Synthesis and structure of substituted 5-phenoxy-1,2,4-dithiazole-3-ones

Article abstract of DOI:10.1002/jhet.717

Seven new substituted 5-phenoxy-1,2,4-dithiazole-3-ones were prepared in modest yield (53-76%) from corresponding O-phenyl thiocarbamates and chlorocarbonylsulfenyl chloride in dry ether at-10 °C. All of the compounds were characterized by NMR and elemental analysis and some of them by X-ray diffraction. Preliminary kinetic measurements showed that the parent 5-phenoxy-1,2,4-dithiazole-3-one is a very efficient sulfurizing agent toward triphenyl phosphite. Copyright

Full text of DOI:10.1002/jhet.717

November 2011
Synthesis and Structure of Substituted 5-Phenoxy-1,2,4-
dithiazole-3-ones
1225
ˇ ˇ ´ ˇ´
Oleksandr Ponomarov, Zdenka Padelkova, and Jirı Hanusek*
Institute of Organic Chemistry and Technology, Faculty of Chemical Technology, University of
Pardubice, 532 10 Pardubice, The Czech Republic
*E-mail: jiri.hanusek@upce.cz
Received March 16, 2010
DOI 10.1002/jhet.717
Published online 30 June 2011 in Wiley Online Library (wileyonlinelibrary.com).
Seven new substituted 5-phenoxy-1,2,4-dithiazole-3-ones were prepared in modest yield (53–76%)
from corresponding O-phenyl thiocarbamates and chlorocarbonylsulfenyl chloride in dry ether at
ꢀ10 ꢁC. All of the compounds were characterized by NMR and elemental analysis and some of them
by X-ray diffraction. Preliminary kinetic measurements showed that the parent 5-phenoxy-1,2,4-dithia-
zole-3-one is a very efficient sulfurizing agent toward triphenyl phosphite.
J. Heterocyclic Chem., 48, 1225 (2011).
INTRODUCTION
starting from compounds having a >NA(C¼¼S)A group
can be found. Chlorocarbonylsulfenyl chloride [5],
which is the most frequently used reagent for such syn-
thesis, smoothly converts aliphatic and aromatic thioa-
mides to 5-alkyl- or 5-aryl-1,2,4-dithiazole-3-ones [6].
The situation is more complex for thiocarbamates and
thioureas. For example, O-ethylthiocarbamate gives 5-
ethoxy-1,2,4-dithiazole-3-one (EDITH) and 3,5-dieth-
oxy-1,2,4-thiadiazole [7] with the relative amounts
depending very much on the solvent, whereas N-mono-
substituted-O-alkylthiocarbamates are cyclized to 4-sub-
stituted 1,2,4-dithiazolidine-3,5-diones [8]. Also, N,N0-
disubstituted thioureas afford [9] either 5-imino-1,2,4-
dithiazole-3-ones or 2,4-disubstituted-1,2,4-thiadiazole-
5-ones depending on the solvent, temperature, and the
presence of a base.
1,2,4-Dithiazoles and related compounds belong among
the group of less common heterocyclic compounds,
although they possess various valuable properties. Their
synthesis, structure, chemistry, and applications up until
2005 have been extensively reviewed in a series [1]. One
of their most significant properties is their ability to serve
as an efficient sulfurizing agent during the synthesis of
oligonucleotide phosphorothioate analogues [2]. In
particular, 5-ethoxy-1,2,4-dithiazole-3-one (EDITH) and
5-amino-1,2,4-dithiazole-3-thione (xanthane hydride)
appear to be advantageous alternatives to existing sulfu-
rizing reagents [2c,3]. In our previous papers [4], we dealt
with the by-products and mechanism of the sulfurization
of phosphines and phosphites using xanthane hydride and
its N-methyl analogue. We found that these reagents are
really efficient toward P(III) compounds (in terms of the
bimolecular rate constants that vary from 0.5 to 3.87 ꢂ
103 L mol–1 s–1 for phosphites and from 2.6 ꢂ 102 to 5.9
ꢂ 105 L mol–1 s–1 for phospines). It is well known that
the substituent(s) in the heterocyclic ring often strongly
affect(s) its reactivity via polar effects. In this work, we
decided to prepare substituted 5-phenoxy-1,2,4-dithia-
zole-3-ones, 2a–g, whose sulfurizing efficiency might be
similar or even better.
Sulfurization of thioacylisocyanates [10] and desulfur-
ization of 1,2,4-dithiazole-3-thiones [11] also give
desired 1,2,4-dithiazole-3-ones.
In our case, we chose the reaction of substituted
O-phenyl thiocarbamates (1a–g) with chlorocarbonylsul-
fenyl chloride in dry ether at ꢀ10ꢁC likewise in ref. 7.
Starting O-phenyl thiocarbamates (1a–g) were prepared
according to combined procedure described elsewhere
[12]. In the first step, substituted phenol was treated
with cyanogen bromide, and the resulting substituted
phenyl cyanate was transformed to 1a–g without isola-
tion (see Scheme 1 and the Experimental part).
RESULTS AND DISCUSSION
The prepared 5-phenoxy-1,2,4-dithiazole-3-ones (2a–g)
were characterized by 1H, 13C-NMR, and elemental
In the literature dealing with the synthesis of various
1,2,4-dithiazole-3-ones, several synthetic approaches
C
V
2011 HeteroCorporation

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O. Ponomarov, Z. Padelkova, and J. Hanusek
1226
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Scheme 1
EXPERIMENTAL
Starting O-phenyl thiocarbamates 1a–g were prepared and
purified by a modified method [12] (see below). All starting
chemicals were purchased from commercial suppliers and used as
1
received. Before use, the solvents were dried and distilled. H-
and 13C-NMR spectra were recorded on a Bruker Avance 3 - 400
MHz instrument in CDCl3 solution. Chemical shifts d were refer-
enced to tetramethylsilane d(TMS) ¼ 0 ppm (1H) or to the solvent
residual peak d(CDCl3) ¼ 77.0 (13C). The coupling constants J
were quoted in Hz. The 13C-NMR spectra were measured in a
standard way and by means of the APT (Attached Proton Test)
pulse sequence to distinguish CH, CH3 and CH2, Cquart. All NMR
experiments were performed with the aid of the manufacturer’s
software. The elemental analyses were performed on an apparatus
of Fisons Instruments, the EA 1108 CHN.
X-ray crystallography of 2b and 2d. The colorless single
crystals of 2b and 2d suitable for X-ray determination were
grown by slow vapor diffusion of hexane into a saturated ethyl
acetate solution. The X-ray data for 2b and 2d were obtained
at 150 K using an Oxford Cryostream low-temperature device
on a Nonius KappaCCD diffractometer with Mo Ka radiation
analysis, and two of them were also characterized by X-ray
diffraction (Figs. 1 and 2).
The X-ray study of 2b and 2d showed that the 1,2,4-
dithiazole ring is essentially planar (torsion angles
C1AS1AS2AC2 and S1AC1AN1AC2 are less than
0.2(3)ꢁ) which supports the idea of its aromatic charac-
ter. In contrast to EDITH [7], where the ethoxy group
is coplanar with the 1,2,4-dithiazole ring, the plane of
the benzene rings in 2b and 2d are strongly deviated
from the plane of the parent heterocycle (dihedral
angles are –103.6(3) and 105.5(3), respectively). Some
bond lengths and angles (Table 1) were found to be
similar to other 1,2,4-dithiazole-3-ones, 3-thiones and
five-membered cyclic disulfides with aromatic charac-
ter [13]. The substitution of the benzene ring had
almost no influence upon the bond lengths and angles
(see Table 1).
˚
(k ¼ 0.71073 A), a graphite monochromator, and the / and v
scan modes. Data reductions were performed with the
DENZO-SMN [14]. The absorption was corrected by integra-
tion methods [15]. Structures were solved by direct methods
(Sir92) [16] and refined by full matrix least-squares based on
F2 (SHELXL97) [17]. The hydrogen atoms were mostly local-
ized on a difference Fourier map: however, to ensure uniform-
ity of the treatment of the crystals, all hydrogen atoms were
recalculated into idealized positions (riding model) and
assigned temperature factors Hiso(H) ¼ 1.2 Ueq(pivot atom) or
Compound 2a was preliminarily tested for sulfuriza-
tion efficiency toward triphenyl phosphite which was
the least reactive P(III) compound used in a previous
study [4b]. The observed rate constant kobs ¼ 100 s–1
measured under pseudo-first order conditions in a
0.05M triphenyl phosphite solution (in THF) showed
that 2a is more than two orders of magnitude more re-
active than xanthane hydride. A detailed study of the
reactivity of the prepared compounds including the
mechanism will, therefore, be the subject of a thorough
kinetic study to be published in a more specialized
journal.
˚
of 1.5 Ueq for the methyl moiety with CAH ¼ 0.96 A and
˚
0.93 A for the methyl and hydrogen atoms, respectively, in the
aromatic ring.
2
2
2
2 2
Rint ¼ RFo ꢀ Fo,mean2|/RFo , GOF ¼ [R(w(Fo ꢀ Fc ) )/
(Ndiffrs ꢀ Nparams)]1/2 for all data, R(F) ¼ R| |Fo| ꢀ |Fc||/R|Fo|
for observed data, wR(F2) ¼ [R(w(Fo ꢀ Fc ) )/(Rw(Fo ) )]1/2
for all data.
2
2 2
2 2
Crystallographic data for structural analysis have been de-
posited with the Cambridge Crystallographic Data Centre,
CCDC no. 769082 and 769083 for 2b and 2d, respectively.
Copies of this information may be obtained free of charge
Figure 1. ORTEP view of compound 2b (thermal ellipsoids at 40% probability).
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

November 2011
Synthesis and Structure of Substituted 5-Phenoxy-1,2,4-dithiazole-3-ones
1227
ArH-2) 6.70 and 6.47 (2 ꢂ bs, 2H, NH2), 3.81 (s, 3H, CH3);
13C-NMR (100 MHz) d ¼ 191.7 (C¼¼S), 160.3 (CAO), 154.2
(CAO), 129.6, 114.6, 112.2, 108.5, 55.4 (OCH3). Anal. Calcd.
for C8H9NO2S: C 52.44; H 4.95; N 7.64; S 17.50. Found: C
52.71; H 5.01; N 7.23; S 17.17.
O-4-Methylphenyl thiocarbamate (1d). Yield: 4.0 g (60%);
1
m.p. 151–152ꢁC (ref. 21 gives 153 ꢁC); H-NMR (400 MHz):
d ¼ 9.19 and 8.98 (2 ꢂ bs, 2H, NH2), 7.16 (AA0XX0, 2H),
6.92 (AA0XX0, 2H), 2.29 (s, 3H, CH3); 13C-NMR (100 MHz):
d ¼ 190.7 (C¼¼S), 151.6 (CAO), 134.8 (C-4), 129.6 (C-3,5),
122.6 (C-2,6), 20.5 (CH3).
O-4-Chlorophenyl thiocarbamate (1e). Yield 4.7 g (63%);
m.p. 155–157ꢁC (ref. 22 gives 165–166ꢁC), 1H-NMR (400 MHz):
d ¼ 8.25 (AA0XX0, 2H), 7.39 (AA0XX0, 2H), 7.48 and 7.21 (2 ꢂ
bs, 2H, NH2); 13C-NMR (100 MHz): d ¼ 191.4 (C¼¼S), 151.7
(CAO), 131.9 (CACl), 129.4 (C-3,5), 123.9 (C-2,6).
Figure 2. ORTEP view of compound 2d (thermal ellipsoids at 40%
probability).
O-3-Chlorophenyl thiocarbamate (1f). Yield: 5.8 g (77%);
1
from The Director, CCDC, 12 Union Road, Cambridge CB2
1EY, UK (fax: þ44-1223-336033; e-mail: deposit@ccdc.
cam.ac.uk or www: http:// www.ccdc.cam.ac.uk). In the struc-
ture of 2d, the Flack parameter has a meaningless standard
uncertainty [18].
m.p. 110–113ꢁC (ref. 23 gives 122ꢁC), H-NMR (400 MHz): d
¼ 7.39 (t, J 8.0 Hz, 1H, ArH-5), 7.28 (m, 1H, ArH), 7.14 (t, J
2.0 Hz, 1H, ArH-2), 7.02 (m, 1H, ArH), 6.80 and 6.49 (2 ꢂ
bs, 2H, NH2); 13C-NMR (100 MHz): d ¼ 191.2 (C¼¼S), 153.6
(CAO), 134.5 (CACl), 129.9, 126.7, 123.2, 121.0.
O-3-Trifluoromethylphenyl thiocarbamate (1g). Yield 4.6 g
(52%); m.p. 108–110ꢁC, 1H-NMR (400 MHz): d ¼ 7.55 (m, 2H,
ArH), 7.38 (m, 1H, ArH), 7.31 (m, 1H, ArH), 6.8 and 6.54 (2 ꢂ
bs, 2H, NH2); 13C-NMR (100 MHz): d ¼ 191.1 (C¼¼S), 153.2
(CAO), 131.8 (q, J 32 Hz, C-3), 129.8 (C-5), 126.3 (C-6), 123.4
(q, J 272 Hz, CF3), 123.2 (q, J 3.7 Hz, C-4), 119.9 (q, J 3.8 Hz,
C-2). Anal. Calcd. for C8H6F3NO2S: C 40.51; H 2.55; N 5.90; S
13.52. Found: C 40.28; H 2.25; N 6.00; S 13.43.
5-Phenoxy-1,2,4-dithiazole-3-ones 2a–g; general procedure. A
solution of corresponding O-phenyl thiocarbamate 1a–g
(5 mmol) in dry Et2O (50 mL) was added dropwise over 30
min into a stirred and externally chilled (–10ꢁC) solution of
chlorocarbonylsulfenyl chloride (0.66 g, 5 mmol) in dry Et2O
Compound 2b. C9H7NO3S2; monoclinic, space group P 21/c,
˚
a ¼ 8.1622(12), b ¼ 11.5321(11), c ¼ 11.0238(6) (A), a ¼
3
ꢁ
ꢁ
ꢁ
˚
90 , b ¼ 102.63(2) , c ¼ 90 , Z ¼ 4, V ¼ 1012.5(2) A , Dc
¼ 1.583 g cm–3. Intensity data collected with 2.56–27.49ꢁ;
8105 independent reflections measured; 1798 observed [I >
2s(I)]. Final R index ¼ 0.0377 (observed reflections), Rw ¼
0.0757 (all reflections), S ¼ 1.126. CCDC 769082.
Compound 2d. C9H7NO2S2; orthorhombic, space group
˚
P212121, a ¼ 7.0232(3), b ¼ 7.6181(3), c ¼ 18.5249(8) (A), a
3
ꢁ
ꢁ
ꢁ
˚
¼ 90 , b ¼ 90 , c ¼ 90 , Z ¼ 4, V ¼ 991.15(7) A , Dc ¼
1.510 g cm–3. Intensity data collected with 2.89–27.49ꢁ; 9857
independent reflections measured; 1868 observed [I > 2s(I)].
Final R index ¼ 0.0382 (observed reflections), Rw ¼ 0.0745
(all reflections), S ¼ 1.102. CCDC 769083.
O-Phenyl thiocarbamates 1a–g; general procedure. A so-
lution of 0.04 mol of phenol and 0.04 mol of triethylamine in
50 mL of dry Et2O was added dropwise to a solution of 0.04
mol cyanogen bromide in 50 mL of dry Et2O over 20 min
under stirring at –5ꢁC, and the stirring was continued for 1.5
h. Triethylamonium-chloride was filtered off and H2S was
bubbled through the filtrate for 3 h at room temperature in the
presence of catalytic amount of triethylamine. The solvent was
then evaporated and the residue was recrystallized from
CHCl3-hexane mixture.
O-Phenyl thiocarbamate (1a). Yield: 4.2 g (69%); m.p.
136–137ꢁC (ref. 19 gives 134ꢁC); 1H-NMR (400 MHz): d ¼
7.40 (m, 2H, ArH-3,5), 7.28 (m, 1H, ArH-4), 7.10 (m, 2H,
ArH-2,6), 7.01 and 6.54 (2 ꢂ bs, 2H, NH2); 13C-NMR (100
MHz): d ¼ 191.8 (C¼¼S), 153.3 (CAO), 129.3 (C-3,5), 126.4
(C-4), 122.4 (C-2,6).
Table 1
Selected bond lengths, bond angles, and torsion angles for 2b and 2d.
2b
2d
EDITH [7]
˚
Bond lengths (A)
1.372(3)
1.276(4)
C1AN1
C2AN1
C1AS1
C2AS2
S1AS2
C1AO1
C2AO2
1.380(3)
1.278(3)
1.800(2)
1.733(2)
2.0454(14)
1.202(3)
1.330(3)
1.36(2)
1.26(2)
1.81(2)
1.76(2)
2.053(6)
1.23(2)
1.31(2)
1.810(2)
1.734(3)
2.0386(10)
1.201(3)
1.332(3)
Bond angles (ꢁ)
114.98(17)
94.41(8)
N1AC1AS1
C1AS1AS2
C2AS2AS1
N1AC2AS2
C1AN1AC2
114.79(16)
94.78(8)
91.50(9)
116(1)
93.3(5)
91.9(5)
123(1)
–
91.78(10)
123.90(18)
114.9(2)
O-4-Methoxyphenyl thiocarbamate (1b). Yield: 5.4
g
124.00(18)
114.93(19)
(73%); m.p. 146–147ꢁC (ref. 20 gives 145–147ꢁC), 1H-NMR
(400 MHz): d ¼ 7.03 (AA0XX0, 2H), 6.89 (AA0XX0, 2H), 6.64
and 6.44 (2 ꢂ bs, 2H, NH2), 3.81 (s, 3H, CH3); 13C-NMR d
192.4 (C¼¼S), 157.6 (CAO), 147.0 (CAO), 123.1 (C-2,6),
114.2 (C-3,5), 55.5 (OCH3).
Torsion (dihedral) angles (ꢁ)
C1AS1AS2AC2
N1AC1AS1AS2
C1AN1AC2AS2
S1AS2AC2AO2
S2AS1AC1AO1
C5AC6AO3AC9
S2AC2/C3AC4
ꢀ0.02(12)
ꢀ0.21(11)
0.28(17)
0.0(3)
–
0.11(17)
0.2(3)
–4(2)
–5(3)
175(1)
180(2)
–
ꢀ179.77(16) ꢀ179.54(16)
O-3-Methoxyphenylꢁ thiocarbamate (1c). Yield: 4.0
g
1
179.9(2)
ꢀ178.4(2)
ꢀ103.6(3)
ꢀ179.66(19)
–
ꢀ105.5(3)
(54%); m.p. 129–132 C, H-NMR (400 MHz): d ¼ 7.28 (t, J
8.0 Hz, 1H, ArH-5), 6.85 (dd, J 8.4 and 1.6 Hz, 1H, ArH-4),
6.71 (dd, J 8.0 and 1.6 Hz, 1H, ArH-6), 6.69 (t, J 2.0 Hz, 1H,
–
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(50 mL). Then reaction mixture was stirred at ꢀ10ꢁC for 2 h.
Solvent was evaporated at reduced pressure, and the residue
was recrystallized from ethyl acetate.
REFERENCES AND NOTES
[1] (a) Sammes, M. P. In Comprehensive Heterocyclic Chemistry,
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[2] (a) Xu, Q.; Musier-Forsyth, K.; Hammer, R. P.; Barany, G.
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5-Phenoxy-1,2,4-dithiazole-3-one (2a). Yield: 0.56 g (53%);
1
m.p. 73ꢁC; H-NMR (400 MHz): d ¼ 7.45 (m, 2H, Ar-H 3,5),
7.36 (m, 1H Ar-H4), 7.27 (m, 2H, Ar-H 2,6); 13C-NMR (100
MHz): d ¼ 188.2 (C¼¼O), 179.2 (C¼¼N), 153.5 (CAO), 130.2
(C-3,5), 127.9 (C-4), 120.6 (C-2,6). Anal. Calcd. for
C8H5NO2S2: C, 45.48; H, 2.39; N, 6.63; S, 30.36. Found: C,
45.28; H, 2.72; N, 7.00; S, 30.07.
5-(4-Methoxyphenoxy)-1,2,4-dithiazole-3-one (2b). Yield: 0.78
1
g (64%); m.p. 84ꢁC; H-NMR (400 MHz): d ¼ 7.21 (AA0XX0,
2H), 6.94 (AA0XX0, 2H), 3.83 (s, 3H, OCH3); 13C-NMR (100
MHz): d ¼ 189.0 (C¼¼O), 179.3 (C¼¼N), 158.9 (CAO), 146.8
(CAO), 121.9, 115.0, 55.7 (OCH3). Anal. Calcd. for
C9H7NO3S2: C, 44.80; H, 2.92; N, 5.80; S, 26.58. Found:
44.91; H, 2.84; N, 6.11; S, 26.64.
[3] (a) Zhang, Z.; Nichols, A.; Tang, J. X.; Alsbeti, M.; Tang,
J.-Y. Nucleosides Nucleotides 1997, 16, 1585; (b) Ma, M. Y. X.;
Dignam, J. C.; Fong, G. W.; Li, L.; Gray, S. H.; Jacob S. B.; George,
S. T. Nucleic Acid Res 1997, 25, 3590.
5-(3-Methoxyphenoxy)-1,2,4-dithiazole-3-one (2c). Yield: 0.78
g (64%); m.p. 102ꢁC; 1H-NMR (400 MHz): d ¼ 7.36 (t, 3J
8.4 Hz, 1H, ArH-5), 6.92 (m, 1H, ArH), 6.86 (m, 1H, ArH),
3
6.82 (t, J 2.2 Hz, 1H, ArH-2), 3.83 (s, 3H, OCH3); 13C-NMR
[4] (a) Hanusek, J.; Russel, M. A.; Laws, A. P.; Page, M. I.
Tetrahedron Lett 2007, 48, 417; (b) Hanusek, J.; Russell, M. A.; Laws,
A. P.; Jansa, P.; Atherton, J. H.; Fettes, K.; Page, M. I. Org Biomol
Chem 2007, 5, 478.
d ¼ 188.1 (C¼¼O), 179.3 (C¼¼N), 160.8 (CAO), 154.1 (CAO),
130.5, 113.7, 112.6, 106.7, 55.6 (OCH3). Anal. Calcd. for
C9H7NO3S2: C, 44.80; H, 2.92; N, 5.80; S, 26.58. Found:
45.02; H, 3.15; N, 6.13; S, 26.84.
[5] Zumach, G.; Ku¨hle, E. Angew Chem Int Ed Engl 1970, 9, 54.
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Goerdeler, J.; Nandi, K. Chem Ber 1981, 114, 549.
5-(4-Methylphenoxy)-1,2,4-dithiazole-3-one (2d). Yield: 0.84 g
1
(74%); m.p. 78ꢁC; H-NMR (400 MHz): d ¼ 7.25 (AA0XX0,
2H), 7.16 (AA0XX0, 2H), 2.39 (s, 3H, CH3); 13C-NMR (100
MHz): d ¼ 188.6 (C¼¼O), 179.4 (C¼¼N), 151.3 (CAO), 138.2
(C-4), 130.7 (C-3,5), 120,5 (C-2,6), 21.0 (CH3). Anal. Calcd.
for C9H7NO2S2: C, 47.98; H, 3.13; N, 6.22; S, 28.47. Found:
C, 47.67; H, 3.38; N, 6.34; S, 28.17.
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J.; Barany, G. J Org Chem 1999, 64, 7281.
5-(4-Chlorophenoxy)-1,2,4-dithiazole-3-one (2e). Yield: 0.89
1
g (72%); m.p. 94ꢁC; H-NMR (400 MHz): d ¼ 7.42 (AA0XX0,
2H), 7.25 (AA0XX0, 2H); 13C-NMR (100 MHz): d ¼ 187.6
(C¼¼O), 178.9 (C¼¼N), 152.1 (CAO), 133.3 (CACl), 130.2 (C-
3,5), 121,9 (C-2,6). Anal. Calcd. for C8H4ClNO2S2: C, 39.11;
H, 1.64; Cl, 14.43; N, 5.70; S, 26.10. Found: C, 39.20; H,
1.83; Cl, 14.58; N, 6.08; S, 25.82.
[9] Tittelbach, F. J Prakt Chem 1990,181.
[10] Goerdeler, J.; Weiss, R. Chem Ber 1967, 100, 1627.
[11] (a) Derocque, J. L.; Vialle, J. Bull Soc Chim Fr 1966,
1183; (b) Behringer, H.; Deichmann, D. Tetrahedron Lett 1967,1013.
[12] (a) Grigat, E.; Puetter, R. Chem Ber 1964, 97, 3022; (b)
Murray, R. E.; Zweifel, G. Synthesis 1980,150; (c) Maeda, R.; Ohsugi,
E.; Fujioka, T.; Hirose K. Chem Pharm Bull 1983, 31, 3424.
[13] Barany, G. Cryst Struct Commun 1982, 11, 91.
5-(3-Chlorophenoxy)-1,2,4-dithiazole-3-one (2f). Yield: 0.94 g
1
3
(76%); m.p. 77ꢁC; H-NMR (400 MHz): d ¼ 7.40 (t, J 8.4 Hz,
1H, ArH-5), 7.35 (m, 1H, ArH), 7.32 (m, 1H, ArH), 7.02 (m, 1H,
ArH); 13C-NMR d ¼ 187.4 (C¼¼O), 178.9 (C¼¼N), 153.9 (CAO),
135.4 (CACl), 130.8, 128.0, 121.2, 118.9. Anal. Calcd. for
C8H4ClNO2S2: C, 39.11; H, 1.64; Cl, 14.43; N, 5.70; S, 26.10.
Found: C, 39.22; H, 1.92; Cl, 14.53; N, 6.00; S, 26.01.
[14] Otwinowski, Z.; Minor, W. Methods Enzymol 1997, 276, 307.
[15] Coppens, P. In Crystallographic Computing; Ahmed, F. R.,
Hall, S. R., Huber, C.P., Eds.; Munksgaard: Copenhagen, 1970; pp 255–
270.
[16] Altomare, A.; Cascarano, G.; Giacovazzo, C.; Guagliardi,
A. J Appl Crystallogr 1993, 26, 343.
5-(3-Trifluoromethylphenoxy)-1,2,4-dithiazole-3-one (2g). Yield
1
0.80 g (57%); m.p. 105ꢁC, H-NMR (400 MHz): d ¼ 7.63 (m,
[17] Sheldrick, G. M. SHELXL-97,
A Program for Crystal
1H, ArH), 7.60 (m, 1H, ArH), 7.56 (m, 1H, ArH), 7.52 (m, 1H,
ArH); 13C-NMR (100 MHz): d ¼ 187.3 (C¼¼O), 178.8 (C¼¼N),
153.8 (CAO), 132.8 (q, J 12.1 Hz, C-3), 130.8, 124.5 (q, J 3.7
Hz), 124.1, 122.1 (q, J 266 Hz, CF3), 117.9 (q, J 3.7 Hz). Anal.
Calcd. for C9H4F3NO2S2: C, 38.71; H, 1.44; Cl, 20.41; N, 5.02;
S, 22.96. Found: C, 38.80; H, 1.63; N, 5.39; S, 22.62.
¨
Structure Refinement; University of Gottingen: Germany, 1997.
[18] Flack, H. D.; Bernardinelli, G. Acta Cryst Sect A 1999, 55, 908.
[19] Martin, D. Chem Ber 1965, 98, 3286.
[20] Walter, W.; Bode, K.-D. Justus Liebigs Ann Chem 1966,
692, 108.
[21] Grigat, E.; Puetter, R. Chem Ber 1965, 98, 2619.
[22] Yagupolskii, L. M.; Kondratenko, N. V. J Gen Chem USSR
1969, 39, 1719.
Acknowledgment. The authors thank to Ministry of Education,
Youth and Sports of the Czech Republic for financial support
(Project MSM 002 162 7501).
[23] Grigat, E.; Puetter, R. Chem Ber 1964, 97, 3022.
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet