Organo-catalytic synthesis of 1,3-thiazole derivatives

Article abstract of DOI:10.3184/174751916X14656621014049

An efficient synthesis of 1,3-thiazolidine derivatives has been achieved in which 2-pyridinecarboxaldehyde oxime was employed as a base catalyst to effect cyclisation between aziridines and CS₂ in DMF at 40°C. A similar reaction between aziridi

Full text of DOI:10.3184/174751916X14656621014049

JOURNAL OF CHEMICAL RESEARCH 2016
VOL. 40 JULY, 445–448
RESEARCH PAPER 445
Organo-catalytic synthesis of 1,3-thiazole derivatives
Arash Khalaj and Mehdi Khalaj*
Young Researchers and Elite Club, Buinzahra Branch, Islamic Azad University, Buinzahra, Iran
An efficient synthesis of 1,3-thiazolidine derivatives has been achieved in which 2-pyridinecarboxaldehyde oxime was employed as a base
catalyst to effect cyclisation between aziridines and CS in DMF at 40 °C. A similar reaction between aziridines and thiocyanates yielded
2
1,3-thiazoline-2-imine derivatives
Keywords: 1,3-thiazoline-2-imine, thyiocyanates, aziridine, carbon disulphide, 1,3-thiazolidine
Aziridines (ethylene imines) are important building blocks due
to their high potential for applications in the fields of organic
Table 1 Optimisation of the reaction conditions (catalyst, solvent) for
the preparation of 4-benzyl-3-tosyl-1,3-thiazolidine-2-thione 3a from
a
2
-benzyl-1-tosylaziridine 1a and CS 2a
1
2
synthesis. They allow for convenient access to amines, amino
S
2
3
4–6
alcohols, diamines, and other useful amine derivatives.
Moreover, many transformations of aziridines with heterallenes
to form the corresponding N-containing heterocycles
Ts
N
TsN
Bn
S
7–9
+
have been well documented. Most of these ring-opening
reactions rely on a catalyst to give the desired heterocyclic
CS2
Bn
10–13
compounds in good yields.
Hou and coworkers have utilised
1a
2
3a
organophosphines to promote the cyclisation reaction between
14
three-membered heterocycles and heteroallenes. Additionally,
nitromethane has also been employed to mediate ring opening
of three-membered heterocycles in reaction with heteroallenes
OH
OH
N
N
N
15
N
at ambient conditions. However, we were especially interested
in a report by Yavari and coworker in which a useful organo-
catalytic route to form 1,3-oxathiolene-2-imines from epoxides
and thiocyanates used 2-pyridinecarboxaldehyde oxime
L1
L2
16
as the basic catalyst, as we planned to carry out a study of
the analogous reaction between thiocyanates and aziridine
using the same catalyst. We here report on that reaction and, as
a simpler variant, the reaction between carbon disulphide and
aziridine to form two types of 1,3-thiazole derivatives.
Entry
Catalyst
MeONa
pyridine N-oxide
MeONa
Solvent
THF
Yield/%
42
–
1
2
3
4
5
6
7
8
9
DMF
DMF
DMF
DMF
80
89
76
74
5
34
40
25
51
94
89
13
Bu NOMe
4
Results and discussion
L2
L1
L1
L1
L1
L1
L1
L1
L1
The reaction was initially examined using 2-benzyl-1-
CS2
tosylaziridine (1a) and CS (2) in the presence of MeONa
2
toluene
dioxane
THF
(10% mol). Stirring in THF at 40 °C for 4 h afforded 4-benzyl-
3
-tosylthiazolidine-2-thione (3a) in 42% yield (Table 1,
entry 1). To optimise the reaction conditions a variety of
solvents and catalysts were examined and the results are shown
in Table 1. Among the solvents examined, DMF was superior
to other solvents (entry 12). Reaction in an apolar solvent
like toluene led to a very low conversion (entry 7). Reaction
conducted in a protic solvent gave the desired product in a
moderate yield, most likely due to the lower nucleophilicity
of ethoxide ion in a protic solvent (entry 11). Ethers and a
chlorinated solvent were not efficient in this transformation
1
0
CH Cl2
2
1
1
EtOH
DMF
DMSO
1
2
1
3
14
L1
H2O
a
Reaction conditions: 1a (1.0 mmol), 2 (2.0 mmol), catalyst (20 mol%), and solvent (3 mL)
at 40 °C for 4 h.
(
entries 8, 9, and 10). Polar-aprotic solvents improved the yield
deduced that the steric issue on catalyst structure influences
the reaction progress. Pyridine N-oxide failed to promote the
desired reaction and resulted in a complicated mixture (entry
2). It is worth mentioning that no reaction took place at ambient
conditions even for longer reaction times.
The scope of this methodology was then evaluated using
substituted aziridines and the results are shown in Table 2.
Alkyl substituted aziridines 1b–e gave exclusively the products
of terminal-attack (entries 2–5). The difference in reactivity
of aryl-substituted aziridines was reflected in the reaction
of 2-phenyl-1-tosylaziridine 1f, where the attack occurred
exclusively at the benzylic position due to the influence of
appreciably, an outcome we attribute to the greater solubility
power towards polar compounds (entries 12 and 13). Reaction
conducted in H Oresultedinaverylowconversion(entry14). No
reaction took place in the absence of the catalyst even at higher
temperatures (not shown in Table 1). Tetrabutylammonium
methoxide achieved a higher conversion, most likely due to
better solubility in organic solvent than that of MeONa (entry
2
4
). Catalyst screening showed that 2-pyridinecarboxaldehyde
oxime L1 afforded the desired product in excellent 94%
yield (entry 12), but the 6-methyl analogue L2 afforded the
desired product in a lower yield of 76% (entry 5). It could be
*
Correspondent. E-mail: khalaj_mehdi@yahoo.com

4
46 JOURNAL OF CHEMICAL RESEARCH 2016
Table 2 Yields of a series of 3-tosyl-1,3-thiazolidine-2-thione derivatives
Table 3 Yields of a series of 3-tosyl-1,3-thiazoline-2-imine derivatives
1 2 3 4
1
2
3
3
a–k (R , R , R = various) prepared from mono- and disubstituted
5a–e (R , R , R , R = various) prepared from mono- and disubstituted
1 2 3
1
2
3
a
1
-tosylaziridines 1a–k (R , R , R = various) and CS 2a
1-tosylaziridines 1a,b,f,i (R , R , R = various) and either of two
2
4
thiocyanates 4 (R = Ph, i-Pr)
S
NR4
Ts
N
N
TsN
S
Ts
N
N
R3
N–OH
TsN
R3
R1
S
+
CS2
R3
R1
R3
N
–
OH
4
+
R NCS
R2
DMF, 40 °C
R1
R2
R2
DMF, 40 °C
R1
R2
1
2
3
1
4
5
1
2
3
Entry
Aziridine
R ,R , R
Bn, H, H
Product, Yield/%
3a, 94
4
1
2
3
Entry Aziridine Isothiocyanate R
R ,R , R
Product, Yield/%
5a, 91
1
2
3
4
5
6
7
8
9
1a
1b
1c
1d
1e
1f
1g
1h
1i
1
2
3
4
5
1a
1a
1b
1f
4a
4b
4b
4b
4b
Ph Bn, H, H
i-Pr Bn, H, H
i-Pr n-C H , H, Me
i-Pr H, Ph, H
n-C H , H, Me
n-C H , H, H
3b, 89
3c, 85
3d, 78
3e, 87
3f, 98
3g, 87
3h, 89
3i, 98
3
7
5b, 87
5c, 84
5d’, 90
5e, 86
4
9
n-C H , CH , H
3 7
5
11
3
n-C H , H, H
6
13
1i
i-Pr -(CH ) -,H
H, Ph, H
Me, Ph, H
2 4
a
Reaction conditions: 1 (1.0 mmol), 4 (1.0 mmol), L (20 mol%), and DMF (3 mL) at
0 °C for 7.
1
4
Ph, CO Me, H
2
-(CH ) -,H
2
4
10
1j
-(CH ) -,H
3j, 52
2
5
11
1k
n-C H , n-C H , H
3k, 94
3
7
3 7
a
Reaction conditions: 1 (1.0 mmol), 2 (2.0 mmol), L (20 mol%), in DMF (3 mL) at 40 °C
1
for 4 h.
Ts
N
N
O
= L1
S
NH
N
R
1
CS2
N
H
O
S
7
2
L1
S
S
S
S
TsN
R
TsN
R
S
R
S
L1 TsN
8
9
3
Scheme 1 Plausible mechanism for the formation of 3.
electronic and steric effects (entry 6). The gem-disubstituted
aziridine 1b gave the desired product in good yield (entry 2).
Among the aziridines derived from cycloalkenes 1i,j, only
the cyclohexene derivative afforded the desired product in
a good yield (entry 9). The regioselectivity of the reaction is
in accordance with that of aziridines with other nucleophiles
reported in the literature.
To extend the scope of this transformation, isothiocyanates 4
were also examined and exhibited a similar reactivity pattern
also showed a characteristic (AB)X spin system for the CH –
2
13
CH group, together with a singlet for the methyl group. The C
NMR spectrum of 5a exhibited 23 signals in agreement with
the proposed structure. The mass spectrum of 5a displayed the
molecular ion peak at m/z 422.
Although the mechanistic details of the formation of
compounds 3 are not known, a plausible rationalisation is
proposed in Scheme 1. Note that no reaction took place using
2-pyridinecarboxaldehyde oxime ethyl ether and benzaldehyde
oxime even for longer reaction times. These results suggest that
17–19
to that observed with CS , as shown in Table 3. Good yields
2
of 1,3-thiazoline-2-imines were obtained from both aryl 4a
the reaction starts presumably with the attack of L1 upon CS (2)
2
(
entry 1) and alkyl isothiocyanates 4b (entries 2–5). However,
to give 7, which adds to aziridine 1 to generate 8. Cyclisation of
this intermediate leads to 9 which affords 3 by elimination of L1.
a longer reaction time (7 h) was required to accomplish the
transformation. No product derived from the hydrolysis of
isothiocyanate was detected in NMR analyses.
Conclusion
The structures of 3a–k and 5a–e were confirmed by
spectroscopic analyses. For example, the H NMR spectrum
We have developed a facile organo-catalytic approach for the
synthesis of 1,3-thiazole derivatives. The reaction is completely
regioselective as shown by NMR analyses. This methodology
did not suffer from the limitations of previous reports such
as costly catalyst, extra dry solvent, strong base, and low
yield. Electronic and steric variations of the substrates showed
no appreciable change in the efficiency of the transformation.
1
of 3a showed a characteristic (AB)X spin system for the CH –
2
1
3
CH group, together with a singlet for the methyl group. The C
NMR spectrum of 3a exhibited 17 signals in agreement with
the proposed structure. The mass spectrum of 3a displayed the
14
14
16
1
molecular ion peak at m/z 363. The H NMR spectrum of 5a

JOURNAL OF CHEMICAL RESEARCH 2016 447
Using this procedure, a simple ether extraction is used to isolate
the pure product.
5-Methyl-4-pentyl-3-tosylthiazolidine-2-thione (3d)
The crude product was purified by washing with cold ether affording
0
.28 g (78%) 3d. Yellow oil; IR: n 2980, 2954, 1648, 1590, 1463, 1325,
Experimental
All chemicals used in this work except the aziridines were purchased
from Merck and were used without further purification. We prepared
–1 1 3
1
244, 1120 cm ; H NMR: δ 0.94 (t, J = 6.8 Hz, Me), 1.32–1.47 (m, 3 CH ),
2
3
1.53 (d, J = 6.5 Hz, Me), 1.78–1.82 (m, CH ), 2.34 (s, Me), 3.79–3.84 (m,
2
3
3
CH), 4.84–4.88 (m, CH), 7.41 (d, J = 6.9 Hz, 2 CH), 7.84 (d, J = 6.7 Hz,
2 CH); C NMR: δ 13.2 (Me), 15.0 (Me), 19.5 (CH ), 20.4 (CH ), 23.4
(Me), 28.2 (CH ), 33.5 (CH ), 51.0 (CH), 68.3 (CH ), 128.3 (2 CH), 130.7
(2 CH), 135.2 (C), 143.4 (C), 197.5 (C); EI-MS (70 eV): m/z (%) 357 (M , 1),
171 (43), 155 (100), 112 (73), 91 (61), 43 (31). Anal. calcd for C H NO S
(357.55): C, 53.75, H, 6.48; N, 3.92, S, 26.90; found: C, 53.89, H, 6.64; N,
4.11, S, 26.93%.
2
0
13
N-tosylaziridines using the literature procedures. Melting points were
measured on an Electrothermal 9100 apparatus. Elemental analyses for
C, H, and N were performed using a Heraeus CHN-O-Rapid analyser.
Mass spectra were recorded on a Finnigan-MAT 8430 spectrometer
operating at an ionisation potential of 70 eV. IR spectra were measured
on a Shimadzu IR-460 spectrometer (the samples were dissolved in
2
2
2
2
2
+
16
23
2 3
1
13
CHCl ). H NMR and C NMR spectra were measured with a Bruker
3
4
-Hexyl-3-tosylthiazolidine-2-thione (3e)
The crude product was purified by re-crystallisation from ether affording
.31 g (87%) 3e. M.p. 77–80 °C; IR: n 3023, 2984, 2963, 1652, 1585, 1457,
DRX-500 Avance spectrometer at 500.1 and 125.8 MHz, respectively.
NMR spectra were obtained for solutions in CDCl using TMS as the
internal standard. Chemical shifts (δ) are given in ppm and coupling
constants (J) are given in Hz.
3
0
–1
1
3
1322, 1278, 1117 cm ; H NMR: δ 0.93 (t, J = 6.4 Hz, Me), 1.30–1.45 (m,
4
CH ), 1.83–1.86 (m, CH ), 2.37 (s, Me), 3.22–3.36 (m, CH ), 4.91–4.94
2
2
2
Synthesis of compounds 4; general procedure
3
3
13
(m, CH), 7.40 (d, J = 6.6 Hz, 2 CH), 7.82 (d, J = 6.9 Hz, 2 CH); C NMR:
A mixture of 2-pyridinecarboxaldehyde oxime (20 mol%, 24 mg) and
δ 13.6 (Me), 21.4 (CH ), 22.7 (CH ), 23.5 (Me), 29.2 (CH ), 31.1 (CH ), 33.8
2
2
2
2
CS or a thicyanate (1–2 mmol) in DMF (3 mL) was heated to 40 °C.
(CH ), 36.1 (CH ), 70.1 (CH), 128.9 (2 CH), 130.2 (2 CH), 135.6 (C), 143.2
2 2
2
+
Aziridine (1 mmol) was then added to the resulting mixture in one
portion. The reaction mixture was then stirred for 4–7 h at 40 °C until
(C), 198.2 (C); EI-MS (70 eV): m/z (%) 357 (M , 1), 171 (51), 155 (100), 112
(76), 91 (44). Anal. calcd for C H NO S (357.55): C, 53.75, H, 6.48; N,
16
23
2 3
the substrate disappeared. Afterwards, the mixture was poured in H O
3.92, S, 26.90; found: C, 53.79, H, 6.56; N, 3.99, S, 26.98%.
-Phenyl-3-tosylthiazolidine-2-thione (3f)
The crude product was purified by recrystallisation from ether affording
2
(5 mL) and the pH was adjusted to 3 by addition of concentrated HCl.
5
The mixture was extracted with EtOAc (3 × 6 mL). The organic layers
were combined, dried over MgSO , filtered, and concentrated in vacuo
4
0
.34 g (98%) 3f. M.p. 116–118 °C; IR: n 3012, 2988, 2973, 1662, 1590,
to give crude products. If solid, the crude product was further purified
by recrystallisation from ether. The catalyst could be recovered for
another run by recrystallisation from EtOH–CH Cl .
–1 1
1448, 1319, 1283, 1109 cm ; H NMR: δ 2.36 (s, Me), 4.64–4.69 (m, CH),
3
1
3
4.81–4.87 (m, CH ), 7.18–7.42 (m, 7 CH), 7.82 (d, J = 7.1, 2 CH); C NMR:
2
2
2
δ 21.7 (Me), 62.5 (CH), 68.5 (CH ), 127.7 (CH), 128.8 (2 CH), 129.2 (2 CH),
2
4
-Benzyl-3-tosylthiazolidine-2-thione (3a)
The crude product was purified by recrystallisation from ether affording
.35 g (94%) 3a. M.p. 86–88.5 °C; IR: n 3017, 2987, 1629, 1589, 1465,
1
30.3 (2 CH), 130.7 (2 CH), 136.7 (C), 139.4 (C), 146.6 (C), 198.1 (C); EI-
+
MS (70 eV): m/z (%) 349 (M , 6), 171 (49), 155 (80), 104 (63), 91 (56), 77
0
(100), 54 (36). Anal. calcd for C H NO S (349.49): C, 54.99, H, 4.33; N,
16
15
2 3
–1 1
1
248, 1309, 1148 cm ; H NMR: δ 2.38 (s, Me), 2.92 (m, CH), 3.10 (dd,
4.01, S, 27.52; found: C, 55.11, H, 4.48, N, 4.18, S, 27.51%.
2
3
2
3
J = 6.9 Hz, J = 7.2 Hz, CH), 3.30 (dd, J = 7.1 Hz, J = 4.6 Hz, CH), 3.45
2
3
3
4-Methyl-5-phenyl-3-tosylthiazolidine-2-thione (3g)
(dd, J = 7.1 Hz, J = 12.1 Hz, CH), 4.93–4.99 (m, CH), 7.11 (t, J = 6.0 Hz,
3
3
The crude product was purified by recrystallisation from ether
affording 0.32 g (87%) 3g. M.p. 93–95 °C; IR: n 3028, 2976,
CH), 7.17 (d, J = 6.8 Hz, 2 CH), 7.24–7.37 (m, 4 CH), 7.82 (d, J = 7.0 Hz, 2
13
CH); C NMR: δ 23.1 (Me), 34.9 (CH ), 39.4 (CH ), 67.8 (CH), 127.0 (CH),
2
2
–
1
1
2
960, 1653, 1587, 1456, 1330, 1276, 1124 cm ; H NMR: δ 1.17 (d,
128.9 (2 CH), 129.2 (2 CH), 129.5 (2 CH), 130.1 (2 CH), 135.6 (C), 138.9
3
3
+
J = 6.1, Me), 2.35 (s, Me), 4.32–4.39 (m, CH), 4.67 (d, J = 6.7, CH),
(
1
C), 143.6 (C), 198.2 (C); EI-MS (70 eV): m/z (%) 363 (M , 3), 171 (63),
55 (34), 91 (100), 77 (52), 43 (44), 34 (18). Anal. calcd for C H NO S
3
13
7
2
.14–7.40 (m, 7 CH), 7.81 (d, J = 6.5, 2 CH); C NMR: δ 14.2 (Me),
3.5 (Me), 57.1 (CH), 62.4 (CH), 125.0 (CH), 128.1 (2 CH), 128.9 (2
CH), 129.1 (2 CH), 130.3 (2 CH), 134.3 (C), 137.1 (C), 143.8 (C), 197.7
17
17
2 3
(363.52): C, 56.17, H, 4.71; N, 3.85, S, 26.46; found: C, 56.43, H, 4.93; N,
3.95, S, 26.43%.
+
(
C); EI-MS (70 eV): m/z (%) 363 (M , 5), 171 (44), 155 (79), 118 (67),
4
-Methyl-4-propyl-3-tosylthiazolidine-2-thione (3b)
The crude product was purified by recrystallisation from ether affording
.29 g (89%) 3b. Yellow oil; IR: n 2983, 2970, 1634, 1594, 1473, 1236, 1324,
9
1 (51), 77 (100). Anal. calcd for C H NO S (363.52): C, 56.17, H,
17 17 2 3
4.71, N, 3.85, S, 26.46; found: C, 56.23, H, 4.79; N, 3.87, S, 26.52%.
0
–1
1
3
Methyl 5-phenyl-2-thioxo-3-tosylthiazolidine-4-carboxylate (3h)
1
132 cm ; H NMR: δ 0.96 (t, J = 6.4 Hz, Me), 1.28 (s, Me), 1.32–1.49 (m,
3
CH CH ), 2.36 (s, Me), 3.31–3.46 (m, CH ), 7.43 (d, J = 6.9 Hz, 2 CH), 7.82
The crude product was purified by recrystallisation from ether affording
2
3
2
2
13
(
d, J = 6.7 Hz, 2 CH); C NMR: δ 15.8 (Me), 16.0 (CH ), 20.1 (Me), 23.7
0.36 g (89%) 3h. M.p. 105–107 °C; IR: n 3031, 2973, 1743, 1652, 1590,
2
–1 1
(Me), 40.4 (CH ), 45.6 (CH ), 78.2 (C), 129.6 (2 CH), 130.5 (2 CH), 134.6
1461, 1327, 1260, 1128 cm ; H NMR: δ 2.36 (s, Me), 3.59 (s, MeO), 4.89
3 3 3
2
2
+
(
1
C), 143.8 (C), 197.9 (C); EI-MS (70 eV): m/z (%) 329 (M , 2), 253 (28),
71 (41), 131 (78), 91 (42), 98 (100), 43 (47). Anal. calcd for C H NO S
2 3
(d, J = 10.9, CH), 5.19 (d, J = 10.8, CH), 7.16 (d, J = 6.8, CH), 7.22 (d,
3
3
13
J = 6.6, 2 CH), 7.27–7.41 (m, 4 CH), 7.82 (d, J = 6.9, 2 CH); C NMR: δ
14
19
(329.50): C, 51.03, H, 5.81; N, 4.25, S, 29.19; found: C, 51.14, H, 5.97; N,
23.4 (Me), 54.6 (MeO), 56.4 (CH), 70.2 (CH), 127.3 (CH), 128.2 (2 CH),
4
.42, S, 29.36%.
128.6 (2 CH), 128.9 (2 CH), 130.9 (2 CH), 134.5 (C), 139.5 (C), 144.1
+
(C), 169.2 (C), 198.1 (C); EI-MS (70 eV): m/z (%) 407 (M , 7), 171 (51),
4
-Butyl-3-tosylthiazolidine-2-thione (3c)
The crude product was purified by recrystallisation from ether affording
.28 g (85%) 3c. M.p. 72–73 °C; IR: n 2980, 2954, 1648, 1590, 1463,
1
62 (68), 155 (71), 78 (46), 77 (100), 54 (28). Anal. calcd for C H NO S
18 17 4 3
(407.53): C, 53.05, H, 4.20; N, 3.44, S, 23.60; found: C, 53.11, H, 4.29; N,
0
3.42, S, 23.61%.
–1
1
3
1
245, 1320, 1122 cm ; H NMR: δ 0.98 (t, J = 6.4 Hz, Me), 1.39–1.50
2
Hexahydro-3-tosyl[1,3]benzothiazole-2(3H)-thione (3i)
(
m, CH CH ), 1.85–1.92 (m, CH ), 2.34 (s, Me), 3.26 (dd, J = 7.3 Hz,
2
2
2
3
2
3
J = 6.7 Hz, CH), 3.37 (dd, J = 6.3 Hz, J = 11.7 Hz, CH), 4.87 (m, CH), 7.40
The crude product was purified by recrystallisation from ether affording
3
3
13
(
2
d, J = 6.9 Hz, 2 CH), 7.81 (d, J = 6.7 Hz, 2 CH); C NMR: δ 15.6 (Me),
0.32 g (98%) 3i. M.p. 181–182 °C; IR: n 3020, 2964, 1645, 1579, 1449, 1313,
–1 1
2.0 (CH ), 23.5 (Me), 28.4 (CH ), 30.0 (CH ), 34.2 (CH ), 78.0 (CH ),
1268, 1121 cm ; H NMR: δ 1.42–2.19 (m, 8 H), 2.34 (s, Me), 3.14–3.22 (m,
3 3
2
2
2
2
2
128.2 (2 CH), 130.3 (2 CH), 136.0 (C), 142.9 (C), 198.2 (C); EI-MS (70 eV):
CH), 4.01–4.05 (m, CH), 7.40 (d, J = 6.7, 2 CH), 7.84 (d, J = 6.9, 2 CH);
+
13
m/z (%) 329 (M , 6), 171 (34), 155 (78), 133 (57), 99 (100), 43 (40). Anal.
C NMR: δ 21.9 (CH ), 23.4 (Me), 26.2 (CH ), 27.8 (CH ), 32.1 (CH ), 53.5
2
2
2
2
calcd for C H NO S (329.50): C, 51.03, H, 5.81; N, 4.25, S, 29.19; found:
C, 51.18, H, 5.97; N, 4.38, S, 29.22%.
(CH), 68.1 (CH), 128.4 (2 CH), 130.0 (2 CH), 135.1 (C), 143.9 (C), 198.9
(C); EI-MS (70 eV): m/z (%) 327 (M , 7), 171 (58), 155 (100), 91 (64), 82
14
19
2 3
+

4
48 JOURNAL OF CHEMICAL RESEARCH 2016
(
71), 54 (60). Anal. calcd for C H NO S (327.49): C, 51.35, H, 5.23; N,
N-(5-Phenyl-3-tosylthiazolidin-2-ylidene)propan-2-amine (5d)
14
17
2 3
4.28, S, 29.37; found: C, 51.42, H, 5.32; N, 4.33, S, 29.36%.
The crude product was purified by recrystallisation from ether affording
0
.34 g (90%) 5d. M.p. 89–91 °C; IR: n 3034, 2989, 1654, 1563, 1488, 1324,
Octahydro-3-tosylcyclohepta[d]thiazole-2-thione (3j)
–1
1
3
1119 cm ; H NMR: δ 0.96 (d, J = 6.5 Hz, 2 Me), 2.31 (s, Me), 3.63–3.68
The crude product was purified by recrystallisation from ether affording
3
(m, CH), 4.30–4.35 (m, CH), 4.58–4.64 (m, CH ), 7.11 (d, J = 6.8, 2 CH),
0
.18 g (52%) 3j. M.p. 178 °C (decomp.); IR: n 3025, 2977, 1631, 1569,
2
–1
1
3
3
1
463, 1341, 1122 cm ; H NMR: δ 1.36–2.16 (m, 10 H), 2.36 (s, Me),
7.15–7.30 (m, 3 CH), 7.41 (d, J = 6.4 Hz, 2 CH), 7.82 (d, J = 6.6 Hz, 2 CH);
13
3
3
.68–3.74 (m, CH), 4.73–4.79 (m, CH), 7.81 (d, J = 6.7, 2 CH), 7.83 (d,
C NMR: δ 21.3 (2 Me), 23.5 (Me), 49.3 (CH), 57.9 (CH), 63.4 (CH2),
3
13
J = 6.8, 2 CH); C NMR: δ 22.1 (CH ), 24.5 (Me), 25.2 (CH ), 26.0
2
2
127.1 (CH), 127.6 (2 CH), 128.3 (2 CH), 129.6 (2 CH), 130.1 (2 CH), 134.1
(
CH ), 31.3 (CH ), 34.7 (CH ), 52.5 (CH), 73.1 (CH), 128.7 (2 CH), 130.2
+
2
2
2
(C), 141.4 (C), 143.5 (C), 156.2 (C); EI-MS (70 eV): m/z (%) 374 (M , 5),
+
(
5
2 CH), 134.5 (C), 143.7 (C), 199.4 (C); EI-MS (70 eV): m/z (%) 341 (M ,
), 265 (23), 171 (48), 155 (100), 96 (78), 91 (54), 54 (44). Anal. calcd
for C H NO S (341.51): C, 52.75, H, 5.61; N, 4.10, S, 28.17; found: C,
171 (45), 155 (76), 104 (51), 110 (65), 77 (100), 54 (32). Anal. calcd for
C H N O S (374.52): C, 60.93, H, 5.92; N, 7.48, S, 17.12; found: C, 61.11,
19
22
2
2 3
15
19
2 3
H, 6.11; N, 7.64, S, 17.19%.
5
2.89, H, 5.79; N, 4.23, S, 28.21%.
,5-Dipropyl-3-tosylthiazolidine-2-thione (3k)
The crude product was purified by recrystallisation from ether affording
N-(Hexahydro-3-tosylbenzo[d]thiazol-2(3H)-ylidene)propan-2-amine
4
(5e)
The crude product was purified by recrystallisation from ether affording
0
.34 g (94%) 3l. Oily solid; IR: n 3011, 2967, 1633, 1577, 1478, 1345,
–1 1
1
122 cm ; H NMR: δ 0.94–2.11 (m, 14 H), 2.34 (s, Me), 3.50–3.58 (m,
0.30 g (86%) 5e. M.p. 158–160 °C; IR: n 3011, 2977, 1645, 1561, 1482, 1321,
1109 cm ; H NMR: δ 0.94 (d, J = 6.4, 2 Me), 1.32–2.24 (m, 8 CH), 2.34
(s, Me), 3.63–3.67 (m, CH), 3.80–3.85 (m, CH), 4.75–4.79 (m, CH), 7.42 (d,
3
3
–1
1
3
CH), 4.76–4.84 (m, CH), 7.41 (d, J = 6.8, 2 CH), 7.82 (d, J = 6.9 Hz, 2
13
CH); C NMR: δ 13.8 (Me), 15.0 (Me), 21.3 (CH ), 22.9 (CH ), 23.7
2
2
(Me), 30.2 (CH ), 31.6 (CH ), 53.1 (CH), 66.8 (CH), 128.7 (2 CH), 130.6
3
3
13
2
2
J = 6.8, 2 CH), 7.83 (d, J = 6.4 Hz, 2 CH); C NMR: δ 21.5 (2 Me), 22.4
CH ), 23.6 (Me),27.4 (CH ), 29.1 (CH ), 30.2 (CH ), 42.6 (CH), 50.3 (CH),
+
(
2 CH), 135.1 (C), 143.5 (C), 197.8 (C); EI-MS (70 eV): m/z (%) 357 (M ,
), 281 (29), 171 (67), 155 (100), 112 (71), 91 (53), 54 (32). Anal. calcd for
C H NO S (357.55): C, 53.75, H, 6.48; N, 3.92, S, 26.90; found: C, 53.89,
(
2
2
2
2
5
67.1 (CH), 128.1 (2 CH), 130.3 (2 CH), 134.6 (C), 144.2 (C), 165.3 (C); EI-
16
23
2
3
+
MS (70 eV): m/z (%) 352 (M , 5), 251 (35), 171 (61), 155 (100), 82 (60), 91
48), 54 (32). Anal. calcd for C H N O S (352.50): C, 57.92, H, 6.86; N,
H, 6.64; N, 4.08, S, 26.98%.
(
17
24
2
2 2
N-(4-Benzyl-3-tosylthiazolidin-2-ylidene)benzenamine (5a)
7.95, S, 18.19; found: C, 58.30, H, 6.93; N, 8.10, S, 18.28%.
The crude product was purified by recrystallisation from ether affording
0
.39 g (91%) 5a. M.p. 118–120 °C; IR: n 3011, 2967, 1643, 1577, 1478, 1345,
This work was supported by a research grant from the Young
Researchers and Elite Club, Islamic Azad University Buinzahra
Branch.
–1 1
1
122 cm ; H NMR: δ 2.34 (s, Me), 2.96–3.42 (m, 4 CH), 4.81–4.85 (m,
3
3
CH), 6.72 (d, J = 6.8, 2 CH), 7.08 (t, J = 6.5, CH), 7.26–7.41 (m, 9 CH),
3
13
7
.82 (d, J = 6.9 Hz, 2 CH); C NMR: δ 23.5 (Me), 34.3 (CH ), 39.7 (CH ),
2
2
68.1 (CH), 120.1 (2 CH), 124.4 (CH), 126.1 (CH), 128.0 (2 CH), 128.4 (2
CH), 129.2 (2 CH), 130.4 (2 CH), 131.6 (2 CH), 135.5 (C), 138.6 (C), 143.9
Received 1 May 2016; accepted 2 May 2016
Paper 1604027 doi: 10.3184/174751916X14656621014049
Published online: 16 June 2016
+
(C), 149.4 (C), 156.2 (C); EI-MS (70 eV): m/z (%) 422 (M , 5), 155 (69),
1
35 (46), 118 (64), 91 (100), 77 (81), 54 (32). Anal. calcd for C H N O S
23
22
2
2 2
(422.56): C, 65.37, H, 5.25; N, 6.63, S, 15.18; found: C, 56.42, H, 5.31; N,
6.67, S, 15.22%.
References
1
2
3
4
5
6
7
8
9
J. Wu, X. Hou and L. Dai, J. Org. Chem., 2000, 65, 1344.
C. Loncanic and W.D. Wulff, Org. Lett., 2001, 3, 3675.
N-(4-Benzyl-3-tosylthiazolidin-2-ylidene)propan-2-amine (5b)
The crude product was purified by recrystallisation from ether affording
Z. Li, M. Fernandez and E.N. Jacobsen, Org. Lett., 1999, 1, 1611.
G. Righi, R. D’Achille and C. Bonini, Tetrahedron Lett., 1996, 37, 6893.
F.A. Davis, G .V . Reddy and C.H. Liang, Tetrahedron Lett., 1997, 38, 5139.
J. Almena, F. Foubelo and M. Yus, J. Org. Chem., 1994, 59, 3210.
U.M. Lindström and P. Somfai, J. Am. Chem. Soc., 1997, 119, 8385.
C. Vogel, Synthesis, 1997, 497.
S.J. Hedley, W.J. Moran, A.H.G.P. Prenzel, D.A. Price and J.P.A. Harrity,
Synlett., 2001, 1596.
L. Dubois, A. Mehta, E. Tourette and R.H. Dodd, J. Org. Chem., 1994, 59, 434.
0
.34 g (87%) 5b. M.p. 78–81 °C; IR: n 3018, 2978, 1658, 1560, 1468,
–
1
1
3
1
322, 1108 cm ; H NMR: δ 0.96 (6 H, d, J = 6.4 Hz, 2 Me), 2.32 (s, Me),
3.33–3.41 (m, 2 CH ), 3.61–3.65 (H, m, CH), 4.56–4.61 (m, CH), 7.12–7.35
2
3
3
13
(m, 5 CH), 7.40 (d, J = 6.7 Hz, 2 CH), 7.83 (d, J= 6.6 Hz, 2 CH); C NMR:
δ 21.5 (2 Me), 23.5 (Me), 34.3 (CH ), 39.1 (CH ), 49.0 (CH), 67.3 (CH),
2
2
125.1 (CH), 127.2 (2 CH), 128.4 (2 CH), 128.9 (2 CH), 130.1 (2 CH),
1
35.7 (C), 137.1 (C), 144.0 (C), 155.9 (C); EI-MS (70 eV): m/z (%) 388
+
(M , 5), 155 (64), 118 (76), 101 (50), 91 (100), 77 (60), 54 (32). Anal. calcd
1
0
for:C H N O S (388.55): C, 61.82, H, 6.23; N, 7.21, S, 16.51; found: C,
20
24
2
2
2
11 P. Dauban, L. Dubois, M.E.T.H. Dau and R.H. Dodd, J. Org. Chem., 1995, 60,
035.
E. Medina, A. Moyano, M.A. Pericàs and A. Riera, J. Org. Chem., 1998, 63,
574.
61.96, H, 6.37; N, 7.36, S, 16.50%.
2
12
N-(4-Methyl-4-propyl-3-tosylthiazolidin-2-ylidene)propan-2-amine (5c)
8
The crude product was purified by recrystallisation from ether affording
1
3
D. Ferraris, W.J. Drury, C. Cox and T. Lectka, J. Org. Chem., 1998, 63, 4568.
J.Y. Wu, Z.B. Luo, L.X. Dai and X.L. Hou, J. Org. Chem., 2008, 73, 9137.
M. Ghazanfarpour-Darjani and A. Khodakarami, Monatsh Chem., 2016, 147,
829.
0
.30 g (84%) 5c. Oily solid; IR: n =3034, 2976, 1652, 1562, 1486, 1331,
1
4
–1 1
1
116 cm ; H NMR: δ 0.93–0.98 (9 H, m, 3 Me), 1.22 (s, Me), 1.33–1.69
15
(
m, 2 CH ), 2.34 (s, Me), 3.21–3.38 (m, CH ), 3.62–3.66 (m, CH), 7.41 (d,
2
2
3
3
13
J = 6.5 Hz, 2 CH), 7.82 (d, J = 6.3 Hz, 2 CH); C NMR: δ 13.4 (Me), 17.8
CH ),21.7 (Me), 22.4 (2 Me), 23.6 (Me), 36.1 (CH ),45.1 (CH ), 49.2 (CH),
1
6
I. Yavari and M. Ghazanfarpour-Darjani, J. Sulphur Chem., 2014, 35, 477.
(
2
2
2
17 D. Tanner, Angew. Chem. Int. Ed. Engl., 1994, 33, 599.
18 H. Stamm, J. Prakt. Chem., 1999, 341, 319.
19 X.E. Hu, Tetrahedron, 2004, 60, 2701.
7
4.3 (C), 128.1 (2 CH), 129.8 (2 CH), 134.1 (C), 143.6(C), 165.1 (C); EI-MS
+
(70 eV): m/z (%) 354 (M , 5), 155 (89), 101 (76), 91 (48), 84 (100), 54 (32).
Anal. calcd for C H N O S (354.53): C, 57.59, H, 7.39; N, 7.90, S, 18.09;
found: C, 57.72, H, 7.50; N, 7.92, S, 18.18%.
20 T. Ando, D. Kano, S. Minakata, N. Ryu and M. Komatsu, Tetrahedron, 1998,
54, 13485.
17
26
2
2 2