1
448
Russ.Chem.Bull., Int.Ed., Vol. 50, No. 8, August, 2001
Rogoza et al.
tially to cation A, which was then deprotonated upon
addition of triethylamine, while the intermediate that
formed underwent intramolecular heterocyclization to
form compound 2 (Scheme 2).
The use of acetonitrile as the solvent makes it pos-
sible to obtain initially kinetic product A (which is,
apparently, associated with the weak tendency of MeCN
to proton transfer and the low solubility of benzimid-
azoline-2-thione in this solvent) followed by activation
of the second nucleophilic center.
and distilled, the first 50 mL of the distillate being discarded.
Subsequent distillation afforded perfluoro-2-methylpent-2-ene
(
950 mL) with b.p. 51 °C and the purity of 98.599.5% (GLC).
2E)-2-(Tetrafluoroethylidene)-3,3-bis(trifluoromethyl)-2,3-
(
dihydrothiazolo[3,2-a]benzimidazole (2). A solution of com-
pound 1 (2.8 g, 9 mmol) and benzimidazoline-2-thione (1.4 g,
9
mmol) in MeCN (10 mL) was stirred at ∼20 °C for 20 h. Then
NEt3 (2.02 g, 20 mmol) was added. The reaction mixture was
stirred at 50 °C for 1 h, poured into water, extracted with
CHCl3, and dried with CaCl2. The solvent was distilled off on a
rotary vacuum evaporator and the solid residue was recrystal-
lized from CH Cl . After sublimation (80 °C, 13 Torr), com-
2
2
To summarize, we synthesized fused polycyclic het-
erocyclic compound 2 with the use of perfluoro-2-
methylpent-2-ene and the ambident nucleophile, viz.,
benzimidazoline-2-thione.
pound 2 was obtained in a yield of 3.3 g (79.5%), m.p. 8990 °C.
1
IR (CCl , 5%), ν/cm : 3025 (CH); 1660, 1610 (C=C); 1520
4
(
C H ); 1445 (CN); 1345, 1325 (CN); 12001270 (CF);
6 4
1
2
150 (C=S). UV (EtOH), λmax/nm: 210 (ε 54000), 244 (ε 14400),
+
80 (ε 10600), 288 (ε 10800). MS, m/z (I (%)): 410 [M]
rel
+
+
(
[
(
(
(
100), 391 [M F] (9.29), 341 [M CF3] (62.09), 293
M CF , N=C=S] (15.88), 214 [M 2 CF , N=C=S]
16.71), 146 [M 3 CF , N=C=S] (10.70), 134 [C H NCS]
3.90), 102 [C H NC] (3.34), 90 [C H N] (5.53), 69 [CF3]
Experimental
+
+
+
+
3
3
+
3
6
4
The 1H, 13C, and 19F NMR spectra were recorded on a
Bruker WP-200 SY spectrometer (200, 50, and 188 MHz,
respectively) relative to Me Si and C F as the internal stan-
+
+
6
4
6
4
+
6.28), 39. Found: m/z = 409.99410 [M ]. C H F N S. Cal-
1
3
4
10
2
1
4
6
6
culated: M = 409.99354. H NMR (CDCl ), δ: 7.63 (m, 1 H,
3
dards (the spin-spin coupling constants JCH were not mea-
sured). The IR spectra were measured on a Specord M-80
H(8)); 7.43 (m, 1 H, H(5)); 7.28 (m, 2 H, H(6), H(7)).
13
C NMR (CDCl ), δ : 152 (C(9A)); 148.9 (C(4A)); 141.6
3
C
spectrometer (in CCl ). The mass spectra were obtained on a
1
2
4
(CF=, JCF = 278 Hz, JCF = 41.7 Hz); 133.2 (C(8A));
VG 707 OE GL-mass spectrometer (EI, 70 eV).
25.1 (C(2), 2J
1
1
= 32.6 Hz); 124.1 (C(7)); 123.8 (C(6));
CF
We used acetonitrile of reagent grade, which was dried by
21.4 (3,3-(CF ) , 1J
= 290.8 Hz); 119.9 (C(5)); 118
CF
3
2
successive distillation over P O5 and CaH , triethylamine of
(CF CF=, 1J
= 275 Hz, 2J
2
2
= 39.6 Hz); 112.5 (C(8));
CF
19
3
CF
reagent grade, which was stored over granulated KOH and then
distilled over sodium, and benzimidazoline-2-thione of reagent
grade, which was recrystallized from benzene.
6.9 (C(3), 2J
7
6
= 31.9 Hz). F NMR (CDCl ), δ : 95.8 (d,
CF 3 F
F, 3,3-(CF ) , J
= 28.5 Hz); 95.5 (d, 3 F, CF CF=,
3
2
FF
3
JFF = 8 Hz); 55.6 (q, 1 F, CF=, JFF = 28.5 and 8 Hz).
X-ray diffraction study of compound 2 was carried out on a
SYNTEX P2 diffractometer (Cu-Êα radiation, graphite mono-
We thank the Russian Foundation for Basic Re-
search (Project No. 96-07-89187) for paying for the
license for the Cambridge Structural Database.
1
chromator). To prevent damage in the course of X-ray data
collection, the single crystal was placed in a polyethylene
capillary. Crystals of compound 2 are monoclinic, a = 32.244(8),
3
b = 11.264(2), c = 18.687(5) Å, β = 119.95(2)°, V = 5881(2) Å ,
References
1
space group C2/c, Z = 16, C H F N S, µ = 3.120 mm
,
1
3
4
10
2
dcalc = 1.853 g cm3. A total of 3900 independent reflections
with 2θ < 120° were measured using the ω scanning technique.
The intensities of the reflections were corrected taking into
account the decay of the intensities of the check reflections to
1
2
. G. G. Furin, Chem. Rev., 1996, 20, 1.
. G. G. Furin and Yu. V. Gatilov, Khim. Geterotsikl. Soedin.,
1
993, 253 [Chem. Heterocycl. Compd., 1993 (Engl. Transl.)].
. G. G. Furin and E. L. Zhuzhgov, Zh. Org. Khim., 1997, 33,
72 [Russ. J. Org. Chem., 1997, 33 (Engl. Transl.)].
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978, 12, 193.
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J. Metzger, J. Heterocycl. Chem., 1980, 17, 393.
. Yu. V. Zefirov and P. M. Zorkii, Zh. Strukt. Khim., 1976,
3
4
5
6
7
8
9
7
5%. The absorption corrections for the crystal habitus (trans-
mission was 0.190.44) and then using the DIFABS program
the correction was 0.811.23) were made. The structure was
7
(
1
solved by the direct method using the SHELXS-86 program
package and refined by the least-squares method in the aniso-
tropic-isotropic (for
H atoms) approximation using the
SHELXL-97 program package to wR2 = 0.1878, S = 0.591 for
all reflections and to R = 0.064 for 1759 reflections with F > 4σ
(
502 parameters were refined). The atomic coordinates and the
1
7, 994 [J. Struct. Chem. (USSR), 1976, 17 (Engl. Transl.)].
equivalent thermal parameters of the nonhydrogen atoms in
two independent molecules were deposited with the Cambridge
Structural Database.
. R. D. Haugwitz, B. Toeplitz, and J. Z. Gougoutas, J. Chem.
Soc., Chem. Commun., 1977, 736.
. V. Martinez-Merino, J. I. Garcia, J. A. Mayoral, M. J. Gil,
J. M. Zabalza, J. P. Fayet, M. C. Vertut, A. Carpy, and
A. Gonzalez, Tetrahedron, 1996, 52, 8947.
Perfluoro-2-methylpent-2-ene (1). Anhydrous MeCN
(
200 mL), CsF (3 g) of reagent grade, which was preliminarily
calcined at 400 °C for 6 h, and the product FOL-62 purchased
from JSC Galogen (Perm, Russia), which consisted of perfluoro-
1
0. H. Allen, O. Kenard, D. G. Watson, L. Bramer, A. G.
Orpen, and R. Taylor, J. Chem. Soc., Perkin Trans. 2, 1987, 1.
1. Cambridge Structural Data Base System, Version 5.15, 2000.
2. J. J. D´Amico, F. G. Bollinger, M. Thompson, J. I. Free-
man, W. E. Dahl, and J. V. Pustinger, J. Heterocycl. Chem.,
4
-methylpent-2-ene (98%) and perfluoro-2-methylpent-2-ene
1
1
(
∼2%) and which was kept over CaCl2 for 24 h before use, were
successively placed in a 2-L flask equipped with an efficient
reflux condenser with a calcium-chloride tube. The reaction
mixture was refluxed for 34 h with intense stirring using a
magnetic stirrer and then cooled to ∼20 °C. The lower fluoro-
carbon layer was separated, washed with H O, dried over CaCl ,
1
988, 25, 1193.
Received June 26, 2000;
in revised form February 27, 2001
2
2