Ring-opening reactions of aziridines with carboxylic acids catalyzed by DBU

Article abstract of DOI:10.3987/COM-15-13372

An efficient ring-opening of aziridines with various carboxylic acids catalyzed by an organocatalyst-DBU afforded the corresponding products in good to excellent yield under mild reaction conditions.

Full text of DOI:10.3987/COM-15-13372

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HETEROCYCLES, Vol. 92, No. 3, 2016
HETEROCYCLES, Vol. 92, No. 3, 2016, pp. 528 - 543. © 2016 The Japan Institute of Heterocyclic Chemistry
Received, 18th November, 2015, Accepted, 18th January, 2016, Published online, 5th February, 2016
DOI: 10.3987/COM-15-13372
RING-OPENING REACTIONS OF AZIRIDINES WITH CARBOXYLIC
ACIDS CATALYZED BY DBU
Yanqin Guo,a Yepeng Xie,a Qin Yang,a,b Songsong Xu,a Zhihong Deng,a
Xuechun Mao,a and Yiyuan Peng*a,b
aKey Laboratory of Small Functional Organic Molecule, Ministry of Education
and Key Laboratory of Green Chemistry, Jiangxi Province, Nanchang, Jiangxi
330022, China
bCollege of Chemistry & Chemical Engineering, Jiangxi Normal University,
Nanchang, Jiangxi 330022, China
E-mail: yypeng@jxnu.edu.cn; yiyuanpeng@yahoo.com
Abstract – An efficient ring-opening of aziridines with various carboxylic acids
catalyzed by an organocatalyst—DBU afforded the corresponding products in
good to excellent yield under mild reaction conditions.
Aziridines have attracted increasing attention as versatile building blocks for the synthesis of many
nitrogen-containing biologically interesting molecules,1 such as amino acids,1b,1h heterocycles,2 and
alkaloids.3 Considerable progress has been achieved in the nucleophilic ring-opening reactions of
aziridines.4-6 They are known to react with various nucleophiles such as thiols, amines, and anhydrides.
However, most of these reactions require a strong base or Lewis acid.5 Recently, organocatalysts have
been successfully employed in such transformation. For instance, phosphine,4a,b tertiary amine,4c-4e
DABCO,4f DMSO,4g N-heterocyclic carbene6a and pyridine-N-oxide6b had been used as a catalyst or
promoter to facilitate the ring-opening reactions of aziridines. Among the nucleophiles, only four
references regarded the carboxylic acid used as the nucleophile for the ring-opening reactions of
aziridines. Yadav reported that aziridines could react smoothly with carboxylic acids in the presence of
indium triflate to afford the corresponding aminoacetates and benzoates in high yields (Scheme 1a).7 Wu
reported DABCO as an efficient organocatalyst in the ring-opening reactions of aziridines with amines or
thiols and adding one example of p-methoxybenzoic acid that could react with aziridine under reflux
condition.4f Recently, Wei described ring opening reactions of N-tosylaziridines with carboxylic acids in
DMF catalyzed by TBAB or by KOH in DMSO (Scheme 1b).8

HETEROCYCLES, Vol. 92, No. 3, 2016
529
Inspired by the recent advance of organocatalysts, we envisioned that the strong σ-donating property of
DBU may catalyze the reactions between aziridines and carboxylic acids. In this paper, as part of our
ongoing study on green and metal-free ring-opening processes,4e,6b we would like to disclose our
preliminary results for the ring-opening reactions of aziridines with carboxylic acids catalyzed by DBU
(Scheme 1c).
In(OTf)3 (Yadav's work)
(a)
NHTs
TBAB -DMF
KOH-DMSO
(b)
or
NTs
+ RCO2H
OCOR
(c)
DBU (this work)
Scheme 1. (a) Indium triflate-catalyzed, (b) TBAB or KOH catalyzed, (c) DBU catalyzed ring opening of
aziridines with carboxylic acids
First, the reaction of aziridine 1a and 3-phenylacrylic acid 2a were selected as the model for condition
optimizing. The results are listed in Table 1. Initially, the reaction was promoted by 40 mol% DBU in
THF at 25 ºC, and no product was obtained even after 48 h (entry 1). To our delight, when the
temperature rising up to 50 ºC, the DBU catalytic reaction gave an excellent yield of 93% (entry 2). The
anti-stereochemistry of the product 3aa was confirmed by the coupling constant for two cyclic methine
hydrogens at the trans-positions.9 Wu reported that DABCO could catalyze the reaction of
p-methoxybenzoic acid with aziridine 1a giving the corresponding product 3al in a yield of 73%.4f
However, when DBU was replaced by DABCO in our reaction model, the reaction afforded low yields
(entries 3 and 4). Other base catalysts such as DABCO, pyridine (Py), Et3N, i-PrNH2, t-BuOK and K2CO3
were then screened for this reaction, however, none of them was more efficient than DBU (entries 5-11).
Various solvents, such as DMSO, toluene, MeOH, and CH2Cl2, were also investigated, only low yields
were obtained (entries 12–15). In addition, a significant drop in yield was observed when 30 mol% of
DBU was used (entry 16). And control experiment indicated that the reaction could not take place without
adding DBU (entry 17).

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HETEROCYCLES, Vol. 92, No. 3, 2016
Table 1. Reaction parameters optimizationa,b,c
Ts
CO2H
NH
catalyst
solvent
+
N Ts
O
O
1a
2a
3aa
Entry
Catalyst
Solvent
Time (h) Yield (%) Entry Catalyst Solvent Time (h) Yield (%)
1
2
3
4
5
6
7
8
9
DBU
DBU
THF
THF
THF
MeCN
THF
THF
THF
THF
THF
48
24
24
24
24
24
24
24
24
trace
93
10
11
12
13
14
15
16e
17
K2CO3
t-BuOK
DBU
DBU
DBU
DBU
DBU
-
THF
THF
24
24
24
24
24
24
24
24
NR
trace
66
DABCO
DABCO
Py
50
DMSO
toluene
MeOH
CH2Cl2
THF
trace
trace
trace
trace
77
69
trace
trace
72
Et3N
i-PrNH2
DMAP
PyN-Od
THF
trace
trace
aAll the reactions were performed in 0.2 mmol scale, standard conditions: 1a (0.2 mmol), 2a (0.24 mmol),
catalyst (0.08 mmol, 40 mol%), solvent (2 mL), 50 ºC, under air. bIsolated yield. cThe reaction was carried
out at 25 ºC. dPyN-O is pyridine-N-oxide. eDBU (0.06 mmol, 30 mol%).
With this promising result in hand, we started to explore the generality of this DBU catalyzed ring
opening reaction of aziridines with carboxylic acids under the conditions highlighted above (40 mol% of
DBU, in THF, at 50 qC). To assess the impact of the structural and functional motifs on the reaction of 1a,
a range of acids 2 was tested, and the results are summarized in Table 2. The results in Table 2 indicated
that aromatic acids and aromatic substituted olefinic acids reacted with 1a leading to the corresponding
products 3 in good to excellent yields (entries 1-21). Moreover, it was found that substrates with strong
electron-withdrawing groups on the phenyl ring were less reactive to some extent than those with the
electron-donating groups. For example, the reaction of 4-NO2 substituted cinnamic or benzoic acid 2i or
2q with 1a gave rise to the desired product 3ai and 3aq in 79% and 77% yield, respectively (entries 9 and
17). While for the Me-, MeO-, -NMe2, or halo-substituted substrates 2, the corresponding yields were all
higher than 85% (entries 2-7 and 11-16). It is noteworthy that the heterocyclic substrate 2r-2t could also
be well tolerated in the reaction, leading to the desired product 3ar-3at in high yields (entries 18-20).
However, alkynyl acid such as 3-phenylpropiolic acid reacted with 1a only gave 40% yield (entry 22).
Not only aryl- but also alkylcarboxylic acids gave good yields (entries 23 and 24). Unfortunately, when
propenoic or propiolic acid was used, only trace amount of product was detected even the reaction was
performed at reflux condition (entries 25 and 26).

HETEROCYCLES, Vol. 92, No. 3, 2016
531
Table 2. Ring-opening reactions of aziridine 1a with various carboxylic acids 2 catalyzed by DBUa
NHTs
DBU (40 mol%)
RCO2H
N Ts
+
THF/50oC
OCOR
1a
2
3
Entry
1
RCO2H
Product Yield (%)b Entry
RCO2H
Product Yield (%)b
Cl
CO2H
93
91
99
99
94
99
95
85
79
84
99
92
94
14
15
16
17
18
19
20
21
22
23
24
25
26
92
93
3aa
3ab
3ac
3ad
3ae
3af
3an
3ao
3ap
3aq
3ar
3as
3at
CO2H
CO2H
2
3
CO2H
Cl
I
CO2H
MeO
N
89
CO2H
O2N
CO2H
4
77
CO2H
CO2H
Cl
CO2H
CO2H
5
88
N
O
S
6
91
CO2H
Cl
7
93
3ag
3ah
3ai
CO2H
CO2H
CO2H
CO2H
Cl
F
8
97
3au
3av
3aw
3ax
3ay
3az
O2N
CO2H
9
40
CO2H
CO2H
10
11
12
13
AcOH
61
3aj
CO2H
C11H23CO2H
75
3ak
3al
MeO
CO2H
CO2H
trace
trace
CO2H
CO2H
N
3am
aStandard conditions: 1a (0.2 mmol), 2 (0.24 mmol), DBU (0.08 mmol, 40 mol%), THF (2 mL), 50 ºC,
24-36 h, under air. bIsolated yield.

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HETEROCYCLES, Vol. 92, No. 3, 2016
In a second set of experiments, the scope with respect to aziridines was investigated. As shown in Table 3,
moderate to excellent yields were obtained for all aziridines. All the expected products were generated
under our standard experimental conditions, whatever the nature of the substrate was. In the case of
unsymmetrically substituted aziridine 1g, completely regioselectivity with the attack of nucleophile on the
less substituted aziridine carbon was observed (entries 11 and 12). When electronic effect participates,
such as substrates 1c-f, the regioselective attack of the acid on the benzyl substituted aziridine carbon was
also observed (entries 3-10). But, it was reasonable that regioselectivity was not as specific as the alkyl
aziridine when aryl aziridine was employed as the substrate.
In conclusion, an organocatalytic approach for the synthesis of β-amino esters with excellent yields has
been described, which DBU is an efficient organocatalyst for the reactions of aziridines with carboxylic
acids. The advantages of this method include high yield, good substrate generality, metal-free conditions,
and experimentally operational ease.
Table 3. Ring-opening reactions of various aziridines 1 with carboxylic acids 2a
O
O
R2
R3
R2 NHTs
OAc2a
:
DBU (40 mol%)
THF/50 oC
NTs
+
R1CO2H
O
R3 OCOR1
O
OAc2j:
3
1
2
Entry
1
Product
Yield (%)b Entry
Product
Yield (%)b
87
85
89
7
8
9
72
(3ba)
(3bj)
(3ea/3ea’=80/20)
(3ej/3ej’=84/16)
2
3
83
27
(3ca/3ca’=80/20)c
(3fa/3fa’=55/45)

HETEROCYCLES, Vol. 92, No. 3, 2016
533
4
5
6
67
90
81
10
11
12
23
71
66
(3fj/3fj’=53/47)
(3cj/3cj’=70/30)
(3da/3da’=70/30)
(3dj/3dj’=70/30)
(3ga)
(3gj)
aStandard conditions: 1a (0.2 mmol), 2 (0.24 mmol), catalyst (0.08 mmol, 40 mol%), THF (2 mL), 50 ºC, 24-36 h,
under air. bIsolated yield. cThe ratio was determined by NMR.
EXPERIMENTAL
General procedure for ring-opening reactions of aziridines with various carboxylic acids
A mixture of aziridine 1 (0.20 mmol), carboxylic acid 2 (0.24 mmol), and DBU (0.08 mmol, 40 mol%) in
THF (2.0 mL) were added subsequently. The mixture was stirred at 50 qC for 24-36 h. After completion
of the reaction as indicated by TLC, evaporation of the solvent followed by purification on silica gel
provided the corresponding product 3.
2-((4-Methylphenyl)sulfonamido)cyclohexyl cinnamate (3aa) This compound was obtained as a white
1
solid; Yield: 74.2 mg (93%); mp 93–94 qC; H NMR (400 MHz, CDCl3): δ 7.71 (d, J = 8.0 Hz, 2H),
7.49–7.39 (m, 6H), 7.12 (d, J = 7.6 Hz, 2H), 5.99 (d, J = 16.0 Hz, 1H), 5.41 (d, J = 7.6 Hz, 1H), 4.71 (td,
J = 10.0, 4.0 Hz, 1H), 3.33–3.25 (m, 1H), 2.17–2.15 (m, 4H), 2.00 (d, J = 11.6 Hz, 1H), 1.71–1.69 (m,
2H), 1.40–1.26 (m, 4H); 13C NMR (100 MHz, CDCl3): δ 167.1, 144.9, 142.7, 138.4, 134.1, 130.4, 129.5,
128.9, 128.0, 126.8, 117.4, 74.1, 57.3, 34.1, 31.2, 24.2, 23.7, 21.1; IR (KBr) (cm-1) v 3430, 3309, 3061,
2944, 2863, 1723, 1636, 1598, 1448, 1366, 1329, 1163, 1025; HRMS (ESI): m/z [M+Na]+ calcd for
C22H25NO4SNa: 422.1402, found: 422.1423.
2-((4-Methylphenyl)sulfonamido)cyclohexyl (E)-3-(p-tolyl)acrylate (3ab) This compound was
obtained as a white solid; Yield: 75.2 mg (91%); mp 134–136 qC; 1H NMR (400 MHz, CDCl3): δ 7.70 (d,
J = 8.0 Hz, 2H), 7.44 (d, J = 15.6 Hz, 1H), 7.34 (d, J = 8.0 Hz, 2H), 7.20 (d, J = 8.0 Hz, 2H), 7.12 (d, J =
8.4 Hz, 2H), 5.93 (d, J = 15.6 Hz, 1H), 5.27–5.24 (m, 1H), 4.69 (td, J = 10.0, 4.4 Hz, 1H), 3.31–3.23 (m,
1H), 2.38 (s, 3H), 2.18 (d, J = 13.2 Hz, 1H), 2.13 (s, 3H), 2.00–1.96 (m, 1H), 1.71–1.68 (m, 2H),

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HETEROCYCLES, Vol. 92, No. 3, 2016
1.42–1.25 (m, 4H); 13C NMR (100 MHz, CDCl3): δ 167.3, 145.0, 142.8, 140.9, 138.5, 131.5, 129.6, 129.6,
128.1, 126.9, 116.5, 74.0, 57.4, 34.1, 31.3, 24.3, 23.8, 21.5, 21.2; IR (KBr) (cm-1) v 3451, 3299, 3031,
2949, 2920, 2856, 1684, 1631, 1605, 1511, 1426, 1358, 1334, 1182, 1020; HRMS (ESI): m/z [M+Na]+
calcd for C23H27NO4SNa: 436.1558, found: 436.1543.
2-((4-Methylphenyl)sulfonamido)cyclohexyl (E)-3-(4-methoxyphenyl)acrylate (3ac) This compound
1
was obtained as a white solid; Yield: 84.9 mg (99%); mp 133–134 qC; H NMR (400 MHz, CDCl3): δ
7.69 (d, J = 8.4 Hz, 2H), 7.44–7.38 (m, 3H), 7.12 (d, J = 8.0 Hz, 2H), 6.91 (d, J = 8.8 Hz, 2H), 5.85 (d, J
= 15.6 Hz, 1H), 5.28–5.22 (m, 1H), 4.69 (td, J = 10.4, 4.4 Hz, 1H), 3.85 (s, 3H), 3.30–3.22 (m, 1H),
13
2.20–2.14 (m, 4H), 1.99–1.96 (m, 1H), 1.72–1.69 (m, 2H), 1.43–1.27 (m, 4H); C NMR (100 MHz,
CDCl3): δ 167.4, 161.6, 144.6, 142.7, 138.7, 129.8, 129.5, 127.1, 126.9, 115.2, 114.4, 74.0, 57.3, 55.4,
34.0, 31.3, 24.3, 23.8, 21.2; IR (KBr) (cm-1) v 3442, 3293, 2929, 2856, 1703, 1514, 1457, 1325, 1170,
1159, 1028; HRMS (ESI): m/z [M+Na]+ calcd for C23H27NO5SNa: 452.1508, found: 452.1478.
2-((4-Methylphenyl)sulfonamido)cyclohexyl (E)-3-(4-(dimethylamino)phenyl)acrylate (3ad) This
1
compound was obtained as a brown solid; Yield: 87.5 mg (99%); mp 146–148 qC; H NMR (400 MHz,
CDCl3): δ 7.69 (d, J = 8.0 Hz, 2H), 7.39 (d, J = 16.0 Hz, 1H), 7.33 (d, J = 8.8 Hz, 2H), 7.12 (d, J = 8.0 Hz,
2H), 6.66 (d, J = 8.8 Hz, 2H), 5.74 (d, J = 15.6 Hz, 1H), 5.36–5.30 (m, 1H), 4.68 (td, J = 10.0, 4.0 Hz,
1H), 3.26–3.18 (m, 1H), 3.02 (s, 6H), 2.21 (d, J = 13.6 Hz, 1H), 2.16 (s, 3H), 1.96 (d, J = 12.8 Hz, 1H),
13
1.75–1.60 (m, 2H), 1.40–1.26 (m, 4H); C NMR (100 MHz, CDCl3): δ = 168.3, 151.9, 145.7, 142.8,
138.2, 129.9, 129.5, 126.9, 121.9, 111.7, 111.6, 73.6, 57.6, 40.2, 34.3, 31.4, 24.3, 23.9, 21.4; IR (KBr)
(cm-1) v 3431, 3322, 3046, 2926, 2859, 2810, 1698, 1627, 1601, 1527, 1446, 1364, 1326, 1159, 1036;
HRMS (ESI): m/z [M+Na]+ calcd for C24H30N2O4SNa: 465.1824; found: 465.1836.
2-((4-Methylphenyl)sulfonamido)cyclohexyl (E)-3-(4-chlorophenyl)acrylate (3ae) This compound
1
was obtained as a white solid; Yield: 81.4 mg (94%); mp 124–125 qC; H NMR (400 MHz, CDCl3): δ
7.71 (d, J = 8.0 Hz, 2H), 7.46–7.34 (m, 5H), 7.14 (d, J = 7.6 Hz, 2H), 6.00 (d, J = 16.0 Hz, 1H), 5.37 (d, J
= 8.0 Hz, 1H), 4.71 (td, J = 10.0, 4.0 Hz, 1H), 3.34–3.26 (m, 1H), 2.16 (s, 3H), 2.11 (d, J = 12.8 Hz, 1H),
2.00 (d, J = 10.8 Hz, 1H), 1.72–1.67 (m, 2H), 1.38–1.27 (m, 4H); 13C NMR (100 MHz, CDCl3): δ 166.8,
143.4, 142.7, 138.7, 136.3, 132.8, 129.5, 129.3, 129.2, 126.9, 118.3, 74.4, 57.1, 33.8, 31.2, 24.3, 23.7,
21.3; IR (KBr) (cm-1) v 3427, 3278, 3065, 2940, 2862, 1688, 1636, 1592, 1491, 1325, 1160, 1092, 1024,
1011; HRMS (ESI): m/z [M+Na]+ calcd for C22H24NO4SClNa: 456.1012; found: 456.0994.
2-((4-Methylphenyl)sulfonamido)cyclohexyl (E)-3-(2-chlorophenyl)acrylate (3af) This compound
1
was obtained as a white solid; Yield: 85.7 mg (99%); mp 146–148 qC; H NMR (400 MHz, CDCl3): δ
7.82 (d, J = 16.0 Hz, 1H), 7.70 (d, J = 8.4 Hz, 2H), 7.51 (dd, J = 7.2, 1.6 Hz, 1H), 7.44 (dd, J = 8.0, 1.6
Hz, 1H), 7.36–7.27 (m, 2H), 7.13 (d, J = 8.0 Hz, 2H), 5.97 (d, J = 16.0 Hz, 1H), 4.99–4.96 (m, 1H), 4.71

HETEROCYCLES, Vol. 92, No. 3, 2016
535
(td, J = 10.4, 4.4 Hz, 1H), 3.34–3.26 (m, 1H), 2.20 (d, J = 13.6 Hz, 1H), 2.07 (s, 3H), 1.99 (d, J = 12.8 Hz,
1H), 1.74–1.66 (m, 2H), 1.47–1.27 (m, 4H); 13C NMR (100 MHz, CDCl3): δ 166.5, 142.7, 140.5, 138.7,
135.0, 132.6, 131.1, 130.3, 129.5, 127.6, 127.1, 126.9, 120.2, 74.3, 57.4, 34.1, 31.2, 24.2, 23.8, 21.0; IR
(KBr) (cm-1) v 3450, 3271, 3067, 2943, 2864, 1706, 1630, 1590, 1450, 1325, 1188, 1086, 1027; HRMS
(ESI): m/z [M+Na]+calcd for C22H24NO4SClNa: 456.1012; found: 456.1031.
2-((4-Methylphenyl)sulfonamido)cyclohexyl (E)-3-(3-chlorophenyl)acrylate (3ag) This compound
was obtained as a pale yellow solid; Yield: 82.3 mg (95%); mp 55–56 qC; 1H NMR (400 MHz, CDCl3): δ
7.71 (d, J = 7.6 Hz, 2H), 7.42–7.33 (m, 5H), 7.15 (d, J = 7.6 Hz, 2H), 6.00 (d, J = 16.0 Hz, 1H), 5.36 (d, J
= 7.6 Hz, 1H), 4.73–4.68 (m, 1H), 3.23–3.23 (m, 1H), 2.17–2.12 (m, 4H), 2.00 (d, J = 11.2 Hz, 1H),
1.71–1.67 (m, 2H), 1.40–1.28 (m, 4H); 13C NMR (100 MHz, CDCl3): δ 166.6, 143.2, 142.8, 138.6, 136.1,
134.9, 130.2, 130.2, 129.5, 127.6, 126.9, 126.4, 119.2, 74.4, 57.1, 33.9, 31.2, 24.3, 23.7, 21.3; IR (KBr)
(cm-1) v 3500, 3274, 3064, 2940, 2861, 1707, 1639, 1597, 1565, 1452, 1325, 1160, 1093, 1030; HRMS
(ESI): m/z [M+Na]+ calcd for C22H24NO4SClNa: 456.1012; found: 456.1027.
2-((4-Methylphenyl)sulfonamido)cyclohexyl (E)-3-(4-fluorophenyl)acrylate (3ah) This compound
was obtained as a pale yellow solid; Yield: 70.9 mg (85%); mp 82–84 qC; 1H NMR (400 MHz, CDCl3): δ
7.77–7.70 (m, 2H), 7.48–7.43 (m, 3H), 7.15–7.00 (m, 4H), 6.04–5.93 (m, 1H), 5.44–5.36 (m, 1H),
4.78–4.68 (m, 1H), 3.35–3.26 (m, 1H), 2.21–2.10 (m, 4H), 2.03–1.99 (m, 1H), 1.78–1.68 (m, 2H),
1.39–1.28 (m, 4H); 13C NMR (100 MHz, CDCl3): δ 166.9, 165.2, 162.7, 143.6, 142.6, 138.8, 130.6, 130.0,
129.9, 129.5, 126.9, 117.6, 116.1, 115.9, 74.3, 57.1, 33.8, 31.2, 24.3, 23.7, 21.2; IR (KBr) (cm-1) v 3450,
3324, 3070, 2948, 2862, 1687, 1635, 1600, 1509, 1415, 1331, 1239, 1179, 1093, 1019, 1002; HRMS
(ESI): m/z [M+Na]+ calcd for C22H24NO4SFNa: 440.1308; found: 440.1331.
2-((4-Methylphenyl)sulfonamido)cyclohexyl (E)-3-(4-nitrophenyl)acrylate (3ai) This compound was
1
obtained as a pale yellow solid; Yield: 70.2 mg (79%); mp 160–161 qC; H NMR (400 MHz, CDCl3): δ
8.25 (d, J = 7.6 Hz, 2H), 7.73 (d, J = 8.0 Hz, 2H), 7.63–7.56 (m, 3H), 7.18 (d, J = 7.6 Hz, 2H), 6.22 (d, J
= 16.0 Hz, 1H), 5.16–5.14 (m, 1H), 4.77–4.68 (m, 1H), 3.37–3.28 (m, 1H), 2.21 (s, 3H), 2.04–2.02 (m,
13
2H), 1.76–1.67 (m, 2H), 1.44–1.29 (m, 4H); C NMR (100 MHz, CDCl3): δ 166.1, 148.5, 142.8, 141.9,
140.5, 138.7, 129.5, 128.7, 126.9, 124.1, 122.0, 74.8, 57.0, 33.5, 31.2, 24.3, 23.7, 21.3; IR (KBr) (cm-1) v
3441, 3284, 2939, 2862, 1712, 1640, 1599, 1520, 1344, 1061, 1091, 1032; HRMS (ESI): m/z [M+Na]+
calcd for C22H24N2O6SNa: 467.1253; found: 467.1268.
2-((4-Methylphenyl)sulfonamido)cyclohexyl benzoate (3aj)10 This compound was obtained as a white
1
solid; Yield: 62.7 mg (84%); mp 170–172 qC; H NMR (400 MHz, CDCl3): δ 7.77 (d, J = 8.0 Hz, 2H),
7.59 (d, J = 8.0 Hz, 2H), 7.54 (t, J = 6.8 Hz, 1H), 7.36 (t, J = 7.6 Hz, 2H), 6.91 (d, J = 8.0 Hz, 2H), 5.20
(d, J = 7.2 Hz, 1H), 4.82 (td, J = 10.4, 4.4 Hz, 1H), 3.36–3.28 (m, 1H), 2.18 (s, 4H), 2.04–2.01 (m, 1H),

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1.73–1.70 (m, 2H), 1.51–1.30 (m, 4H); 13C NMR (100 MHz, CDCl3): δ 166.8, 142.7, 138.1, 133.0, 129.7,
129.4, 128.1, 126.6, 74.6, 57.2, 34.0, 31.2, 24.2, 23.8, 21.4; IR (KBr) (cm-1) v 3440, 3329, 2927, 2862,
1707, 1599, 1450, 1323, 1158, 1015; HRMS (ESI): m/z [M+Na]+ calcd for C20H23NO4SNa: 396.1245;
found: 396.1259.
2-((4-Methylphenyl)sulfonamido)cyclohexyl 4-methylbenzoate (3ak)7 This compound was obtained as
a white solid; Yield: 76.6 mg (99%); mp 147–149 qC; 1H NMR (400 MHz, CDCl3): δ 7.64 (d, J = 8.4 Hz,
2H), 7.58 (d, J = 8.0 Hz, 2H), 7.15 (d, J = 8.0 Hz, 2H), 6.91 (d, J = 8.0 Hz, 2H), 5.13 (d, J = 6.4 Hz, 1H),
4.80 (td, J = 10.4, 4.4 Hz, 1H), 3.33–3.25 (m, 1H), 2.42 (s, 3H), 2.23–2.18 (m, 4H), 2.00 (d, J = 13.6 Hz,
1H), 1.76–1.69 (m, 2H), 1.51–1.30 (m, 4H); 13C NMR (100 MHz, CDCl3): δ 166.9, 143.7, 142.6, 138.0,
129.8, 129.4, 128.8, 126.9, 126.5, 74.4, 57.4, 34.2, 31.3, 24.2, 23.8, 21.7, 21.4; IR (KBr) (cm-1) v 3410,
3323, 3052, 3035, 2930, 2919, 2855, 1708, 1613, 1443, 1324, 1272, 1157, 1087, 1027, 1020; HRMS
(ESI): m/z [M+Na]+ calcd for C21H25NO4SNa: 410.1402; found: 410.1413.
2-((4-Methylphenyl)sulfonamido)cyclohexyl 4-methoxybenzoate (3al)10 This compound was obtained
as a white solid; Yield: 74.2 mg (92%); mp 132–134 qC; 1H NMR (400 MHz, CDCl3): δ 7.71 (d, J = 8.8
Hz, 2H), 7.59 (d, J = 8.0 Hz, 2H), 6.94 (d, J = 8.0 Hz, 2H), 6.83 (d, J = 8.8 Hz, 2H), 5.29 (d, J = 6.8 Hz,
1H), 4.78 (td, J = 10.4, 4.4 Hz, 1H), 3.87 (s, 3H), 3.33–3.25 (m, 1H), 2.20–2.17 (m, 4H), 2.01 (d, J = 13.2
13
Hz, 1H), 1.74–1.68 (m, 2H), 1.49–1.26 (m, 4H); C NMR (100 MHz, CDCl3): δ 166.6, 163.4, 142.6,
138.1, 131.8, 129.4, 126.6, 122.1, 113.3, 74.3, 57.3, 55.5, 34.0, 31.3, 24.2, 23.8, 21.4; IR (KBr) (cm-1) v
3399, 3331, 3083, 2932, 2863, 1706, 1607, 1441, 1326, 1261, 1158, 1080, 1033, 1016; HRMS (ESI): m/z
[M+Na]+ calcd for C21H25NO5SNa: 426.1351; found: 426.1355.
2-((4-Methylphenyl)sulfonamido)cyclohexyl 4-(dimethylamino)benzoate (3am) This compound was
1
obtained as a pale yellow solid; Yield: 78.2 mg (94%); mp 148–150 qC; H NMR (400 MHz, CDCl3): δ
7.61–7.57 (m, 4H), 6.92 (d, J = 8.0 Hz, 2H), 6.56 (d, J = 9.2 Hz, 2H), 5.33 (d, J = 6.4 Hz, 1H), 4.75 (td, J
= 10.4, 4.4 Hz, 1H), 3.26–3.05 (m, 1H), 3.05 (s, 6H), 2.26–2.19 (m, 4H), 1.98 (d, J = 13.6 Hz, 1H),
1.77–1.63 (m, 2H), 1.46– 1.28 (m, 4H); 13C NMR (100 MHz, CDCl3): δ 167.5, 153.4, 142.4, 137.8, 131.5,
129.4, 126.6, 116.3, 110.4, 73.7, 57.7, 40.1, 34.3, 31.4, 24.2, 23.9, 21.4; IR (KBr) (cm-1) v 3422, 3303,
3066, 2935, 2863, 1679, 1609, 1534, 1443, 1374, 1330, 1284, 1181, 1088, 1026; HRMS (ESI): m/z
[M+Na]+ calcd for C22H28N2O4SNa: 439.1667; found: 439.1647.
2-((4-Methylphenyl)sulfonamido)cyclohexyl 4-chlorobenzoate (3an)10 This compound was obtained as
a white solid; Yield: 74.9 mg (92%); mp 145–146 qC; 1H NMR (400 MHz, CDCl3): δ 7.70 (d, J = 8.4 Hz,
2H), 7.59 (d, J = 8.0 Hz, 2H), 7.32 (d, J = 8.4 Hz, 2H), 6.95 (d, J = 8.0 Hz, 2H), 5.18–5.15 (m, 1H), 4.81
(td, J = 10.4, 4.0 Hz, 1H), 3.38–3.30 (m, 1H), 2.22 (s, 3H), 2.13 (d, J = 12.8 Hz, 1H), 2.02 (d, J = 14.0 Hz,
13
1H), 1.75–1.68 (m, 2H), 1.50–1.29 (m, 4H); C NMR (100 MHz, CDCl3): δ 165.8, 142.8, 139.4, 138.2,

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537
131.1, 129.4, 128.4, 128.2, 126.5, 74.9, 57.2, 34.0, 31.3, 24.3, 23.8, 21.4; IR (KBr) (cm-1) v 3435, 3271,
2940, 1712, 1595, 1467, 1400, 1327, 1280, 1154, 1093, 1014; HRMS (ESI): m/z [M+Na]+ calcd for
C20H22NO4SClNa: 430.0856; found: 430.0864.
2-((4-Methylphenyl)sulfonamido)cyclohexyl 2-chlorobenzoate (3ao)10 This compound was obtained as
a white solid; Yield: 75.7 mg (93%); mp 138–140 qC; 1H NMR (400 MHz, CDCl3): δ 7.68 (dd, J = 16.0,
8.0 Hz, 3H), 7.40 (d, J = 3.6 Hz, 2H), 7.28–7.23 (m, 1H), 7.01 (d, J = 8.0 Hz, 2H), 5.28 (d, J = 7.6 Hz,
1H), 4.85 (td, J = 10.0, 4.4 Hz, 1H), 3.39–3.31 (m, 1H), 2.23 (s, 3H), 2.10–2.03 (m, 2H), 1.74–1.64 (m,
2H), 1.52–1.29 (m, 4H); 13C NMR (100 MHz, CDCl3): δ 165.3, 142.8, 138.2, 134.0, 132.7, 131.9, 131.0,
129.4, 129.3, 126.6, 126.5, 75.3, 56.8, 33.4, 31.0, 24.2, 23.7, 21.5; IR (KBr) (cm-1) v 3442, 3261, 2942,
2862, 1733, 1590, 1472, 1440, 1324, 1254, 1158, 1117, 1084, 1052, 1013; HRMS (ESI): m/z [M+Na]+
calcd for C20H22NO4SClNa: 430.0856; found: 430.0833.
2-((4-Methylphenyl)sulfonamido)cyclohexyl 2-iodobenzoate (3ap) This compound was obtained as a
white solid; Yield: 88.8 mg (89%); mp 165–167 qC; 1H NMR (400 MHz, CDCl3): δ 7.97 (d, J = 8.0 Hz,
1H), 7.67–7.64 (m, 3H), 7.33 (t, J = 7.6 Hz, 1H), 7.14 (td, J = 7.6, 1.2 Hz, 1H), 7.00 (d, J = 8.0 Hz, 2H),
5.12 (d, J = 7.2 Hz, 1H), 4.84 (td, J = 10.0, 4.4 Hz, 1H), 3.40–3.32 (m, 1H), 2.23 (s, 3H), 2.12–2.09 (m,
13
2H), 1.76–1.66 (m, 2H), 1.54–1.27 (m, 4H); C NMR (100 MHz, CDCl3): δ 166.0, 142.8, 141.3, 138.2,
133.8, 132.8, 131.5, 129.5, 127.8, 126.6, 94.7, 75.6, 56.8, 33.6, 31.2, 24.3, 23.7, 21.6; IR (KBr) (cm-1) v
3435, 3264, 2938, 2861, 1728, 1582, 1452, 1323, 1254, 1160, 1086, 1045, 1016; HRMS (ESI): m/z
[M+Na]+ calcd for C20H22NO4SINa: 522.0212; found: 522.0177.
2-((4-Methylphenyl)sulfonamido)cyclohexyl 4-nitrobenzoate (3aq)8a This compound was obtained as a
white solid; Yield: 64.4 mg (77%); mp 151–153 qC; 1H NMR (400 MHz, CDCl3): δ 8.20 (d, J = 8.4 Hz,
2H), 8.01 (d, J = 8.8 Hz, 2H), 7.63 (d, J = 8.0 Hz, 2H), 7.03 (d, J = 7.6 Hz, 2H), 5.17–5.06 (m, 1H), 4.85
(td, J = 10.0, 4.4 Hz, 1H), 3.46–3.37 (m, 1H), 2.24 (s, 3H), 2.10–2.00 (m, 2H), 1.77–1.68 (m, 2H),
1.54–1.29 (m, 4H); 13C NMR (100 MHz, CDCl3): δ 164.6, 150.4, 143.0, 138.4, 135.3, 130.9, 129.5, 126.6,
123.2, 75.9, 56.7, 33.3, 31.1, 24.3, 23.7, 21.4; IR (KBr) (cm-1) v 3429, 3305, 2952, 2860, 1724, 1608,
1600, 1527, 1436, 1328, 1272, 1163, 1088, 1011; HRMS (ESI): m/z [M+Na]+ calcd for C20H22N2O6SNa:
441.1096; found: 441.1116.
2-((4-Methylphenyl)sulfonamido)cyclohexyl nicotinate (3ar) This compound was obtained as a white
1
solid; Yield: 65.8 mg (88%); mp 151–153 qC; H NMR (400 MHz, CDCl3): δ 8.94 (s, 1H), 8.75 (d, J =
3.6 Hz, 1H), 8.10 (d, J = 8.0 Hz, 1H), 7.62 (d, J = 8.4 Hz, 2H), 7.35–7.30 (m, 1H), 6.99 (d, J = 8.0 Hz,
2H), 5.57–5.54 (m, 1H), 4.87 (td, J = 10.4, 4.4 Hz, 1H), 3.42–3.34 (m, 1H), 2.22 (s, 3H), 2.07 (t, J = 16.4
13
Hz, 2H), 1.77–1.69 (m, 2H), 1.50–1.29 (m, 4H); C NMR (100 MHz, CDCl3): δ 165.1, 153.1, 150.7,
142.9, 138.4, 137.3, 129.4, 126.5, 125.7, 123.2, 75.3, 56.8, 33.6, 31.1, 24.3, 23.7, 21.5; IR (KBr) (cm-1) v

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3431, 3095, 2942, 2868, 1730, 1595, 1474, 1430, 1315, 1276, 1157, 1093, 1027, 1014; HRMS (ESI): m/z
[M+Na]+ calcd for C19H22N2O4SNa: 397.1198; found: 397.1222.
2-((4-Methylphenyl)sulfonamido)cyclohexyl furan-2-carboxylate (3as)10 This compound was obtained
as a white solid; Yield: 66.1 mg (91%); mp 124–127 qC; 1H NMR (400 MHz, CDCl3): δ 7.65 (d, J = 8.0
Hz, 2H), 7.53 (s, 1H), 7.06 (d, J = 8.0 Hz, 2H), 6.92 (d, J = 3.2 Hz, 1H), 6.47–6.46 (m, 1H), 5.25 (d, J =
7.6 Hz, 1H), 4.78 (td, J = 10.8, 4.4 Hz, 1H), 3.35–3.27 (m, 1H), 2.29 (s, 3H), 2.13 (d, J = 12.8 Hz, 1H),
2.01 (d, J = 13.2 Hz, 1H), 1.72–1.67 (m, 2H), 1.50–1.26 (m, 4H); 13C NMR (100 MHz, CDCl3): δ 158.8,
146.4, 144.1, 142.7, 138.1, 129.3, 126.7, 118.4, 111.8, 74.7, 57.1, 33.9, 31.2, 24.2, 23.7, 21.5; IR (KBr)
(cm-1) v 3424, 3318, 2936, 2859, 1716, 1472, 1398, 1321, 1296, 1235, 1158, 1085, 1012; HRMS (ESI):
m/z [M+Na]+ calcd for C18H21NO5SNa: 386.1038; found: 386.1012.
2-((4-Methylphenyl)sulfonamido)cyclohexyl thiophene-2-carboxylate (3at) This compound was
obtained as a white solid; Yield: 70.5 mg (93%); mp 179–181 qC; 1H NMR (400 MHz, CDCl3): δ 7.62 (d,
J = 8.0 Hz, 2H), 7.54–7.52 (m, 2H), 7.05–7.02 (m, 1H), 6.99 (d, J = 8.0 Hz, 2H), 5.25 (d, J = 7.2 Hz, 1H),
4.77 (td, J = 10.0, 4.8 Hz, 1H), 3.34–3.25 (m, 1H), 2.24 (s, 3H), 2.19–2.15 (m, 1H), 2.03–1.99 (m, 1H),
1.75–1.67 (m, 2H), 1.52–1.29 (m, 4H); 13C NMR (100MHz, CDCl3): δ 162.5, 142.7, 138.0, 133.8, 133.5,
132.7, 129.4, 127.6, 126.6, 74.9, 57.1, 33.9, 31.2, 24.1, 23.7, 21.5; IR (KBr) (cm-1) v 3434, 3272, 3096,
3059, 2924, 2854, 1685, 1597, 1523, 1455, 1416, 1364, 1287, 1267, 1163, 1107, 1094, 1039, 1006;
HRMS (ESI): m/z [M+Na]+ calcd for C18H21NO4S2Na: 402.0810; found: 402.0790.
2-((4-Methylphenyl)sulfonamido)cyclohexyl 1-naphthoate (3au)10 This compound was obtained as a
white solid; Yield: 82.1 mg (97%); mp 125–126 qC; 1H NMR (400 MHz, CDCl3): δ 8.85 (d, J = 8.4 Hz,
1H), 7.96 (dd, J = 18.0, 8.0 Hz, 2H), 7.86 (d, J = 8.0 Hz, 1H), 7.59–7.50 (m, 4H), 7.37 (t, J = 7.6 Hz, 1H),
6.67 (d, J = 8.0 Hz, 2H), 5.45 (d, J = 7.2 Hz, 1H), 4.93 (td, J = 10.4, 4.8 Hz, 1H), 3.44–3.36 (m, 1H),
2.12–2.09 (m, 2H), 1.97 (s, 3H), 1.73–1.64 (m, 2H), 1.55–1.29 (m, 4H); 13C NMR (100 MHz, CDCl3): δ
167.4, 142.5, 138.2, 133.7, 133.5, 131.5, 130.7, 129.2, 128.5, 127.8, 126.5, 126.3, 126.2, 125.9, 124.4,
74.6, 57.2, 33.9, 31.3, 24.3, 23.8, 21.2; IR (KBr) (cm-1) v 3422, 3303, 3066, 2935, 2863, 1679, 1609,
1534, 1443, 1374, 1330, 1284, 1181, 1088, 1026; HRMS (ESI): m/z [M+Na]+ calcd for C24H25NO4SNa:
446,1402; found: 446.1413.
2-((4-Methylphenyl)sulfonamido)cyclohexyl 3-phenylpropiolate (3av) This compound was obtained
as a white solid; Yield: 31.8 mg (40%); mp 149–150 qC; 1H NMR (400 MHz, CDCl3): δ 7.77 (d, J = 8.4
Hz, 2H), 7.57 (d, J = 7.2 Hz, 2H), 7.48 (t, J = 7.2 Hz, 1H), 7.40 (t, J = 7.6 Hz, 2H), 7.21 (d, J = 8.4 Hz,
2H), 4.89 (d, J = 6.8 Hz, 1H), 4.73 (td, J = 10.0, 4.4 Hz, 1H), 3.33–3.25 (m, 1H), 2.20–2.17 (m, 4H),
2.02–1.99 (m, 1H), 1.73–1.68 (m, 2H), 1.46–1.27 (m, 4H); 13C NMR (100 MHz, CDCl3): δ 153.9, 143.0,
138.3, 133.0, 130.8, 129.6, 128.6, 127.0, 119.6, 87.0, 80.5, 75.8, 56.6, 33.6, 30.8, 24.0, 23.6, 21.2; IR

HETEROCYCLES, Vol. 92, No. 3, 2016
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(KBr) (cm-1) v 3386, 3251, 3064, 2939, 2859, 2224, 1706, 1596, 1468, 1360, 1325, 1161, 1023; HRMS
(ESI): m/z [M+K]+ calcd for C22H23NO4SK: 436.0985, found: 436.1009.
2-((4-Methylphenyl)sulfonamido)cyclohexyl acetate (3aw)10 This compound was obtained as a white
1
solid; Yield: 37.9 mg (61%); mp 123–125 qC; H NMR (400 MHz, CDCl3): δ 7.75 (d, J = 8.0 Hz, 2H),
7.29 (d, J = 8.0 Hz, 2H), 5.08 (d, J = 7.6 Hz, 1H), 4.56 (td, J = 10.0, 4.4 Hz, 1H), 3.22–3.15 (m, 1H), 2.42
13
(s, 3H), 2.05–1.90 (m, 2H), 1.78 (s, 3H), 1.70–1.63 (m, 2H), 1.37–1.24 (m, 4H); C NMR (100 MHz,
CDCl3): δ 171.5, 143.1, 138.6, 129.6, 126.9, 74.1, 56.9, 33.4, 31.1, 24.2, 23.7, 21.5, 21.0; IR (KBr) (cm-1)
v 3406, 3245, 2942, 2865, 1715, 1597, 1494, 1454, 1373, 1336, 1259, 1160, 1090, 1039; HRMS (ESI):
m/z [M+Na]+ calcd for C15H21NO4SNa: 334.1089; found: 334.1055.
2-((4-Methylphenyl)sulfonamido)cyclohexyl dodecanoate (3ax) This compound was obtained as a
white solid; Yield: 67.7 mg (75%); mp 38–39 qC; 1H NMR (400 MHz, CDCl3): δ 7.75 (d, J = 8.0 Hz, 2H),
7.28 (d, J = 7.2 Hz, 2H), 5.22 (d, J = 7.6 Hz, 1H), 4.60–4.55 (m, 1H), 3.26–3.27 (m, 1H), 2.41 (s, 3H),
2.04–1.91 (m, 5H), 1.69–1.61 (m, 2H), 1.49–1.46 (m, 3H), 1.26 (s, 21H); 13C NMR (100 MHz, CDCl3): δ
174.1, 142.8, 138.9, 129.5, 126.9, 73.8, 56.8, 34.2, 33.2, 31.9, 31.0, 29.6, 29.5, 29.3, 29.3, 29.1, 24.7, 24.2,
23.6, 22.6, 21.4, 14.1; IR (KBr) (cm-1) v 3305, 2923, 2853, 1731, 1455, 1383, 1326, 1304, 1206, 1161,
1090, 1020; HRMS (ESI): m/z [M+Na]+ calcd for C25H41NO4SNa: 474.2654; found: 474.2650.
2-((4-Methylphenyl)sulfonamido)cyclopentyl cinnamate (3ba)7 This compound was obtained as a
white solid; Yield: 67.0 mg (87%); mp 125–126 qC; 1H NMR (400 MHz, CDCl3): δ 7.77 (d, J = 8.0 Hz,
2H), 7.55–7.39 (m, 6H), 7.21 (d, J = 7.6 Hz, 2H), 6.21 (d, J = 16.0 Hz, 1H), 5.70 (d, J = 5.2 Hz, 1H),
13
5.03–4.98 (m, 1H), 3.62–3.56 (m, 1H), 2.24 (s, 3H), 2.10–2.03 (m, 2H), 1.74–1.52 (m, 4H); C NMR
(100 MHz, CDCl3): δ 166.9, 145.1, 143.2, 137.5, 134.2, 130.5, 129.6, 129.0, 128.1, 127.2, 117.6, 79.6,
59.9, 31.3, 29.5, 21.4, 20.8; IR (KBr) (cm-1) v 3270, 3059, 2866, 1702, 1630, 1576, 1493, 1449, 1326,
1152, 1088, 1074, 1018, 991; HRMS (ESI): m/z [M+Na]+ calcd for C21H23NO4SNa: 408.1245; found:
408.1248.
2-((4-Methylphenyl)sulfonamido)cyclopentyl benzoate (3bj) This compound was obtained as a white
1
solid; Yield: 61.0 mg (85%); mp 147–148 qC; H NMR (400 MHz, CDCl3): δ 7.85 (d, J = 8.4 Hz, 2H),
7.70 (d, J = 8.0 Hz, 2H), 7.56 (t, J = 7.6 Hz, 1H), 7.41 (t, J = 8.0 Hz, 2H), 7.08 (d, J = 8.0 Hz, 2H),
13
5.32–5.28 (m, 1H), 5.11–5.06 (m, 1H), 3.63–3.57 (m, 1H), 2.23–2.08 (m, 5H), 1.74–1.59 (m, 4H); C
NMR (100 MHz, CDCl3): δ 166.6, 143.2, 137.0, 133.2, 129.6, 128.3, 127.1, 80.0, 77.4, 77.1, 76.7, 60.1,
31.6, 29.5, 21.4, 20; IR (KBr) (cm-1) v 3321, 2961, 2927, 2870, 1712, 1599, 1450, 1358, 1322, 1274,
1151, 1113, 1091, 1070, 1029; HRMS (ESI): m/z [M+Na]+ calcd for C19H21NO4SNa: 382.1089; found:
382.1074.
2-((4-Methylphenyl)sulfonamido)-2-phenylethyl
cinnamate
(3ca)
/
2-((4-methylphenyl)-

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sulfonamido)-1-phenylethyl cinnamate (3ca') These compounds were obtained as mixture white solid;
Yield: 74.9 mg (89%, 3ca/3ca' = 80/20); mp 106–108 qC; 1H NMR (400 MHz, CDCl3): δ 7.73 (d, J = 8.0
Hz, 0.4H), 7.64–7.21 (m, 13H), 7.06 (d, J = 7.6 Hz, 1.6H), 6.36 (d, J = 16.0 Hz, 0.2H), 6.21 (d, J = 16.0
Hz, 0.8H), 6.09–6.08 (m, 0.8H), 5.88–5.85 (m, 0.2H), 5.55–5.52 (m, 0.2H), 4.74–4.69 (m, 0.8H),
4.36–4.24 (m, 1.6H), 3.43–3.38 (m, 0.4H), 2.33 (s, 0.6H), 2.20 (s, 2.4H); 13C NMR (100 MHz, CDCl3): δ
166.6, 165.9, 145.7, 145.6, 143.4, 143.1, 137.8, 137.5, 137.3, 134.2, 130.5, 129.7, 129.4, 128.9, 128.7,
128.6, 128.2, 128.0, 127.1, 126.9, 126.4, 117.5, 117.2, 74.3, 66.6, 57.2, 47.9, 21.4, 21.3; IR (KBr) (cm-1)
v 3446, 3258, 3063, 3030, 2922, 1719, 1698, 1638, 1495, 1450, 1331, 1283, 1205, 1161, 1091, 1021;
HRMS (ESI): m/z [M+Na]+ calcd for C24H23NO4SNa: 444.1245; found: 444.1256.
2-((4-Methylphenyl)sulfonamido)-2-phenylethyl
benzoate
(3cj)
/
2-((4-methylphenyl)-
sulfonamido)-1-phenylethyl benzoate (3cj') These compounds were obtained as mixture white solid;
Yield: 52.9 mg (67%, 3cj/3cj' = 70/30); mp 160–162 qC; 1H NMR (400 MHz, CDCl3): δ 8.00 (d, J = 7.2
Hz, 0.6H), 7.87 (d, J = 7.2 Hz, 1.4H), 7.70 (d, J = 8.4 Hz, 0.6H), 7.59–7.22 (m, 10H), 7.02 (d, J = 8.0 Hz,
1.4H), 5.97–5.94 (m, 0.3H), 5.47–5.44 (m, 0.7H), 4.91–4.86 (m, 0.3H), 4.77–4.73 (m, 0.7H), 4.49–4.35
13
(m, 1.4H), 3.54–3.47 (m, 0.6H), 2.38 (s, 0.9H), 2.27 (s, 2.1H); C NMR (100 MHz, CDCl3): δ 166.4,
165.6, 143.6, 143.2, 137.3, 137.2, 133.4, 133.4, 129.8, 129.8, 129.7, 129.5, 129.2, 128.9, 128.7, 128.5,
128.4, 128.2, 127.0, 127.0, 126.9, 126.4, 74.6, 67.0, 57.2, 47.9, 21.6, 21.5; IR (KBr) (cm-1) v 3437, 3343,
3062, 2924, 1709, 1600, 1495, 1434, 1322, 1278, 1157, 1128, 1090, 1026; HRMS (ESI): m/z [M+Na]+
calcd for C22H21NO4SNa: 418.1089; found: 418.1070.
2-((4-Methylphenyl)sulfonamido)-2-(p-tolyl)ethyl cinnamate (3da)
/
2-((4-methylphenyl)-
sulfonamido)-1-(p-tolyl)ethyl cinnamate (3da')7 These compounds were obtained as mixture white
solid; Yield: 78.3 mg (90%, 3da/3da' = 70/30); mp 128–130 qC; 1H NMR (400 MHz, CDCl3): δ 7.73 (d,
J = 8.0 Hz, 0.6H), 7.63–7.08 (m, 12H), 7.02 (d, J = 8.0 Hz, 1.4H), 6.34 (d, J = 16.0 Hz, 0.3H), 6.21 (d, J
= 16.0 Hz, 0.7H), 5.88–5.80 (m, 1H), 5.39–5.31 (m, 0.3H), 4.68–4.64 (m, 0.7H), 4.36–4.23 (m, 1.4H),
13
3.46–3.33 (m, 0.6H), 2.34 (s, 0.9H), 2.30 (s, 0.9H), 2.27 (s, 2.1H), 2.22 (s, 2.1H); C NMR (100 MHz,
CDCl3): δ 166.8, 166.1, 145.7, 145.6, 143.5, 143.1, 138.5, 137.8, 137.6, 137.0, 134.4, 134.2, 134.2, 134.1,
130.6, 130.5, 129.8, 129.4, 129.3, 128.9, 128.9, 128.2, 127.1, 127.1, 126.9, 126.4, 117.4, 117.1, 74.3, 66.7,
56.9, 47.9, 21.5, 21.4, 21.2, 21.1; IR (KBr) (cm-1) v 3312, 3061, 3027, 2955, 2922, 1698, 1634, 1598,
1578, 1516, 1496, 1450, 1384, 1330, 1285, 1156, 1118, 1089, 1017, 982; HRMS (ESI): m/z [M+Na]+
calcd for C25H25NO4SNa: 458.1402; found: 458.1411.
2-((4-Methylphenyl)sulfonamido)-2-(p-tolyl)ethyl
benzoate
(3dj)
/
2-((4-methylphenyl)-
sulfonamido)-1-(p-tolyl)ethyl benzoate (3dj')7 These compounds were obtained as mixture pale yellow
solid; Yield: 66.3 mg (81%, 3dj/3dj' = 70/30); mp 151–154 qC; 1H NMR (400 MHz, CDCl3): δ 7.97 (d, J

HETEROCYCLES, Vol. 92, No. 3, 2016
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= 7.2 Hz, 0.6H), 7.88–7.85 (m, 1.4H), 7.70 (d, J = 8.0 Hz, 0.6H), 7.59–6.98 (m, 10.4H), 5.95–5.91 (m,
0.3H), 5.87 (d, J = 6.8 Hz, 0.7H), 5.31 (t, J = 6.8 Hz, 0.3H), 4.73–4.68 (m, 0.7H), 4.45–4.33 (m, 1.4H),
13
3.53–3.38 (m, 0.6H), 2.35 (s, 0.9H), 2.29 (s, 0.9H), 2.27 (s, 2.1H), 2.25 (s, 2.1H); C NMR (100 MHz,
CDCl3): δ 166.4, 165.7, 143.4, 143.1, 138.5, 137.8, 137.4, 137.1, 134.4, 134.2, 133.2, 129.8, 129.5, 129.4,
129.3, 128.4, 128.3, 127.0, 126.8, 126.4, 74.7, 67.1, 56.9, 47.9, 21.5, 21.4, 21.2, 21.1; IR (KBr) (cm-1) v
3332, 3030, 2956, 2921, 1712, 1599, 1515, 1494, 1449, 1384, 1321, 1270, 1152, 1122, 1090, 1019, 996;
HRMS (ESI): m/z [M+Na]+ calcd for C23H23NO4SNa: 432.1245; found: 432.1264.
2-(4-Chlorophenyl)-2-((4-methylphenyl)sulfonamido)ethyl cinnamate (3ea) / 1-(4-chlorophenyl)-2-
((4-methylphenyl)sulfonamido)ethyl cinnamate (3ea')7 These compounds were obtained as mixture
1
white solid; Yield: 65.5 mg (72%, 3ea/3ea' = 80/20); mp 160–163 qC; H NMR (400 MHz, CDCl3): δ
7.70 (d, J = 8.0 Hz, 0.4H), 7.66–7.14 (m, 12H), 7.11 (d, J = 8.0 Hz, 1.6H), 6.36 (d, J = 16.0 Hz, 0.2H),
6.22 (d, J = 16.0 Hz, 0.8H), 5.95–5.88 (m, 0.8H), 5.82 (t, J = 6.0 Hz, 0.2H), 5.38–5.31 (m, 0.2H),
4.70–4.64 (m, 0.8H), 4.34–4.21 (m, 1.6H), 3.43–3.34 (m, 0.4H), 2.37 (s, 0.6H), 2.25 (s, 2.4H); 13C NMR
(100 MHz, CDCl3): δ 166.6, 145.9, 143.4, 137.4, 135.9, 134.1, 134.0, 130.6, 129.8, 129.5, 128.9, 128.8,
128.4, 128.2, 127.8, 127.1, 127.0, 116.8, 66.3, 56.6, 21.3; IR (KBr) (cm-1) v 3442, 3271, 2924, 1717,
1707, 1636, 1599, 1494, 1450, 1319, 1170, 1156, 1091, 1014, 980; HRMS (ESI): m/z [M+Na]+ calcd for
C24H22NO4SClNa: 478.0856; found: 478.0861.
2-(4-Chlorophenyl)-2-((4-methylphenyl)sulfonamido)ethyl benzoate (3ej) / 1-(4-chlorophenyl)-
2-((4-methylphenyl)sulfonamido)ethyl benzoate (3ej')7 These compounds were obtained as mixture
1
white solid; Yield: 71.2 mg (83%, 3ej/3ej' = 84/16); mp 155–156 qC; H NMR (400 MHz, CDCl3): δ
7.98 (d, J = 7.2 Hz, 0.32H), 7.86 (d, J = 7.2 Hz, 1.68H), 7.68 (d, J = 8.4 Hz, 0.32H), 7.59–7.18 (m, 9H),
7.02 (d, J = 7.2 Hz, 1.68H), 5.95–5.92 (m, 0.16H), 5.72 (d, J = 6.8 Hz, 0.84H), 5.10 (t, J = 6.4 Hz, 0.16H),
4.74–4.69 (m, 0.84H), 4.44–4.32 (m, 1.68H), 3.49–3.44 (m, 0.32H), 2.39 (s, 0.48H), 2.28 (s, 2.52H); 13C
NMR (100 MHz, CDCl3): δ 166.3, 143.5, 137.0, 135.8, 135.6, 134.0, 133.5, 133.4, 129.8, 129.8, 129.7,
129.5, 129.1, 129.0, 128.8, 128.5, 128.4, 128.3, 127.8, 126.9, 74.1, 66.7, 56.6, 47.7, 21.6, 21.5; IR (KBr)
(cm-1) v 3429, 3272, 2955, 2923, 1721, 1697, 1599, 1491, 1441, 1385, 1330, 1269, 1156, 1123, 1092,
1071, 1027, 1015, 989; HRMS (ESI): m/z [M+Na]+ calcd for C22H20NO4SClNa: 452.0699; found:
452.0672.
2-((4-Methylphenyl)sulfonamido)-2-(4-nitrophenyl)ethyl cinnamate (3fa) / 2-((4-methylphenyl)-
sulfonamido)-1-(4-nitrophenyl)ethyl cinnamate (3fa') These compounds were obtained as mixture pale
1
yellow solid; Yield: 25.2 mg (27%, 3fa/3fa' = 55/45); mp 139–142 qC; H NMR (400 MHz, CDCl3): δ
8.16–8.09 (m, 2.0H), 7.70–7.24 (m, 10.9H), 7.13 (d, J = 8.0 Hz, 1.1H), 6.41 (d, J = 16.0 Hz, 0.45H), 6.21
(d, J = 16.0 Hz, 0.55H), 6.15–6.02 (m, 0.55H), 5.94 (t, J = 5.6 Hz, 0.45H), 5.47–5.34 (m, 0.45H),

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HETEROCYCLES, Vol. 92, No. 3, 2016
13
4.80–4.77 (m, 0.55H), 4.37–4.22(m, 1.1H), 3.63–3.44 (m, 0.9H), 2.37 (s, 1.35H), 2.24 (s, 1.65H); C
NMR (100 MHz, CDCl3): δ 166.6, 165.6, 147.8, 147.6, 146.7, 146.4, 144.7, 144.4, 143.9, 136.9, 136.8,
133.8, 130.9, 129.9, 129.7, 129.0, 129.0, 128.3, 128.3, 128.0, 127.3, 127.0, 127.0, 123.9, 123.8, 116.5,
116.3, 73.5, 65.9, 56.8, 47.5, 21.5, 21.4; IR (KBr) (cm-1) v 3447, 3273, 2923, 2853, 1709, 1636, 1600,
1520, 1450, 1347, 1332, 1204, 1164, 1090, 1018, 982; HRMS (ESI): m/z [M+Na]+ calcd for
C24H22N2O6SNa: 489.1096; found: 489.1107.
2-((4-Methylphenyl)sulfonamido)-2-(4-nitrophenyl)ethyl benzoate (3fj) / 2-((4-methylphenyl)-
sulfonamido)-1-(4-nitrophenyl)ethyl benzoate (3fj') These compounds were obtained as mixture pale
1
yellow solid; Yield: 20.2 mg (23%, 3fj/3fj' = 67/33); mp 139–142 qC; H NMR (400 MHz, CDCl3): δ
8.16–8.10 (m, 2.0H), 8.01 (d, J = 7.6 Hz, 0.66H), 7.84 (d, J = 7.6 Hz, 1.34H), 7.68–7.38 (m, 7.0H), 7.21
(d, J = 8.0 Hz, 0.66H), 7.03 (d, J = 8.0 Hz, 1.34H), 6.11–6.05 (m, 1H), 5.45–5.30 (m, 0.33H), 4.85–4.82
(m, 0.67H), 4.47–4.37 (m, 1.34H), 3.52–3.44 (m, 0.66H), 2.38 (s, 0.99H), 2.27 (s, 2.01H); 13C NMR (100
MHz, CDCl3): δ 166.3, 165.3, 147.9, 147.6, 144.7, 144.3, 143.9, 143.8, 136.7, 133.8, 133.6, 129.8, 129.8,
129.7, 129.6, 128.9, 128.8, 128.6, 128.5, 128.0, 127.3, 126.9, 124.0, 123.9, 73.9, 66.4, 56.8, 47.5, 21.5,
21.5; IR (KBr) (cm-1) v 3436, 3276, 3066, 2924, 2853, 1714, 1600, 1520, 1451, 1439, 1348, 1271, 1158,
1090, 1027; HRMS (ESI): m/z [M+Na]+ calcd for C22H20N2O6SNa: 463.0940; found: 463.0941.
2-((4-Methylphenyl)sulfonamido)hexyl cinnamate (3ga) This compound was obtained as a white solid;
Yield: 56.9 mg (71%); mp 105–106 qC; 1H NMR (400 MHz, CDCl3): δ 7.78 (d, J = 8.0 Hz, 2H), 7.60 (d,
J = 16.0 Hz, 1H), 7.48–7.46 (m, 2H), 7.38–7.37 (m, 3H), 7.23 (d, J = 8.0 Hz, 2H), 6.23 (d, J = 16.0 Hz,
1H), 5.43 (d, J = 8.4 Hz, 1H), 4.15–4.00 (m, 2H), 3.58–3.50 (m, 1H), 2.29 (s, 3H), 1.54–1.47 (m, 2H),
1.26–1.20 (m, 4H), 0.81 (t, J = 6.8 Hz, 3H); 13C NMR (100 MHz, CDCl3): δ 166.7, 145.3, 143.2, 138.4,
134.3, 130.4, 129.6, 128.9, 128.1, 127.0, 117.4, 65.8, 53.2, 32.2, 27.5, 22.3, 21.3, 13.7; IR (KBr) (cm-1) v
3320, 2956, 2853, 1704, 1634, 1579, 1499, 1453, 1430, 1389, 1317, 1286, 1187, 1159, 1142, 1093, 1008,
983; HRMS (ESI): m/z [M+Na]+ calcd for C22H27NO4SNa: 424.1558; found: 424.1580.
2-((4-Methylphenyl)sulfonamido)hexyl benzoate (3gj) This compound was obtained as a white solid;
Yield: 49.5 mg (66%); mp 104–106 qC; 1H NMR (400 MHz, CDCl3): δ 7.91 (d, J = 7.6 Hz, 2H), 7.74 (d,
J = 8.0 Hz, 2H), 7.55 (t, J = 7.6 Hz, 1H), 7.40 (t, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 5.19 (d, J =
8.0, 1H), 4.27–4.11 (m, 2H), 3.64–3.56 (m, 1H), 2.32 (s, 3H), 1.60–1.51 (m, 2H), 1.30–1.20 (m, 4H), 0.80
(t, J = 6.8 Hz, 3H); 13C NMR (100 MHz, CDCl3): δ 166.4, 143.3, 137.9, 133.2, 129.7, 129.6, 129.5, 128.4,
126.9, 66.2, 53.1, 32.3, 27.6, 22.3, 21.5, 13.9; IR (KBr) (cm-1) v 3406, 3299, 2933, 2858, 1709, 1601,
1495, 1452, 1428, 1395, 1325, 1280, 1164, 1114, 1092, 1044, 1028, 971; HRMS (ESI): m/z [M+Na]+
calcd for C20H25NO4SNa: 398.1402; found: 398.1412.

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ACKNOWLEDGEMENTS
We are grateful to the National Natural Science Foundation of China (grant no. 21162012 and 21362014),
Jiangxi Provincial Department of Science and Technoloy (for Jiangxi’s Key Laboratory of Green
Chemistry, and no. 20122BAB203007), and the Science Foundation of Education Department of Jiangxi
provice (grant no. GJJ10386 and GJJ12616) for their financial supported.
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