Design, synthesis and antifibrotic activities of carbohydrate-modified 1-(substituted aryl)-5-trifluoromethyl-2(1H) pyridones

Article abstract of DOI:10.3390/molecules17010884

Pirfenidone, a pyridone compound, is an effective and novel antifibrotic agent. In this article, we describe the design, synthesis and activity evaluation of novel antifibrotic agents, 1-(substituted aryl)-5-trifluoromethyl- 2(1H) pyridones modified with

Full text of DOI:10.3390/molecules17010884

Molecules 2012, 17, 884-896; doi:10.3390/molecules17010884
OPEN ACCESS
molecules
ISSN 1420-3049
www.mdpi.com/journal/molecules
Article
Design, Synthesis and Antifibrotic Activities of Carbohydrate-
Modified 1-(Substituted aryl)-5-trifluoromethyl-2(1H) Pyridones
Qinghua Lou 1, Xiangbao Meng 1, Zhiqi Lao 1, Lingling Xuan 2, Jinye Bai 2, Qi Hou 2,
Gaoyun Hu 3, Renna Luo 4, Lijian Tao 4 and Zhongjun Li 1,*
1
State Key Laboratory of Natural and Biomimetic Drug, Department of Chemical Biology,
School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
2
Department of Pharmacology, Institute of Materia Medica, Chinese Academy of Medical Sciences
and Peking Union Medical College, Beijing 100050, China
3
Department of Medicinal Chemistry, School of Pharmaceutical Sciences, Central South University,
Changsha, Hunan 410013, China
4
Division of Nephrology, Xiangya Hospital, Central South University, Changsha, Hunan 410008,
China
* Authors to whom correspondence should be addressed; E-Mail: zjli@bjmu.edu.cn;
Tel.: +86-10-8280-1714; Fax: +86-10-8280-5496.
Received: 16 November 2011; in revised form: 10 January 2012 / Accepted: 12 January 2012 /
Published: 17 January 2012
Abstract: Pirfenidone, a pyridone compound, is an effective and novel antifibrotic agent.
In this article, we describe the design, synthesis and activity evaluation of novel antifibrotic
agents, 1-(substituted aryl)-5-trifluoromethyl-2(1H) pyridones modified with carbohydrate.
Most of the title compounds exhibited comparable or better inhibitory activity than
fluorofenidone. Notably, compound 19a demonstrated the highest cell-based inhibitory
activity against NIH 3T3 (IC50 = 0.17 mM).
Keywords: antifibrotic; pirfenidone; fluorofenidone; carbohydrate modified; glucose
1. Introduction
Fibrosis of organs and tissues (e.g., heart, lungs, liver, kidneys, blood vessel and skin) is an
important pathological change associated with many diseases that are major causes of human
morbidity and mortality [1,2]. Generally, fibrosis can occur as a consequence of different pathological

Molecules 2012, 17
885
conditions, such as tissue damage, inflammatory diseases, foreign implants, and tumors. It is clear that
fibrosis of different organs and tissues possesses the same feature of fibroblast accumulation and
excess deposition of extracellular matrix (ECM), which leads to distorted organ architecture and
function [3,4]. There are various cytokines, chemokines, and growth factors involved in the
development of fibrosis [5]. In spite of the increased knowledge about the pathogenesis of fibrosis and
the different mediators involved, there is still no effective treatment for fibrosis.
Pirfenidone (5-methyl-1-phenyl-2(1H)-pyridone, Figure 1, compound 1a), is an effective and novel
antifibrotic agent that is potentially effective for the treatment of idiopathic pulmonary fibrosis (IPF) [6]
that was launched in Japan in 2008. Pirfenidone can inhibit fibroblast proliferation and collagen
synthesis, and it ameliorates bleomycin-induced and cyclophosphamide-induced lung fibrosis [7,8]. In
order to improve the antifibrotic activity of pirfenidone, a series of pirfenidone derivatives (Figure 1)
were synthesized [9–12]. Fluorofenidone (Figure 1, compound 1b), an analogue of pirfenidone, shows
equivalent antifibrotic activity, lower toxicity and longer half-life than the parent compound
pirfenidone. However, the activities of pirfenidone and fluorofenidone are relatively weak; their
effective doses are 500 mg/kg for the treatment of renal fibrosis in rats and the regular dose of
pirfenidone for Japanese patients with IPF is 400–600 mg three-times daily [6,13]. The metabolized
products have no in vivo activity, which could be the cause of high effective doses of pirfenidone and
fluorofenidone. Replacement of the methyl group with trifluoromethyl (Figure 1) could protect the
derivative from metabolism, but trifluoromethyl substitution increases lipid solubility and toxicity.
Therefore, it is necessary to prepare more effective antifibrotic agents with novel chemical structures
and improved water solubility.
Figure 1. Structures of Pirfenidone and analogues.
F3C
F3C
F3C
O
N
O
R
N
O
N
N
O
R
Cl
1a: R = H
1b: R = F
2a: R = H
2b: R = F
3
4
The aim of this study was to prepare antifibrotic compounds with higher water solubility. Because
carbohydrates are a kind of polyhydroxy compounds with no toxicity and high water solubility,
attachment of a carbohydrate moiety should increase hydrophilicity [14]. The modification with
carbohydrate also influences the pharmacokinetic properties of the modified compounds. Recent
advancements in molecular glycobiology have facilitated the development of effective glycodrugs [15].
A series of N-substituted 1-(4-amino-2-chlorophenyl)-5-trifluoromethyl-2(1H) pyridones were
previously synthesized and tested for NIH 3T3 inhibitory activity [10]. Therefore, we selected amines
15–19 (Table 1, R = H) as parent compounds for modification with monosaccharides. Herein, we
report the design, synthesis and biological evaluation of carbohydrate-modified 1-(substituted aryl)-5-
trifluoromethyl-2(1H) pyridones. The structures of the final target compounds are shown in Table 1.
We explored the SAR using methyl 6-deoxy--D-glucopyranoside, methyl 6-deoxy--D-
mannopyranoside and methyl 6-deoxy--D-galactofuranoside.

Molecules 2012, 17
886
Table 1. NIH 3T3 inhibitory activity.
F3C
F3C
CF3
F3C
N
O
Cl
N
O
N
O
(CH2)n
N
O
R
HN
R
HN
R
N
H
HN
R
15,15a-c n =0
18,18a-c n = 1
19,19a-c n = 1
17,17 a-c
16, 16a-c
Compound
1b
R
--
IC50 (mM) * Compound
R
H
IC50 (mM) *
4.18
3.93
5.68
18
1.31
2.47
13.17
O
O
HO
HO
HO
HO
HO
HO
15a
15b
18a
18b
OCH3
OCH3
OH
OH
O
O
HO
HO
HO
HO
OCH3
OCH3
OCH3
OCH3
O
O
OH
OH
15c
8.40
18c
3.30
OH
OH
OH
OH
16
H
0.46
19
H
1.71
0.17
0.79
O
O
HO
HO
HO
HO
N.D. a
1.13
19a
19b
HO
HO
16a
16b
OCH3
OCH3
OH
OH
O
O
HO
HO
HO
HO
OCH3
OCH3
OCH3
OCH3
O
O
OH
OH
16c
N.D. a
19c
0.84
OH
OH
OH
OH
O
HO
HO
HO
17a
17b
2.63
5.81
OCH3
OH
O
HO
HO
OCH3
OCH3
O
OH
17c
0.42
OH
OH
* p < 0.05; a N.D.: not determined.
2. Results and Discussion
The preparation of methyl 2,3,4-tri-O-acetyl-6-aldehydo--D-gluco-hexodialdo-1,5-pyranoside (8)
and methyl 2,3,4-tri-O-acetyl-6-aldehydo--D-manno-hexodialdo-1,5-pyranoside (12) is described in
Scheme 1. Methyl 2,3,4-tri-O-acetyl-6-O-trityl--D-glucopyranoside (6) was prepared directly from
methyl -D-glucopyranoside in two steps. Removal of trityl protection was accomplished by treatment
with boron trifluoride etherate in methanol and methylene chloride to produce compound 7 [16].
Subsequently selective oxidation of a primary hydroxyl group to an aldehydo group was performed at
room temperature with a mild oxidation reagent, 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) and
[bis(acetoxy)iodo]benzene (BAIB) [17]. Using the same method, compound 12 was obtained from

Molecules 2012, 17
887
methyl -D-mannopyranoside 9. Galactose aldehyde can be prepared with a isopropylidene moiety as a
protective group (Scheme 1). Isopropylidenation of D-galactose with sulfuric acid-copper sulfate as
catalyst in acetone produced 1,2;3,4-di-O-isopropylidene-D-galactose (13) in 58.3% yield [18]. The
conversion of compound 13 to 14 was performed with the same method used in the conversion of
compound 7 to 8. The structure of compounds 7–8 and 11–14 were in accordance with their reported
spectroscopic data [19–21].
Scheme 1. Synthesis of compounds 8, 12 and 14.
OTr
R1
O
OH
R1
O
OH
R1
R1
OHC
AcO
O
O
a
b
c
d
AcO
AcO
AcO
AcO
HO
HO
AcO
R2
R2
R2
R2
OCH3
OCH3
OCH3
OCH3
5 R1 = H, R2 = OH
9 R1 = OH, R2 = H
7 (98%)
11 (98%)
8 (86%)
12 (85%)
6 (94%)
10 (91%)
6-8 R1 = H, R2 = OAc
10-12 R1 = OAc, R2 = H
OH
O
O
CHO
O
O
d
O
O
O
O
O
O
13
14 (96%)
Reagents and conditions: (a) Ph3CCl, DMAP, pyridine, 60 °C, 5 h; (b) Ac2O, rt, 2 h; (c) BF3-Et2O,
CH2Cl2, rt, 2 h; (d) TEMPO, BAIB, CH2Cl2, rt, overnight.
The synthesis of 15a-19a and 15b-19b is shown in Scheme 2. Nucleophilic addition of the aldehyde
8 or 12 with amine 15–19 [10] in methanol and acetic acid followed by dehydration produced the
corresponding imines, which were further reduced with sodium cyanoborohydride to give the
corresponding secondary amines [22]. Amines were converted to the desired compounds 15a-19a and
15b–19b by treatment with sodium methoxide in methanol. The synthesis of 15c–19c is also described
in Scheme 2. Using the same method [22], secondary amines 14a–e were prepared. Treatment of 14a–e
with a solution of 0.5 M HCl/CH3OH under room temperature, caused removal of the isopropylidene
groups and the formation of methyl -D-galactofuranosides 15c–19c as the main product. Under these
conditions, deprotection of 14a also gave a minor amount of the corresponding galactopyranoside (5.7%)
except for 15c, but deprotection of 14b–e gave little of the corresponding galactopyranosides (<1%).
Scheme 2. Synthesis of compounds 15a-19a, 15b-19b and 15c-19c.
OCH3
Ar
Ar
O
HN
R1
HN
O
O
OH
a , b
O
14, c
O
d
HO
HO
ArNH2
O
R1
OHC
AcO
R2
O
OH
OH
OCH3
O
AcO
NHAr
R2
15a-19a R1 = H, R2 = OH
15b-19b R1 = OH, R2 = H
OCH3
15-19
14a-e
15c-19c
8 R1 = H, R2 = OAc
12 R1 = OAc, R2 = H
Reagents and conditions: (a) HOAc, CH3OH, 0.5 h, then NaCNBH3, 2 h; (b) 0.05 M
NaOCH3/CH3OH, rt, 1 h; (c) HOAc, CH3OH, 0.5h, then NaCNBH3, 2h; (d) 0.5 M HCl/CH3OH, rt,
12 h.

Molecules 2012, 17
888
Biological Assay
A cell-based fibrosis inhibition assay was performed to evaluate the inhibitory effects of the
prepared compounds on NIH 3T3 cells. NIH 3T3 (mouse embryonic lung fibroblast, State Key
Laboratory of Genetics) cells were seeded on 96-well plates (Costar) in DMEM containing 10% NBS
(3 × 104 cell per well in 100 μL medium) in humidified air with 5% CO2 at 37 °C. Different
concentrations of test compounds and fluorofenidone were added to the medium, and DMSO was used
as a solvent for the test compounds and fluorofenidone, which were applied at a final concentration of
0.1% (v/v) in cell culture medium. Cells were then incubated for 48 hours, followed by detecting with
MTT spectrophotometry. Briefly, 5 mg/mL MTT (100 μL) was added to each well, and incubated for
4 hours at 37 °C. All liquid in each well was then discarded and DMSO (150 μL) was added. The OD
at 570 nm was detected by spectrometry. IC50 was determined by nonlinear regression analysis using
GraphPad PRISM.
Of the aryl amines connected with a carbohydrate that were tested, compound 19a exhibited the
highest inhibitory activity against NIH 3T3 (IC50 = 0.17 mM) among the five aryl amines modified
with glucose. When the carbohydrate moiety was mannose, 19b appeared to have the highest
inhibitory activity (IC50 = 0.79 mM). When the carbohydrate moiety was galactose, 17c demonstrated
the highest inhibitory activity (IC50 = 0.42 mM), while 19c showed two-fold lower inhibitory activity
(IC50 = 0.84 mM) than 17c. Thus, among the five aryl amines that were modified with carbohydrate,
19 yielded more active compounds than the other aryl amines.
The same aryl amine-type compounds were also explored. Compound 15a demonstrated better
inhibitory activity than 15b and 15c (IC50 = 3.93 mM for 15a, IC50 = 5.68 mM for 15b, IC50 = 8.40 mM
for 15c); compound 17c showed the highest inhibitory activity among compounds 17a–c (IC50 = 2.63 mM
for 17a, IC50 = 5.81 mM for 17b, IC50 = 0.42 mM for 17c); compound 18a appeared to have
significantly higher activity than 18b and slightly better activity than 18c in NIH 3T3 inhibition
(IC50 = 2.47 mM for 18a, IC50 = 13.17 mM for 18b, IC50 = 3.30 mM for 18c); compound 19a exhibited
better activity than either 19b or 19c (IC50 = 0.17 mM for 19a, IC50 = 0.79 mM for 19b,
IC50 = 0.84 mM for 19c). These results indicate that among the three carbohydrates used for the
modification of pirfenidone analogues, glucose appeared to be a better candidate (e.g., 19a,
IC50 = 0.17 mM), although some compounds that were modified with galactose also had high
inhibitory activity (e.g., 17c, IC50 = 0.42 mM).
Compounds 17, 18, and 19 differ in the NHR (R= various carbohydrate moieties) positions. When
NHR was modified at the ortho position, the antifibrotic activities of all three compounds were
increased, especially compound 19a which showed ten-fold higher activity compared with compound
19 (R = H); when NHR was modified at the para position, the antifibrotic activities were decreased;
when NHR was modified at the meta position, compound 17c showed better antifibrotic activities
compared with 17a and 17b. Among these compounds, compound 19a, that is NHR modified with
glucose at the ortho position, exhibited the highest antifibrotic activity.
When a CH2 group was used to link the substituted phenyl ring with 5-trifluoromethyl-2(1H)-
pyridone (Table 1, compounds 18a–c and 19a–c), some of the resulting products showed obviously
higher NIH 3T3 inhibitory activities (Table 1, compound 19a–c), perhaps due to the increased
flexibility between two substituted aryl rings.

Molecules 2012, 17
889
Some modifications of pirfenidone analogues with different monosaccharides appeared to increase
the inhibitory activity. For example, compounds 19a–c, which were prepared by modification of
pirfenidone analogue 19 with a carbohydrate ring, showed a significant increase of inhibitory activity
in NIH 3T3 cells. Compound 19a demonstrated ten-fold higher activity compared with pirfenidone
analogue 19, but modifications of 16 and 18 with carbohydrates led to decreases in inhibitory activities
against NIH 3T3 cells.
3. Experimental
3.1. General
Unless specified, all reagents and starting materials were purchased from commercial sources and
used as received. Solvents were purified following standard literature procedures. Analytical TLC was
performed on silica gel60 F254 precoated on glass plates, with detection by fluorescence and/or by
staining with 5% concentrated sulphuric acid in EtOH. 1H- (400 MHz) and 13C-NMR spectra (100 MHz)
were recorded on a Bruker DRX-400 spectrometer at 25 °C. Chemical shifts (δ) for 1H and 13C spectra
are expressed in ppm relative to internal Me4Si as standard. Signals were abbreviated as s, singlet; bs,
broad singlet; d, doublet; t, triplet; q, quartet; m, multiplet. Sugar signals were numbered as customary.
ESI mass spectra and high resolution mass spectrometry (HRMS) were recorded using an Agilent
Technologies 1100 Series instrument (ESI ionization). Optical rotations were measured in a 1.00 dm
tube with an Optical Activity AA-10R polarimeter in methanol or chloroform.
3.2. General Procedure for the Synthesis of Compounds 14a–e
Amine (compounds 15–19, 0.5 mmol) was added to a solution of compounds 14 (155 mg, 0.6 mmol)
in dry methanol (2 mL) and acetic acid (1.5 mL) under stirring and under a nitrogen atmosphere at
room temperature. After 10 min NaCNBH3 (40 mg, 0.6 mmol) was added. The solution was stirred at
room temperature for 30 min. After completion of the reaction (TLC 3:1 petroleum ether b.p.
60–90 °C-EtOAc), the methanol was evaporated under reduced pressure, the reaction mixture was
diluted with CH2Cl2 (5 mL) and washed with saturated NaHCO3 (3 × 5 mL) and with water (5 mL).
The organic phase was dried over sodium sulphate and the solvent was evaporated under reduced
pressure to give a crude mass which was purified by flash chromatography (4:1 petroleum ether
b.p. 60–90 °C-EtOAc).
1,2;3,4-di-O-Isopropylidene-6-deoxy-6-(4-(5-trifluoromethyl-2(1H)-pyridone-1-yl)-anilino)--D-
galactopyranose (14a). Compound 15 (127 mg, 0.5 mmol) was used to prepare compound 14a (205 mg,
1
82.3%) as a colorless syrup; []25 −75 (c 0.10, CHCl3); H-NMR (CDCl3):  7.72 (s, 1H), 7.46 (dd,
D
J1 = 2.8 Hz, J2 = 9.6 Hz, 1H), 7.15–7.13 (m, 2H), 6.73–6.68 (m, 3H), 5.56 (d, J = 5.2 Hz, 1H, H-1),
4.64 (dd, J1 = 2.4 Hz, J2 = 8.0 Hz, 1H, H-3), 4.34 (dd, J1 = 2.4 Hz, J2 = 5.2 Hz, 1H, H-2), 4.26 (dd,
J1 = 2.0 Hz, J2 = 8.0 Hz, 1H, H-4), 4.04–4.00 (m, 1H, H-5), 3.40–3.37 (m, 2H, H-6), 1.48 (s, 3H, CH3),
1.44 (s, 3H, CH3), 1.37 (s, 3H, CH3), 1.33 (s, 3H, CH3); 13C-NMR(CDCl3):  162.1 (C=O), 148.7,
138.3, 138.2, 135.0, 129.7, 122.0, 113.2, 109.5, 109.1, 108.7, 96.4 (C-1), 71.6, 70.8, 70.6 and 65.7

Molecules 2012, 17
890
(C-2, C-3, C-4, C-5), 43.9 (C-6), 26.0 (CH3), 26.0 (CH3), 24.9 (CH3), 24.4 (CH3); ESI-MS: Calcd for
C24H27N2O6F3: 497.2[M+H]+, found: 497.2[M+H]+.
1,2;3,4-di-O-Isopropylidene-6-deoxy-6-(3-chloro-4-(5-trifluoromethyl-2(1H)-pyridone-1-yl)-anilino)-
-D-galactopyranose (14b). Compound 16 (145 mg, 0.5 mmol) was used to prepare compound 14b
1
(195 mg, 73.6%) as a colorless syrup; []25 −59 (c 0.10, CHCl3); H-NMR (CDCl3):  7.58 (s, 1H),
D
7.51 (dd, J1 = 2.8 Hz, J2 = 9.6 Hz, 1H), 7.10 (dd, J1 = 1.6 Hz, J2 = 8.8 Hz, 1H), 6.78 (d,
J = 2.4 Hz, 1H), 6.71 (d, J = 2.8 Hz, 1H), 6.63–6.60 (m, 1H), 5.56 (d, J = 5.2 Hz, 1H, H-1), 4.64 (dd,
J1 = 2.4 Hz, J2 = 8.0 Hz, 1H, H-3), 4.35 (dd, J1 = 2.4 Hz, J2 = 5.2 Hz, 1H, H-2), 4.26 (dd, J1 = 2.0 Hz,
J2 = 8.0 Hz, 1H, H-4), 4.02–3.99 (m, 1H, H-5), 3.38–3.35 (m, 2H, H-6), 1.48 (s, 3H, CH3), 1.47 (s, 3H,
13
CH3), 1.37 (s, 3H, CH3), 1.34 (s, 3H, CH3); C-NMR (CDCl3):  161.7 (C=O), 150.0, 138.7, 135.5,
132.0, 129.2, 126.5, 122.3, 113.3, 112.2, 112.1, 109.6, 108.8, 96.4 (C-1), 71.6, 70.8, 70.6 and 65.6
(C-2, C-3, C-4, C-5), 43.8 (C-6), 26.0 (CH3), 24.9 (CH3), 24.4 (CH3); ESI-MS: Calcd for
C24H26N2O6F3Cl: 531.2 [M+H]+, found: 531.1 [M+H]+.
1,2;3,4-di-O-Isopropylidene-6-deoxy-6-(3-(5-trifluoromethyl-2(1H)-pyridone-1-yl-methylene)-anilino)
--D-galactopyranose (14c). Compound 17 (135 mg, 0.5 mmol) was used to prepare compound 14c
1
(192 mg, 75.3%) as a colorless syrup; []25 −47 (c 0.10, CHCl3); H-NMR (CDCl3):  7.63 (s, 1H),
D
7.41 (d, J = 1.6 Hz, 1H), 7.18–7.14 (m, 1H), 6.67–6.59 (m, 4H), 5.54 (d, J = 4.8 Hz, 1H,
H-1), 5.04 (m, 2H, CH2), 4.62 (dd, J1 = 1.6 Hz, J2 = 8.0 Hz, 1H, H-3), 4.33 (t, J = 2.4 Hz, 1H, H-2),
4.25 (d, J = 7.6 Hz, 1H, H-4), 3.98 (d, J = 4.8 Hz, 1H, H-5), 3.40–3.29 (m, 2H, H-6), 1.47 (s, 3H,
13
CH3), 1.37 (s, 3H, CH3), 1.36 (s, 3H, CH3), 1.31 (s, 3H, CH3); C-NMR (CDCl3):  161.9 (C=O),
148.8, 136.7, 136.1, 134.8, 130.0, 121.5, 117.3, 113.1, 109.5, 108.7, 96.4 (C-1), 71.7, 70.8, 70.6 and
65.7 (C-2, C-3, C-4, C-5), 52.3 (CH2), 43.9 (C-6), 26.0 (CH3), 25.8 (CH3), 24.9 (CH3), 24.4 (CH3);
ESI-MS: Calcd for C25H29N2O6F3: 511.2 [M+H]+, found: 511.2 [M+H]+.
1,2;3,4-di-O-Isopropylidene-6-deoxy-6-(4-(5-trifluoromethyl-2(1H)-pyridone-1-yl-methylene)-anilino)
--D-galactopyranose (14d). Compound 18 (135 mg, 0.5 mmol) was used to prepare compound 14d
1
(207 mg, 81.2%) as a colorless syrup; []25 −68 (c 0.10, CHCl3); H-NMR (CDCl3):  7.60 (s, 1H),
D
7.39 (dd, J1 = 2.0 Hz, J2 = 9.6 Hz, 1H), 7.15 (d, J = 8.4 Hz, 2H), 6.65–6.62 (m, 3H), 5.54 (d, J = 4.8 Hz,
1H, H-1), 5.00 (s, 2H, CH2), 4.62 (dd, J1 = 2.0 Hz, J2 = 8.0 Hz, 1H, H-3), 4.33–4.31 (m, 1H, H-2),
4.25–4.23 (m, 1H, H-4), 3.99 (t, J = 6.0 Hz, 1H, H-5), 3.41–3.30 (m, 2H, H-6), 1.47 (s, 3H, CH3), 1.36
13
(s, 3H, CH3), 1.33 (s, 3H, CH3), 1.30 (s, 3H, CH3); C-NMR (CDCl3):  162.0 (C=O), 148.4, 136.4,
136.3, 134.7, 134.6, 130.1, 123.5, 121.4, 113.6, 109.5, 108.7, 96.4 (C-1), 71.7, 70.8, 70.6 and 65.6
(C-2, C-3, C-4, C-5), 52.1 (CH2), 43.9 (C-6), 26.0 (CH3), 25.7 (CH3), 24.9 (CH3), 24.4 (CH3); ESI-
MS: Calcd for C25H29N2O6F3: 511.2 [M+H]+, found: 511.2 [M+H]+.
1,2;3,4-di-O-Isopropylidene-6-deoxy-6-(2-(5-trifluoromethyl-2(1H)-pyridone-1-yl-methylene)-
anilino)--D-galactopyranose (14e). Compound 19 (135 mg, 0.5 mmol) was used to prepare
compound 14e (210 mg, 82.4%) as a colorless syrup; []25D −62 (c 0.10, CHCl3); 1H-NMR (CDCl3): 
7.68 (s, 1H), 7.42 (dd, J1 = 2.0 Hz, J2 = 9.6 Hz, 1H), 7.25 (m, 1H), 7.14 (d, J = 7.2 Hz, 1H), 6.72–6.64
(m, 3H), 5.44 (d, J = 5.2 Hz, 1H, H-1), 5.20–4.95 (m, 2H, CH2), 4.57 (dd, J1 = 2.0 Hz,
J2 = 8.0 Hz, 1H H-3), 4.27 (dd, J1 = 2.0 Hz, J2 = 5.2 Hz, 1H H-2), 4.21 (d, J = 8.8 Hz, 1H, H-4), 3.94

Molecules 2012, 17
891
(t, J = 6.4 Hz, 1H, H-5), 3.50–3.43 (m, 1H, H-6), 3.36–3.31 (m, 1H, H-6), 1.47 (s, 3H, CH3), 1.34 (s,
3H, CH3), 1.26 (d, 6H, 2xCH3); 13C-NMR (CDCl3):  162.4 (C=O), 146.6, 136.1, 136.1, 135.0, 131.3,
130.5, 121.3, 119.3, 116.9, 111.6, 110.3, 109.3, 108.5, 96.4 (C-1), 71.4, 70.8, 70.6 and 65.1 (C-2, C-3,
C-4, C-5), 49.1 (CH2), 43.6 (C-6), 26.0 (CH3), 25.6 (CH3), 24.9 (CH3), 24.4 (CH3); ESI-MS: Calcd for
C25H29N2O6F3: 511.2 [M+H]+, found: 511.2 [M+H]+.
3.3. General Procedure for the Synthesis of Compounds 15a–19a and 15b–19b
Amine (compound 15–19, 0.5 mmol) was added to a solution of compounds 8 or 12 (0.6 mmol) in
dry methanol (2 ml) and acetic acid (1.5 mL) under stirring and under nitrogen atmosphere at room
temperature. After 10 min NaCNBH3 (40 mg, 0.6 mmol) was added. The solution was stirred at
room temperature for 30 min. After completion of the reaction (TLC 3:1 petroleum ether b.p.
60–90 °C-EtOAc), the methanol was evaporated under reduced pressure, the reaction mixture was
diluted with CH2Cl2 (5 mL) and washed with saturated NaHCO3 (3 × 5 mL) and with water (5 mL).
The organic phase was dried over sodium sulphate and the solvent was evaporated under reduced
pressure to give a crude mass which was dissolved in 0.05 M NaOMe/MeOH (5 mL) and stirred at
ambient temperature for 30 min. The stirring reaction mixture was neutralized with prewashed
Amberlite IR 120-H+. The resin was filtered off and the solvent was evaporated under reduced
pressure. The crude product was purified by flash chromatography (7:1 CHCl3-MeOH).
Methyl 6-deoxy-6-(4-(5-trifluoromethyl-2(1H)-pyridone-1-yl)-anilino)--D-glucopyranoside (15a).
Compound 15 (127 mg, 0.5 mmol) and 8 (190 mg, 0.6 mmol) were used to prepare compound 15a
(143 mg, 66.5%) as a colorless syrup; []25D −63 (c 0.10, MeOH); 1H-NMR (MeOH-d4)  7.97 (s, 1H),
7.66 (dd, J1 = 2.4 Hz, J2 = 9.6 Hz, 1H), 7.01 (d, J = 8.8 Hz, 2H), 6.76 (d, J = 8.4 Hz, 2H), 6.64 (d,
J = 9.2 Hz, 1H), 4.62 (d, J = 3.6 Hz, 1H, H-1), 3.71–3.63 (m, 1H), 3.59–3.55 (m, 2H), 3.38–3.35 (m,
1H), 3.28 (s, 3H), 3.22–3.17 (m, 2H); 13C-NMR (MeOH-d4)  164.5 (C=O), 151.0, 140.6, 140.5,
137.3, 130.3, 128.1, 122.2, 113.6, 101.2 (C-1), 75.1, 73.6, 73.5 and 71.4 (C-2, C-3, C-4, C-5), 55.5
(OCH3), 45.7 (C-6); HRMS: Calcd for C19H21N2O6F3 [M+H]+ 431.1431, found 431.1425.
Methyl 6-deoxy-6-(3-chloro-4-(5-trifluoromethyl-2(1H)-pyridone-1-yl)-anilino)--D-glucopyranoside
(16a). Compound 16 (145 mg, 0.5 mmol) and 8 (190 mg, 0.6 mmol) were used to prepare compound
16a (152 mg, 65.5%) as a colorless syrup; []25D −34 (c 0.10, MeOH); 1H-NMR (MeOH-d4):  7.92 (s,
1H), 7.70 (dd, J1 = 2.8 Hz, J2 = 9.6 Hz, 1H), 7.08 (d, J = 8.8 Hz, 2H), 6.84 (m, 1H), 6.68 (m, 2H), 4.62
(d, J = 3.6 Hz, 1H, H-1), 3.63–3.60 (m, 1H), 3.59–3.51 (m, 2H), 3.38–3.34 (m, 1H), 3.29 (s, 3H,
13
OCH3), 3.26–3.17 (m, 3H); C-NMR (MeOH-d4):  164.1 (C=O), 152.5, 141.2, 137.8, 132.7, 130.2,
126.7, 122.5, 113.8, 112.8, 101.2 (C-1), 75.1, 73.6, 73.3 and 71.6 (C-2, C-3, C-4, C-5), 55.6 (OCH3),
45.5 (C-6); HRMS: Calcd for C19H21N2O6F3Cl: 465.1041 [M+H]+, found: 465.1038 [M+H]+.
Methyl 6-deoxy-6-(3-(5-trifluoromethyl-2(1H)-pyridone-1-yl-methylene)-anilino)--D-glucopyranoside
(17a). Compound 17 (135 mg, 0.5 mmol) and 8 (190 mg, 0.6 mmol) were used to prepare compound
1
17a (150 mg, 67.6%) as a colorless syrup; []25 −45 (c 0.10, MeOH); H-NMR (MeOH-d4):  8.06
D
(s, 1H), 7.55 (dd, J1 = 2.4 Hz, J2 = 9.6 Hz, 1H), 7.02 (t, J = 8.0 Hz, 1H), 6.61–6.58 (m, 3H), 6.49 (d,
J = 7.6 Hz, 1H), 5.03 (s, 2H, CH2), 4.57 (d, J = 2.8 Hz, 1H, H-1), 3.62–3.48 (m, 3H), 3.35–3.12 (m,

Molecules 2012, 17
892
1H), 3.16 (s, 3H, OCH3), 3.19–3.06 (m, 2H); 13C-NMR (MeOH-d4):  161.2 (C=O), 147.8, 136.6,
136.6, 135.0, 134.1, 127.8, 123.3, 120.6, 118.9, 114.6, 111.3, 111.0, 108.7, 108.4, 98.2 (C-1), 72.2,
70.7, 70.7 and 68.19 (C-2, C-3, C-4, C-5), 52.5 (OCH3), 50.9 (CH2), 43.0 (C-6); HRMS: Calcd for
C20H23N2O6F3: 445.1587 [M+H]+, found: 445.1583 [M+H]+.
Methyl 6-deoxy-6-(4-(5-trifluoromethyl-2(1H)-pyridone-1-yl-methylene)-anilino)--D-glucopyranoside
(18a). Compound 18 (135 mg, 0.5 mmol) and 8 (190 mg, 0.6 mmol) were used to prepare compound
18a (155 mg, 69.8%) as a colorless syrup; []25D −54 (c 0.10, MeOH); 1H-NMR (MeOH-d4):  8.03 (s,
1H), 7.54 (dd, J1 = 2.8 Hz, J2 =9.6 Hz, 1H), 7.07 (d, J = 8.4 Hz, 2H), 6.64 (d, J = 4.4 Hz, 2H), 6.56 (d,
J = 9.6 Hz, 1H), 4.98 (s, 2H, CH2), 4.57 (d, J = 3.6 Hz, 1H, H-1), 3.63–3.58 (m, 1H), 3.55–3.49 (m,
2H), 3.34–3.31 (m, 1H), 3.24–3.23 (m, 1H), 3.18 (s, 3H, OCH3), 3.15–3.06 (m, 2H); 13C-NMR
(MeOH-d4):  162.8 (C=O), 148.9, 137.7, 137.7, 135.5, 129.3, 123.5, 120.3, 113.1, 99.8 (C-1), 73.7,
72.2, 72.2 and 69.6 (C-2, C-3, C-4, C-5), 54.0 (OCH3), 52.1 (CH2), 44.5 (C-6); HRMS: Calcd for
C20H23N2O6F3: 467.1400 [M+Na]+, found: 465.1391 [M+Na]+.
Methyl 6-deoxy-6-(2-(5-trifluoromethyl-2(1H)-pyridone-1-yl-methylene)-anilino)--D-glucopyranoside
(19a). Compound 19 (135 mg, 0.5 mmol) and 8 (190 mg, 0.6 mmol) were used to prepare compound
19a (147 mg, 66.2%) as a colorless syrup; []25D −57 (c 0.10, MeOH); 1H-NMR (MeOH-d4):  7.90 (s,
1H), 7.55 (dd, J1 = 1.6 Hz, J2 =7.6 Hz, 1H), 7.15 (m, 2H), 6.70 (d, J = 8.0 Hz, 1H), 6.61 (m, 2H), 5.06
(m, 2H, CH2), 4.51 (d, J = 3.6 Hz, 1H, H-1), 3.67–3.59 (m, 1H), 3.52–3.47 (m, 2H), 3.37–3.31 (m,
1H), 3.22 (s, 1H), 3.16–3.10 (m, 2H), 3.02 (s, 3H, OCH3); 13C-NMR (MeOH-d4):  162.9 (C=O),
146.6, 137.0, 137.0, 135.6, 131.0, 130.0, 127.3, 120.3, 119.5, 116.6, 111.1, 110.6, 99.8 (C-1), 73.7,
72.2, 72.1 and 69.0 (C-2, C-3, C-4, C-5), 54.0 (OCH3), 48.2 (CH2), 44.2 (C-6); HRMS: Calcd for
C20H23N2O6F3: 445.1587 [M+H]+, found: 445.1586 [M+H]+.
Methyl 6-deoxy-6-(4-(5-trifluoromethyl-2(1H)-pyridone-1-yl)-anilino)--D-mannopyranoside (15b).
Compound 15 (127 mg, 0.5 mmol) and 12 (190 mg, 0.6 mmol) were used to prepare compound 15b
1
(140 mg, 65.1%) as a colorless syrup; []25 +82 (c 0.10, MeOH); H-NMR (MeOH-d4):  7.98 (s,
D
1H), 7.67 (dd, J1 = 2.4 Hz, J2 = 9.6 Hz, 1H), 7.08 (d, J = 8.8 Hz, 2H), 6.76 (d, J = 8.4 Hz, 2H), 6.65 (d,
J = 9.2 Hz, 1H), 4.61 (d, J = 1.2 Hz, 1H, H-1), 3.76 (s, 1H), 3.64–3.59 (m, 3H), 3.54–3.51 (m, 1H),
13
3.32–3.28 (m, 1H), 3.26 (s, 3H, OCH3), C-NMR (MeOH-d4):  164.5 (C=O), 151.0, 140.6, 140.5,
140.5, 137.3, 130.2, 128.1, 126.2, 123.6, 122.2, 113.0, 111.5, 111.1, 102.8(C-1), 72.6, 72.1, 72.1 and
69.9 (C-2, C-3, C-4, C-5), 55.2 (OCH3), 45.5 (C-6); HRMS: Calcd for C19H21N2O6F3: 431.1431
[M+H]+, found: 431.1425 [M+H]+.
Methyl 6-deoxy-6-(3-chloro-4-(5-trifluoromethyl-2(1H)-pyridone-1-yl)-anilino)--D-mannopyranoside
(16b). Compound 16 (145 mg, 0.5 mmol) and 12 (190 mg, 0.6 mmol) were used to prepare compound
16b (145 mg, 62.5%) as a colorless syrup; []25D −59 (c 0.10, MeOH); 1H-NMR (MeOH-d4):  7.93 (s,
1H), 7.71 (dd, J1 = 2.4 Hz, J2 = 9.6 Hz, 1H), 7.09 (d, J = 2.2 Hz, 2H), 6.84 (dd, J1 = 0.4 Hz, J2 = 1.6 Hz,
1H), 6.71–6.66 (m, 2H), 4.60 (d, J = 1.6 Hz, 1H, H-1), 3.76 (s, 1H), 3.64–3.57 (m, 3H), 3.52–3.48 (m,
1H), 3.30–3.26 (m, 2H), 3.28 (s, 3H, OCH3); 13C-NMR (MeOH-d4):  162.7 (C=O), 151.1, 139.8,
139.7, 136.4, 131.3, 128.8, 125.3, 124.7, 122.1, 121.1, 112.3, 111.4, 111.4, 110.2, 109.9, 101.4 (C-1),

Molecules 2012, 17
893
71.2, 70.9, 70.7 and 68.4 (C-2, C-3, C-4, C-5), 53.9 (OCH3), 43.8 (C-6); HRMS: Calcd for
C19H21N2O6F3Cl: 465.1041 [M+H]+, found: 465.1039 [M+H]+.
Methyl 6-deoxy-6-(3-(5-trifluoromethyl-2(1H)-pyridone-1-yl-methylene)-anilino)--D-mannopyranoside
(17b). Compound 17 (135 mg, 0.5 mmol) and 12 (190 mg, 0.6 mmol) were used to prepare compound
1
17b (154 mg, 69.4%) as a colorless syrup; []25 −83 (c 0.10, MeOH); H-NMR (MeOH-d4):  8.08
D
(s, 1H), 7.60 (dd, J1 = 2.8 Hz, J2 = 9.6 Hz, 1H), 7.06 (dd, J1 = 7.6 Hz, J2 = 8.0 Hz, 1H), 6.63–6.60 (m,
3H), 6.52 (d, J = 7.2 Hz, 1H), 5.07 (s, 2H, CH2), 4.57 (d, J = 1.6 Hz, 1H, H-1), 3.74 (t, 1H), 3.62–3.56
13
(m, 3H), 3.49–3.46 (m, 1H), 3.27–3.25 (m, 1H), 3.17 (s, 3H, OCH3); C-NMR (MeOH-d4):  162.7
(C=O), 149.3, 138.1, 138.1, 136.5,135.7, 129.3, 124.8, 120.4, 116.0, 112.7, 112.3, 110.2, 109.9, 101.3
(C-1), 71.2, 70.7, 70.3 and 68.6 (C-2, C-3, C-4, C-5), 53.7 (OCH3), 52.4 (CH2), 44.2 (C-6); HRMS:
Calcd for C20H23N2O6F3: 445.1587 [M+H]+, found: 445.1585 [M+H]+.
Methyl 6-deoxy-6-(4-(5-trifluoromethyl-2(1H)-pyridone-1-yl-methylene)-anilino)--D-mannopyranoside
(18b). Compound 18 (135 mg, 0.5 mmol) and 12 (190 mg, 0.6 mmol) were used to prepare compound
1
18b (150 mg, 67.6%) as a colorless syrup; []25 −67 (c 0.10, MeOH); H-NMR (MeOH-d4):  8.06
D
(s, 1H), 7.58 (dd, J1 = 2.8 Hz, J2 = 2.4 Hz, 1H), 7.11 (d, J = 8.4 Hz, 2H), 6.65 (d, J = 8.4 Hz, 2H), 6.58
(d, J = 9.6 Hz, 1H), 5.01 (s, 2H, CH2), 4.57 (d, J = 1.6 Hz, 1H, H-1), 3.73 (t, 1H), 3.61–3.55 (m, 3H),
3.51–3.46 (m, 1H), 3.27–3.25 (m, 3H), 3.19 (s, 3H, OCH3); 13C-NMR (MeOH-d4):  164.2 (C=O),
150.4, 139.1, 139.1, 136.9,130.7, 126.2, 124.9, 123.5, 121.7, 114.4, 111.6, 111.2, 102.7 (C-1), 72.6,
72.1, 71.8 and 70.1 (C-2, C-3, C-4, C-5), 55.1 (OCH3), 53.5 (CH2), 45.7 (C-6); HRMS: Calcd for
C20H23N2O6F3: 445.1587 [M+H]+, found: 445.1589 [M+H]+.
Methyl 6-deoxy-6-(2-(5-trifluoromethyl-2(1H)-pyridone-1-yl-methylene)-anilino)--D-mannopyranoside
(19b). Compound 19 (135 mg, 0.5 mmol) and 12 (190 mg, 0.6 mmol) were used to prepare compound
1
19b (151 mg, 68.0%) as a colorless syrup; []25 −72 (c 0.10, MeOH); H-NMR (MeOH-d4):  7.95
D
(s, 1H), 7.58 (d, J = 9.6 Hz 1H), 7.23–7.17 (m, 2H), 6.72–6.70 (m, 2H), 6.65 (t, J = 7.6 Hz, 1H),
5.19–5.09 (m, 2H, CH2), 4.62 (s, 1H, H-1), 3.75 (s, 1H), 3.69–3.60 (m, 3H), 3.46–3.42 (m, 1H),
13
3.34–3.27 (m, 2H), 3.14 (s, 3H, OCH3); C-NMR (MeOH-d4):  163.0 (C=O), 146.7, 137.1, 137.0,
136.9, 135.7, 130.9, 130.1, 124.6, 121.9, 120.2, 119.5, 116.5, 110.9, 110.9, 110.6, 101.5(C-1), 71.3,
71.0, 70.0 and 68.5 (C-2, C-3, C-4, C-5), 53.8 (OCH3), 43.8 (C-6); HRMS: Calcd for C20H23N2O6F3:
445.1587 [M+H]+, found: 445.1581 [M+H]+.
3.4. General Procedure for the Synthesis of Compounds 15c–19c
Compound 14a–e (0.2 mmol) was added to a solution of 0.5 M HCl/MeOH (5 mL) under stirring
and under nitrogen atmosphere at room temperature. The progress of reaction was monitored by TLC
(6:1CHCl3-MeOH). After completion of the reaction the solvent was evaporated under reduced
pressure, the residue was purified by flash chromatography (7:1CHCl3-MeOH).
Methyl 6-deoxy-6-(4-(5-trifluoromethyl-2(1H)-pyridone-1-yl)-anilino)--D-galactofuranoside (15c).
Compound 14a (100 mg, 0.2 mmol) was used to prepare compound 15c (45 mg, 52.3%) as a colorless
1
syrup; []25 −48 (c 0.10, MeOH); H-NMR (MeOH-d4):  7.93 (s, 1H), 7.62 (dd, J1 = 2.8 Hz,
D

Molecules 2012, 17
894
J2 = 9.6 Hz, 1H), 7.02 (d, J = 8.4 Hz, 2H), 6.66 (d, J = 8.8 Hz, 2H), 6.58 (d, J = 9.6 Hz, 1H), 4.69 (s,
1H, H-1), 3.85–3.77 (m, 4H), 3.34–3.13 (m, 5H); 13C-NMR (MeOH-d4):  163.3 (C=O), 149.7, 139.4,
136.1, 129.0, 127.0, 121.0, 114.8, 112.4, 110.3, 109.9, 109.3 (C-1), 83.9, 82.0, 77.6 and 68.8 (C-2,
C-3, C-4, C-5), 54.3 (OCH3), 46.3 (C-6); HRMS: Calcd for C19H21N2O6F3: 431.1424 [M+H]+, found:
431.1420 [M+H]+.
Methyl 6-deoxy-6-(3-chloro-4-(5-trifluoromethyl-2(1H)-pyridone-1-yl)-anilino)--D-galactofuranoside
(16c). Compound 14b (106 mg, 0.2 mmol) was used to prepare compound 16c (42 mg, 45.2%) as a
yellow syrup; []25D −64 (c 0.10, MeOH); 1H-NMR (MeOH-d4):  7.95 (s, 1H), 7.69 (dd, J1 = 2.8 Hz,
J2 = 9.6 Hz, 1H), 7.07 (d, J = 8.8 Hz, 1H), 6.79 (t, J = 2.4 Hz, 1H), 6.66–6.63 (m, 2H), 4.73 (d, J = 1.6 Hz,
1H, H-1), 3.96–3.95 (m, 1H), 3.87–3.85 (m, 2H), 3.83–3.78 (m, 1H), 3.38–3.35 (m, 1H), 3.32 (s, 3H,
13
OCH3)，3.25–3.23 (m, 1H), 3.22–3.16 (m, 1H); C-NMR (MeOH-d4):  162.7 (C=O), 150.9, 139.7,
136.4, 131.3, 128.9, 125.2, 112.0, 111.2, 109.1, 83.6, 81.7, 77.3 and 68.5 (C-2, C-3, C-4, C-5), 54.0
(OCH3), 45.8 (C-6); HRMS: Calcd for C19H20N2O6F3Cl: 465.1035 [M+H] +, found: 465.1038 [M+H]+.
Methyl 6-deoxy-6-(3-(5-trifluoromethyl-2(1H)-pyridone-1-yl-methylene)-anilino)--D-galactofuranoside
(17c). Compound 14c (100 mg, 0.2 mmol) was used to prepare compound 17c (52 mg, 58.4%) as a
yellow syrup; []25D −34 (c 0.10, MeOH); 1H-NMR (MeOH-d4):  8.07 (s, 1H), 7.58 (dd, J1 = 2.8 Hz,
J2 = 9.6 Hz, 1H), 7.05–7.01 (m, 1H), 6.60–6.55 (m, 3H), 6.48 (d, J = 7.6 Hz, 1H), 5.04 (s, 2H, CH2),
4.71 (d, J = 1.2 Hz, 1H, H-1), 3.95–3.93 (m, 1H), 3.87–3.83 (m, 2H), 3.80–3.79 (m, 1H), 3.30 (s, 3H,
13
OCH3), 3.24 (m, 1H), 3.15–3.10 (m, 1H); C-NMR (MeOH-d4):  164.1(C=O), 150.7, 139.5, 138.0,
137.1, 130.7, 121.8, 117.2, 113.6, 113.4, 111.7, 110.5, 85.3, 83.2, 78.9 and 70.0 (C-2, C-3, C-4, C-5),
55.3 (OCH3), 53.8 (CH2), 47.7 (C-6); HRMS: Calcd for C20H23N2O6F3: 445.1581 [M+H]+, found:
445.1587 [M+H]+.
Methyl 6-deoxy-6-(4-(5-trifluoromethyl-2(1H)-pyridone-1-yl-methylene)-anilino)--D-galactofuranoside
(18c). Compound 14d (100 mg, 0.2 mmol) was used to prepare compound 18c (47 mg, 52.8%) as a
yellow syrup; []25D −75 (c 0.10, MeOH); 1H-NMR (MeOH-d4):  8.06 (s, 1H), 7.56 (dd, J1 = 2.8 Hz,
J2 = 9.6 Hz, 1H), 7.09 (d, J = 8.4 Hz, 2H), 6.61–6.54 (m, 3H), 4.98 (s, 2H, CH2), 4.70 (d, J = 2.0 Hz,
1H, H-1), 3.94–3.91 (m, 1H), 3.85–3.82 (m, 2H), 3.80–3.76 (m, 1H), 3.29 (s, 3H, OCH3)，3.25–3.23
(m, 3H), 3.16–3.11 (m, 1H); 13C-NMR (MeOH-d4):  162.8 (C=O), 148.9, 137.8, 135.5, 129.4, 123.4,
120.3, 112.6, 109.1, 83.7, 81.9, 77.4 and 68.6 (C-2, C-3, C-4, C-5), 54.0 (OCH3), 52.1 (CH2), 46.2
(C-6); HRMS: Calcd for C20H23N2O6F3: 467.1400 [M+Na]+, found: 465.1380 [M+Na]+.
Methyl 6-deoxy-6-(2-(5-trifluoromethyl-2(1H)-pyridone-1-yl-methylene)-anilino)--D-galactofuranoside
(19c). Compound 14e (100 mg, 0.2 mmol) was used to prepare compound 19c (49 mg, 55.1%) as a
yellow syrup; []25D −72 (c 0.10, MeOH); 1H-NMR (MeOH-d4):  7.97 (s, 1H), 7.57 (dd, J1 = 2.8 Hz,
J2 = 7.2 Hz, 1H), 7.16–7.10 (m, 2H), 6.68 (d, J = 8.0 Hz, 1H), 6.63–6.59 (m, 2H), 5.09 (s, 2H, CH2),
4.73 (s, 1H, H-1), 3.97–3.96 (m, 1H), 3.88–3.84 (m, 3H), 3.36–3.17 (m, 5H); 13C-NMR (MeOH-d4): 
163.0 (C=O), 146.5, 137.3, 137.2, 135.7, 130.4, 129.9, 120.3, 119.5, 116.5, 110.8, 109.1, 84.0, 81.8,
77.5 and 68.5 (C-2, C-3, C-4, C-5), 54.0 (OCH3), 48.5 (CH2), 46.2 (C-6); HRMS: Calcd for
C20H23N2O6F3: 445.1581 [M+H]+, found: 445.1583 [M+H]+.

Molecules 2012, 17
895
4. Conclusions
In conclusion, we report the design, synthesis and biological evaluation of some carbohydrate-
modified 1-(substituted aryl)-5-trifluoromethyl-2(1H) pyridones. Our studies suggest that some
modifications of pirfenidone analogues with carbohydrates appear to increase the inhibitory activity
against NIH 3T3 cell proliferation. Among the compounds tested, compound 19a, which was
synthesized by modification of pirfenidone analogue 19 with glucose, demonstrated the highest
cell-based inhibitory activity (IC50 = 0.17 mM).
References and Notes
1. du Bois, R.M. Strategies for treating idiopathic pulmonary fibrosis. Nat. Rev. Drug Dis. 2010, 9,
129–140.
2. Balsano1, C.; Alisi, A.; Nobili, V. Liver fibrosis and therapeutic strategies: The goal for
improving metabolism. Curr. Drug Targets 2009, 10, 505–512.
3. Krenning, G.; Zeisberg, E.M.; Kalluri, R. The origin of fibroblasts and mechanism of cardiac
fibrosis. J. Cell Physiol. 2010, 225, 631–637.
4. Weber, K.T. Fibrosis and hypertensive heart disease. Curr. Opin. Cardiol. 2000, 5, 264–272.
5. Wick, G.; Backovic, A.; Rabensteiner, E.; Plank, N.; Schwentner, C.; Sgonc, R. The immunology
of fibrosis: Innate and adaptive responses. Trends Immunol. 2010, 31, 110–119.
6. Azuma, A. Pirfenidone: Antifibrotic agent for idiopathic pulmonary fibrosis. Expert Rev. Resp. Med.
2010, 4, 301–310.
7. Iyer, S.N.; Hyde, D.M.; Giri, S.N. Anti-inflammatory effect of pirfenidone in the bleomycin-
hamster model of lung inflammation. Inflammation 2000, 24, 477–491.
8. Spond, J.; Case, N.; Chapman, R.W.; Crawley, Y.; Egan, R.W.; Fine, J.; Hey, J.A.; Kreutner, W.;
Kung, T.; Wang, P.; Minnicozzi, M. Inhibition of experimental acute pulmonary inflammation by
pirfenidone. Pulm. Pham. Ther. 2003, 16, 207–214.
9. Tao, L.; Hu, G. 1-(substituted phenyl)-5-methyl-2-(1H) pyridone in the manufacture of
medicaments for treating fibrosis in organs or tissues. PCT Int. Appl. WO 2006/108354 A1,
19 October 2000.
10. Hu, G.; Tao, L.; Chen, J. Preparation methods and uses of 1-(substituted aryl)-5-trifluoromethyl-
2-(1H) pyridone compounds and their salts. PCT Int. Appl. WO2010/135972 A1, 2 December 2010.
11. Tao, L.; Zhang, J.; Hu, G.; Chen, Z.; Gong, J. Effects of 1-(3-fluorophenyl)-5-methyl-2-(1H)-
pyridone on renal fibroblast in rats. J. Cent. South Univ. (Med. Sci.) 2004, 29, 139–141.
12. Peng, Z.; Hu, G.; Shen, H.; Wang, L.; Ning, W.; Xie, Y.; Wang, N.; Li, B.; Tang, Y.; Tao, L.
Fluorofenidone attenuates collagen I and transforming growth factor-β1 expression through a
nicotinamide adenine dinucleotide phosphate oxidase-dependent way in NRK-52E cells.
Nephrology 2009, 14, 565–572.
13. Shimizu, T.; Fukagawa, M.; Kuroda, T.; Hata, S.; Iwasaki, Y.; Nemoto, M.; Shirai, K.; Yamauchi, S.;
Margolin, S.B.; Shimizu, F.; Kurokawa, K. Pirfenidone prevents collagen accumulation in the
remnant kidney in rats with partial nephrectomy. Kidney Int. Suppl. 1996, 63, S239–S243.

Molecules 2012, 17
896
14. Stallforth, P.; Lepenies, B.; Adibekian, A.; Seeberger, P.H. Carbohydrates: A frontier in medicinal
chemistry. J. Med. Chem. 2009, 52, 5561–5577.
15. Kren, V.; Martínková, L. Glycosides in medicine: “The role of glycosidic residue in biological
activity”. Curr. Med. Chem. 2001, 8, 303–1328.
16. Reynolds, D.D.; Evans, W.L. The synthesis of certain oligosaccharide acetates in the mannose
series. J. Am. Chem. Soc. 1940, 62, 66–69.
17. Sixta, G.; Hofinger, A.; Kosma, P. Synthesis of spacer-containing chlamydial disaccharides as
analogues of the α-Kdop-(2→8)-α-Kdop-(2→4)-α-Kdop trisaccharide epitope. Carbohydr. Res.
2007, 342, 576–585.
18. Klier, A.H.; Alves, R.J.; Auxiliadora, M.; Prado, F.; de Souza Filho J.D.; D’Accorso, N.B.
Synthesis of new five membered nitrogen containing heterocycles bearing D-galactose side chains.
Syn. Comm. 2000, 30, 4361–4374.
19. Lee, H.H.; Hodgson Philip, G.; Bernacki, R.J.; Korytnyk, W.; Sharma, M. Analogs of cell surface
carbohydrates. Synthesis of D-galactose derivatives having an ethynyl, vinyl or epoxy residue at
C-5. Carbohydr. Res. 1998, 176, 59–72.
20. Terreni, M.; Salvetti, R.; Linati, L.; Fernandez-Lafuente, R.; Fernandez-Lorento, G.; Bastida, A.;
Guisan, J.M. Regioselective enzymatic hydrolysis of acetylated pyranoses and pyranosides using
immobilised lipases. An easy chemoenzymatic synthesis of α- and β-D-glucopyranose acetates
bearing a free secondary c-4 hydroxyl group. Carbohydr. Res. 2002, 337, 1615–1622.
21. Horrobin, T.; Tran, C.H.; Crout, D. Esterase-catalysed regioselective 6-deacylation of
hexopyranose per-acetates, acid-catalysed rearrangement to the 4-deprotected products and
conversions of these into hexose 4- and 6-sulfates. J. Chem. Soc. Perkin Trans. 1 1998, 1069–1080.
22. Romero, D.L.; Morge, R.A.; Biles, C.; Berrios-Pena, N.; May, P.D.; Palmer, J.R.; Johnson, P.D.;
Smith, H.W.; Busso, M.; Tan, C.K.; et al. Discovery, synthesis, and bioactivity of
bis(heteroaryl)piperazines. 1. A novel class of non-nucleoside HIV-1 reverse transcriptase
inhibitors. J. Med. Chem. 1994, 37, 999–1014.
Sample Availability: Samples of the compounds are available from the authors.
© 2012 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access article
distributed under the terms and conditions of the Creative Commons Attribution license
(http://creativecommons.org/licenses/by/3.0/).