Regioselective synthesis of 1,3-oxathiolane-2-imine derivatives

Article abstract of DOI:10.1007/s00706-013-1107-3

An efficient one-pot synthesis of functionalized 1,3-oxathiolane-2-imine derivatives via the reaction of aryl isothiocyanates and oxiranes is developed. This catalytic procedure takes place in the presence of MeONa in THF at 25 °C in good to excellent yie

Full text of DOI:10.1007/s00706-013-1107-3

Monatsh Chem (2014) 145:611–616
DOI 10.1007/s00706-013-1107-3
ORIGINAL PAPER
Regioselective synthesis of 1,3-oxathiolane-2-imine derivatives
Alireza Samzadeh-Kermani
Received: 8 May 2013 / Accepted: 14 October 2013 / Published online: 10 December 2013
Ó Springer-Verlag Wien 2013
Abstract An efficient one-pot synthesis of functionalized
1,3-oxathiolane-2-imine derivatives via the reaction of aryl
isothiocyanates and oxiranes is developed. This catalytic
procedure takes place in the presence of MeONa in THF at
25 °C in good to excellent yields.
imine derivatives suffered from low yields, harsh condi-
tions, and formation of by-products [19, 20].
Results and discussion
Keywords Heterocycles Á Oxirane Á Methoxide Á
Aryl isothiocyanate Á One-pot synthesis
Herein, we describe an efficient one-pot method for the
synthesis of 1,3-oxathiolan-2-imine derivatives 3 from the
reaction of oxiranes 1 and aryl isothiocyanates 2 in the
presence of a catalytic amount of methoxide at room
temperature in acceptable yields.
Introduction
2-(Phenoxymethyl)oxirane (1a) and phenylisothiocya-
nate (2a) were selected as prototypical reaction partners for
alkoxide catalyzed one-pot reaction. To explore the opti-
mum reaction conditions, the effects of catalyst and solvent
were considered. The solvent had a great impact on the
reaction. No product was obtained when the reaction was
carried out in MeOH using methoxide as a catalyst
(Table 1, entry 10). DMF was found to be unsuccessful for
the transformation, too (Table 1, entry 8). Changing the
solvent to hexane afforded 3a in 53 % yield (Table 1, entry
9). The yield of 3a increased dramatically to 76 and 90 %
when CH2Cl2 and THF were the solvents, respectively
(Table 1, entries 6, 1). Different catalysts were also tested,
but MeONa proved to be most effective (Table 1, entry 1).
Although t-BuONa completely inhibited the reaction, 3a
was achieved in 71 and 41 % yield in the presence of
EtONa and i-PrONa as catalyst, respectively (Table 1,
entries 2, 3). The yield of 3a remained almost the same
upon increasing the catalyst loading to 20 mol% (Table 1,
entry 12), but reducing the loading of the catalyst to
5 mol% adversely affected the yield of product (Table 1,
entry 13). My investigations for the reaction condition
optimization demonstrated that 1a (1 mmol), 2a (1 mmol),
NaH (10 mol%), and MeOH (1 mmol) in 3 cm3 THF at
Within the last decades, many transformations of oxiranes
have been well developed, and the ring-opening reactions
are among the most studied. Most of the ring-opening
methods proceeded in the presence of Lewis acids, Lewis
bases, Bronsted acids, thioxanthenone-fused azacrown
ethers, Schiff base, and porphyrin complexes [1–11]. These
smallest of heterocyclic compounds exhibit a synthetically
very useful utility in the synthesis of other oxygen-con-
taining heterocyclic compounds [12], 1,2-amino alcohols
[13, 14], and alcohols [15]. In many cases, the regiose-
lectivity has been found to be sensitive to the operating
opening reactions [16–18], and the methods are limited to
the oxiranes bearing a chelate-forming substituent.
1,3-Oxathiolane-2-imine derivatives are highly valuable
intermediates in organic synthesis and have been used as
core structures for the development of herbicidal agents.
The earlier attempts at the synthesis of 1,3-oxathiolane-2-
A. Samzadeh-Kermani (&)
Chemistry Department, Faculty of Science, University of Zabol,
Zabol, Iran
e-mail: drsamzadeh@gmail.com
123

612
A. Samzadeh-Kermani
Table 1 Optimization of reaction conditions
NPh
S
O
O
Catalyst (10 mol%)
Solvent, rt, 8 h
Ph
N
C
S
+
Ph
H
OC
2
PhOCH2
1a
2a
3a
Entry
Catalyst
Solvent
Yield/%
1
MeONa
EtONa
THF
90
71
41
Trace
23
76
41
14
53
–
2
THF
3
i-PrONa
t-BuONa
DMAP
THF
4
THF
5
THF
6
MeONa
MeONa
MeONa
MeONa
MeONa
MeONa
MeONaa
MeONab
CH2Cl2
MeCN
DMF
Hexane
MeOH
Toluene
THF
7
8
9
10
11
12
13
a
43
91
42
THF
20 mol% of catalyst was used
b
5 mol% of catalyst was used
25 °C for 8 h provided an improved reaction condition for
this transformation, and the desired product was achieved
in excellent yield.
Mechanistically, it is conceivable that the reaction
involves the initial formation of anionic adduct 4 from the
reaction of methoxide and aryl isothiocyanate. This anionic
adduct reacts with oxirane to produce ring-opened inter-
mediate 5. Ring closure of this intermediate affords 6, and
finally, elimination of methoxide completes the catalytic
cycle and gives 3 (Scheme 2). In both oxirane and aryl
isothiocyanate derivatives, electron-poor substrates react
more efficiently than electron-rich substrates in accordance
with the proposed reaction mechanism.
With the optimized reaction condition in hand, the gen-
erality of this transformation was explored, and the results
are summarized in Scheme 1. Good yields were obtained
from the reaction of oxiranes 1a, 1e, and 1f. The polar effect
of the C–O bond bound to the three-membered rings prob-
ably increases the electrophilicity of the oxiranes
(Scheme 1). Excellent yields were obtained from the reac-
tion of oxirane 1f derived from cyclohexene and aryl
isothiocyanates. In alkyl-substituted oxiranes, only the pro-
ducts formed by the attack of the S-atom of ArNCS at the
terminal carbon were detected by 1H NMR. For the phenyl-
substituted oxiranes, terminal- and benzylic-attacked pro-
ducts were formed in a ratio of 4:1 caused by the interference
of electronic and steric effects (Scheme 1). Structures of
compounds 3a–3r were assigned by IR, 1H NMR, 13C NMR,
and mass spectral data. Due to the presence of a stereogenic
In conclusion, we have described a convenient and
efficient one-pot method for the regioselective synthesis
of 1,3-oxathiolane-2-imine derivatives. It should be
noted that several functional groups such as methyl
methacrylate, alkoxy, phenoxy, and cyano could be well
tolerated. Further studies are being conducted to develop
catalytic cyclization in the presence of aziridine and
heterocumulenes.
1
center, the H NMR spectrum of 3a exhibited three multi-
plets at 3.50–3.59, 4.24–4.35, and 5.01–5.05 ppm arising
from two CH2 and CH protons, respectively. The 13C NMR
spectrum of 3a shows 16 signals, in agreement with the
proposed structure. The mass spectrum of 3a displayed the
molecular ion peak at m/z = 285.
Experimental
Oxiranes, aryl isothiocyanate derivatives, alcohols, and NaH
were obtained from Merck and were used without further
purification. Melting points were measured on an
123

Regioselective synthesis of 1,3-oxathiolane-2-imine derivatives
613
NAr
Scheme 1
O
S
O
MeONa
Ar
N
C
S
+
R1
R2
THF, rt, 8 h
R2
R1
1
2
3
R1
R2
H
Ar
R1
PhOCH2
CH3
(CH3)2CHOCH2
CH3CH2CH2
CH3C(CH2)COOCH2 H
R1,R2 = -(CH2)4-
R2
Ar
3a PhOCH2
Ph
2a
2b
2c
Ph
4-Me-C6H4
4-MeO-C6H4
1a
1b
1c
1d
1e
1f
1g
1h
1i
H
H
H
H
3b PhOCH2
3c PhOCH2
3d CH3
3e CH3
3f CH3
3g (CH3)2CHOCH2
3h (CH3)2CHOCH2
3i (CH3)2CHOCH2
3j CH3CH2CH2
H
H
H
H
H
H
H
H
H
H
H
H
4-Me-C6H4
4-MeO-C6H4
Ph
4-Me-C6H4
4-MeO-C6H
Ph
4-Me-C6H4
4-MeO-C6H
4-Me-C6H4
4-MeO-C6H
Ph
4-Me-C6H4
Ph
4-Me-C6H4
Ph
Ph
Ph
Ph
H
H
H
4-MeO-C6H4
4-CN-C6H4
3k CH3CH2CH2
3l CH3C(CH2)COOCH2
3m CH3C(CH2)COOCH2
R1, R2 = -(CH2)4-
3n
3o
3p
3q
R1, R2 = -(CH2)4-
Ph
H
H
H
4-MeO-C6H4
4-CN-C6H4
3r
were performed with a Heraeus CHN–O-Rapid analyzer. The
results agreed favorably with the calculated values.
Scheme 2
+
NaH
MeOH
NAr
S
O
General procedure for the preparation of compounds 3
MeO Na
R'
Ar
R
N
C
S
3
To a stirred solution of MeOH (1 mmol) in 3 cm3 THF as a
solvent were added NaH (10 mol%) and aryl isothiocya-
nate (1 mmol); the mixture was stirred for 15 min at 0 °C.
After addition of oxirane (1 mmol) at room temperature,
the reaction mixture was stirred for 8 h. After completion
of the reaction (monitored by TLC), the solvent was
removed under reduced pressure, and the residue was
purified by column chromatography (SiO2; hexane/AcOEt)
to afford pure title compounds.
2
Na
NAr
S
MeO
MeO
Na S
NAr
O
6
4
R'
R
ArN
R'
R
S
N-[4-(Phenoxymethyl)-1,3-oxathiolan-2-ylidene]benzen-
amine(3a, C16H15NO2S)
O
MeO
Na O
R
R'
1
The crude product was purified by column chromatography
(SiO2, hexane/EtOAc 8/1, Rf = 0.39) affording 0.26 g
5
ꢀ
(90 %) 3a. M.p.: 118–120 °C; IR (KBr): m = 3,017, 2,987,
1,629, 1,559, 1,309, 1,148 cm-1 1H NMR (500 MHz,
;
CDCl3): d = 3.50–3.59 (m, CH2), 4.24–4.35 (m, CH2),
5.01–5.05 (m, CH), 6.91 (d, J = 8.2 Hz, 2CH), 6.96 (d,
Electrothermal-9100 apparatus. IR Spectra: Shimadzu IR-460
1
3
spectrometer. H and 13C NMR spectra: Bruker DRX-500
3
3J = 8.3 Hz, 2CH), 7.02 (t, J = 7.3 Hz, CH), 7.16–7.33
AVANCE instrument in CDCl3 at 500.1 and 125.7 MHz,
respectively, d in ppm, J in Hz. EIMS (70 eV): Finnigan-
MAT-8430 mass spectrometer. Elemental analyses (C, H, N)
(m, 5CH) ppm; 13C NMR (125.7 MHz, CDCl3): d = 36.1
(CH2), 60.9 (CH2), 78.9 (CH), 114.6 (2CH), 121.2 (CH),
123

614
A. Samzadeh-Kermani
121.7 (CH), 124.4 (2CH), 129.1 (2CH), 129.6 (2CH), 148.9
(C), 158.0 (C), 161.9 (C) ppm; EI-MS (70 eV):
m/z (%) = 285 (M?, 3), 152 (25), 133 (34), 119 (86), 93
(78), 77 (100), 43 (44), 34 (18).
(78 %) 3e. M.p.: 80–82 °C; IR (KBr): mꢀ = 3,023, 2,956,
1,633, 1,593, 1,314, 1,121 cm-1 1H NMR (500 MHz,
;
CDCl3)): d = 1.40 (d, 3J = 6.5 Hz, Me), 1.52 (s, Me),
3.34–3.40 (m, CH2), 4.69–4.81 (m, CH), 7.00 (d,
3
3J = 6.5 Hz, 2 CH), 7.14 (d, J = 7.1 Hz, 2 CH) ppm;
13C NMR (125.7 MHz, CDCl3): d = 21.3 (Me), 24.5 (Me),
39.4 (CH2), 68.1 (CH), 120.1 (2 CH), 128.7 (2 CH), 136.1
(C), 144.6 (C), 159.3 (C) ppm; EI-MS (70 eV):
m/z (%) = 207 (M?, 1), 150 (100), 91 (76), 59 (51), 57
(75), 54 (60), 40 (44), 18 (15).
4-Methyl-N-[4-(phenoxymethyl)-1,3-oxathiolan-2-yli-
dene]benzenamine (3b, C17H17NO2S)
The crude product was purified by column chromatography
(SiO2, hexane/EtOAc 8/1, Rf = 0.32) affording 0.26 g
ꢀ
(86 %) 3b. M.p.: 127–129 °C; IR (KBr): m = 3,014, 2,965,
1,621, 1,568, 1,334, 1,142 cm-1 1H NMR (500 MHz,
;
4-Methoxy-N-(4-methyl-1,3-oxathiolan-2-ylidene)benzen-
amine(3f, C11H13NO2S)
CDCl3): d = 2.36 (s, Me), 3.49–3.58 (m, CH2), 4.35–4.48
(m, CH2), 4.99–5.04 (m, CH), 6.91 (d, 3J = 8.2 Hz, 2CH),
The crude product was purified by column chromatography
(SiO2, hexane/EtOAc 8/1, Rf = 0.44) affording 0.16 g
3
6.96 (d, J = 8.3 Hz, 2CH), 7.02 (t, 3J = 7.3 Hz, CH),
3
3
7.16 (d, J = 8.2 Hz, 2CH), 7.33 (t, J = 7.9 Hz, 2CH)
ppm; 13C NMR (125.7 MHz, CDCl3): d = 20.9 (Me), 36.5
(CH2), 58.9 (CH2), 77.9 (CH), 114.7 (2CH), 121.0 (CH),
121.7 (2CH), 129.6 (2CH), 129.7 (2CH), 133.9 (C), 146.4
(C), 158.1 (C), 162.6 (C) ppm; EI-MS (70 eV): m/
z (%) = 299 (M?, 2), 165 (29), 133 (41), 131 (78), 93
(100), 91 (55), 43 (47), 34 (20).
ꢀ
(73 %) 3f. M.p.: 87–90 °C; IR (KBr): m = 3,012, 2,965,
1,632, 1,576, 1,326, 1,108 cm-1 1H NMR (500 MHz,
;
CDCl3): d = 1.52 (d, 3J = 6.2 Hz, Me), 3.46–3.59 (m,
CH2), 3.65 (s, OMe), 4.67–4.79 (m, CH), 6.76 (d,
3J = 6.9 Hz, 2 CH), 7.27 (d, J = 7.1 Hz, 2 CH) ppm;
13C NMR (125.7 MHz, CDCl3): d = 21.3 (Me), 38.9
(CH2), 55.6 (OMe), 67.5 (CH), 115.1 (2 CH), 124.6 (2
CH), 141.6 (C), 158.2 (C), 160.3 (C) ppm; EI-MS (70 eV):
m/z (%) = 223 (M?, 6), 165 (100), 107 (74), 59 (63), 57
(78), 54 (36), 40 (40), 18 (13).
3
4-Methoxy-N-[4-(phenoxymethyl)-1,3-oxathiolan-2-yli-
dene]benzenamine (3c, C17H17NO3S)
The crude product was purified by column chromatography
(SiO2, hexane/EtOAc 8/1, Rf = 0.28) affording 0.25 g (80 %)
N-[4-(Isopropoxymethyl)-1,3-oxathiolan-2-ylidene]benzen-
amine(3g, C13H17NO2S)
ꢀ
3c. M.p.: 133–135 °C; IR (KBr): m = 3,019, 2,967, 1,650,
1,542, 1,314, 1,124 cm-1 1H NMR (500 MHz, CDCl3):
;
The crude product was purified by column chromatogra-
phy (SiO2, hexane/EtOAc 8/1, Rf = 0.64) affording
d = 3.42–3.55 (m, CH2), 3.73 (s, OMe), 4.25–4.34 (m, CH2),
4.91–5.00 (m, CH), 6.77–7.28 (m, 9CH) ppm; 13C NMR
(125.7 MHz, CDCl3): d = 37.7 (CH2), 55.4(OMe), 62.9
(CH2), 77.6 (CH), 114.7 (2CH), 115.3 (2CH), 121.0 (CH),
123.7 (2CH), 129.6 (2CH), 141.3 (C), 156.4 (C), 159.1 (C),
160.1 (C) ppm; EI-MS (70 eV): m/z (%) = 315 (M?, 6), 182
(34), 149 (78), 133 (57), 107 (40), 93 (100), 43 (40), 34 (21).
ꢀ
0.22 g (88 %) 3g. M.p.: 93–95 °C; IR (KBr): m = 3,015,
2,988, 1,643, 1,571, 1,321, 1,122 cm-1
;
1H NMR
(500.1 MHz, CDCl3): d = 1.14 (d, 3J = 6.1 Hz, 2Me),
3.53–3.62 (m, CH2), 3.83–3.92 (m, CH), 4.11–4.14 (m,
3
CH2), 4.72–4.79 (m, CH), 7.03 (d, J = 6.9 Hz, 2 CH),
7.10–7.21 (m, 3CH) ppm;13C NMR (125.7 MHz, CDCl3):
d = 21.0 (2Me), 38.3 (CH2), 63.4 (CH), 69.9 (CH2), 74.3
(CH), 122.2 (2 CH), 127.6 (CH), 130.3 (2 CH), 149.3 (C),
163.7 (C) ppm; EI-MS (70 eV): m/z (%) = 251 (M?, 5),
192 (58), 135 (85), 116 (44), 77 (100), 59 (67), 57 (51),
54 (32).
N-(4-Methyl-1,3-oxathiolan-2-ylidene)benzenamine
(3d, C10H11NOS)
The crude product was purified by column chromatography
(SiO2, hexane/EtOAc 8/1, Rf = 0.59) affording 0.16 g
ꢀ
(81 %) 3d. M.p.: 75–77 °C; IR (KBr): m = 3,011, 2,988,
1,641, 1,556, 1,325, 1,114 cm-1 1H NMR (500 MHz,
;
N-[4-(Isopropoxymethyl)-1,3-oxathiolan-2-ylidene]-4-
methylbenzenamine (3h, C14H19NO2S)
CDCl3): d = 1.45 (d, 3J = 6.5 Hz, Me), 3.30–3.38 (m,
3
CH2), 4.75–4.84 (m, CH), 7.06 (d, J = 7.8 Hz, 2 CH),
The crude product was purified by column chromatography
(SiO2, hexane/EtOAc 8/1, Rf = 0.57) affording 0.23 g
7.11–7.25 (m, 3CH) ppm; 13C NMR (125.7 MHz, CDCl3):
d = 20.3 (Me), 38.4 (CH2), 70.3 (CH), 117.1 (2 CH), 120.1
(CH), 125.7 (2 CH), 141.6 (C), 160.1 (C) ppm; EI-MS
(70 eV): m/z (%) = 193 (M?, 1), 136 (81), 77 (100), 59 (53),
57 (78), 41 (31), 18 (22).
ꢀ
(85 %) 3h. M.p.: 101–103 °C; IR (KBr): m = 3,031, 2,973,
1,652, 1,577, 1,341, 1,142 cm-1; H NMR (500.1 MHz,
1
CDCl3): d = 1.15 (d, 3J = 6.7 Hz, 2Me), 2.33 (s, Me),
3.41–3.48 (m, CH2), 3.79–4.08 (m, 3CH), 4.71–4.83 (m,
3
3
CH), 7.06 (d, J = 7.8 Hz, 2 CH), 7.25 (d, J = 7.6 Hz, 2
CH) ppm; 13C NMR (125.7 MHz, CDCl3): d = 21.9 (Me),
23.1 (2Me), 37.4 (CH2), 64.2 (CH), 70.7 (CH2), 73.3 (CH),
122.3 (2 CH), 129.7 (2 CH), 135.6 (C), 144.5 (C), 160.0
4-Methyl-N-(4-methyl-1,3-oxathiolan-2-ylidene)benzen-
amine (3e, C11H13NOS)
The crude product was purified by column chromatography
(SiO2, hexane/EtOAc 8/1, Rf = 0.50) affording 0.16 g
123

Regioselective synthesis of 1,3-oxathiolane-2-imine derivatives
615
(C) ppm; EI-MS (70 eV): m/z (%) = 265 (M?, 7), 206
1,731, 1,633, 1,577, 1,345, 1,122 cm-1
;
1H NMR
(51), 149 (68), 116 (100), 91 (70), 59 (56), 57 (42), 54 (28).
(500.1 MHz, CDCl3): d = 1.90 (s, Me), 3.46–3.55 (m,
CH2), 4.50–4.63 (m, CH2), 4.91–5.00 (m, CH), 5.64 (m,
N-[4-(Isopropoxymethyl)-1,3-oxathiolan-2-ylidene]-4-
methoxybenzenamine (3i, C14H19NO3S)
3
CH), 6.17 (m, CH), 7.02 (t, J = 7.3 Hz, CH), 7.16 (d,
3J = 8.2 Hz, 2 CH), 7.33 (t, 3J = 7.9 Hz, 2 CH) ppm; 13
C
The crude product was purified by column chromatography
(SiO2, hexane/EtOAc 8/1, Rf = 0.50) affording 0.23 g
NMR (125.7 MHz, CDCl3): d = 18.0 (Me), 35.3
(CH2),65.9(CH2), 76.0 (CH), 122.3 (2 CH), 125.1 (CH2),
127.3 (CH), 130.1 (2 CH), 137.1 (C), 148.1 (C), 162.2 (C),
168.5 (C) ppm; EI-MS (70 eV): m/z (%) = 251 (M?, 5),
222 (78), 142 (76), 135 (80), 85 (65), 77 (100), 59 (51), 54
(32).
ꢀ
(81 %) 3i. M.p.: 107–109 °C; IR (KBr): m = 3,009, 2,967,
1
1,631, 1,590, 1,311, 1,130 cm-1; H NMR (500.1 MHz,
3
CDCl3): d = 1.17 (d, J = 6.5 Hz, 2Me), 3.42–3.50 (m,
CH2), 3.74–3.78 (m, CH2), 3.79 (s, OMe), 3.82–3.85 (m,
CH), 4.61–4.67 (m, CH), 6.84 (d, 3J = 7.1 Hz, 2 CH), 6.91
(d, 3J = 7.3 Hz, 2 CH) ppm; 13C NMR (125.7 MHz,
CDCl3): d = 22.0 (2Me), 36.5 (CH2), 55.4 (OMe), 62.3
(CH), 70.3 (CH2), 73.2 (CH), 115.3 (2 CH), 123.3 (2 CH),
141.3 (C), 157.5 (C), 159.3 (C) ppm; EI-MS (70 eV): m/
z (%) = 281 (M?, 5), 222 (51), 165 (100), 116 (63), 107
(75), 59 (58), 54 (27).
[2-(4-Methylphenylimino)-1,3-oxathiolan-4-yl]methyl
methacrylate (3m, C15H17NO3S)
The crude product was purified by column chromatography
(SiO2, hexane/EtOAc 8/1, Rf = 0.30) affording 0.25 g
ꢀ
(87 %) 3m. M.p.:121–123 °C; IR (KBr): m = 3,010, 2,977,
1,734, 1,644, 1,573, 1,340, 1,143 cm-1
;
1H NMR
(500.1 MHz, CDCl3): d = 1.93 (s, Me), 2.35(s, Me),
3.42–3.63 (m, CH2), 4.53–4.58 (m, CH2), 4.85–4.92 (m,
4-Methyl-N-(4-propyl-1,3-oxathiolan-2-ylidene)benzen-
amine(3j, C13H17NOS)
3
CH), 5.60 (m, CH), 6.14 (m, CH), 7.16 (d, J = 7.3 Hz, 2
The crude product was purified by column chromatography
(SiO2, hexane/EtOAc 8/1, Rf = 0.65) affording 0.19 g
CH), 7.33 (d, 3J = 6.9 Hz, 2 CH) ppm; 13C NMR
(125.7 MHz, CDCl3): d = 18.2 (Me), 24.3 (Me), 35.7
(CH2),65.1(CH2), 75.2 (CH), 123.1 (2 CH), 124.7(CH2),
130.1(2 CH), 136.1 (C), 139.1 (C), 149.0 (C), 163.0 (C),
167.2 (C) ppm; EI-MS (70 eV): m/z (%) = 251 (M?, 5),
206 (51), 149 (100), 142 (67), 91 (72), 59 (60), 57 (56), 54
(27).
ꢀ
(80 %) 3j. M.p.: 94–96 °C; IR (KBr): m = 3,020, 2,964,
1
1,645, 1,579, 1,313, 1,121 cm-1; H NMR (500.1 MHz,
CDCl3): d = 1.07 (t, 3J = 7.4 Hz, Me), 1.37–1.69 (m,
2CH2), 2.32 (s, Me), 3.47–3.55 (m, CH2), 4.62–4.76 (m,
3
3
CH), 7.10 (d, J = 6.9 Hz, 2 CH), 7.32 (d, J = 7.4 Hz, 2
CH) ppm; 13C NMR (125.7 MHz, CDCl3): d = 13.9 (Me),
17.6 (CH2), 23.9 (Me), 27.8 (CH2), 36.8 (CH2), 67.5 (CH),
122.7 (2 CH), 130.4 (2 CH), 134.5 (C), 147.4 (C), 162.1
(C) ppm; EI-MS (70 eV): m/z (%) = 235 (M?, 7), 202
(58), 149 (100), 91 (64), 86 (71), 59 (60), 57 (43), 54 (26).
N-(Hexahydrobenzo[d][1,3]oxathiol-2-ylidene)benzen-
amine (3n, C13H15NOS)
The crude product was purified by column chromatography
(SiO2, hexane/EtOAc 8/1, Rf = 0.69) affording 0.22 g
ꢀ
(93 %) 3n. M.p.: 168–170 °C; IR (KBr): m = 3,011, 2,968,
4-Methoxy-N-(4-propyl-1,3-oxathiolan-2-ylidene)benzen-
amine (3k, C13H17NO2S)
1
1,629, 1,573, 1,341, 1,119 cm-1; H NMR (500.1 MHz,
CDCl3): d = 1.39–2.14 (m, 8H), 2.56–2.63 (m, CH),
3.54–3.71 (m, CH), 7.13 (t, J = 7.1 Hz, CH), 7.20 (d,
The crude product was purified by column chromatography
(SiO2, hexane/EtOAc 8/1, Rf = 0.58) affording 0.20 g
3
3J = 8.2 Hz, 2 CH), 7.33 (t, 3J = 7.9 Hz, 2 CH) ppm; 13
C
ꢀ
(78 %) 3k. M.p.: 109–111 °C; IR (KBr): m = 3,025, 2,977,
1
1,631, 1,569, 1,341, 1,122 cm-1; H NMR (500.1 MHz,
NMR (125.7 MHz, CDCl3): d = 21.4 (CH2), 24.7 (CH2),
28.2 (CH2), 35.5 (CH2), 44.4 (CH), 80.1 (CH), 122.2 (2
CH), 127.6 (CH), 130.4 (2 CH), 147.4 (C), 164.6 (C) ppm;
EI-MS (70 eV): m/z (%) = 233 (M?, 4), 135 (100), 98
(67), 77 (85), 70 (54), 59 (60), 54 (20).
CDCl3): d = 1.11 (t, 3J = 7.0 Hz, Me), 1.35–1.62 (m,
2CH2), 3.32–3.50 (m, CH2), 3.65 (s, OMe), 4.61–4.70 (m,
3
3
CH), 6.81 (d, J = 6.3 Hz, 2 CH), 7.20 (d, J = 6.9 Hz, 2
CH) ppm; 13C NMR (125.7 MHz, CDCl3): d = 14.5 (Me),
16.3 (CH2), 28.2 (CH2), 35.2 (CH2), 55.4 (OMe), 64.8
(CH), 115.7 (2 CH), 123.4 (2 CH), 140.5 (C), 158.4 (C),
160.1 (C) ppm; EI-MS (70 eV): m/z (%) = 251 (M?, 5),
218 (42), 165 (100), 107 (40), 86 (78), 59 (60), 57 (54), 54
(26).
N-(Hexahydrobenzo[d][1,3]oxathiol-2-ylidene)-4-methyl-
benzenamine (3o, C14H17NOS)
The crude product was purified by column chromatography
(SiO2, hexane/EtOAc 8/1, Rf = 0.61) affording 0.22 g
ꢀ
(90 %) 3o. M.p.: 182–184 °C; IR (KBr): m = 3,028, 2,976,
1
1,633, 1,565, 1,323, 1,109 cm-1; H NMR (500.1 MHz,
[2-(Phenylimino)-1,3-oxathiolan-4-yl]methyl methacrylate
(3l, C14H15NO3S)
CDCl3): d = 1.44–2.11 (m, 8H), 2.35 (s, Me), 2.64–2.68
(m, CH), 3.63–3.70 (m, CH), 7.14 (d, 3J = 7.0 Hz, 2 CH),
The crude product was purified by column chromatography
(SiO2, hexane/EtOAc 8/1, Rf = 0.33) affording 0.25 g
3
7.33 (d, J = 7.2 Hz, 2 CH) ppm; 13C NMR (125.7 MHz,
CDCl3): d = 21.4 (CH2), 23.4 (Me), 24.7 (CH2),28.2
ꢀ
(91 %) 3l. M.p.: 110–112 °C; IR (KBr): m = 3,011, 2,967,
123

616
A. Samzadeh-Kermani
(CH2), 30.5 (CH2), 43.7 (CH), 81.1 (CH), 123.4 (2 CH),
130.1 (2 CH), 136.9 (C), 146.0 (C), 163.0 (C) ppm; EI-MS
(70 eV): m/z (%) = 247 (M?, 5), 149 (100), 98 (75), 91
(63), 71 (55), 59 (48), 54 (26).
(500 MHz, CDCl3): d = 3.27–3.50 (m, CH2), 4.89 (dd,
3
3
2J = 10.1 Hz, J = 5.6 Hz, CH), 7.12 (d, J = 7.0 Hz, 2
3
CH), 7.15–7.28 (m, 3CH), 7.38 (d, J = 8.1 Hz, 2 CH),
3
7.52 (d, J = 8.1 Hz, 2 CH) ppm;13C NMR (125.7 MHz,
CDCl3): d = 38.3 (CH2), 80.3 (CH), 112.5 (C), 116.2
(CN), 122.2 (2 CH), 127.5 (CH), 128.2 (2 CH), 130.1 (2
CH), 133.3 (2 CH), 145.1 (C), 148.4 (C), 164.2 (C) ppm;
EI-MS (70 eV): m/z (%) = 280 (M?, 4), 162 (21), 146
(34), 135 (74), 119 (80), 102 (58), 77 (100), 43 (32).
N-(4-Phenyl-1,3-oxathiolan-2-ylidene)benzenamine
(3p, C15H13NOS)
The crude product was purified by column chromatography
(SiO2, hexane/EtOAc7/1, Rf = 0.34) affording 0.20 g
ꢀ
(77 %) 3p. M.p.: 108–110 °C; IR (KBr): m = 3,051,
2,917, 1,631, 1,540, 1,312, 1,123 cm-1 1H NMR
;
(500 MHz, CDCl3): d = 3.21–3.44 (m, CH2), 4.79–4.83
(dd, 2J = 10.3 Hz, 3J = 5.7 Hz, CH), 7.13 (t, 3J = 7.1 Hz,
References
3
CH), 7.20 (d, J = 8.2 Hz, 2 CH), 7.33–7.61 (m, 7CH)
1. Jaramillo J, Chiara L (1994) J Org Chem 59:3135
2. Brunel JM, Legrand O, Reymond S, Buono G (2000) Angew
Chem Int Ed 39:2554
3. Reymond S, Legrand O, Brunel JM, Buono G (2001) Eur J Org
Chem 2819
4. Zhang R, Yu WY, Lai TS, Che CM (1999) Chem Comm 409
ppm;13C NMR (125.7 MHz, CDCl3): d = 37.1 (CH2), 79.3
(CH), 121.6 (2 CH), 126.4 (2 CH), 127.2 (CH), 128.0 (CH),
129.5 (2 CH), 130.9 (2 CH), 137.2 (C), 148.7 (C), 162.2
(C) ppm; EI-MS (70 eV): m/z (%) = 255 (M?, 2), 137
(41), 135 (74), 121 (53), 119 (86), 77 (100), 43 (34).
´ ´
5. Das U, Crousse B, Kesavan V, Bonnet-Delpon D, Begue JP
(2000) J Org Chem 65:6749
6. Reymond S, Brunel JM, Buono G (2002) Tetrahedron Asym-
metry 12:3457
7. Moghadam M, Tangestaninejad S, Mirkhani V, Shaibani R
(2004) Tetrahedron 60:6105
8. Sharghi H, Salimi Beni AR, Khalifeh R (2007) Helv Chim Acta
90:1373
9. Naeimi H, Moradian M (2006) Can J Chem 84:1575
10. Eshghi H, Rahimizadeh M, Shoryabi A (2005) J Iran Chem Soc
2:155
N-[4-(4-Methoxyphenyl)-1,3-oxathiolan-2-ylidene]benzen-
amine (3q, C16H15NO2S)
The crude product was purified by column chromatography
(SiO2, hexane/EtOAc7/1, Rf = 0.24) affording 0.20 g
ꢀ
(72 %) 3q. M.p.: 125–127 °C; IR (KBr): m = 3,037,
2,922, 1,632, 1,546, 1,324, 1,136 cm-1 1H NMR
(500 MHz, CDCl3): d = 3.23–3.45 (m, CH2), 3.65 (s,
;
2
3
OMe), 4.72 (dd, J = 9.6 Hz, J = 5.2 Hz, CH), 6.75 (d,
3
11. Sharghi H, Nejad AH (2004) Phosphorus Sulfur Silicon Relat
Elem 179:2297
3J = 7.5 Hz, 2 CH), 7.02 (d, J = 7.5 Hz, 2 CH), 7.10 (d,
3J = 7.5 Hz, 2 CH), 7.14–7.28 (m, 3CH) ppm;13C NMR
(125.7 MHz, CDCl3): d = 37.3 (CH2), 55.4 (OMe), 76.4
(CH), 114.0 (2 CH), 122.3 (2 CH), 127.5 (CH), 128.2 (2
CH), 130.4 (2 CH), 134.1 (C), 148.4 (C), 159.3 (C), 162.5
(C) ppm; EI-MS (70 eV): m/z (%) = 285 (M?, 5), 167
(28), 151 (34), 135 (72), 119 (80), 107 (54), 77 (100), 43
(40).
12. Yavari I, Ghazanfarpour-Darjani M, Hossaini Z, Sabbaghan M,
Hosseini N (2008) Synlett 889
13. Ollevier T, Lavie-Coupin G (2004) Tetrahedron Lett 45:49
´
14. Carree F, Gil R, Collin J (2004) Tetrahedron Lett 45:7749
15. Gil S, Torres M, Ortuzar N, Wincewicz R, Parra M (2004) Eur J
´
Org Chem 10:2160
16. Crotti P, Bussolo VD, Favero L, Pineschi M, Marianucci F, Renzi
G, Amici G, Roselli G (2000) Tetrahedron 56:7513
17. Arbelo DO, Prieto JA (2002) Tetrahedron Lett 43:4111
18. Jacobsen EN, Kakiuchi F, Konsler RG, Larrow JF, Tokunaga M
(1997) Tetrahedron Lett 38:773
19. Shirayev AK, Moiseev IK, Karpeev SS (2005) Arkivoc 199
20. Franke W, Dorfmeister G, Ganzer M, Johann G, Rees R (1990)
Substituted N-phenyl-4-alkyliden-1,3-oxathiolane-2-imines, pro-
cess for their preparation and their use as herbicidal agents.
EP0347789, 27 Dec 1989 Chem Abstr 112:235285
4-[2-(Phenylimino)-1,3-oxathiolan-4-yl]benzonitrile
(3r, C16H12N2OS)
The crude product was purified by column chromatography
(SiO2, hexane/EtOAc5/1, Rf = 0.32) affording 0.22 g
ꢀ
(80 %) 3r. M.p.: 146–149 °C; IR (KBr): m = 3,041,
1
2,938, 2,231, 1,634, 1,547, 1,318, 1,134 cm-1; H NMR
123