Pyridine-N-oxide: An efficient organocatalyst for ring-opening reactions of aziridines with aryl thiols

Article abstract of DOI:10.1002/cjoc.201190064

Pyridine-N-oxide serves as an efficient catalyst for the ring-opening reactions of N-tosylaziridines with various aryl thiols under mild conditions. This transformation is highly effective, which gives rise to the corresponding β-amino sulfides in good to

Full text of DOI:10.1002/cjoc.201190064

FULL PAPER
Pyridine-N-oxide: An Efficient Organocatalyst for Ring-
Opening Reactions of Aziridines with Aryl Thiols
Yang, Qina,b(杨琴)
Yin, Zhenlana(尹正兰)
Yang, Mina(杨民)
Peng, Yiyuan*,a,b(彭以元)
a Jiangxi Key Laboratory of Green Chemistry, Department of Chemistry, Jiangxi Normal University, Nanchang,
Jiangxi 330027, China
b Key Laboratory of Functional Small Organic Molecule, Ministry of Education, College of Life Science, Jiangxi
Normal University, Nanchang, Jiangxi 330022, China
Pyridine-N-oxide serves as an efficient catalyst for the ring-opening reactions of N-tosylaziridines with various
aryl thiols under mild conditions. This transformation is highly effective, which gives rise to the corresponding
β-amino sulfides in good to excellent yields.
Keywords pyridine-N-oxide, ring-opening reaction, N-tosylaziridine, thiol, β-amino sulfide
Introduction
phophine or tertiary amine as organocatalyst in the
ring-opening reactions of aziridines, we envisioned that
N-oxide might be utilized as an attractive alternative
catalyst in the reactions due to its unique characteristics
as well as its stability and nucleophilic similarity. To
verify the practicability of this projected route, we
started to investigate the possibility for N-oxide cata-
lyzed ring-opening reactions of aziridines with thiols.
Aziridines have attracted increasing attention as
versatile building blocks and important precursors for
the synthesis of many nitrogen-containing biologically
interesting molecules.1 Considerable progress has been
achieved in the nucleophilic ring-opening reactions of
aziridines.2 They are known to react with various nu-
cleophiles and their properties to undergo regioselective
ring opening reactions contribute largely to their syn-
thetic value.3 Among these reactions, the ring-opening
reactions of aziridines with thiols are the most interest-
ing4 because the resultant β-amino sulfides are important
for the synthesis of many other biologically interesting
molecules such as amino acids,1b,1h heterocycles,5 and
alkaloids.6 However, most of these reactions require a
strong base or Lewis acid.7 Recently, organocatalysts
have been successfully employed in such transformation.
For instance, phosphine,2a,2b tertiary amine,2c,2d or
DMSO2e had been used as catalyst or promoter to fa-
cilitate the ring-opening reactions of aziridines with
thiols.
It is well-known that the interest in the field of or-
ganocatalysis has increased spectacularly in the last few
years as result of both the novelty of the concept and,
more importantly, the fact that the efficiency and selec-
tivity of many organocatalytic reactions meet the stan-
dards of established organic reactions. Besides phophine
and tertiaryamine, N-oxide is another example of a
privileged catalyst class. They are able to mediate an
astonishingly wide variety of transformations both as
organocatalysts and ligands.8,9 Prompted by the facts of
Results and discussion
At the outset, aziridine 1a and p-methylbenzenethiol
(2a) were utilized as model substrates to optimize the
reaction conditions (Table 1). Initially, 10 mol% pyri-
dine-N-oxide as catalyst was employed in the reaction.
To our delight, we observed the formation of the desired
product 3aa in acetonitrile with 65% yield (Table 1,
Entry 1). It is noteworthy that this reaction could be run
under the air without loss of efficiency. The anti-
stereochemistry of the product 3aa was confirmed by its
1H NOESY NMR coupling constant for two cyclic me-
thine hydrogens at the trans-positions.2a,2d,4f Further
screening of solvents revealed that this reaction also
worked well in water, although the yield was low (30%
yield) (Table 1, Entry 2). 92% yield of product 3aa
could be obtained when the reaction was performed in
THF (Table 1, Entry 6). The same result was observed
when methanol was used as a replacement in the reac-
tion (Table 1, Entry 8). In addition, the reaction was
completed in 5 h at room temperature. Decreasing the
amount of catalyst diminished the product yield with
prolonged reaction time (data not shown in Table 1).
*
E-mail: yiyuanpeng@yahoo.com
Received June 21, 2010; revised September 16, 2010; accepted September 30, 2010.
Project supported by the National Natural Science Foundation of China (Nos. 20862009 and 20962010) and the Natural Science Foundation of
Jiangxi Province (No. 2008GQH0026).
Chin. J. Chem. 2011, 29, 79— 84
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79

Yang et al.
FULL PAPER
Blank experiment showed that the reaction only gave
25% yield after 10 h in the absence of N-oxide (Entry 9),
which differs from Lejon’s result.10
Table 2 Ring-opening reactions of aziridine 1a with various
thiols in methanol catalyzed by pyridine-N-oxide
Table 1 Ring-opening reactions of aziridine with p-methyl-
benzenethiol in various solvents
Entry
1
RSH
Product 3
Time/h Yielda/%
(3aa)
(3ab)
5
5
92
90
92
90
96
Entry
Solvent
CH3CN
H2O
Time/h
25
24
16
18
24
16
5
Yielda/%
65
2
3
4
5
1
2
30
3
CH2Cl2
CHCl3
82
(3ac) 4.5
4
80
5
CH3COOEt
THF
65
6
92
(3ad)
4
7
C2H5OH
CH3OH
CH3OH
80
8
9b
5
92
10
25
a Isolated yield based on the aziridine; b pyridine-N-oxide was not
added.
(3ae) 4.5
Effects of thios on the ring-opening reactions
We investigated the reaction scope of this N-oxide
catalytic system and its tolerance of functional groups in
the case of other aziridines 1 and thiols 2 under the op-
timized conditions [pyridine-N-oxide (10 mol%),
methanol, 25 ℃] (Tables 2 and 3). We rapidly noticed
the broad field of application of the process and its re-
markable functional group compatibility on both re-
agents. With respect to the thiophenols, the expected
products resulting from reactions of aziridine 1a were
obtained and isolated in good to excellent yields (Table
2, Entris 1—6). It is found that the conditions had
proven to be useful for various thiophenols. Aryl thiols,
whether the substituent on the benzene ring is electron
withdrawing or donating produced in excellent yields
(Entries 1—5, yields from 90%—96%). 2-Aminoben-
zenethiol reacted with aziridine 1a to afford the mixture
of corresponding S-nucleophile and N-nucleophile
ring-opening product in 88% yield with 90/10 ratio (Ta-
ble 2, Entry 6).
(3af)
88
6
8
(90∶ 10)b
(3ag)
7
8
(3ah) 30
25
23
10
12
(3ah) 24
(3ai) 30
(3ai) 40
9c
10d
When alkyl thiols were used as the nucleophile un-
der the similar condituion, the expected S-nucleophile
ring opening products 3 were not obtained, but the
methanol (solvent) nucleophile ring-opening product of
aziridine 1a was obtained in low yields (Entries 7—8).
When THF or CH3CN replaced methanol as the solvent,
a Isolated yield based on the aziridine. b Ratios of the two regio-
isomers were determined by H NMR. c THF was used as the
1
reaction solvent. d CH3CN was used as the reaction solvent.
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Chin. J. Chem. 2011, 29, 79— 84

Ring-Opening Reactions of Aziridines with Aryl Thiols
the correspound group, were reacted with 1a and gave
the corresponding alkyl thiol nucleophile ring-opening
product only obtained in very low yeilds (Entries 9—
10).
Table 3 Ring-opening reactions of various aziridines with ben-
zenethiol in methanol with 10 mol% pyridine-N-oxide
Effects of aziridines on the ring-opening reaction
In a second set of experiments, the scope of the
process with respect to aziridines was investigated. All
the expected products were generated under our stan-
dard experimental conditions, whatever the nature of the
substituents was. As shown in Table 3, moderate to ex-
cellent yields (71% — 96%) were obtained for all
aziridines. In the case of the unsymmetric aziridines (1c
and 1d), regioselective attack of the thiol on the less
substituted aziridine carbon was observed (Entries 3 and
4). When electronic effect participates, such as sub-
strates 1e, 1f, 1g and 1h, the regioselective attack of the
thiol on the benzyl substituted aziridine carbon was ob-
served (Table 3, Entries 5, 6, 7, and 8). These results
reflect that the electron effect is the main influence in
the reaction.
Entry Reactant
Product
Time/h Yielda/%
1
2
3
4
5
6
7
8
1a
1b
1c
1d
1e
1f
3ab
3bb
5
4.5
5
89
76
95
96
71
75
85
73
3cb/4cb (96/4)b
3db/4db (80/20)
3eb/4eb (18/82)
3fb/4fb (25/75)
3gb/4gb (10/90)
3hb/4hb (20/80)
5
4
Mechanism of the ring-opening reaction catalyzed by
pyridine-N-oxide
5
For the mechanism, based on the previous reports2,9i
we reasoned that the pyridine-N-oxide would act as a
nucleophilic trigger in the reaction process, which at-
tacked the aziridine 1 to form intermediate A. Subse-
quently, deprotonation of thiol 2 would occur to gener-
ate RS－ . Then RS－ reacted with aziridine 1 leading to
the ring-opened intermediate C. Meanwhile another
thiol would be involved in the reaction, which gave rise
to the corresponding product 3 and regenerated the RS－
to complete the catalytic cycle (Scheme 1). In addition,
the product from oxidation process which was described
by Hou9k was not observed. It might be due to the pres-
ence of thiol in the reaction, which inhibited the intra-
molecular deprotonation process. Furthermore, when
1g
1h
5
10
a Isolated yield based on the arziridine. b Ratio was determined by
1H NMR.
alkyl thiols were used as the nucleophile, the nucleo-
phile is not acidic enough to generate RS－ , and the
yields are low.
Conclusions
We have developed an efficient method for the ring
opening of aziridines with various aryl thiols catalyzed
by pyridine-N-oxide. The advantages of this method
Scheme 1 Proposed reaction pathway
Chin. J. Chem. 2011, 29, 79— 84
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81

Yang et al.
FULL PAPER
161.4, 163.9; IR (KBr) ν: 3294.4, 3028.8, 2934.7,
include the use of air-stable, inexpensive pyridine-
N-oxide as catalyst under mild conditions, good sub-
strate generality, and experimentally operational ease.
Desymmetrization of meso aziridines with thiols by us-
ing chiral N-oxide as catalysts is under investigation in
our laboratory.
2852.6, 1597.2, 1494.9, 1443.9, 1327.0, 1158.4, 1083.8,
－
1
817.0, 710.0, 668.0 cm
; HRMS calcd for
C19H22FNO2S2 379.1076, found 379.1072.
N-[2-(2-Chlorophenyl)thiocyclohexyl]-4-methyl-
benzenesulfonamide (3ae)11 White solid; m.p. 100—
101 ℃; 1H NMR (CDCl3, 400 MHz) δ: 1.25—1.35 (m,
3H), 1.50—1.53 (m, 1H), 1.58—1.65 (m, 2H), 2.02—
2.06 (m, 1H), 2.24—2.37 (m, 1H), 2.43 (s, 3H), 3.12—
3.13 (m, 2H), 5.34 (d, J＝4.0 Hz, 1H, NH), 7.18—7.20
(m, 2H), 7.27 (d, J＝8.0 Hz, 2H), 7.36—7.40 (m, 2H),
7.75 (d, J＝8.0 Hz, 2H); 13C NMR (CDCl3, 100 MHz) δ:
21.6, 23.0, 24.0, 31.1, 32.1, 50.0, 55.2, 127.2, 127.3,
128.2, 129.6, 130.0, 132.9, 133.2, 136.2, 137.1, 143.3.
N-[2-(2-Aminophenyl)thiocyclohexyl]-4-methyl-
benzenesulfonamide (3af) Solid; m.p. 131—133 ℃;
1H NMR (CDCl3, 400 MHz) δ: 1.18—1.25 (m, 4H),
1.31—1.38 (m, 1H), 1.56—1.62 (m, 1H), 1.91—2.02
(m, 1H), 2.18—2.19 (m, 1H), 2.43 (s, 3H), 2.71—2.72
(m, 1H), 2.98—3.10 (m, 1H), 4.45 (br, 2H), 5.15 (d, J＝
5.2 Hz, 1H), 6.61—6.65 (m, 1H), 6.71 (d, J＝7.6 Hz,
1H), 7.11—7.16 (m, 2H), 7.28 (d, J＝8.4 Hz, 2H), 7.74
(d, J＝8.0 Hz, 2H); 13C NMR (CDCl3, 100 MHz) δ:
21.6, 23.7, 24.9, 32.3, 52.0, 56.1, 60.5, 115.2, 115.7,
118.6, 127.2, 129.7, 130.4, 137.4, 137.6, 143.3, 149.1;
IR (KBr) ν: 3468.2, 3371.7, 3279.8, 2931.1, 2861.4,
1615.3, 1481.9, 1447.5, 1408.4, 1334.2, 1311.1, 1154.8,
1094.8, 814.0, 749.7, 671.0 cm－ 1; HRMS calcd for
C19H24N2O2S2 376.1279, found 376.1278.
Experimental section
General procedure for the reactions of aziridines
with various thiols
Thiol 2 (0.22 mmol) was added to a solution of
aziridine 1 (0.20 mmol) in methanol (2.0 mL). The re-
action mixture was stirred at room temperature for time
indicated in Tables 2 and 3. After the reaction was com-
pleted (as indicated by TLC), the mixture was extracted
with CH2Cl2. The organic extracts were dried (MgSO4)
and concentrated under reduced pressure. Purification
by silica gel column chromatography afforded the cor-
responding products 3 and 4. All the products were con-
firmed by 1H NMR and 13C NMR spectra.
N-[2-(4-Methylphenyl)thiocyclohexyl]-4-methyl-
benzenesulfonamide (3aa)2c White solid; m.p. 94—
1
96 ℃; H NMR (CDCl3, 400 MHz) δ: 1.15—1.36 (m,
4H), 1.57—1.64 (m, 2H), 1.97—2.01 (m, 1H), 2.27—
2.28 (m, 1H), 2.32 (s, 3H), 2.43 (s, 3H), 2.76—2.82 (m,
3
1H), 2.91—2.95 (m, 1H), 5.31 (brs, 1H), 7.04 (d, J＝
8.0 Hz, 2H), 7.14 (d, J＝8.0 Hz, 2H), 7.28 (d, J＝8.0 Hz,
2H), 7.74 (d, J＝8.0 Hz, 2H); 13C NMR (CDCl3, 100
MHz) δ 21.1, 21.5, 22.7, 23.4, 29.6, 39.7, 51.8, 55.3,
127.3, 128.3, 129.7, 129.9, 133.9, 137.1, 138.0, 143.3.
N-[2-(Phenylthio)cyclohexyl]-4-methylbenzene-
sulfonamide (3ab)2a White solid; m.p. 131—132 ℃;
1H NMR (DMSO-d6, 400 MHz) δ: 1.21—1.35 (m, 4H),
1.47—1.51 (m, 2H), 1.61—1.68 (m, 1H), 1.96—1.97
(m, 1H), 2.37 (s, 3H), 3.04—3.12 (m, 2H), 7.25—7.29
(m, 5H), 7.34 (d, J＝7.2 Hz, 2H), 7.63 (d, J＝8 Hz, 2H),
7.79 (d, J＝7.2 Hz, 1H); 13C NMR (CDCl3, 100 MHz) δ:
21.4, 22.7, 23.5, 30.5, 31.0, 49.7, 54.5, 126.8, 127.0,
129.4, 129.9, 131.4, 134.9, 139.4, 142.8.
N-[2-(2-Mercaptophenylamino)-cyclohexyl]-4-me-
thylbenzenesulfonamide (3ag) Solid; m.p. 87—90
℃; 1H NMR (CDCl3, 400 MHz) δ: 1.17—1.28 (m, 4H),
1.92—1.93 (m, 2H), 1.94—2.04 (m, 2H), 2.42 (s, 3H),
2.97—3.03 (m, 1H), 3.18—3.23 (m, 1H), 4.67—4.71
(m, 1H), 5.08—5.15 (m, 1H), 6.48—6.56 (m, 2H),
7.06—7.09 (m, 1H), 7.13—7.17 (m, 1H), 7.25—7.27
(m, 3H), 7.73—7.75 (m, 2H); 13C NMR (CDCl3, 100
MHz) δ: 21.6, 23.7, 31.2, 33.4, 55.4, 56.2, 111.2, 117.0,
119.7, 127.0, 129.7, 131.6, 137.1, 137.5, 143.3, 147.8;
IR (KBr) ν: 3467.8, 3274.8, 2936.1, 2856.5, 1590.2,
1491.0, 1413.1, 1333.6, 1234.5, 1169.9, 1163.0, 1151.9,
N-[2-(4-Chlorophenyl)thiocyclohexyl]-4-methyl-
benzenesulfonamide (3ac)2d White solid; m.p. 109—
111 ℃; 1H NMR (CDCl3, 400 MHz) δ: 1.25—1.39 (m,
4H), 1.56—1.62 (m, 2H), 1.97—2.01 (m, 1H), 2.26—
2.27 (m, 1H), 2.44 (s, 3H), 2.87—2.97 (m, 2H), 5.03
(brs, 1H), 7.20—7.22 (m, 4H), 7.26—7.30 (m, 2H),
7.73 (d, J＝7.6 Hz, 2H); 13C NMR (CDCl3, 100 MHz) δ:
21.6, 23.1, 24.4, 29.7, 32.0, 51.4, 54.9, 127.2, 129.1,
129.7, 131.2, 133.8, 134.4, 137.2, 143.5.
N-[2-(4-Fluorophenylthio)cyclohexyl]-4-methyl-
benzenesulfonamide (3ad) White solid; m.p. 102—
103 ℃; 1H NMR (CDCl3, 400 MHz) δ: 1.24—1.39 (m,
4H), 1.61 (t, J＝6.0 Hz, 2H), 1.98—2.01 (m, 1H),
2.26—2.27 (m, 1H), 2.45 (s, 3H), 2.81—2.83 (m, 1H),
2.94—2.95 (m, 1H), 5.29 (br s, 1H), 6.93—6.99 (m,
2H), 7.25—7.33 (m, 4H), 7.76 (d, J＝8.4 Hz); 13C NMR
(CDCl3, 100 MHz) δ: 21.5, 23.2, 24.5, 31.4, 32.1, 51.9,
55.0, 115.9 (d), 127.2 (d), 129.6, 136.0 (d), 137.3, 143.4,
－
1
1015.7, 834.5, 674.8 cm
; HRMS calcd for
C19H24N2O2S2 376.1279, found 376.1278.
N-(2-Methoxycyclohexyl)-4-methylbenzenesulfon-
amide (3ah)12 White solid; m.p. 60—62 ℃; 1H NMR
(CDCl3, 400 MHz) δ: 1.12—1.25 (m, 4H), 1.58—1.67
(m, 2H), 2.02—2.05 (m, 1H), 2.17—2.20 (m, 1H), 2.42
(s, 3H), 2.84—2.93 (m, 2H), 3.19 (s, 3H), 5.10 (brs, 1H),
7.26—7.30 (m, 2H), 7.74 (d, J＝8.0 Hz, 2H); 13C NMR
(CDCl3, 100 MHz) δ: 21.5, 23.4, 23.6, 28.6, 31.0, 55.8,
57.0, 81.3, 127.1, 127.2, 129.5, 129.6, 137.3, 143.1.
N-(2-Benzylthio-cyclohexyl)-4-methylbenzenesul-
1
fonamide (3ai)2d Yellow liquid; H NMR (CDCl3) δ:
1.18—1.26 (m, 4H), 1.38—1.39 (m, 1H), 1.59—1.69
(m, 1H), 1.99—2.04 (m, 1H), 2.20—2.24 (m, 1H),
2.39—2.42 (m, 1H), 2.43 (s, 3H), 2.89—2.93 (m, 1H),
4.11 (dd, J＝3.2, 14.4 Hz, 2H), 5.11 (d, J＝4.0 Hz, 1H),
7.21—7.34 (m, 7H), 7.75 (d, J＝8.4 Hz, 2H); 13C NMR
Chin. J. Chem. 2011, 29, 79— 84
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Ring-Opening Reactions of Aziridines with Aryl Thiols
(CDCl3) δ: 21.1, 21.6, 23.7, 25.1, 34.3, 48.2, 55.4, 60.4,
127.2, 127.3, 128.6, 128.8, 129.6, 137.2, 137.9, 143.4.
N-[(2-Phenylthio)cyclopentyl]-4-methylbenzene-
sulfonamide (3bb)2a White solid; m.p. 78—80 ℃; 1H
NMR (CDCl3, 400 MHz) δ: 1.47—1.59 (m, 2H), 1.64—
1.71 (m, 2H), 2.04—2.14 (m, 2H), 2.42 (s, 3H), 3.28—
3.31 (m, 1H), 3.33—3.38 (m, 1H), 5.11 (d, J＝5.2 Hz,
1H), 7.22—7.26 (m, 7H), 7.65 (d, J＝8.0 Hz, 2H); 13C
NMR (CDCl3, 100 MHz) δ: 21.5, 21.6, 30.2, 31.5, 52.4,
59.5, 127.1, 127.3, 128.9, 129.7, 132.0, 134.0, 136.8,
143.4.
phenyl)-2-(phenylthio)ethyl)-4-methylbenzenesulfon-
amide12 (4gb) mixture (10/90) White solid; m.p.
1
137—139 ℃; H NMR (CDCl3, 400 MHz) δ: 2.39 (s,
0.3H), 2.44 (s, 2.7H), 3.09—3.15 (m, 0.2H), 3.30—3.35
(m, 1.8H), 4.13 (t, J＝7.2 Hz, 0.9H), 4.15 (t, J＝7.2 Hz,
0.1H) 4.69 (t, J＝6.4 Hz, 0.9H), 5.25 (s, 0.1H) 6.93 (d,
J＝8.4 Hz, 0.2H), 6.98 (d, J＝8.4 Hz, 1.8H), 7.12 (d,
J＝8.0 Hz, 0.2H), 7.18—7.24 (m, 6.8H), 7.28—7.31 (m,
1.8H), 7.37 (d, J＝8.4 Hz, 0.2H), 7.47 (d, J＝8.0 Hz,
0.2H), 7.62 (d, J＝8.0 Hz, 1.8H); 13C NMR (CDCl3,
400 MHz) δ: 21.5, 46.9, 52.2, 121.9, 127.0, 127.2, 128.0,
128.8, 129.8, 132.3, 132.8, 136.6, 137.4, 138.1, 143.7.
N-(1-(2-Chlorophenyl)-2-(phenylthio)ethyl)-4-me-
thylbenzenesulfonamide (3hb) and N-(2-(2-chloro-
phenyl)-2-(phenylthio)ethyl)-4-methylbenzenesulfon-
amide (4hb) mixture (20/80) Liquid; 1H NMR
(CDCl3, 400 MHz) δ: 2.35 (s, 0.6H), 2.42 (s, 2.4H),
2.89—3.92 (m, 0.2H), 3.26—3.37 (m, 0.8H), 3.42—
3.49 (m, 0.8H), 3.57—3.60 (m, 0.2H), 4.62—4.66 (m,
0.8H), 4.67—4.68 (m, 0.2H), 4.87 (t, J＝6.0 Hz, 0.8H),
5.30 (t, J＝5.6 Hz, 0.2H), 7.09—7.38 (m, 10.6H), 7.53
(d, J＝7.6 Hz, 0.4H) 7.64 (d, J＝8.0 Hz, 1.6H), 7.73 (d,
J＝8.0 Hz, 0.4H); 13C NMR (CDCl3, 100 MHz) δ: 21.6,
45.9, 48.5, 127.1, 127.6, 128.0, 128.5, 129.1, 129.06,
129.9, 132.4, 133.9, 135.6, 136.6, 143.6; IR (KBr) ν:
3287.5, 2926.4, 1598.1, 1439.3, 1331.7, 1265.7, 1160.6,
1092.0, 739.9; HRMS calcd for C21H20ClNO2S2
417.0624, found 417.0624.
4-Methyl-N-(1-(phenylthio)hexan-2-yl)benzene-
1
sulfonamide (3cb)2e Liquid; H NMR (CDCl3, 400
MHz) δ: 0.74 (t, J＝6.0 Hz, 3H), 0.98—1.17 (m, 4H),
1.35—1.44 (m, 1H), 1.58—1.64 (m, 1H), 2.40 (s, 3H),
2.75—2.80 (m, 1H), 3.10—3.14 (m 1H), 3.30—3.35 (m,
1H), 4.76 (d, J＝8.0 Hz, 1H), 7.20—7.32 (m, 7H), 7.63
(d, J＝7.2 Hz, 2H); 13C NMR (CDCl3, 400 MHz) δ:
13.8, 21.5, 22.1, 27.3, 33.4, 39.3, 52.9, 126.5, 127.0,
129.0, 129.6, 129.8, 137.4, 143.3.
4-Methyl-N-(1-phenylthiomethylheptadecyl)-ben-
zenesulfonamide (3db) and 4-methyl-N-(2-(phenyl-
thio)octadecyl)benzenesulfonamide (4db)2d mixture
1
(80/20) White solid mixture; H NMR (CDCl3, 400
MHz) δ: 0.86 (t, J＝6.8 Hz, 3H), 1.04—1.42 (m, 30H),
2.39 (s, 2.4H), 2.43 (s, 0.6H), 2.76—2.81 (m, 0.8H),
3.12—3.19 (m, 1H), 3.31—3.39 (m, 1H), 3.95 (d, J＝
6.4 Hz, 0.2H), 4.70 (d, J＝7.6 Hz, 0.8H), 4.89 (d, J＝
6.4 Hz, 0.2H), 7.20—7.29 (m, 7H), 7.63 (d, J＝8.0 Hz,
1.6H), 7.74 (d, J＝8.0 Hz, 0.4H); 13C NMR (CDCl3,
100 MHz) δ: 14.1, 22.7, 25.2, 29.0, 29.4, 29.5, 29.7,
31.9, 39.3, 52.9, 126.5, 127.1, 129.0, 129.6, 129.8.
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true (18/82) Colourless liquid; H NMR (CDCl3, 400
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N-(1-(4-Chlorophenyl)-2-(phenylthio)ethyl)-4-me-
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MHz) δ: 21.6, 46.9, 52.1, 127.0, 128.0, 128.1, 128.9,
129.0, 129.1, 129.2, 129.8, 132.8, 136.7, 136.9, 143.7.
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84
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© 2011 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chin. J. Chem. 2011, 29, 79— 84