMISTRYVol. 41 No. 5 2005

HETROCYCLIC THIONES AND THEIR ANALOGS IN REACTIONS OF 1,3-DIPOLARADDITION: V.
761
(CH3), 61.452 (CH2), 79.911 (C3), 110.591 (C1(2')),
120.527, 124.253, 124.738, 124.910, 126.651, 127.508,
127.721, 127.907, 128.322, 128.536, 128.978, 130.177,
130.606, 131.748, 138.386, 141.641 (Carom), 143.883 (C5'),
159.458 (C=O). Mass spectrum, m/z (Irel, %): 567 (10)
[C36H29N3O2S]+, 458 (50) [C30H24N3O2]+, 377 (20)
[C26H19NS]+, 376 (30) [C26H18NS]+, 300 (23)
[C20H13NS]+, 190 (10) [C10H10N2O2]+, 91 (28)
[C6H5N]+, 77 (100) [C6H5]+. Found, %: C 75.94; H 5.23;
S 5.36. C36H29N3O2S. Calculated, %: C 76.15; H 5.16;
S 5.65.
5'-Benzoyl-2,3,3,3'-tetraphenylbenzo[c]pyrro-
lidine-1-spiro-2'-(2',3'-dihydro-1',3',4'-thiadiazole)
–1
(IIId). Yield 81%, mp 140–141.5°C. IR spectrum, n,cm :
1595 (C=N), 1369 (C–N), 1312 (C–N), 1634 (C=O).
Electronic spectrum (CH3CN), lmax, nm (log e): 386
(3.96). 1H NMR spectrum, d, ppm: 6.54–7.88 (m) (29H,
Harom). 13C NMR spectrum, d, ppm: 80.054 (C3), 109.420
(C1(2')), 120.255, 124.452, 124.938, 127.094, 127.522,
127.793, 127.951, 128.164, 128.322, 128.479, 128.621,
128.750, 129.007, 129.335, 130.691, 130.934, 132.847,
135.588, 137.872, 138.301, 140.999, 141.270, 141.684
(Carom), 144.154 (C5'), 184.370 (C=O). Mass spectrum,
m/z (Irel, %): 599 (30) [C40H29N3OS]+, 490 (50)
[C34H24N3O]+, 377 (20) [C26H19NS]+, 376 (25)
[C26H18NS]+, 105 (95) [C6H5N2], 77 (100) [C6H5]+.
Found, %: C 79.87; H 5.02; S 4.98. C40H29N3OS.
Calculated, %: C 80.10; H 4.88; S 5.34.
REFERENCES
1. Budarina, E.V., Plotnikov, V.F., Labeish, N.N., Bel’skii, V.K.,
and Galishev, V.A., Zh. Org. Khim., 2005, vol. 41, p. 462.
2. Labeish, N.N., Oparin, D.A., Bel’skii, V.K.,and Galishev,V.A.,
Zh. Org. Khim., 1997, vol. 33, p. 430.
3. Oparin, D.A., Motovilin, D.B., and Galishev, V.A., Zh. Org.
Khim., 1992, vol. 28, p. 1100.
4. Oparin, D.A., Yakovlev, S.V., Motovilin, D.B., and Gali-
shev, V.A., Zh. Org. Khim., 1992, vol. 28, p. 1317.
5. Fisher, O. and Hepp, E., Ber., 1894, vol. 27, p. 2793.
6. Huisgen, R., Seidel, M., Wallbilich, G., and Knupfer, H., Tet-
rahedron, 1962, vol. 17, p. 3.
5'-Ethoxycarbonyl-2,3,3,3'-tetraphenylbenzo-
[c]pyrrolidine-1-spiro-2'-(2',3'-dihydro-1',3',4'-thia-
diazole) (IIIe). Yield 84%, mp 196–197°C. IR spectrum,
–1
n, cm : 1596 (C=N), 1342, 1319 (C–N), 1703 (C=O),
1139, 1071 (C–O). Electronic spectrum (CH3CN), lmax
,
1
nm (lg e): 345 (3.92). H NMR spectrum, d, ppm: 1.18 t
(3H, CH3, J 7 Hz), 4.17 q (2H, CH2, J 7 Hz), 6.48–
7.83 m (24H, Harom). 13C NMR spectrum, d, ppm: 13.927
RUSSIAN JOURNALOF ORGANIC CHEMISTRYVol. 41 No. 5 2005