Synthesis and biological activities of 2-oxocycloalkylsulfonamides

Article abstract of DOI:10.1016/j.bmc.2008.02.048

A series of novel 2-oxocycloalkylsulfonamides (4) were synthesized and their structures confirmed by IR, ¹H NMR, and elemental analysis. The bioassay showed that they have fair to excellent fungicidal activities against Botrytis cinerea Pers and Sclerotinia sclerotiorum. Among them, compounds 4A₁₀, 4A₁₁, 4A₁₂, 4B₂, and 4B₃, the EC₅₀ values of which were 2.12, 3.66, 3.96, 2.38, and 2.43 μg/mL, respectively, displayed excellent fungicidal activity against B. cinerea Pers, and are comparable with commercial fungicide procymidone (the EC₅₀ value is 2.45 μg/mL). 3D QSAR against B. cinerea Pers was studied, a statistically significant and chemically meaningful CoMFA model was developed and some compounds which have a high predicted activity were forecasted. In addition, the bioassay also showed that the compounds have good inhibitory activities against human tumor cells HL-60, BGC-823, Bel-7402 and KB. It is interesting to point out that the antitumor activities of compounds 4 are in accordance with their fungicidal activity to a great extent: compounds having relatively best antitumor activities (4A₁₀, 4A₁₁, 4A₁₂, and 4B₃) also displayed excellent fungicidal activity.

Full text of DOI:10.1016/j.bmc.2008.02.048

Available online at www.sciencedirect.com
Bioorganic & Medicinal Chemistry 16 (2008) 4538–4544
Synthesis and biological activities of 2-oxocycloalkylsulfonamides
Xinghai Li,a Xinling Yang,a Xiaomei Liang,a Zhenpeng Kai,a Huizu Yuan,b Dekai Yuan,a
Jianjun Zhang,a Ruiqing Wang,c Fuxiang Ran,c Shuhua Qi,b Yun Ling,a
Fuheng Chena and Daoquan Wanga,*
aKey Laboratory of Pesticide Chemistry and Application Technology, Department of Applied Chemistry,
China Agricultural University, Beijing 100094, People’s Republic of China
bInstitute of Plant Protection, Chinese Academy of Agricultural Science, Beijing 100094, People’s Republic of China
cState Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Science, Peking University,
Beijing 100083, People’s Republic of China
Received 12 December 2007; revised 30 January 2008; accepted 13 February 2008
Available online 16 February 2008
Abstract—A series of novel 2-oxocycloalkylsulfonamides (4) were synthesized and their structures confirmed by IR, 1H NMR, and
elemental analysis. The bioassay showed that they have fair to excellent fungicidal activities against Botrytis cinerea Pers and Scle-
rotinia sclerotiorum. Among them, compounds 4A10, 4A11, 4A12, 4B2, and 4B3, the EC50 values of which were 2.12, 3.66, 3.96, 2.38,
and 2.43 lg/mL, respectively, displayed excellent fungicidal activity against B. cinerea Pers, and are comparable with commercial
fungicide procymidone (the EC50 value is 2.45 lg/mL). 3D QSAR against B. cinerea Pers was studied, a statistically significant
and chemically meaningful CoMFA model was developed and some compounds which have a high predicted activity were fore-
casted. In addition, the bioassay also showed that the compounds have good inhibitory activities against human tumor cells HL-
60, BGC-823, Bel-7402 and KB. It is interesting to point out that the antitumor activities of compounds 4 are in accordance with
their fungicidal activity to a great extent: compounds having relatively best antitumor activities (4A10, 4A11, 4A12, and 4B3) also
displayed excellent fungicidal activity.
ꢀ 2008 Elsevier Ltd. All rights reserved.
F3C
SO2NH2 Cl
Cl
1. Introduction
O
H2N
SO2NH
NO2
It is common knowledge that sulfanilamide (1) was the
first synthetic antibacterial agent active against a wide
range of infections. Further developments led to a range
of sulfonamides which proved effective against Gram-
positive organisms, especially pneumococci and meningo-
cocci.1 Sulfonamides are also used as agricultural fungi-
cides. For example, flusulfamide (2) is used as a soil
fungicide for the control of Plasmodiophora brassicae
on the Chinese cabbage.2 On the other hand, we found
that several 2-oxocyclododecylsulfonamides (3) have
some fungicidal activity.3
SO2NHR
1
3
2
Based on our discovery and the fact that all of the sul-
fonamide drugs and fungicides are benzene sulfonamide
derivatives, we decided to explore whether latter’s cyclo-
alkane analogues (cyclohexane and cycloheptane deriva-
tives) have a similar biological activity. Thus, a series of
2-oxocyclohexylsulfonamides (4A) and 2-oxocyclohep-
tylsulfonamides (4B) were synthesized, and their fungi-
cidal activity against some economically important
fungus species (Botrytis cinerea Pers and Sclerotinia scle-
rotiorum) was evaluated. Then 3D QSAR against B.
cinerea Pers was studied by CoMFA (Comparative
Molecular Field Analysis) and a statistically significant
and chemically meaningful CoMFA model was devel-
oped. According to the model, five new 2-oxocycloalkyl-
sulfonamides (4P1–4P5) were designed and synthesized
to check their predictive ability. In addition, antitumor
Keywords: 2-Oxocycloalkylsulfonamide; Fungicidal activity; Antitu-
mor activity; QSAR.
*
Corresponding author. Tel./fax: +86 10 62732219; e-mail:
wangdq@cau.edu.cn
0968-0896/$ - see front matter ꢀ 2008 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmc.2008.02.048

X. Li et al. / Bioorg. Med. Chem. 16 (2008) 4538–4544
4539
activities of compounds 4A and 4B were also evaluated.
In this paper, we would like to report their synthesis and
biological activities.
an equatorial hydrogen) and the long-range coupling
with a0-equatorial hydrogen, respectively.
2.2. Fungicidal activity
2. Results and discussion
2.1. Chemical synthesis
The fungicidal activities of compounds 4 against phyto-
pathogen B. cinerea Pers and S. sclerotiorum were eval-
uated using commercial fungicides procymidone or
chlorothalonil as the controls. The results are shown
in Table 1.
The synthetic route of compounds 4 is shown in Scheme
1. Potassium 2-oxocycloalkylsulfonates (5), prepared
from readily available cycloalkanes by sulfonation with
a sulfur trioxide–dioxane adduct and neutralization with
potassium hydroxide,4 were allowed to react with oxalyl
chloride to give the corresponding sulfonyl chloride,
which were converted into title compounds (4) by ami-
nation with amines.3
From Table 1, we can see that compounds 4 have fair to
excellent fungicidal activities against B. cinerea Pers.
Among them, compounds 4A10, 4A11, 4A12, 4B2, and
4B3, the EC50 values of which were 2.12, 3.66, 3.96,
2.38, and 2.43 lg/mL, respectively, displayed excellent
fungicidal activity, and are comparable with that of pro-
cymidone (the EC50 value is 2.45 lg/mL). In general, the
structure–activity relationship is as follows: the com-
pounds with two substituents, especially two electron-
withdrawing groups such as trifluoromethyl and chlo-
rine atom on the benzene ring have good fungicidal
activity against B. cinerea Pers. In addition, compounds
4 have fair to good fungicidal activity against S. sclero-
tiorum. Among them, compound 4B3 has excellent fun-
The yields of compounds 4 from potassium 2-
oxocycloalkylsulfonamides are good (60–88%). The
1
structures of compounds 4 were confirmed by IR, H
1
NMR, and elemental analysis. In the H NMR spectra,
the a-hydrogen of most of 2-oxocyclohexylsulfonamides
displayed a ddd at d 3.72–3.92 due to the coupling with
two hydrogens of b-methylene (an axial hydrogen and
O
O
O
.
SO3
1.
O
O
3. (COCl)2
4. R'R"NH
)n
(CH2
)n
(CH2
(CH2)n
2. KOH/H2O
SO2NR'R"
SO3K
4
5
n=4, 5, 10
Scheme 1.
Table 1. The fungicidal activities of compounds 4 against Botrytis cinerea Pers and Sclerotinia sclerotiorum
Compound
R0
B. cinerea
r
S. sclerotiorum
r
No.
n
R00
Regression eq
EC50 (lg/mL)
Regression eq
EC50 (lg/mL)
4A1
4A2
4A3
4A4
4A5
4A6
4A7
4A8
4A9
4A10
4A11
4A12
4A13
4
4
4
4
4
4
4
4
4
4
4
4
4
p-MeC6H4
o-ClC6H4
H
H
H
H
H
H
H
H
H
H
H
H
Y = 3.33 + 1.26x
Y = 1.63 + 2.18x
Y = 3.09 + 1.55x
Y = 0.03 + 2.92x
Y = 3.57 + 0.74x
Y = 2.93 + 1.50x
Y = 3.09 + 1.55x
Y = 2.59 + 1.53x
Y = 3.40 + 1.86x
Y = 4.53 + 1.44x
Y = 4.01 + 1.75x
Y = 3.98 + 1.71x
Y = 3.57 + 0.74x
0.9179
0.9966
0.9669
0.9988
0.9867
0.9527
0.9669
0.9773
0.9796
0.9941
0.9832
0.9985
0.9867
21.22
35.21
16.97
50.58
85.24
24.19
16.97
37.67
7.23
Y = 0.18 + 2.33x
Y = 0.20 + 2.61x
Y = 1.01 + 2.31x
Y = 1.98 + 1.80x
Y = 0.90 + 1.90x
Y = 2.37 + 1.48x
0.9982
0.9999
0.8748
0.8801
0.9686
0.9637
115.94
69.41
53.44
47.83
143.88
59.34
111.82
136.88
24.24
47.50
70.52
24.15
331.16
p-ClC6H4
o-BrC6H4
m-CF3C6H4
2,3-Me2C6H3
2,4-Me2C6H3
2-Me-4-FC6H3
3,4-Cl2C6H3
2-CF3-4-ClC6H3
2,5-(CF3)2C6H3
3,5-(CF3)2C6H3
CH2CH2OCH2CH2
Y = ꢀ0.41 + 2.64x
Y = 2.82 + 1.02x
Y = 2.48 + 1.82x
Y = 1.45 + 2.12x
Y = 2.16 + 1.54x
Y = 1.56 + 2.49x
Y = 1.54 + 1.37x
0.9907
0.9645
0.9633
0.9897
0.9974
0.9934
0.9989
2.12
3.66
3.96
85.24
OCH3
N
4A14
4
H
Y = 3.57 + 0.98x
0.9538
28.63
Y = 1.20 + 1.66x
0.9886
197.42
N
OCH3
4B1
4B2
4B3
5
5
5
2,3-Me2C6H3
3,4-Cl2C6H3
3,5-(CF3)2C6H3
H
H
H
Y = 3.25 + 1.64x
Y = 4.41 + 1.56x
Y = 4.51 + 1.28x
Y = 3.46x + 3.66
0.9865
0.9701
0.9930
0.9920
11.62
2.38
2.43
2.45
Y = 2.52 + 1.48x
Y = 2.59 + 1.98x
Y = 3.29 + 1.89x
0.9946
0.9867
0.9992
47.56
16.37
8.05
Procymidone
Chlorothalonil
Y = 4.08 + 1.08x
0.9924
7.16

4540
X. Li et al. / Bioorg. Med. Chem. 16 (2008) 4538–4544
gicidal activity (the EC50 value is 8.05 lg/mL), and is
comparable with that of chlorothalonil (the EC50 value
is 7.16 lg/mL).
Yellow regions nearly surrounding the positions 4 and
5 of the benzene ring indicate that small groups will im-
prove the activity. Yellow and green regions near posi-
tion 2 of the benzene ring, according to the proportion
of two types of regions, indicate that suitable small
groups tend to increase the activity. A yellow region
pointed to the parent ring shows that the activity will
be increased, if the bulk of the ring is enlarged suitably.
Red and blue regions near positions 2 and 5, according
to the proportion of two types of regions, indicate that
suitable electronegative groups are favorable to the in-
crease of the activity. Five new compounds (4P1–4P5)
were designed, synthesized, and evaluated based on the
CoMFA result (Table 3).
2.3. 3D QSAR of compounds 4 against B. cinerea Pers
Statistically significant and chemically meaningful
CoMFA models were developed using the data of fungi-
cidal activity of 14 compounds 4 against B. cinerea Pers.
The results of the CoMFA studies are summarized in
Table 2.
The model M1, in which the q2 values are 0.000 (leave-
one-out) and 0.149 (cross-validate), respectively, was
bad. 4A13 and 4A14 were deleted to develop a better
model (model M4) which showed a predictive ability
with a leave-one-out q2 value of 0.552 and a cross-vali-
date q2 value of 0.572. The non-cross-validated r2 value
was 0.969, F = 42.229, standard error of estimate was
4.646. The contributions of the steric and the electro-
static field to the activity were 55.8% and 44.2%, respec-
tively, by PLS analysis. Figure 1 shows the distribution
of the steric and electrostatic fields of the model M4.
The results showed that the predicated values (the EC50
values are 31.34, 4.52, 16.93, 31.63, and 18.31 lg/mL,
respectively) are in accordance with the experimental
values (the EC50 values are 41.98, 6.05, 6.44, 29.45 and
28.90 lg/mL, respectively) in the order of magnitude.
In the other words, the CoMFA model 4 has a better
predicative ability. The results also showed that a-oxo-
cyclododecyl group may be too large to obtain the deriv-
Table 2. CoMFA models of compounds 4
Models
Deleted compounds
q2
No validation
Leave-one-out
Cross-validate
Standard error of estimate
r2
F values
M1
M2
M3
M4
0
4A13
0.000
0.447
0.149
0.422
4A14
4A13, 4A14
ꢀ0.019
0.552
ꢀ0.039
0.572
4.646
0.969
42.229
Figure 1. Steric (left) and electrostatic (right) contour map of CoMFA M4 represented by the skeleton of a-oxocyclohexylsulfonamide.
Table 3. The predicted and experimental EC50 values of designed compounds
Compound
R0
Predicted value (EC50, lg/mL)
Experimental value (EC50, lg/mL)
No
n
R00
Regression eq
r
EC50 (lg/mL)
4P1
4P2
4P3
4P4
4P5
4
4
4-FC6H4
2,5-Cl2C6H3
H
H
H
H
H
31.34
4.52
Y = 2.60 + 1.48x
Y = 3.55 + 1.85x
Y = 4.37 + 0.78x
Y = 3.95 + 0.72x
Y = 3.57 + 0.98x
0.9712
0.9852
0.9279
0.9410
0.9229
41.98
6.05
6.44
10
10
10
2,3-Me2C6H3
3,4-Cl2C6H3
3,5-(CF3)2C6H3
11.31
16.93
31.63
29.45
28.90

X. Li et al. / Bioorg. Med. Chem. 16 (2008) 4538–4544
4541
Table 5. Inhibition of compounds 4 to human tumor cell lines at
100 lg/mL
atives possessing a high activity, and only two substitu-
ents on the benzene ring are not enough to obtain the
compounds possessing a high activity. Based on the
above results, the second group of compounds in which
the parent rings are cyclohexyl and cycloheptal and phe-
nyl bearing two or three substituents on the side chain
were designed and their fungicidal activity (EC50 values)
was predicated (Table 4).
Compound
Inhibition rate (%)
HL-60
BGC-823
Bel-7402
KB
4A1
4A2
4A3
4A4
4A5
4A6
4A7
4A8
4A9
4A10
4A11
4A12
4A13
4A14
4B1
4B2
4B3
ꢀ3.55
0.29
32.05
29.18
16.03
29.58
21.65
24.47
15.63
28.68
5.54
27.46
1.98
4.47
ꢀ22.21
ꢀ10.06
ꢀ3.83
ꢀ14.39
ꢀ6.30
ꢀ20.62
7.97
ꢀ12.96
15.35
16.98
9.38
22.13
11.40
21.76
0.52
The predicated results showed that the seven-membered
ring derivatives are more active than the six-membered
ring derivatives for the same substituted pattern, and the
derivatives bearing three substituents on the benzene ring
are more active than those bearing two substituents on the
benzene ring. Among the designed compounds, 4P15 and
4P16 have the best predicated activity against B. cinerea
Pers (the predicted EC50 values of 4P15 and 4P16 are 0.50
and 0.12, respectively). Therefore, the compounds pos-
sessing a still better activity may be obtained through
structural modification. Further work has been planned.
12.15
ꢀ0.99
13.47
78.61
95.67
95.88
10.97
2.62
3.22
1.39
ꢀ3.72
17.75
11.22
68.61
75.95
ꢀ4.35
2.73
36.35
57.72
70.76
21.32
26.41
23.84
28.88
56.95
20.95
68.31
66.93
6.01
39.26
12.09
4.03
22.88
15.04
95.79
2.01
ꢀ6.30
58.97
45.27
2.4. Antitumor activity
3. Conclusion
Compounds 4 (4A and 4B) were evaluated for their abil-
ity to inhibit human tumor cells HL-60, BGC-823, Bel-
7402, and KB (Table 5). Among them, compounds 4A11,
4A12, and 4B3 have high inhibitory activity against HL-
60 (the inhibition rate exceeds 90% at 100 lg/mL) and a
good inhibitory activity against BGC-823, Bel-7402, and
KB (the inhibition rates exceed 50% except 4B3 against
Bel-7402). In addition, compound 4A10 has a good
inhibitory activity against HL-60 (inhibition rate is
78.61% at 100 lg/mL). It is interesting to point out that
the antitumor activities of compounds 4 are in accor-
dance with their fungicidal activity to a great extent.
2-Oxocycloalkylsulfonamides (4A and 4B) obtained by
the replacement of the benzene ring of traditional sul-
fonamide fungicide with saturated six- and seven-mem-
bered rings have fair to excellent fungicidal activities
against B. cinerea Pers and S. sclerotiorum. Among
them, compounds 4A10, 4A11, 4A12, 4B2, and 4B3 dis-
played excellent fungicidal activity against B. cinerea
Pers, and are comparable with commercial fungicide
procymidone. 3D QSAR study indicated that their fun-
gicidal activity may be further improved through struc-
tural modification. The fact that the antitumor activity
of compounds 4A and 4B against four human tumor cell
lines in accordance with their fungicidal activity to a
great extent lays a foundation for further research.
Trifluoromethyl group on the benzene ring may play a
more important role in the antitumor activity than in
the fungicidal activity: compounds 4A11, 4A12, and 4B3
bearing two trifluoromethyls on the benzene ring have
good activities against four human tumor cells and plant
pathogen B. cinerea Pers; however, 4A10 bearing one tri-
fluoromethyl on the benzene ring has a good fungicidal
activity against B. cinerea Pers and a good antitumor
activity only against HL-60; and 4B1 and 4B2 having
no trifluoromethyl on the benzene ring have a good fun-
gicidal activity and a low antitumor activity.
4. Materials and methods
4.1. Chemical synthesis
4.1.1. General. Infrared spectra were recorded in potas-
sium bromide discs on a Shimadzu IR-435 spectropho-
tometer; NMR spectra were recorded in CDCl3 with a
Bruker DPX300 spectrometer, using TMS as an internal
standard; elemental analysis was performed by the ana-
lytical center in the Institute of Chemistry (Beijing), Chi-
nese Academy of Science; melting points were measured
on a Yanagimoto melting point apparatus and are
uncorrected. The solvents and reagents were used as re-
ceived or were dried prior to use as needed.
Table 4. The predicted EC50 values of second group of designed
compounds
Compound
R0
Predicted EC50
values (lg/mL)
No
n
R00
4P6
4P7
4
4
4
4
4
5
5
5
5
5
5
2-CF3-4-FC6H3
H
H
H
H
H
H
H
H
H
H
H
3.64
1.20
1.47
0.83
0.76
1.10
1.90
0.51
1.29
0.50
0.12
2-CF3-4-BrC6H3
2-CF3-4-OHC6H3
2-CF3 -4,5-Cl2C6H2
2-CF3-4-Cl-5-BrC6H2
2-CF3-4-FC6H3
4P8
4P9
4.1.2. Potassium 2-oxocycloalkylsulfonamides (5). Com-
pounds 5A, 5B, and 5C were prepared according to
the method given in Ref. 4.
4P10
4P11
4P12
4P13
4P14
4P15
4P16
2-CF3-4-ClC6H3
2-CF3-4-BrC6H3
2-CF3-4-OHC6H3
2-CF3-4,5-Cl2C6H2
2-CF3-4-Cl-5-BrC6H2
4.1.3. General synthetic procedure for N-aryl-2-
oxocycloalkylsulfonamides (4). To the slurry of 5
(0.009 mol) and DMF (0.05 mL) in methylene chloride
(15 mL) was added oxalyl chloride (0.80 mL,

4542
X. Li et al. / Bioorg. Med. Chem. 16 (2008) 4538–4544
0.009 mol); the mixture was stirred at 5–15 ꢁC for 1 h.
After the slurry had been cooled in ice-water bath, it
was filtered at reduced pressure. The filtrate was added
to the solution of arylamine (0.008 mol) and triethyl-
amine in methylene chloride (10 mL) at 5–10 ꢁC. After
being stirred at rt for 2 h, water (10 mL) was poured into
the mixture. The organic layer was separated, washed
with 6 mol HCl (2· 5 mL) and water (2· 5 mL), and
dried over sodium sulfate. After evaporating the solvent
in vacuum, the crude product was recrystallized from
the acetone/petroleum ether to give pure 4.
for C13H14F3NO3S: C, 48.59; H, 4.39; N, 4.36. Found:
C, 48.76; H, 4.48; N, 4.78.
4.1.3.6. N-(2,3-Dimethylphenyl)-a-oxocyclohexylsulf-
onamide (4A6). White crystals, mp 71–72 ꢁC; yield,
80%; IR (KBr, cmꢀ1) mmax: 3200, 2920, 2850, 1690,
1580, 1310, 1160; 1H NMR, d: 1.62–1.69 (m, 1H),
1.86–1.87 (m, 1H), 1.98–2.06 (m, 2H), 2.25 (s, 3H),
2.29 (s, 3H), 2.20–2.47 (m, 3H), 2.65–2.72 (m, 1H),
3.90 (ddd, 1H, J = 10.11, 5.96, 1.04 Hz), 6.67 (s, 1H,
N–H), 7.03–7.09 (m, 2H), 7.16–7.20 (m, 1H). Anal.
Calcd for C14H19NO3S: C, 59.76; H, 6.81; N, 4.98.
Found: C, 59.80; H, 6.80; N, 4.88.
4.1.3.1. N-(4-Methylphenyl)-a-oxocyclohexylsulfona-
mide (4A1). White crystals, mp 103–104 ꢁC; yield, 68%;
IR (KBr, cmꢀ1) mmax: 3200, 2950, 2880, 1700, 1590,
4.1.3.7. N-(2,4-Dimethylphenyl)-a-oxocyclohexylsulf-
onamide (4A7). Yellow crystals, mp 84–86 ꢁC; yield,
60%; IR (KBr, cmꢀ1) mmax: 3300, 2950, 2880, 1700,
1
1340, 1160, 815; H NMR, d: 1.58–2.16 (m, 5H), 2.20–
2.67 (m, 3H), 2.32 (s, 3H, CH3), 3.72 (ddd, 1H,
J = 10.41, 5.94, 0.85 Hz), 6.79 (s, 1H, N–H), 7.11 (s,
4H). Anal. Calcd for C13H17NO3S: C, 58.40; H, 6.41;
N, 5.24. Found: C, 58.56; H, 6.46; N, 5.11.
1
1610, 1315, 1160, 800; H NMR, d: 1.61–1.69 (m, 1H),
1.85–1.87 (m, 1H), 1.97–2.08 (m, 2H), 2.18–2.45 (m,
9H), 2.66–2.71 (m, 1H), 3.89 (ddd, 1H, J = 10.02, 5.94,
1.04 Hz), 6.58 (s, 1H, N–H), 6.95–7.01 (m, 2H), 7.24–
7.27 (m, 1H). Anal. Calcd for C14H19NO3S: C, 59.76;
H, 6.81; N, 4.98. Found: C, 59.89; H, 6.86; N, 4.94.
4.1.3.2. N-(2-Chlorophenyl)-a-oxocyclohexylsulfona-
mide (4A2). White crystals, mp 112–113 ꢁC; yield, 84%;
IR (KBr, cmꢀ1) mmax: 3250, 2920, 2850, 1705, 1590,
1
1330, 1160; H NMR, d: 1.66–1.84 (m, 2H), 2.00–2.16
4.1.3.8. N-(4-Fluoro-2-methylphenyl)-a-oxocyclohexyl-
sulfonamide (4A8). White crystals, mp 107–108 ꢁC; yield,
76%; IR (KBr, cmꢀ1) mmax: 3200, 2920, 2860, 1690, 1610,
(m, 3H), 2.36–2.40 (m, 1H), 2.46–2.49 (m, 1H), 2.62–
2.68 (m, 1H), 3.92 (ddd, 1H, J = 10.64, 5.74, 0.92 Hz),
7.08–7.13 (m, 1H, Ar–H), 7.23–7.28 (m, 1H, Ar–H),
7.35 (s, 1H, NH), 7.37 (dd, 1H, J = 8.04, 1.41 Hz),
7.67 (dd, 1H, J = 8.17, 1.37 Hz). Anal. Calcd for
C12H14ClNO3S: C, 50.59; H, 4.90; N, 4.87. Found: C,
50.10; H, 4.94; N, 4.81.
1
1310, 1140; H NMR, d: 1.69–1.85 (m, 2H), 2.02–2.19
(m, 3H), 2.37–2.40 (m, 1H), 2.53–2.70 (m, 2H), 3.81
(ddd, 1H, J = 10.67, 5.92, 0.81 Hz), 7.46 (s, 1H, NH),
7.69 (s, 3H). Anal. Calcd for C13H16FNO3S: C, 54.72;
H, 5.65; N, 4.91. Found: C, 54.87; H, 5.66; N, 5.08.
4.1.3.3. N-(4-Chlorophenyl)-a-oxocyclohexylsulfona-
mide (4A3). White crystals, mp 81–83 ꢁC; yield, 70%;
IR (KBr, cmꢀ1) mmax: 3250, 2870, 2950, 1710, 1600,
4.1.3.9. N-(3,4-Dichlorophenyl)-a-oxocyclohexylsulf-
onamide (4A9). White crystals, mp 109–110 ꢁC; yield,
75%; IR (KBr, cmꢀ1) mmax: 3300, 2950, 1700, 1595,
1
1
1315, 1160, 810; H NMR, d: 1.61–1.83 (m, 2H), 1.98–
1320, 1150, 820; H NMR, d: 1.61–1.84 (m, 2H), 1.99–
2.08 (m, 2H), 2.11–2.17 (m, 1H), 2.32–2.36 (m, 1H),
2.43–2.45 (m, 1H), 2.60–2.67 (m, 1H), 3.72 (ddd, 1H,
J = 10.52, 5.92, 0.97 Hz), 6.95 (s, 1H, NH), 7.15–7.19
(m, 2H, CH), 7.26–7.31 (m, 2H). Anal. Calcd for
C12H14ClNO3S: C, 50.59; H, 4.90; N, 4.87. Found: C,
50.11; H, 4.91; N, 4.80.
2.18 (m, 3H), 2.34–2.37 (m, 1H), 2.47–2.51 (m, 1H),
2.61–2.68 (m, 1H), 3.75 (ddd, 1H, J = 10.68, 5.95,
0.86 Hz), 6.99 (s, 1H, N–H), 7.09 (dd, 1H, J = 8.70,
2.52 Hz), 7.37 (d, 1H, J = 2.60 Hz), 7.38 (d, 1H,
J = 8.60 Hz). Anal. Calcd for C12H13Cl2NO3S: C,
44.73; H, 4.07; N, 4.35. Found: C, 44.92; H, 4.13; N,
4.27.
4.1.3.4. N-(2-Bromophenyl)-a-oxocyclohexylsulfona-
mide (4A4). White crystals, mp 75–76 ꢁC; yield, 77%;
IR (KBr, cmꢀ1) mmax: 3300, 2920, 2850, 1710, 1590,
4.1.3.10. N-(4-Chloro-2-trifluoromethylphenyl)-a-oxo-
cyclohexylsulfonamide (4A10). White crystals, mp 119–
120 ꢁC; yield, 78%; IR (KBr, cmꢀ1) mmax: 3330, 2950,
1
1330, 1160; H NMR, d: 1.66–1.85 (m, 2H), 2.00–2.18
1
(m, 3H), 2.34–2.40 (m, 1H), 2.47–2.53 (m, 1H), 2.61–
2.68 (m, 1H), 3.90 (dd, 1H, J = 10.82, 5.74 Hz), 7.00–
7.06 (m, 1H, Ar–H), 7.27–7.32 (m, 1H, Ar–H), 7.35 (s,
1H, NH), 7.54 (dd, 1H, J = 8.04, 1.44 Hz), 7.67 (dd,
1H, J = 8.22, 1.51 Hz). Anal. Calcd for C12H14BrNO3S:
C, 43.38; H, 4.25; N, 4.22. Found: C, 42.84; H, 4.18; N,
4.22.
2880, 1710, 1600, 1310, 1120; H NMR, d: 1.67–1.81
(m, 2H), 2.04–2.11 (m, 3H), 2.30–2.38 (m, 1H), 2.54–
2.66 (m, 2H), 3.76 (dd, 1H, J = 12.45, 6.38 Hz), 7.30
(s, 1H, NH), 7.51 (dd, 1H, J = 8.80, 2.45 Hz), 7.59 (d,
1H, J = 2.45 Hz), 7.70 (d, 1H, J = 8.80 Hz). Anal. Calcd
for C13H13ClF3NO3S: C, 43.89; H, 3.68; N, 3.94. Found:
C, 43.74; H, 3.64; N, 3.99.
4.1.3.5. N-(3-Trifluoromethylphenyl)-a-oxocyclohexyl-
sulfonamide (4A5). White crystals, mp 103–104 ꢁC; yield,
73%; IR (KBr, cmꢀ1) mmax: 3300, 2950, 2880, 1710, 1600,
4.1.3.11. N-[2,5-Di(trifluoromethyl)phenyl]-a-oxocyclo-
hexylsulfonamide (4A11). White crystals, mp 107–108 ꢁC;
yield, 83%; IR (KBr, cmꢀ1) mmax: 3330, 2950, 2880, 1710,
1
1
1310, 1160; H NMR, d: 1.65–1.84 (m, 2H), 1.99–2.18
1600, 1310, 1120; H NMR, d: 1.69–1.82 (m, 2H), 2.07–
(m, 3H), 2.34–2.39 (m, 1H), 2.46–2.49 (m, 1H), 2.62–
2.69 (m, 1H), 3.76 (ddd, 1H, J = 10.51, 5.96, 0.81 Hz),
7.19 (s, 1H, NH), 7.40–7.50 (m, 4H, Ar–H). Anal. Calcd
2.17 (m, 3H), 2.31–2.42 (m, 1H), 2.59–2.67 (m, 2H), 3.99
(dd, 1H, J = 11.91, 5.58 Hz), 7.51 (s, 1H), 7.54 (s, 1H,
NH), 7.75 (d, 1H, J = 8.25 Hz), 8.05 (s, 1H). Anal. Calcd

X. Li et al. / Bioorg. Med. Chem. 16 (2008) 4538–4544
4543
for C14H13F6NO3S: C, 43.19; H, 3.37; N, 3.60. Found:
C, 43.19; H, 3.52; N, 4.11.
4.1.3.18. N-(4-Fluorophenyl)-a-oxocyclohexylsulfona-
mide (4P1). White crystals, mp 115–116 ꢁC; yield, 71%;
IR (KBr, cmꢀ1) mmax: 3300, 2950, 2880, 1700, 1600,
1
4.1.3.12. N-[3,5-Di(trifluoromethyl)phenyl]-a-oxocyclo-
hexylsulfonamide (4A12). White crystals, mp 91–92 ꢁC;
yield, 80%; IR (KBr, cmꢀ1) mmax: 3200, 2920, 2860,
1690, 1610, 1310, 1140; 1H NMR, d: 1.69–1.85 (m,
2H), 2.02–2.19 (m, 3H), 2.37–2.40 (m, 1H), 2.53–2.70
(m, 2H), 3.81 (ddd, 1H, J = 10.67, 5.92, 0.81 Hz), 7.46
(s, 1H, NH), 7.69 (s, 3H). Anal. Calcd for
C14H13F6NO3S: C, 43.19; H, 3.37; N, 3.60. Found: C,
43.32; H, 3.36; N, 3.75.
1310, 1160; H NMR, d: 1.63–1.67 (m, 1H), 1.81–1.84
(m, 1H), 1.97–2.05 (m, 2H), 2.09–2.18 (m, 1H), 2.34–
2.45 (m, 2H), 2.62–2.69 (m, 1H), 3.72 (ddd, 1H,
J = 10.18, 5.99, 0.95 Hz), 6.93 (s, 1H, N–H), 6.98–7.06
(m, 2H), 7.18–7.26 (m, 2H) Anal. Calcd for
C12H14FNO3S: C, 53.52; H, 5.20; N, 5.16. Found: C,
53.26; H, 5.24; N, 4.21.
4.1.3.19. N-(2,5-Dichlorophenyl)-a-oxocyclohexylsulf-
onamide (4P2). Yellow crystals, mp 125–126 ꢁC; yield,
69%; IR (KBr, cmꢀ1) mmax: 3300, 2950, 2870, 1710,
4.1.3.13. N-(a-Oxocyclohexylsulfonyl)morpholine (4A13).
White crystals, mp 90 ꢁC; yield, 80%; IR (KBr, cmꢀ1
)
1585, 1340, 1160, 850; H NMR, d: 1.67–1.84 (m, 2H),
1
m
max: 3400, 2920, 2850, 1700, 1590, 1330, 1160; 1H
2.03–2.16 (m, 3H), 2.35–2.39 (m, 1H), 2.53–2.68 (m,
2H), 3.92 (ddd, 1H, J = 10.92, 5.73, 0.93 Hz), 7.07 (dd,
1H, J = 8.58, 2.4 Hz), 7.30 (d, 1H, J = 8.61 Hz), 7.40
(s, 1H, N–H), 7.71 (d, 1H, J = 2.4 Hz). Anal. Calcd
for C12H13Cl2NO3S: C, 44.73; H, 4.07; N, 4.35. Found:
C, 44.87; H, 4.07; N, 4.21.
NMR, d: 1.71–1.80 (m, 2H), 2.03–2.20 (m, 3H), 2.43–
2.55 (m, 2H), 2.74–2.85 (m, 1H), 3.30–3.33 (m, 4H),
3.71 (t, 4H, J = 4.7)3.72–3.81 (m, 1H, J = 4.20,
1.20 Hz). Anal. Calcd for C10H17NO4S: C, 48.57; H,
6.93; N, 5.66. Found: C, 48.12; H, 6.81; N, 5.81.
4.1.3.14. N-(4,6-Dimethoxy-2-pyrimidyl)-a-oxocyclohexyl-
sulfonamide (4A14). White crystals, mp 129–130 ꢁC;
yield, 72%; IR (KBr, cmꢀ1) mmax: 3250, 2950, 1720,
1600, 1330, 1160; 1H NMR, d: 1.70–1.80 (m, 1H),
1.89–2.00 (m, 2H), 2.10–2.19 (m, 1H), 2.38–2.54 (m,
3H), 2.70–2.80 (m, 1H), 3.88 (s, 6H, OCH3), 4.77 (t,
1H, J = 6.74 Hz), 5.75 (s, 1H), 7.28 (s, 1H, N–H). Anal.
Calcd for C12H17N3O3S: C, 45.70; H, 5.43; N, 13.33.
Found: C, 45.87; H, 5.48; N, 13.04.
4.1.3.20. N-(2,3-Dimethylphenyl)-a-oxocyclododecyl-
sulfonamide (4P3). White crystals, mp 116–117 ꢁC; yield,
80%; IR (KBr, cmꢀ1) mmax: 3250, 2920, 2850, 1700, 1580,
1
1320, 1150; H NMR, d: 1.27–1.42 (m, 14H), 1.56–1.63
(m, 1H), 1.79–1.96 (m, 2H), 2.25 (s, 3H), 2.30 (s, 3H),
2.71–2.89 (m, 2H), 4.22 (dd, 1H, J = 11.78, 2.88 Hz),
6.25 (s, 1H, NH), 7.05–7.12 (m, 2H), 7.29–7.32 (m,
1H). Anal. Calcd for C20H31NO3S: C, 65.72; H, 8.55;
N, 3.83. Found: C, 65.61; H, 8.42; N, 3.70.
4.1.3.15. N-(2,3-Dimethylphenyl)-a-oxocycloheptyl-
sulfonamide (4B1). White crystals, mp 142–143 ꢁC; yield,
75%; IR (KBr, cmꢀ1) mmax: 3200, 2920, 2850, 1700, 1580,
4.1.3.21. N-(3,4-Dichlorophenyl)-a-oxocyclododecyl-
sulfonamide (4P4). White crystals, mp 144–145 ꢁC; yield,
74%; IR (KBr, cmꢀ1) mmax: 3250, 2920, 2850, 1710, 1590,
1
1
1320, 1150; H NMR, d: 1.28–1.51 (m, 3H), 1.88–2.11
1320, 1140; H NMR, d: 1.28–1.42 (m, 14H), 1.72–1.90
(m, 4H), 2.30 (s, 6H), 2.33–2.39 (m, 1H), 2.58–2.65 (m,
1H), 2.79–2.88 (m, 1H), 3.98 (dd, 1H, J = 11.08,
4.51 Hz), 6.56 (s, 1H, NH), 7.04–7.11 (m, 2H), 7.36–
7.39 (m, 1H). Anal. Calcd for C15H21NO3S: C, 60.99;
H, 7.17; N, 4.74. Found: C, 60.87; H, 7.04; N, 4.86.
(m, 3H), 2.15–2.25 (m, 1H), 2.67–2.77 (m, 1H), 2.83–
2.92 (m, 1H), 4.31 (dd, 1H, J = 11.52, 3.03 Hz), 6.92
(s, 1H, NH), 7.14 (dd, 1H, J = 8.67, 2.58 Hz), 7.38–
7.42 (m, 2H). Anal. Calcd for C18H25Cl2NO3S: C,
53.20; H, 6.20; N, 3.45. Found: C, 52.88; H, 6.11; N,
3.43.
4.1.3.16.
N-(3,4-Dichlorophenyl)-a-oxocycloheptyl-
sulfonamide (4B2). White crystals, mp 122–123 ꢁC; yield,
4.1.3.22. N-[3,5-Di(trifluoromethyl)phenyl]-a-oxocy-
clododecylsulfonamide (4P5). White crystals, mp 85–
86 ꢁC; yield, 71%; IR (KBr, cmꢀ1) mmax: 3200, 2920,
80%; IR (KBr, cmꢀ1) mmax: 3200, 2920, 2850, 1680, 1590,
1
1330, 1160; H NMR, d: 1.30–1.51 (m, 3H), 1.86–2.11
1
(m, 4H), 2.31–2.39 (m, 1H), 2.60–2.67 (m, 1H), 2.75–
2.84 (m, 1H), 3.81 (dd, 1H, J = 11.11, 4.24 Hz), 7.05
(s, 1H, NH), 7.21 (dd, 1H, J = 8.66, 2.53 Hz), 7.41 (d,
1H, J = 8.67 Hz), 7.50 (d, 1H, J = 2.52 Hz). Anal. Calcd
for C13H15Cl2NO3S: C, 46.44; H, 4.50; N, 4.17. Found:
C, 46.07; H, 4.47; N, 4.19.
2850, 1690, 1610, 1340, 1140; H NMR, d: 1.30–1.42
(m, 14H), 1.76–1.93 (m, 3H), 2.13–2.21 (m, 1H), 2.65–
2.74 (m, 1H), 2.90–2.99 (m, 1H), 4.39 (dd, 1H,
J = 11.32, 3.16 Hz), 6.99 (s, 1H, NH), 7.68 (s, 1H),
7.73 (s, 2H). Anal. Calcd for C20H25F6NO3S: C, 50.73;
H, 5.32; N, 2.96. Found: C, 50.54; H, 5.51; N, 2.88.
4.1.3.17. N-[3,5-Di(trifluoromethyl)phenyl]-a-oxocy-
cloheptylsulfonamide (4B3). White crystals, mp 86–
87 ꢁC; yield, 88%; IR (KBr, cmꢀ1) mmax: 3250, 2920,
4.2. Fungicidal activities of compounds 4
4.2.1. Method. Fungicidal activities of the title com-
pounds against B. cinerea Pers and S. sclerotiorum were
evaluated in vitro using the method given in Ref. 4.
1
2850, 1690, 1610, 1330, 1140; H NMR, d: 1.26–1.53
(m, 3H), 1.88–2.12 (m, 4H), 2.35–2.42 (m, 1H),
2.63–2.69 (m, 1H), 2.76–2.86 (m, 1H), 3.82 (dd, 1H,
J = 11.04, 4.08 Hz), 7.31 (s, 1H, NH), 7.71 (s, 1H),
7.79 (s, 2H). Anal. Calcd for C15H15F6NO3S: C,
44.67; H, 3.75; N, 3.47. Found: C, 44.78; H, 3.74;
N, 3.55.
4.2.2. Fungicidal activities. The inhibition rates of com-
pounds 4 against the above-mentioned two fungi were
determined at concentrations of 100, 50, 25, 12.5, and
6.25 lg/mL, respectively. EC50 values were estimated

4544
X. Li et al. / Bioorg. Med. Chem. 16 (2008) 4538–4544
using logit analysis.5 The results are shown in Table 1.
Commercial fungicides procymidone or chlorothalonil
were used as control in the above bioassay.
property method in QSAR module. The results are
shown in Table 3.
4.4. Antitumor activity of compounds 4
4.3. 3D QSAR of compounds 4 against B. cinerea Pers
Human promyelocytic leukemic cell line (HL 60), hu-
man gastric carcinoma cell line (BGC-823), human
hepatocellular carcinoma cell line (Bel-7402), and hu-
man nasopharyngeal carcinoma cell line (KB) were
grown and maintained in RPMI-1640 medium supple-
mented with 10% fetal bovine serum, penicillin
(10 U mLꢀ1), and streptomycin (100 lg mLꢀ1) at 37 ꢁC
in a humidified incubator in an atmosphere of 5%
CO2. All the experiments were performed on exponen-
tially growing cancer cells.
4.3.1. Method and software. CoMFA (Comparative
Molecular Field Analysis)6 was used and all molecular
modeling calculations utilized the software of Sybyl
7.0 (Tripos Inc., USA) running on the Silicon Graphics
Fuel Visual workstation (Silicon Graphics Inc., USA).
4.3.2. Optimization. Minimum energy conformations of
all the structures were calculated using the Minimize
module of Sybyl 7.0. The force field was MMFF947 with
˚
an 8 A cutoff for non-bonded interactions, and the
HL-60 cell line was assayed by the MTT [3-(4,5-dimeth-
ylthiazol-2-yl)-2,5-diphenyl tetrazoliumbromide] meth-
od (Roche Molecular Biochemicals, 1465-007). BGC-
823, Bel-7402 and KB were assayed by SRB method.12
The results are listed in Table 5.
atomic point charges were also calculated by MMFF94.
The minimizations were implemented with the steepest
descent method for the first 100 steps, followed by the
BFGS method8 until the RMS of gradient was less than
˚
0.005 kcal/(mol A).
4.3.3. CoMFA model. The alignment procedure was cal-
culated with the Align Database module.9 The best ac-
tive compound 4A10 was selected as the template,
C(O)CS(O2)N was chosen as the common substructure,
and all of the compounds (4A1–4A14, 4B1–4B3) were
aligned to a new database.
Acknowledgment
We acknowledge the financial support of this investiga-
tion by the National Basic Research Program of China
(2003CB114407).
All CoMFA calculations were done with the Tripos
CoMFA module.9 For the CoMFA calculation, the
alignment molecules were placed in a 3D cubic lattice
References and notes
3
1. Patrick, G. L. An Introduction to Medicinal Chemistry;
Oxford University Press, 1995.
˚
with 2 A spacing. The default sp carbon atom with
+1 charge was selected as the probe atom for the calcu-
lation of the steric (Lennard-Jones 6–12 potential) and
electrostatic fields (Coulombic potential) around the
aligned molecules with a distance-dependent dielectric
constant at all lattice points. The column filtering was
set to 1.0 kcal/mol. Values of steric and electrostatic
energies were truncated at 30 kcal/mol.
2. (a) Yoshimoto, T.; Umemoto, M.; Igarashi, K.; Kubota,
Y.; Yamazaki, H.; Enomoto, Y.; Yanagita, H. USP
4851445, 1989; (b) Fujita, T. Agrochem. Jpn. 1994, 65, 17.
3. Wang, X.-P.;Wang, D.-Q.Chem.J. Chin. Univ. 1997, 18, 889.
4. Li, X.-H.; Yang, X.-L.; Ling, Y.; Fan, Z.-J.; Liang, X.-M.;
Wang, D.-Q.; Chen, F.-H.; Li, Z.-M. J. Agric. Food.
Chem. 2005, 53, 2202.
5. Berkson, J. J. Am. Stat. Assoc. 1953, 48, 565.
6. Ki, H. K.; Yvonne, C. M. J. Med. Chem. 1991, 34, 2056.
7. (a) Halgren, T. J. Am. Chem. Soc. 1990, 112, 4710; (b)
Halgren, T. J. Comput. Chem. 1999, 20, 720; (c) Halgren,
T. J. Comput. Chem. 1996, 17, 490; (d) Halgren, T. J.
Comput. Chem. 1996, 17, 520; (e) Halgren, T. J. Comput.
Chem. 1996, 17, 553.
The regression analysis was carried out using the partial
least squares (PLS) method.10 To check the statistical
significance of the models, leave-one-out method and
cross-validate method were done with SAMPLS meth-
od.11 The optimum number of components to be used
in the conventional analysis was defined as that which
yielded the highest cross-validated q2. The results of
the CoMFA studies are summarized in Table 2.
8. Press, W. H.; Flannery, B. P.; Teukolsky, S. A.; Vetterling,
W. T. Numerical Recipes in C. The Art of Scientific
Computing; Cambridge University Press, 1988.
9. SYBYL Molecular Modeling Software, Version 7.0.
Tripos Inc., 1699 South Hanley Road, Suite 303, St.
Louis, MO 63144.
10. (a) Hoskuldsson, A. J. Chemom. 1988, 2, 211; (b) Rannar, S.;
Lindgren, F.; Geladi, P.; Wold, S. J. Chemom. 1994, 8, 111.
11. Bush, B. L.; Nachbar, R. B., Jr. J. Comput. Aided Mol.
Des. 1993, 7, 587.
12. Skehan, P.; Storeng, R.; Scudiero, D.; Monks, A.; McMa-
hon, J.; Vistica, D.; Warren, J. T.; Bokessch, H.; Kenney, S.;
Boyd, M. R. J. Natl. Cancer Inst. 1990, 82, 1107.
4.3.4. Design of new compounds and prediction of
fungicidal activity. Five new compounds (4P1-4P5) were
designed and synthesized based on the CoMFA results.
For their physical and elemental data, see Table 1 and
the 1H NMR and IR data, see Table 2. Their fungicidal
activity (EC50) against B. cinerea Pers was evaluated
using the method given in Section 2.3 and the pre-
dicted EC50 values were calculated by the predict