CYCLOCONDENSATION OF 1-TOSYL-2,2-DICHLOROETHENYL ISOTHIOCYANATE
1733
sodium hydrosulfide VII
III and VII
X are
Table 2. 1H NMR spectra of 1,3-thiazole derivatives
II XIII
kinetically controlled. Note that, even in those re-
presentatives of compounds XI where R2R3N =
(CH3)2N, O(CH2CH2)2N, the C2 center remains
noticeably electrophilic, which makes it possible to
perform condensations with sodium hydrosulfide and
Comp.
, ppm
no.
thiols XI
XII and XI
XIII on heating in ethanol. IIba
1.37 t (3H, CH3CH2), 2.44 s (3H, CH3C6H4),
4.45 q (2H, CH2), 7.35 d (2H, ArH), 7.94 d (2H,
ArH)
2.45 s (3H, CH3), 4.37 s (2H, CH2), 7.26 7.97 m
(9H, ArH)
2.42 s (3H, CH3), 4.62 s (4H, CH2), 7.21 7.83 m
(14H, ArH)
2.19 s (3H, CH3), 2.42 s (3H, CH3), 7.03 7.85 m
(8H, ArH), 9.90 s (1H, NH)
2.08 m (1H, CH2), 2.41 2.46 m (4H, CH2, CH3),
2.92 m (1H, CH2), 3.12 3.45 m (3H, CH2), 4.35 m
(1H, CHN), 7.47 d (2H, ArH), 7.83 d (2H, ArH)
8.63 br.s (1H, NH)
It is quite possible that introduction of bulky
N-substituents in position 5 of the thiazole ring with
the tosyl group present at the C4 center distorts the
conjugation between the unshared electron pair of the
nitrogen atom in the substituent and the system of
the azole fragment, so that the electrophilicity of the
C2 atom is not fully supressed. At the same time,
5-methylamino-2,4-ditosyl-1,3-thiazole does not react
with thiols even on prolonged heating; it seems likely
IIIca
IVdb
IVeb
IVib
that its inertness is due to the transfer onto the C2
center of a considerable electron density because of
this conjugation.
IVlb
2.41 s (3H, CH3), 7.46 d (2H, ArH), 7.77 d (2H,
ArH), 8.82 s (2H, HtH), 11.65 br.s (1H, NH)
1.25 d (3H, CH3CH), 2.41 s (3H, CH3C6H4),
2.75 m (1H, CH2), 3.45 m (1H, CH2), 4.43 m
(1H, CHN), 7.00 7.93 m (8H, ArH)
2.40 s (3H, CH3), 5.24 br.s (2H, NH2), 7.47 d
(2H, ArH), 7.80 d (2H, ArH), 9.31 s (1H, NH)
2.35 s (3H, CH3C6H4), 3.19 s (3H, CH3O),
6.96 7.64 m (19H, ArH)
In conclusion, it should be noted that the majority
of transformations described in this work are not only
of scientific, but also of practical synthetic interest,
since the known routes to 4-tosylthiazole derivatives
summarized in the comprehensive monograph [2] and
some papers [3 6] do not allow preparation of
the twelve types of 3-functionally substituted thiazoles
II XIII which can be readily prepared from accessible
agent I.
IVob
IVgb
Vaa
VIIaa 2.44 s (3H, CH3), 2.46 s (3H, CH3), 7.32 7.91 m
(8H, ArH)
EXPERIMENTAL
VIIca 2.47 s (3H, CH3), 4.64 s (2H, CH2), 7.08 8.01 m
(9H, ArH)
The IR spectra were recorded on a Specord IR-71
instrument in dichloromethane. The H NMR spectra
of the majority of compounds were taken on a Varian
VXR-300 spectrometer, and that of IVe, on a Varian
Gemini-200 spectrometr with TMS as internal re-
ference.
VIIIab 2.42 s (3H, CH3), 7.41 7.85 m (9H, ArH), 7.98 s
(1H, CH=N), 12.71 s (1H, NH)
1
IXaa
XIfb
2.45 s (3H, CH3), 7.27 8.02 m (9H, ArH), 8.17 s
(1H, CH=C)
2.42 s (3H, CH3), 3.24 t (4H, CH2N), 3.75 t (4H,
CH2O), 4.79 s (2H, CH2SO2), 6.89 7.92 m (9H,
ArH)
XIIIaa 2.40 s (3H, CH3), 2.44 s (3H, CH3), 3.00 t (4H,
1-Tosyl-2,2-dichloroethenyl isothiocyanate I. A
suspension of 0.14 mol of N-(1-tosyl-2,2,2-trichloro-
ethyl)iminodichloromethane [1] and 0.29 mol of
thiourea in 250 ml of acetonitrile was refluxed with
stirring for 1 h, the precipitate was filtered off, the
solvent from the filtrate was removed in vacuo, and
the residue was recrystallized from 250 ml of diethyl
ether. Yield 77%, mp 94 C (cf. [1]).
CH2N), 3.80 t (4H, CH2O), 7.20 7.94 m (8H, ArH)
a
b
Notes:
In CDCl .
In DMSO-d .
6
3
and IIIg. A solution of 16.2 mmol of I and
16.2 mmol of pyridine in 35 ml of benzene was sa-
turated with methyl mercaptan or mixed with
16.2 mmol of other liquid or solid thiol, the reaction
mixture was stirred for 48 h at 20 25 C, the solvent
was removed in vacuo, and the residue was washed
with water.
2-Alkoxy-4-tosyl-5-chloro-1,3-thiazoles IIa IIc.
A mixture of 16.2 mmol of I, 10 ml of the appropriate
alcohol, and 16.2 mmol of pyridine was stirred for
72 h at 20 25 C; the precipitated product was filtered
off and washed with ethanol.
2-Benzylthio-4-tosyl-5-chloro-1,3-thiazole IIIc.
4-Tosyl-2-p-tolyl(p-chlorophenyl, 2-furylmethyl, a. To a solution of 15 mmol of I in 30 ml of benzene,
methyl)thio-5-chloro-1,3-thiazoles IIIa, IIIb, IIIe, we added 15 mmol of pyridine and 15 mmol of
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 72 No. 11 2002
Babii
