Structure-activity relationships of 3,5-disubstituted benzamides as glucokinase activators with potent in vivo efficacy

Article abstract of DOI:10.1016/j.bmc.2009.04.040

The optimization of our lead GK activator 2a to 3-[(1S)-2-hydroxy-1-methylethoxy]-5-[4-(methylsulfonyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (6g), a potent GK activator with good oral availability, is described, including to uncouple the relationship betwe

Full text of DOI:10.1016/j.bmc.2009.04.040

Bioorganic & Medicinal Chemistry 17 (2009) 3800–3809
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry
journal homepage: www.elsevier.com/locate/bmc
Structure–activity relationships of 3,5-disubstituted benzamides
as glucokinase activators with potent in vivo efficacy
*
Tomoharu Iino , Noriaki Hashimoto, Kaori Sasaki, Sumika Ohyama, Riki Yoshimoto, Hideka Hosaka,
Takuro Hasegawa, Masato Chiba, Yasufumi Nagata, Jun-ichi Eiki, Teruyuki Nishimura
Banyu Tsukuba Research Institute, Banyu Pharmaceutical Co. Ltd, Okubo-3, Tsukuba 300-2611, Ibaraki, Japan
a r t i c l e i n f o
a b s t r a c t
Article history:
The optimization of our lead GK activator 2a to 3-[(1S)-2-hydroxy-1-methylethoxy]-5-[4-(methylsulfo-
nyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (6g), a potent GK activator with good oral availability, is
described, including to uncouple the relationship between potency and hydrophobicity. Following oral
administration, this compound exhibited robust glucose lowering in diabetic model rodents.
Ó 2009 Elsevier Ltd. All rights reserved.
Received 17 March 2009
Revised 17 April 2009
Accepted 18 April 2009
Available online 24 April 2009
Keywords:
Glucokinase
Glucokinase activator
3,5-Disubstituted benzamides
Glucose lowering efficacy
Log D
1. Introduction
derivative (6g).14,15 We also describe the in vivo profile of 6g, phar-
macokinetic profiles in animals and glucose lowering effects in dia-
betic rodent models.
Glucokinase (GK), a member of the hexokinase family,1 cata-
lyzes the first step in glycolysis involving the phosphorylation of
glucose to glucose-6-phosphate. GK plays an important role as a
glucose sensor for maintaining plasma glucose homeostasis by
enhancing insulin secretion from pancreatic b-cells and glucose
metabolism in the liver.2–4 Therefore, activation of GK is expected
to be a novel therapeutic strategy for the treatment of Type 2 dia-
betes.5–8
We previously reported discovery of orally active 3-alkoxy-5-
phenoxy-N-thiazolylbenzamide GK activators (2a and 2b),9 which
was discovered by optimization of our original lead GK activator,
2-aminobenzamide (1)10,11 (Fig. 1). As shown in the report, com-
pound 2a demonstrated good glucose lowering effects in normal
mice at 30 mg/kg oral dosing and in oral glucose tolerance test
(OGTT) studies in rats at 10 and 30 mg/kg dosing. On the other
2. Chemistry
The preparation of lead compounds is summarized in Schemes
1–4. Alkylation of 39 was conducted by substitution reaction or
O
S
O
S
R
O
S
N
N
N
N
N
H
N
H
N
NH2
O
1
MeO2S
2a R=Me
2b R=H
Figure 1. Previously reported our GK activators.
hand, the solubility in water (pH 7.4) was very low: <0.1 lg/mL.
The hydrophobicity was also high, log D (pH 7.4): >5 (Table 1). In
pre-clinical or clinical studies, the poor solubility of candidates
may cause trouble,12 such as absorption saturation.13 Therefore,
development of more soluble and hydrophilic GK activators is
required.
Table 1
Profiles of the lead compounds 2a and 2b
Compound
2.5 mM Glc
10 mM Glc
Solubility in water
Log D
(pH 7.4)
Here, we describe the optimization of our lead GK activators 2a
and 2b, and the identification of a aqueous soluble and hydrophilic
EC50
(l
M)
EC50
(lM)
(pH 7.4,
lg/mL)
2a
2b
0.33
0.17
0.13
0.06
<0.1
NT
>5
>5
* Corresponding author. Tel.: +8136 272 1857; fax: +81 36 238 9097.
E-mail address: tomoharu_iino@merck.com (T. Iino).
NT: not tested.
0968-0896/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmc.2009.04.040

T. Iino et al. / Bioorg. Med. Chem. 17 (2009) 3800–3809
3801
O
O
O
S
R
HO
R
O
N
O
N
H
b
a
O
O
O
MeS
MeS
MeO2S
4a-s
2b, 5a-n, 6b, 6g, 6b, 7g
3
4f, 5f:
R=
4e, 5e:
4a, 5a:
4b, 5b:
4c, 5c:
4d, 5d:
4s, 2b:
O
O
O
O
O
O
O
O
O
O
O
O
O
5g:
4g:
4h:
5h:
5i:
HO
4i:
TBDPSO
O
O
O
O
HO
TBSO
TBSO
HO
O
O
5l:
HO
5j:
HO
5k:
4l:
4j:
4k:
O
TBDPSO
O
HO
O
TBSO
O
TBSO
O
O
CF3
CF3
4m:
4n:
5m:
5n:
O
O
O
O
TBSO
HO
BocN
HN
iPr
iPr
4o, 6b:
4p, 7b:
4r:
TBSO
7g:
4q:
6g:
O
O
O
O
O
O
TBSO
HO
HO
O
O
Scheme 1. Reagents and conditions: (a) (i) RX, K2CO3, DMF, rt ꢀ60 °C or ROH, Ph3P, DEAD, THF (R: including protecting groups; TBS or TBDPS for OH group, Boc for NH group);
(b) (i) mCPBA, THF, 0 °C; (ii) NaOHaq, MeOH; (iii) 2-aminothiazole, WSC, HOBT, CH2Cl2 or POCl3, pyridine then 2-aminothiazole; (iv) HClaq, dioxane or TBAF, THF (for hydroxy
derivatives); HClaq dioxane (5n).
O
S
O
S
O
S
O
O
O
N
HO
N
H
N
N
H2N
N
H
N
N
H
a
b
O
O
O
MeO2S
MeO2S
S
MeO2S
5p
5g
5o
O
O
S
N
O
O
N
N
N
HN
N
H
H
c
O
O
MeO2S
MeO2S
5n
5q
Scheme 2. Reagents and conditions: (a) (i) MsCl, Et3N, 0 °C; (ii) NaN3, DMF, 60 °C; (iii) Ph3P, H2O, THF, 60 °C; (b) HCHO, NaBH4–ZnCl2, MeOH; (c) HCHO, NaBH4–ZnCl2, MeOH.
O
O
t-BuO2C
MeS
O
HO
O
O
b
a
O
O
S
O
O
O
H2N
I
I
N
O
N
H
O
a
b
MeS
OH
O
OH
3
12
O
S
O
S
8
10
MeO2S
HO
9
HO2C
O
ROC
O
N
N
N
H
N
H
O
S
c
O
S
N
O
HO
N
H
O
N
c
d
N
H
MeO2S
MeO2S
O
O
5s
5t: R=NHMe
5u: R=NMe2
MeO2S
MeO2S
11
5r
Scheme 3. Reagents and conditions: (a) (i) NaNO2, HClaq, dioxane then KI, H2O,
Et2O; (b) (i) 4-MeSO2C6H4B(OH)2, Cu(OAc)2, Et3N, CH2Cl2; (ii) NaOHaq, MeOH; (iii)
2-aminothiazole, WSC, HOBT, CH2Cl2; (c) 2-methyl-2-propen-1-ol, PdCl2(PPh3)2,
NaHCO3, DMF, 110 °C; (d) H2, Pd–C, MeOH.
Scheme 4. Reagents and conditions: (a) (i) tert-butyl 2-bromopropanoate, NaH,
DMF, rt; (b) (i) mCPBA, THF, 0 °C; (ii) NaOHaq, MeOH; (iii) 2-amino-4-methylthi-
azole, WSC, HOBT, CH2Cl2; (iv) HClaq dioxane; (c) MeNH2–HCl or Me2NH–HCl,
HOBT, Et3N, WSC, DMF, CH2Cl2.

3802
T. Iino et al. / Bioorg. Med. Chem. 17 (2009) 3800–3809
Table 2
Mitsunobu reaction to afford intermediates 4a–s (Scheme 1). Inter-
mediates 4b–d, 4g, 4i–m are racemates, while 4o–r are chiral. Oxi-
dation of the methanesulfonyl group using mCPBA, hydrolysis of
the methyl ester by NaOH and amidation with 2-aminothiazole
or 2-amino-4-methylthiazole gave racemic 5a–n and chiral deriv-
atives 6b, 7b, 6g, and 7g after removing the hydroxy, amine or car-
boxylic acid protecting groups.
GK activity and log D (pH 7.4) of GK activators around isopropyl moiety of 2b
O
S
R
N
N
H
O
MeO2S
Racemate 5c was optically resolved using chiral HPLC to give
enantiomers 6c and 7c. In the same manner, 6i and 7i were pre-
pared from 5i, and 6j and 7j from 5j.
Primary amine 5o was prepared from hydroxy compound 5g by
converting the alcohol to the azide followed by reduction using the
Ph3P–H2O system. Dimethylamino derivative 5p was prepared by
reductive amination of 5o with formaldehyde. N-Methyl pyrroli-
dine derivative 5q was also obtained by reductive amination of
5n with formaldehyde (Scheme 2).
Iodophenol compound 9 was prepared from aminophenol 8 by
diazonium reaction followed by addition of KI (Scheme 3). Coupling
of 9 with 4-MeSO2C6H4B(OH)2 and amidation with 2-aminothiazole
afforded the key intermediate 10.16 Heck reaction of 10 with 2-
methyl-2-propen-1-ol gave the olefin compound 11.17 The carbon-
linked derivative 5r was obtained after hydrogenation of 11.
Condensation of 5s with methylamine or dimethylamine affor-
ded 5t or 5u, respectively (Scheme 4).
Compound
R
2.5 mM Glc
10 mM Glc
Log D
(pH 7.4)
a
a
EC50
(l
M)
EC50
(lM)
O
2b
5a
0.17
0.06
>5
>5
O
0.49
0.43
0.24
0.11
O
5bb
4.2
O
O
5cb
5db
5e
0.19
0.19
0.46
0.06
0.07
0.12
>5
O
O
4.0
4.1
O
O
O
O
3. Biological results and discussion
O
5f
0.61
0.12
>4
O
An in vitro GK assay was conducted at two different glucose
concentrations, 2.5 mM and 10 mM, which simulated low and high
(post prandial) blood glucose conditions, respectively. SARs around
the isopropoxy moiety of 2a and 2b were explored from the point
of view of GK potency and hydrophilicity (log D value) (Table 2).
The ring derivatives, cyclopentyl (5a) and tetrahydrofuryl (5b)
were less potent than 2b, however, the log D value of 5b improved
to 4.2 (Table 2). We focused on the tetrahydrofuran group and mod-
ified 5b to prepare 5c–f. Ring-opened derivatives (5c–d) were found
comparable to 2b in GK potency, but their hydrophilicities were not
significantly improved. Compounds with no chiral center (5e–f)
showed weaker GK potency. To enhance the hydrophilicity of these
derivatives, hydroxyl derivatives were prepared. 2-Hydroxy-1-
methylethoxy derivative (5g) was strongly potent (equipotent to
2b as racemate) and more hydrophilic than 2b (log D value: 2.7). A
drop in GK potency of 2-hydroxyethoxy derivative 5h indicated
the importance of the branched methyl group of 5g. Cyclic analogs
of 5g (5i and 5j), conversion to a carbon linker (5r), and conversion
of the branched methyl group of 5g to trifluoromethyl (5l) or isopro-
pyl (5m) groups resulted in a decrease in GK potency compared to
that of 5g. Elongation of 5g (5k) did not affect GK potency but led
to less hydrophilicity (log D: 3.4). Amine derivatives (5o–q) and car-
boxyl derivatives (5s–u) exhibited weak potency (Table 3).
O
O
5gb
5h
0.15
0.78
0.07
0.20
2.7
2.4
HO
HO
HO
5ib
5jb
0.46
0.28
0.12
0.17
3.4
NT
O
HO
O
CH2
5rb
0.75
0.15
0.25
0.06
3.4
3.4
HO
HO
O
5kb
O
5lb
0.79
0.24
>4
HO
HO
CF3
O
5mb
5ob
0.36
1.5
0.20
0.21
>4
iPr
O
1.1
H2N
N
To confirm the effect of the chiral center on GK activity, chiral
isomers were assessed by in vitro assay (Table 4). The S-tetrahy-
drofuran compound (6b) was twice as potent as racemate 5b,
while the R-tetrahydrofuranyl isomer (7b) was not effective in
GK. Ring-opened isomers 6c and 7c showed the same trend,
though their absolute structures are not yet confirmed. These re-
sults suggested that the chiral center affected the GK potency.
We also studied the effect of chirality in the alcohol derivatives.
In the same manner of 6b, S-isomer (6g) showed excellent potency.
Enantiomers of 5i and 5j were prepared to study the effect of the
alcohol of 6g in GK. Chiral diastereomers 6i and 6j showed good
potency but their enantiomers (7i and 7j) were less potent. How-
ever, stereoconfiguration such as trans and cis did not confer con-
siderably different potencies. trans Derivative 6j was only slightly
more potent than the corresponding cis isomer 6i.
O
O
O
5pb
5nb
5qb
12
18
24
2.6
4.2
7.3
NT
NT
NT
HN
N
NT: not tested.
a
Values are the means of two or more independent assays. Compound 1 is the
internal standard (EC50: 0.42 0.09 and 0.14 0.04).
b
Racemate.

T. Iino et al. / Bioorg. Med. Chem. 17 (2009) 3800–3809
3803
Table 3
GK activity and log D (pH 7.4) of carboxylic acid derivatives of 2a
Table 4
GK activity of chiral derivatives of 5g
O
S
O
S
R
R
N
N
N
H
N
H
O
O
MeO2S
MeO2S
Compound
R
2.5 mM Glc
10 mM Glc
Log D
(pH 7.4)
Racemate
Compound
Chiral
Compound
R
2.5 mM Glc
10 mM Glc
a
a
a
a
EC50
(
lM)
EC50
(
lM)
EC50
(lM)
EC50
(lM)
O
O
O
2a
0.33
0.13
>5
2b
5b
2b
0.17
0.06
O
5sb
5tb
5ub
30
7.4
NT
2.9
2.6
6b
7b
6cb
0.19
1.8
0.05
0.3
O
O
O
O
HO
O
O
O
>30
>30
>30
>30
N
H
O
O
5c
5g
5i
0.13
0.06
O
N
O
7cb
6g
1.2
0.36
0.05
0.91
0.11
1.2
O
NT: not tested.
a
Values are the means of two or more independent assays. Compound 1 is the
internal standard (EC50: 0.42 0.09 and 0.14 0.04).
b
Racemate.
O
O
0.08
2.2
HO
4. Pharmacological results and discussion
7g
HO
HO
To compare the efficacy of the lead derivative 2a (log D: >5) and
the alcohol 6g (log D: 2.7) that showed excellent GK activity and
hydrophilicity, in vivo studies in mice were conducted. In normal
fed mice, at 3 and 10 mpk oral dosing, 2a did not show any glucose
lowering effects, while 6g was sufficiently efficacious (Fig. 2). We
supposed that this difference of efficacy in vivo was due to the
6ib
7ib
6jb
6jb
0.26
3.4
O
O
O
O
HO
HO
HO
GK potency and solubility of 6g (5.2 lg/mL in water (pH 7.4)).
Evaluation of glucose lowering effects of 6g in HFD mice and
KKAy mice was conducted (Figs. 3 and 4). 6g was significantly effi-
cacious at 3 and 10 mg/kg by oral dosing in HFD mice and 10 and
30 mpk in KKAy mice.
The PK study of 6g in SD rats and beagle dogs indicated that oral
bioavailability was good, 33% and 57%, and half lives were 1.3 h
and 5.4 h, respectively (Table 5).
5j
0.16
3.7
0.09
1.6
5. Conclusion
a
Values are the means of two or more independent assays. Compound 1 is the
internal standard (EC50: 0.42 0.09 and 0.14 0.04).
b
In conclusion, exploration of SAR around the lead compounds
2a and 2b with the aim to find a more soluble orally active GK acti-
vator led to the identification of compound 6g. Aqueous solubility
Absolute stereostructure speculated.
of this compound was improved to 5.2 lg/mL and 6g demon-
or atmospheric pressure chemical ionization (APCI) on a Waters
micromass ZQ, micromass Quattro II or micromass Q-TOF-2 instru-
ment. Flash chromatography was carried out with prepacked silica
gel columns (KP-Sil silica) from Biotage or (Purif-Pack) from Mori-
tex. Preparative thin-layer chromatography (TLC) was performed
with TLC Silica Gel 60 F (Merck KGaA). Preparative HPLC purifica-
tion was carried out on a YMC-Pack Pro C18 (YMC, 50 mm ꢁ
30 mm i.d.), eluting with a gradient of CH3CN:aqueous CF3CO2H
(0.1%) 10:90 to 50:50 over 8 min at a flow rate of 40 mL/min.
High-resolution mass spectra were recorded with electron-spray
ionization on a micromass Q-TOF-2 instrument. HPLC analysis
was performed on a SUPELCO Ascentis Express (4.6 ꢁ 150 mm
i.d.), eluting with a gradient of (a) 5:95–90:10 CH3CN/aqueous
H3PO4 (0.1%), linear gradient over 7 min followed by 90:10 iso-
cratic over 1 min and (b) 5:95–80:20 CH3CN/potassium phosphate
strated significant glucose lowering efficacy in HFD mice at 3 and
10 mg/kg dosing and in KKAy mice at 10 and 30 mg/kg dosing. Fur-
ther development of this GK activator is currently underway.
6. Experimental
6.1. Chemistry
In general, reagents and solvents were used as purchased with-
out further purification. The 1H NMR spectra were obtained at
300 MHz on a Gemini-300, 400 MHz on a Mercury-400 (Varian)
or 400 MHz on a JMN-AL400 (JEOL) spectrometer, with chemical
shifts (d, ppm) expressed relative to TMS as an internal standard.
Mass spectra were recorded with electron-spray ionization (ESI)

3804
T. Iino et al. / Bioorg. Med. Chem. 17 (2009) 3800–3809
Figure 2. Glucose lowering effects of 2a and 6g in normal fed mice.
Figure 4. (a) Blood glucose levels of 6g in KKAy mice. (b) Glucose AUC of 6g in KKAy
mice.
Table 5
Pharmacokinetic parameters of compound 6g in SD rats and Beagle dogs
O
S
O
N
HO
N
H
O
MeO2S
AUC0-1
CLp
T1/2 Vdss
Cmax Tmax
M) (h)
F
(%)
(lM
h) (mL/min/kg) (h) (L/kg)
(
l
*
Rat
IV (1 mg/kg, 40% PEG)
PO (3 mg/kg, 0.5% MC)
10
12
3.9
4.6
1.3 0.19
5.4 1.56
3.4
0.3
1.2
33
57
Dog
Figure 3. (a) Blood glucose levels of 6g in HFD mice. (b) Glucose AUC of 6g in HFD
mice.
IV (0.3 mg/kg, 40% PEG) 2.4
PO (1 mg/kg, 0.5% MC) 4.6
0.8
F: oral bioavailability; PEG: polyethylene glycol 400; MC: methylcellulose.
buffer (10 mM), linear gradient over 7 min followed by 80:20 iso-
cratic over 1 min (detection at 210 nm).
was stirred at room temperature overnight. The mixture was evap-
orated and the residue was purified by silica gel column chroma-
tography (70% EtOAc/hexane) to give 2b (7.2 mg, 49%) as a
6.1.1. 3-Isopropoxy-5-[4-(methylsulfonyl)phenoxy]-N-1,3-
thiazol-2-ylbenzamide (2b)
colorless foam. 1H NMR (300 MHz, CDCl3)
d 1.35 (6H, d,
To a solution of 4s (41.0 mg, 0.12 mmol) in CHCl3 (5 mL) was
added mCPBA (64.0 mg, 0.37 mmol) at 0 °C and the mixture was
stirred for 20 min. The reaction was quenched with saturated
Na2S2O3 solution and the resulting mixture was extracted with
EtOAc. The organic phase was washed with saturated NaHCO3
solution and brine, dried over MgSO4, and evaporated. The residue
was purified by preparative TLC on silica gel (50% EtOAc/hexane) to
provide the sulfone product (43.9 mg, 98%) as a colorless foam.
To a solution of the above-obtained ester (14.0 mg, 0.035 mmol)
in MeOH (0.5 mL) was added 2 N NaOH solution (0.18 mL,
0.36 mmol), and the mixture was stirred at room temperature
overnight. The mixture was neutralized with 2 N HCl solution
and extracted with EtOAc. The organic phase was washed with
brine, dried over MgSO4, and evaporated. To a solution of the
above–obtained carboxylic acid in CHCl3 (0.5 mL) were added 2-
amino-1,3-thiazole (5.1 mg, 0.051 mmol), HOBt-hydrate (9.3 mg,
0.068 mmol) and EDCI (13.0 mg, 0.068 mmol), and the mixture
J = 6.0 Hz), 3.07 (3H, s), 4.57–4.61 (1H, m), 6.83 (1H, t, J = 2.0 Hz),
6.99 (1H, d, J = 3.4 Hz), 7.14 (2H, d, J = 8.8 Hz), 7.20 (1H, d,
J = 2.0 Hz), 7.28 (1H, d, J = 3.4 Hz), 7.34 (1H, d, J = 2.0 Hz), 7.92
(2H, d, J = 8.8 Hz); MS (ESI) m/z = 433 [M+H]+; HRMS (ESI) calcd
for C20H21N2O5S2 433.0892; found 433.0896 [M+H]+.
6.1.2. 3-(Cyclopentyloxy)-5-[4-(methylsulfonyl)phenoxy]-N-
1,3-thiazol-2-ylbenzamide (5a)
To a solution of 3 (30.0 mg, 0.10 mmol) in DMF (1 mL) were
added K2CO3 (71.0 mg, 0.52 mmol) and bromocyclopentane
(0.033 mL, 0.31 mmol), and the mixture was stirred at 80 °C over-
night. After cooling, the mixture was partitioned between water
and EtOAc. The organic phase was washed with brine, dried over
MgSO4, and evaporated. The residue was purified by silica gel col-
umn chromatography (25% EtOAc/hexane) to give 4a (31.9 mg,
86%) as a colorless foam.

T. Iino et al. / Bioorg. Med. Chem. 17 (2009) 3800–3809
3805
Compound 5a was prepared as a colorless foam from 4a in a sim-
6.1.6. 3-{[1-(Methoxymethyl)propyl]oxy}-5-[4-
ilar manner as described for compound 2b. Yield: 74%; 1H NMR
(300 MHz, CDCl3) d 1.61–1.93 (8H, m), 3.07 (3H, s), 4.75–4.79 (1H,
m), 6.81 (1H, d, J = 2.0 Hz), 6.97 (1H, d, J = 3.6 Hz), 7.13 (2H, d,
J = 8.6 Hz), 7.20 (1H, s), 7.21 (1H, d, J = 3.6 Hz), 7.33 (1H, d,
J = 2.0 Hz), 7.92 (2H, d, J = 8.6 Hz); MS (ESI) m/z = 459 [M+H]+; HRMS
(ESI) calcd for C22H23N2O5S2 459.1048; found 459.1054 [M+H]+.
(methylsulfonyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (5c)
Compound 5c was prepared as a colorless oil from 3 with 1-
methoxybutan-2-ol in a similar manner as described for compound
2b. Yield: 16%; 1H NMR (300 MHz, CDCl3) d 0.98 (3H, t, J = 7.4 Hz),
1.70–1.76 (2H, m), 3.08 (3H, s), 3.37 (3H, s), 3.53–3.61 (2H, m),
4.34–4.40 (1H, m), 6.89–6.95 (1H, m), 6.97–7.01 (1H, m), 7.15
(2H, d, J = 8.8 Hz), 7.22–7.24 (1H, m), 7.25–7.29 (1H, m), 7.42–
7.43 (1H, m), 7.93 (2H, d, J = 8.8 Hz); MS (ESI) m/z = 477 [M+H]+.
6.1.3. 3-[4-(Methylsulfonyl)phenoxy]-5-[tetrahydrofuran-3-
yloxy]-N-1,3-thiazol-2-ylbenzamide (5b)
To a solution of 3 (40.0 mg, 0.14 mmol) in THF (1.0 mL) were
added tetrahydrofuran-3-ol (0.022 mL, 0.28 mmol), PPh3 (72.0 mg,
0.28 mmol) and DIAD (0.055 mL, 0.39 mmol), and the mixture was
stirred at room temperature overnight. The mixture was evaporated
and the residue was purified by preparative TLC on silica gel (33%
EtOAc/hexane) to give 4b (37.6 mg, 76%) as a colorless foam.
Compound 5b was prepared as a colorless foam from 4b in a
similar manner as described for compound 2b. Yield: 77%; 1H
NMR (400 MHz, CDCl3) d 2.14–2.27 (2H, m), 3.08 (3H, s), 3.91–
3.99 (4H, m), 4.96–4.97 (1H, m), 6.82 (1H, d, J = 1.7 Hz), 6.99 (1H,
d, J = 3.6 Hz), 7.13 (2H, d, J = 8.9 Hz), 7.18 (1H, d, J = 3.6 Hz), 7.25
(1H, s), 7.30 (1H, d, J = 1.7 Hz), 7.93 (2H, d, J = 8.9 Hz); MS (ESI)
m/z = 461 [M+H]+.
6.1.7. 3-{[(1S or 1R)-1-(Methoxymethyl)propyl]oxy}-5-[4-
(methylsulfonyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (6c)
and 3-{[(1R or 1S)-1-(Methoxymethyl)propyl]oxy}-5-[4-
(methylsulfonyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (7c)
Optical resolution of 5c by Chiralpak AD column (2 ꢁ 25 cm,
hexane/EtOH = 1:2, 10 mL/min) afforded 6c (slower, 2.2 mg) as a
colorless oil and 7c (faster, 2.5 mg) as a colorless oil.
Compound 6c: HPLC (Chiralpak AD, 0.5 ꢁ 25 cm, hexane/
EtOH = 1:2, 0.4 mL/min) tR = 36.0 min, 96% ee; 1H NMR (300 MHz,
CDCl3) d 0.98 (3H, t, J = 7.4 Hz), 1.70–1.76 (2H, m), 3.08 (3H, s),
3.37 (3H, s), 3.53–3.61 (2H, m), 4.34–4.40 (1H, m), 6.89–6.95 (1H,
m), 6.97–7.01 (1H, m), 7.15 (2H, d, J = 8.8 Hz), 7.22–7.24 (1H, m),
7.25–7.29 (1H, m), 7.42–7.43 (1H, m), 7.93 (2H, d, J = 8.8 Hz); MS
(ESI) m/z = 477 [M+H]+; HRMS (ESI) calcd for C22H25N2O6S2
477.1154; found 477.1156 [M+H]+; HPLC (a) 99.3%; (b) 99.5%.
Compound 7c: HPLC (Chiralpak AD, 0.5 ꢁ 25 cm, hexane/
EtOH = 1:2, 0.4 mL/min) tR = 31.0 min, >98% ee; 1H NMR
(300 MHz, CDCl3) d 0.98 (3H, t, J = 7.4 Hz), 1.70–1.76 (2H, m),
3.08 (3H, s), 3.37 (3H, s), 3.53–3.61 (2H, m), 4.34–4.40 (1H, m),
6.89–6.95 (1H, m), 6.97–7.01 (1H, m), 7.15 (2H, d, J = 8.8 Hz),
7.22–7.24 (1H, m), 7.25–7.29 (1H, m), 7.42–7.43 (1H, m), 7.93
(2H, d, J = 8.8 Hz); MS (ESI) m/z = 477 [M+H]+; HRMS (ESI) calcd
for C22H25N2O6S2 477.1154; found 477.1147 [M+H]+; HPLC (a)
99.4%; (b) 99.6%.
6.1.4. 3-[4-(Methylsulfonyl)phenoxy]-5-[(3S)-tetrahydrofuran-
3-yloxy]-N-1,3-thiazol-2-ylbenzamide (6b)
To a solution of 3 (40.0 mg, 0.14 mmol) in THF (1.5 mL) were
added (3R)-tetrahydrofuran-3-ol (0.022 mL, 0.28 mmol), PPh3
(72.3 mg, 0.28 mmol) and DIAD (0.076 mL, 0.39 mmol), and the
mixture was stirred at room temperature overnight. The reaction
was quenched with saturated NH4Cl solution and the resulting
mixture was extracted with EtOAc. The organic phase was washed
with brine, dried over MgSO4, and evaporated. The residue was
purified by silica gel column chromatography (50% CHCl3/hexane)
to give 4o (12.1 mg, 24%) as a colorless foam. HPLC (Chiralpak AD-
H, 0.5 ꢁ 25 cm, hexane.EtOH = 75:25, 0.4 mL/min) tR = 27.7 min,
>98% ee.
Compound 6b was prepared as a colorless foam from 4o in a
similar manner as described for compound 2b. Yield: 57%; 1H
NMR (400 MHz, CDCl3) d 2.14–2.27 (2H, m), 3.08 (3H, s), 3.91–
3.99 (4H, m), 4.96–4.97 (1H, m), 6.82 (1H, d, J = 1.7 Hz), 6.99 (1H,
d, J = 3.6 Hz), 7.13 (2H, d, J = 8.9 Hz), 7.18 (1H, d, J = 3.6 Hz), 7.25
(1H, s), 7.30 (1H, d, J = 1.7 Hz), 7.93 (2H, d, J = 8.9 Hz); MS (ESI)
m/z = 461 [M+H]+; HRMS (ESI) calcd for C21H21N2O6S2 461.0841;
found 461.0840 [M+H]+; HPLC (a) 96.7%; (b) 97.4%.
6.1.8. 3-(2-Methoxy-1-methylethoxy)-5-[4-
(methylsulfonyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (5d)
Compound 5d was prepared as a colorless oil from 3 with 1-
methoxypropan-2-ol in a similar manner as described for com-
pound 2b. Yield: 14%; 1H NMR (300 MHz, CDCl3) d 1.31 (3H, d,
J = 6.3 Hz), 3.07 (3H, s), 3.38 (3H, s), 3.54–3.56 (2H, m), 4.58–4.59
(1H, m), 6.89–6.90 (1H, m), 6.98 (1H, d, J = 3.6 Hz), 7.13 (2H, d,
J = 8.8 Hz), 7.21–7.22 (1H, m), 7.25 (1H, d, J = 3.6 Hz), 7.37–7.39
(1H, m), 7.92 (2H, d, J = 8.8 Hz); MS (ESI) m/z = 463 [M+H]+; HRMS
(ESI) calcd for C21H23N2O6S2 463.0998; found 463.1004 [M+H]+.
6.1.5. 3-[4-(Methylsulfonyl)phenoxy]-5-[(3R)-tetrahydrofuran-
3-yloxy]-N-1,3-thiazol-2-ylbenzamide (7b)
6.1.9. 3-[4-(Methylsulfonyl)phenoxy]-5-(tetrahydro-2H-pyran-
4-yloxy)-N-1,3-thiazol-2-ylbenzamide (5e)
To a solution of 3 (40.0 mg, 0.14 mmol) in THF (1.5 mL) were
added (3S)-tetrahydrofuran-3-ol (0.022 mL, 0.28 mmol), PPh3
(72.3 mg, 0.28 mmol)and DIAD (0.076 mL, 0.39 mmol), and themix-
ture was stirred at room temperature overnight. The reaction was
quenched with saturated NH4Cl solution and the resulting mixture
wasextractedwithEtOAc. Theorganicphasewaswashedwithbrine,
dried over MgSO4, and evaporated. The residue was purified by silica
gel column chromatography (50% CHCl3/hexane) to give 4p
(14.9 mg, 30%) as a colorless foam. HPLC (Chiralpak AD-H, 0.5 ꢁ
25 cm, hexane/EtOH = 75:25, 0.4 mL/min) tR = 37.2 min, 97% ee.
Compound 7b was prepared as a colorless foam from 4p in a
similar manner as described for compound 2b. Yield: 49%; 1H
NMR (400 MHz, CDCl3) d 2.14–2.27 (2H, m), 3.08 (3H, s), 3.91–
3.99 (4H, m), 4.96–4.97 (1H, m), 6.82 (1H, d, J = 1.7 Hz), 6.99 (1H,
d, J = 3.6 Hz), 7.13 (2H, d, J = 8.9 Hz), 7.18 (1H, d, J = 3.6 Hz), 7.25
(1H, s), 7.30 (1H, d, J = 1.7 Hz), 7.93 (2H, d, J = 8.9 Hz); MS (ESI)
m/z = 461 [M+H]+; HRMS (ESI) calcd for C21H21N2O6S2 461.0841;
found 461.0840 [M+H]+; HPLC (a) 97.9%; (b) 98.5%.
Compound 5e was prepared as a colorless foam from 3 with tet-
rahydro-2H-pyran-4-ol in a similar manner as described for com-
pound 2b. Yield: 28%; 1H NMR (400 MHz, CDCl3) d 1.76–1.84 (2H,
m), 2.03–2.08 (2H, m), 3.07 (3H, s), 3.55–3.61 (2H, m), 3.94–3.99
(2H, m), 4.54–4.58 (1H, m), 6.84 (1H, t, J = 2.2 Hz), 6.99 (1H, d,
J = 2.1 Hz), 7.12 (2H, d, J = 7.7 Hz), 7.22 (1H, s), 7.30 (1H, br s),
7.38 (1H, s), 7.90 (2H, d, J = 7.7 Hz); MS (ESI) m/z = 475 [M+H]+;
HRMS (ESI) calcd for C22H23N2O6S2 475.0998; found 475.0995
[M+H]+.
6.1.10. 3-[2-Methoxy-1-(methoxymethyl)ethoxy]-5-[4-
(methylsulfonyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (5f)
Compound 5f was prepared as a colorless oil from 3 with 2-bro-
mo-1,3-dimethoxypropane in a similar manner as described for
compound 2b and 5a. Yield: 14%; 1H NMR (300 MHz, CDCl3) d
3.08 (3H, s), 3.39 (6H, s), 3.63 (4H, d, J = 4.7 Hz), 4.56–4.58 (1H,
m), 6.97–6.99 (2H, m), 7.15 (2H, d, J = 8.9 Hz), 7.25–7.28 (2H, m),

3806
T. Iino et al. / Bioorg. Med. Chem. 17 (2009) 3800–3809
7.44–7.45 (1H, m), 7.93 (2H, d, J = 8.9 Hz); MS (ESI) m/z = 493
[M+H]+; HRMS (ESI) calcd for C22H25N2O7S2 493.1103; found
493.1102 [M+H]+.
J = 3.6 Hz), 7.17 (2H, d, J = 8.8 Hz), 7.20–7.23 (1H, m), 7.35–7.39
(2H, m), 7.96 (2H, d, J = 8.8 Hz), 10.8 (1H, br s); MS (ESI) m/
z = 449 [M+H]+; HRMS (ESI) calcd for C20H21N2O6S2 449.0841;
found 449.0840 [M+H]+; HPLC (a) 99.8%; (b) 99.8%.
6.1.11. 3-(2-Hydroxy-1-methylethoxy)-5-[4-
(methylsulfonyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (5g)
To a solution of 3 (700 mg, 2.4 mmol) in THF (10 mL) were
Compound 7g: HPLC (Chiralpak AS, 0.5 ꢁ 25 cm, hex-
ane:EtOH = 50:50, 0.4 mL/min) tR = 23.3 min, 98% ee; 1H NMR
(300 MHz, CDCl3) d 1.33 (3H, d, J = 6.2 Hz), 3.10 (3H, s), 3.79–3.81
(2H, m), 4.54–4.57 (1H, m), 6.87–6.89 (1H, m), 7.03 (1H, d,
J = 3.6 Hz), 7.17 (2H, d, J = 8.8 Hz), 7.20–7.23 (1H, m), 7.35–7.39
(2H, m), 7.96 (2H, d, J = 8.8 Hz), 10.8 (1H, br s); MS (ESI) m/
z = 449 [M+H]+; HRMS (ESI) calcd for C20H21N2O6S2 449.0841;
found 449.0849 [M+H]+; HPLC (a) 98.7%; (b) 99.4%.
added
1-(t-butyldimethylsiloxy)-2-hydroxypropane
(1.14 g,
6.0 mmol), PPh3 (1.50 g, 6.0 mmol) and DEAD (2.6 mL, 6.0 mmol)
at 0 °C, and the mixture was stirred at room temperature over-
night. The reaction was quenched with water and the resulting
mixture was extracted with EtOAc. The organic phase was washed
with brine, dried over MgSO4, and evaporated. The residue was
purified by silica gel column chromatography (5% EtOAc/hexane)
to give racemate 4g (1.04 g, 95%) as a colorless oil.
6.1.13. 3-(2-Hydroxyethoxy)-5-[4-(methylsulfonyl)phenoxy]-N-
1,3-thiazol-2-ylbenzamide (5h)
To a solution of 4g (800 mg, 1.73 mmol) in CHCl3 (17 mL) was
added mCPBA (896 mg, 5.19 mmol) at 0 °C and the mixture was
stirred for 30 min. The reaction was quenched with saturated
Na2S2O3 solution and the resulting mixture was extracted with
EtOAc. The organic phase was washed with saturated NaHCO3
solution and brine, dried over MgSO4, and evaporated to give the
crude sulfone.
To a solution of the above-obtained sulfone in MeOH (17 mL)
was added 2 N NaOH solution (4.3 mL, 8.65 mmol), and the mix-
ture was stirred at room temperature overnight. The mixture was
neutralized with 10% citric acid solution and extracted with EtOAc.
The organic phase was washed with brine, dried over MgSO4, and
evaporated. The residue was purified by silica gel column chroma-
tography (2% MeOH/CHCl3) to give the carboxylic acid (402 mg,
49%) as a colorless oil.
To a solution of the above-obtained carboxylic acid (402 mg,
0.84 mmol) in CHCl3 (8.4 mL) were added 2-amino-1,3-thiazole
(252 mg, 2.52 mmol), HOBt-hydrate (341 mg, 2.52 mmol) and EDCI
(321 mg, 1.68 mmol), and the mixture was stirred at room temper-
ature overnight. The mixture was quenched with water and ex-
tracted with EtOAc. The organic phase was washed with 10% citric
acid solution and brine, dried over MgSO4, and evaporated to give
the crude amide.
To a solution of the above-mentioned amide in 1,4-dioxane
(6.0 mL)wasadded 6 NHClsolution(2.0 mL, 12 mmol), andthemix-
ture was stirred at room temperature for 1 h. The reaction was evap-
orated, and then excess Et3N was added to the residue and the
reaction was evaporated again. The residue was purified by silica
gel column chromatography (80% EtOAc/hexane) to give the race-
mate 5g (290 mg, 77%) as a colorless solid. 1H NMR (300 MHz, CDCl3)
d 1.33 (3H, d, J = 6.2 Hz), 3.10 (3H, s), 3.79–3.81 (2H, m), 4.54–4.57
(1H, m), 6.87–6.89 (1H, m), 7.03 (1H, d, J = 3.6 Hz), 7.17 (2H, d,
J = 8.8 Hz), 7.20–7.23 (1H, m), 7.35–7.39 (2H, m), 7.96 (2H, d,
J = 8.8 Hz), 10.8 (1H, br s); MS (ESI) m/z = 449 [M+H]+.
Compound 5h was prepared as a colorless foam from 3 with 2-
{[tert-butyl(dimethyl)silyl]oxy}ethanol in a similar manner as de-
scribed for compound 5g. Yield: 12%; 1H NMR (300 MHz, CDCl3)
d 3.10 (3H, s), 4.01 (2H, t, J = 4.5 Hz), 4.14 (2H, t, J = 4.5 Hz), 6.85–
6.88 (1H, m), 7.02 (1H, d, J = 3.0 Hz), 7.16 (2H, d, J = 8.4 Hz),
7.29–7.32 (2H, m), 7.36–7.38 (1H, m), 7.95 (2H, d, J = 8.4 Hz),
11.3 (1H, br s); MS (ESI) m/z = 435 [M+H]+; HRMS (ESI) calcd for
C19H19N2O6S2 435.0685; found 435.0686 [M+H]+.
6.1.14. 3-{[(cis)-2-Hydroxycyclopentyl]oxy}-5-[4-
(methylsulfonyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (5i)
Compound 5i was prepared as a colorless foam from 3 with
trans-2-{[tert-butyl(diphenyl)silyl]oxy}cyclopentanol in a similar
manner as described for compound 5g. Yield: 10%. 1H NMR
(300 MHz, CDCl3) d 1.62–2.08 (6H, m), 3.08 (3H, s), 4.24–4.30
(1H, m), 4.55–4.60 (1H, m), 6.87 (1H, t, J = 2.0 Hz), 7.00 (1H, d,
J = 3.6 Hz), 7.14 (2H, d, J = 8.8 Hz), 7.25 (1H, t, J = 2.0 Hz), 7.25
(1H, d, J = 3.6 Hz), 7.40 (1H, t, J = 2.0 Hz), 7.93 (2H, d, J = 8.8 Hz);
MS (ESI) m/z = 475 [M+H]+.
6.1.15. 3-{[(1S,2R or 1R,2S)-2-Hydroxycyclopentyl]oxy}-5-[4-
(methylsulfonyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (6i)
and 3-{[(1R,2S or 1S,2R)-2-Hydroxycyclopentyl]oxy}-5-[4-
(methylsulfonyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (7i)
Optical resolution of 5i by Chiralpak AS column (2 ꢁ 25 cm,
hexane/EtOH = 1:2) afforded 6i (faster, 3.8 mg) as a colorless solid
and the antipode 7i (slower, 4.2 mg) as a colorless solid.
Compound 6i: HPLC (Chiralpak AS, 0.5 ꢁ 25 cm, hexane/
EtOH = 1:2, 0.4 mL/min) tR = 16.3 min, >99% ee; 1H NMR
(300 MHz, CDCl3) d 1.62–2.08 (6H, m), 3.08 (3H, s), 4.24–4.30
(1H, m), 4.55–4.60 (1H, m), 6.87 (1H, t, J = 2.0 Hz), 7.00 (1H, d,
J = 3.6 Hz), 7.14 (2H, d, J = 8.8 Hz), 7.25 (1H, t, J = 2.0 Hz), 7.25
(1H, d, J = 3.6 Hz), 7.40 (1H, t, J = 2.0 Hz), 7.93 (2H, d, J = 8.8 Hz);
MS (ESI) m/z = 475 [M+H]+; HRMS (ESI) calcd for C22H23N2O6S2
475.0998; found 475.0990 [M+H]+; HPLC (a) 99.4%; (b) 99.4%.
Compound 7i: HPLC (Chiralpak AS, 0.5 ꢁ 25 cm, hexane/
EtOH = 1:2, 0.4 mL/min) tR = 25.2 min, 98% ee; 1H NMR (300 MHz,
CDCl3) d 1.62–2.08 (6H, m), 3.08 (3H, s), 4.24–4.30 (1H, m), 4.55–
4.60 (1H, m), 6.87 (1H, t, J = 2.0 Hz), 7.00 (1H, d, J = 3.6 Hz), 7.14
(2H, d, J = 8.8 Hz), 7.25 (1H, t, J = 2.0 Hz), 7.25 (1H, d, J = 3.6 Hz),
7.40 (1H, t, J = 2.0 Hz), 7.93 (2H, d, J = 8.8 Hz); MS (ESI) m/z = 475
[M+H]+; HRMS (ESI) calcd for C22H23N2O6S2 475.0998; found
475.0994 [M+H]+; HPLC (a) 99.4%; (b) 99.7%.
6.1.12. 3-[(1S)-2-Hydroxy-1-methylethoxy]-5-[4-
(methylsulfonyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (6g)
and 3-[(1R)-2-hydroxy-1-methylethoxy]-5-[4-
(methylsulfonyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (7g)
Optical resolution of 5g by Chiralpak AS column (2 ꢁ 25 cm,
hexane/EtOH = 50:50) afforded 6g (faster, 91.3 mg) as a colorless
solid and 7g (slower, 83.5 mg) as a colorless solid.
Using (2R)-1-(t-butyldimethylsiloxy)-2-hydroxypropane in-
stead of 1-(t-butyldimethylsiloxy)-2-hydroxypropane, 6g was pre-
pared from 3 in a similar manner as described for compound 5g.
On the other hand, 7g was obtained from 3 with (2S)-1-(t-butyl-
dimethylsiloxy)-2-hydroxypropane.
Compound 6g: HPLC (Chiralpak AS, 0.5 ꢁ 25 cm, hexane/
EtOH = 50:50, 0.4 mL/min) tR = 17.9 min, 98% ee; 1H NMR
(300 MHz, CDCl3) d 1.33 (3H, d, J = 6.2 Hz), 3.10 (3H, s), 3.79–3.81
(2H, m), 4.54–4.57 (1H, m), 6.87–6.89 (1H, m), 7.03 (1H, d,
6.1.16. 3-{[(trans)-2-Hydroxycyclopentyl]oxy}-5-[4-
(methylsulfonyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (5j)
Compound 5j was prepared as a colorless foam from 3 with cis-
2-{[tert-butyl(diphenyl)silyl]oxy}cyclopentanol in a similar man-
ner as described for compound 5g. Yield: 9%; 1H NMR (300 MHz,
CDCl3) d 1.27–1.35 (6H, m), 3.08 (3H, s), 4.29–4.33 (1H, m), 4.54–

T. Iino et al. / Bioorg. Med. Chem. 17 (2009) 3800–3809
3807
4.56 (1H, m), 6.86 (1H, s), 6.99 (1H, d, J = 3.6 Hz), 7.13 (2H, d,
J = 8.8 Hz), 7.23 (1H, s), 7.27 (1H, d, J = 3.6 Hz), 7.39 (1H, s), 7.92
(2H, d, J = 8.8 Hz); MS (ESI) m/z = 475 [M+H]+.
sulfonyl chloride (0.052 mL, 0.66 mmol) at 0 °C, and the mixture
was stirred for 30 min. The reaction was quenched with saturated
NaHCO3 solution and the resulting mixture was extracted with
EtOAc. The organic phase was washed with brine, dried over
MgSO4, and evaporated to give the crude mesylate.
6.1.17. 3-{[(1S,2S or 1R,2R)-2-Hydroxycyclopentyl]oxy}-5-[4-
(methylsulfonyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (6j)
and 3-{[(1R,2R or 1S,2S)-2-Hydroxycyclopentyl]oxy}-5-[4-
(methylsulfonyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (7j)
Optical resolution of 5j by Chiralpak AD column (2 ꢁ 25 cm,
EtOH) afforded 6j (faster, 3.0 mg) as a colorless solid and the anti-
pode 7j (slower, 3.3 mg) as a colorless solid.
Compound 6j: HPLC (Chiralpak AD, 0.5 ꢁ 25 cm, EtOH, 0.4 mL/
min) tR = 17.7 min, >99% ee; 1H NMR (300 MHz, CDCl3) d 1.27–
1.35 (6H, m), 3.08 (3H, s), 4.29–4.33 (1H, m), 4.54–4.56 (1H, m),
6.86 (1H, s), 6.99 (1H, d, J = 3.6 Hz), 7.13 (2H, d, J = 8.8 Hz), 7.23
(1H, s), 7.27 (1H, d, J = 3.6 Hz), 7.39 (1H, s), 7.92 (2H, d,
J = 8.8 Hz); MS (ESI) m/z = 475 [M+H]+; HRMS (ESI) calcd for
C22H23N2O6S2 475.0998; found 475.0989 [M+H]+; HPLC (a) 99.5%;
(b) 99.3%.
Compound 7j: HPLC (Chiralpak AD, 0.5 ꢁ 25 cm, EtOH, 0.4 mL/
min) tR = 26.2 min, 98% ee; 1H NMR (300 MHz, CDCl3) d 1.27–1.35
(6H, m), 3.08 (3H, s), 4.29–4.33 (1H, m), 4.54–4.56 (1H, m), 6.86
(1H, s), 6.99 (1H, d, J = 3.6 Hz), 7.13 (2H, d, J = 8.8 Hz), 7.23 (1H, s),
7.27 (1H, d, J = 3.6 Hz), 7.39 (1H, s), 7.92 (2H, d, J = 8.8 Hz); MS
(ESI) m/z = 475 [M+H]+; HRMS (ESI) calcd for C22H23N2O6S2
475.0998; found 475.0993 [M+H]+; HPLC (a) 99.3%; (b) 99.2%.
To a solution of the above-obtained mesylate in DMF (8.2 mL)
was added sodium azide (73 mg, 0.11 mmol), and the mixture was
stirred at 60 °C for 4 h. The reaction was cooled, quenched with
water and the resulting mixture was extracted with EtOAc. The or-
ganic phase was washed with brine, dried over MgSO4, and evapo-
rated. The residue was purified by preparative TLC (10% MeOH/
CHCl3) to give the azide compound (83.0 mg, 79%) as a colorless oil.
To a solution of the above-obtained azide compound in THF
(1 mL) were added Ph3P (71 mg, 0.27 mmol) and water
(0.032 mL, 1.75 mmol), and the mixture was stirred at 60 °C for
2 h. The reaction was cooled and evaporated. The residue was puri-
fied by preparative TLC (5% MeOH/CHCl3) to give 5o (66.8 mg, 85%)
as a colorless foam. 1H NMR (300 MHz, CDCl3) d 1.30 (3H, d,
J = 6.0 Hz), 2.92 (2H, d, J = 6.0 Hz), 3.09 (3H, s), 4.41 (1H, sextet,
J = 6.0 Hz), 6.85–6.87 (1H, m), 6.98 (1H, d, J = 3.5 Hz), 7.14 (2H, d,
J = 8.9 Hz), 7.21 (1H, d, J = 3.5 Hz), 7.24–7.26 (1H, m), 7.41–7.43
(1H, m), 8.87 (2H, d, J = 8.9 Hz); MS (ESI) m/z = 448 [M+H]+; HRMS
(ESI) calcd for C20H22N3O5S2 448.1001; found 448.1002 [M+H]+.
6.1.22. 3-[2-(Dimethylamino)-1-methylethoxy]-5-[4-
(methylsulfonyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (5p)
To a solution of the above-obtained racemate 5o (10.0 mg,
0.022 mmol) in methanol (0.20 mL) were added formaldehyde
solution (0.5 mL) and NaBH4–ZnCl2 (2:1) methanol solution
(0.5 mL), and the mixture was stirred at room temperature over-
night. The reaction was quenched with saturated NaHCO3 solution
and the resulting mixture was extracted with EtOAc. The organic
phase was washed with brine, dried over MgSO4, and evaporated.
The residue was purified by preparative TLC (3% MeOH:CHCl3) to
give 5p (4.6 mg, 44%) as a colorless foam. 1H NMR (300 MHz,
CDCl3) d 1.28 (3H, d, J = 6.2 Hz), 2.30 (6H, s), 2.42 (1H, dd, J = 4.4,
13.0 Hz), 2.68 (1H, dd, J = 6.2, 13.0 Hz), 3.09 (3H, s), 4.56 (1H, dt,
J = 4.5, 6.2 Hz), 6.88–6.89 (1H, m), 7.00 (1H, d, J = 3.6 Hz), 7.15
(2H, d, J = 8.9 Hz), 7.21–7.23 (1H, m), 7.28 (1H, d, J = 3.6 Hz),
7.40–7.42 (1H, m), 7.93 (2H, d, J = 8.9 Hz), 11.4 (1H, br s); MS
(ESI) m/z = 476 [M+H]+; HRMS (ESI) calcd for C22H26N3O5S2
476.1314; found 476.1324 [M+H]+.
6.1.18. 3-(3-Hydroxy-1-methylpropoxy)-5-[4-
(methylsulfonyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (5k)
Compound 5k was prepared as a colorless foam from 3 with 4-
{[t-butyl(dimethyl)silyl]oxy}butan-2-ol in a similar manner as de-
scribed for compound 5g. Yield: 40%; 1H NMR (300 MHz, CDCl3) d
1.39 (3H, d, J = 6.1 Hz), 1.87–1.89 (1H, m), 2.00–2.02 (1H, m), 3.10
(3H, s), 3.82–3.85 (2H, m), 4.70–4.71(1H, m), 6.88–6.90 (1H, m),
7.01 (1H, d, J = 3.5 Hz), 7.17 (2H, d, J = 8.9 Hz), 7.22–7.25 (1H, m),
7.35 (1H, d, J = 3.5 Hz), 7.47–7.48 (1H, m), 7.95 (2H, d, J = 8.9 Hz),
11.0 (1H, br s); MS (ESI) m/z = 463 [M+H]+; HRMS (ESI) calcd for
C21H23N2O6S2 463.0998; found 463.0999 [M+H]+.
6.1.19. 3-[4-(Methylsulfonyl)phenoxy]-N-1,3-thiazol-2-yl-5-
[2,2,2-trifluoro-1-(hydroxymethyl)ethoxy]benzamide (5l)
Compound 5l was prepared as a colorless foam from 3 with 3-
{[tert-butyl(dimethyl)silyl]oxy}-1,1,1-trifluoropropan-2-ol in
a
similar manner as described for compound 5g. Yield: 16%; 1H
NMR (300 MHz, CDCl3) d 3.08 (3H, s), 4.21–4.27 (2H, m), 4.40–
4.41 (1H, m), 6.84 (1H, s), 7.01 (1H, d, J = 3.6 Hz), 7.12 (2H, d,
J = 8.7 Hz), 7.28 (1H, d, J = 2.4 Hz), 7.36 (1H, d, J = 1.0 Hz), 7.92
(2H, d, J = 8.7 Hz); MS (ESI) m/z = 503 [M+H]+; HRMS (ESI) calcd
for C20H18N2O6F3S2 503.0558; found 503.0546 [M+H]+.
6.1.23. 3-[4-(Methylsulfonyl)phenoxy]-5-(pyrrolidin-3-yloxy)-
N-1,3-thiazol-2-ylbenzamide (5n)
Compound 5n was prepared as a colorless foam from 3 with
tert-butyl 3-hydroxypyrrolidine-1-carboxylate in a similar manner
as described for compound 5g. Yield: 38%; 1H NMR (400 MHz,
CDCl3) d 2.04–2.17 (2H, m), 3.08 (3H, s), 3.04–3.28 (4H, m), 4.91
(1H, s), 6.78–6.79 (1H, m), 6.98 (1H, d, J = 3.3 Hz), 7.12 (2H, d,
J = 8.8 Hz), 7.21–7.25 (1H, m), 7.29 (1H, d, J = 3.3 Hz), 7.32–7.33
(1H, m), 7.90 (2H, d, J = 8.8 Hz); MS (ESI) m/z = 460 [M+H]+; HRMS
(ESI) calcd for C21H22N3O5S2 460.1001; found 460.1000 [M+H]+.
6.1.20. 3-[1-(Hydroxymethyl)-2-methylpropoxy]-5-[4-
(methylsulfonyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (5m)
Compound 5m was prepared as a colorless foam from 3 with 1-
{[tert-butyl(dimethyl)silyl]oxy}-3-methylbutan-2-ol in a similar
manner as described for compound 5g. Yield: 33%; 1H NMR
(300 MHz, CDCl3) d 0.95–0.98 (6H, m), 2.04–2.06 (1H, m), 3.07
(3H, s), 3.32–3.85 (2H, m), 4.21–4.23 (1H, m), 6.83–6.85 (1H, m),
6.96 (1H, d, J = 3.7 Hz), 7.11 (2H, d, J = 8.9 Hz), 7.17–7.18 (1H, m),
7.23 (1H, d, J = 3.7 Hz), 7.38–7.40 (1H, m), 7.91 (2H, d, J = 8.8 Hz),
12.0 (1H, br s); MS (ESI) m/z = 477 [M+H]+; HRMS (ESI) calcd for
C22H25N2O6S2 477.1154; found 477.1156 [M+H]+.
6.1.24. 3-[(1-Methylpyrrolidin-3-yl)oxy]-5-[4-
(methylsulfonyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (5q)
To a solution of 5n (6.0 mg, 0.013 mmol) in MeOH (0.5 mL) was
added 37% HCHO solution (5 drops), and the mixture was stirred at
room temperature for 1 h. To the mixture was added NaBH4
(4.0 mg, 0.13 mmol), and the mixture was stirred at room temper-
ature for 1 h. The reaction was quenched with water and evapo-
rated. The residue was purified by preparative TLC (10% MeOH/
CHCl3) to give 5q (3.2 mg, 52%) as a colorless foam. 1H NMR
(400 MHz, CDCl3) d 2.01–2.02 (1H, m), 2.34–2.46 (2H, m), 2.41
(3H, s), 2.80–2.88 (3H, m), 3.07 (3H, s), 4.96 (1H, s), 6.79–6.80
(1H, m), 6.99 (1H, d, J = 3.6 Hz), 7.12 (2H, d, J = 8.8 Hz), 7.18–7.19
6.1.21. 3-(2-Amino-1-methylethoxy)-5-[4-
(methylsulfonyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (5o)
To a solution of the above-obtained 5g (100 mg, 0.22 mmol) in
THF (2.2 mL) were added Et3N (0.19 mL, 1.32 mmol) and methane-

3808
T. Iino et al. / Bioorg. Med. Chem. 17 (2009) 3800–3809
(1H, m), 7.27–7.29 (2H, m), 7.91 (2H, d, J = 8.8 Hz); MS (ESI) m/
z = 474 [M+H]+; HRMS (ESI) calcd for C22H24N3O5S2 474.1157;
found 474.1156 [M+H]+.
The residue was purified by silica gel column chromatography
(33% EtOAc/hexane) to give 9 (380 mg, 56%) as a colorless solid. 1H
NMR (300 MHz, CD3OD) d 3.91 (3H, s), 5.38 (1H, br s), 7.42 (1H, s),
7.47 (1H, s), 7.94 (1H, s); MS (ESI) m/z = 277 [MꢀH]ꢀ.
6.1.25. 2-(3-[4-(Methylsulfonyl)phenoxy]-5-{[(4-methyl-1,3-
thiazol-2-yl)amino]carbonyl}phenoxy)propanoic acid (5s)
To a solution of 3 (290 mg, 1.0 mmol) in DMF (10 mL) were added
NaH (44.0 mg, 1.1 mmol) and tert-butyl 2-bromopropanoate
(42.0 mg, 2.0 mmol), and the mixture was stirred at room tempera-
ture for 3 h. The mixture was quenched with saturated NH4Cl solu-
tion and the resulting mixture was extracted with EtOAc. The
organic phase was washed with brine, dried over MgSO4, and evap-
orated. The residue was purified by silica gel column chromatogra-
phy (10% EtOAc/hexane) to give 12 (374 mg, 89%) as a colorless solid.
Compound 5s was prepared as a colorless solid from 12 with 4-
methylthiazol-2-amine in a similar manner as described for com-
pound 5g. Yield: 34%; 1H NMR (400 MHz, CDCl3) d 1.53 (3H, d,
J = 6.8 Hz), 2.28 (3H, s), 3.27 (3H, s), 5.03 (1H, septet, J = 6.8 Hz),
6.81–6.83 (1H, m), 6.92–6.95 (1H, m), 7.25 (2H, d, J = 8.8 Hz),
7.41–7.43 (1H, m), 7.48–7.51 (1H, m), 7.95 (2H, d, J = 8.8 Hz); MS
(ESI) m/z = 477 [M+H]+; HRMS (ESI) calcd for C21H21N2O7S2
477.0790; found 477.0794 [M+H]+.
6.1.29. 3-Iodo-5-[4-(methylsulfonyl)phenoxy]-N-(1,3-thiazol-2-
yl)benzamide (10)
To a solution of 9 (869 mg, 3.13 mmol) in CH2Cl2 (32 mL) were
added 4-MeSO2–PhB(OH)2 (1.25 g, 6.25 mmol), Cu(OAc)2 (568 mg,
3.13 mmol) and Et3N (2.18 mL, 15.6 mmol), and the mixture was
stirred under oxygen atmosphere at room temperature overnight.
The mixture was filtered through a Celite pad and the filtrate
was evaporated. The residue was partitioned with H2O and CHCl3.
The organic phase was washed with brine, dried over MgSO4, and
evaporated. The residue was purified by silica gel column chroma-
tography (33% EtOAc/hexane) to give methyl 3-iodo-5-[4-(methyl-
sulfonyl)phenoxy]benzoate (913 mg, 68%) as a white solid.
Compound 10 was prepared as a colorless foam from the above
obtained ester in a similar manner as described for compound 5g.
Yield: 54%; 1H NMR (300 MHz, CDCl3) d 3.09 (3H, s), 7.04 (1H, s),
7.15 (2H, d, J = 8.6 Hz), 7.32 (1H, s), 7.62–7.68 (2H, m), 7.97 (2H,
d, J = 8.6 Hz), 8.10 (1H, s).
6.1.26. 3-[1-Methyl-2-(methylamino)-2-oxoethoxy]-5-[4-
(methylsulfonyl)phenoxy]-N-(4-methyl-1,3-thiazol-2-
yl)benzamide (5t)
6.1.30. 3-[2-(Hydroxymethyl)prop-2-en-1-yl]-5-[4-
(methylsulfonyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (11)
To a solution of 10 (57.6 mg, 0.12 mmol) in DMF (2.0 mL)
were added NaHCO3 (19.0 mg, 0.23 mmol), 2-methylprop-2-en-
1-ol (0.097 mL, 1.15 mmol), nBu4NBr (19.0 mg, 0.058 mmol)
and Pd(PPh3)2Cl2 (8.0 mg, 0.012 mmol), and the mixture was
stirred at 110 °C overnight. After cooling, the reaction was
quenched with H2O and EtOAc. The organic phase was washed
with brine, dried over MgSO4, and evaporated. The residue was
purified by preparative TLC (75% EtOAc/hexane) to give 11
(5.6 mg, 11%) as a colorless oil. 1H NMR (300 MHz, CDCl3) d
3.08 (3H, s), 3.49 (2H, s), 4.06 (2H, s), 4.91 (1H, s), 5.19 (1H,
s), 7.00 (1H, d, J = 3.3 Hz), 7.11 (2H, d, J = 9.0 Hz), 7.13 (1H, d,
J = 3.3 Hz), 7.20 (1H, s), 7.55 (1H, s), 7.67 (1H, s), 7.92 (2H, d,
J = 9.0 Hz); MS (ESI) m/z = 445 [M+H]+.
To a solution of 5s (10.0 mg, 0.025 mmol) in DMF (0.1 mL) and
CH2Cl2 (0.5 mL) were added HOBT (10.0 mg, 0.075 mmol), methyl-
amine hydrochloride (15.0 mg, 0.23 mmol), Et3N (0.031 mL,
0.23 mmol) and EDCI (10.0 mg, 0.075 mmol), and the mixture
was stirred at room temperature overnight. The reaction was
quenched with 10% citric acid solution and the resulting mixture
was extracted with CHCl3-MeOH. The organic phase was dried over
MgSO4, and evaporated. The residue was purified by preparative
TLC (10% MeOH/CHCl3) to give 5t (7.3 mg, 60%) as a colorless foam.
1H NMR (300 MHz, CDCl3) d 1.59 (3H, s), 2.26 (3H, s), 2.86 (3H, d,
J = 4.7 Hz), 3.10 (3H, s), 4.73 (1H, q, J = 6.6 Hz), 6.47 (1H, br s),
6.56–6.58 (1H, m), 6.81–6.84 (1H, m), 7.12 (2H, d, J = 8.8 Hz),
7.20–7.23 (1H, m), 7.30–7.32 (1H, m), 7.93 (2H, d, J = 8.8 Hz),
11.0 (1H, br s); MS (ESI) m/z = 490 [M+H]+; HRMS (ESI) calcd for
C22H24N3O6S2 490.1107; found 490.1099 [M+H]+.
6.1.31. 3-(3-Hydroxy-2-methylpropyl)-5-[4-
(methylsulfonyl)phenoxy]-N-1,3-thiazol-2-ylbenzamide (5r)
To a solution of 11 (4.2 mg, 0.0094 mmol) in MeOH (2.0 mL)
was added 10% Pd–C (4.0 mg), and the mixture was stirred under
hydrogen atmosphere for 3 h. The mixture was filtered through a
Celite pad and the filtrate was evaporated. The residue was purified
by preparative TLC (75% EtOAc/hexane) to give 5r (1.0 mg, 25%) as
a colorless oil. 1H NMR (300 MHz, CDCl3) d 0.94 (6H, d, J = 6.7 Hz),
1.97–2.05 (1H, m), 2.50–2.94 (2H, m), 3.08 (3H, s), 3.50–3.56 (2H,
m), 7.03 (1H, d, J = 3.5 Hz), 7.13 (2H, d, J = 8.8 Hz), 7.17 (1H, s),
7.42 (1H, d, J = 3.5 Hz), 7.52 (1H, s), 7.63 (1H, s), 7.93 (2H, d,
J = 8.8 Hz); MS (ESI) m/z = 447 [M+H]+; HRMS (ESI) calcd for
C21H23N2O5S2 447.1048; found 447.1055 [M+H]+.
6.1.27. 3-[2-(Dimethylamino)-1-methyl-2-oxoethoxy]-5-[4-
(methylsulfonyl)phenoxy]-N-(4-methyl-1,3-thiazol-2-
yl)benzamide (5u)
Compound 5u was prepared as a colorless oil from 3 with
dimethylamine hydrochloride in a similar manner as described
for compound 5t. Yield: 6%; 1H NMR (300 MHz, CDCl3) d 1.62
(3H, d, J = 6.7 Hz), 2.35 (3H, s), 2.98 (3H, s), 3.10 (3H, s), 3.14 (3H,
s), 5.06 (1H, q, J = 6.7 Hz), 6.56–6.59 (1H, m), 6.81–6.84 (1H, m),
7.15 (2H, d, J = 8.8 Hz), 7.19–7.22 (1H, m), 7.28–7.30 (1H, m),
7.95 (2H, d, J = 8.8 Hz); MS (ESI) m/z = 504 [M+H]+; HRMS (ESI)
calcd for C23H26N3O6S2 504.1263; found 504.1262 [M+H]+.
6.2. Log D
6.1.28. Methyl 3-hydroxy-5-iodobenzoate (9)
To a solution of 8 (400 mg, 2.45 mmol) in 1,4-dioxane (2.0 mL)
and H2O (3.0 mL) were added 4 N HCl in 1,4-dioxane solution
(1.80 mL, 7.20 mmol) and NaNO2 (186 mg, 2.70 mmol) in H2O
(2.0 mL) at 0 °C, and the mixture was stirred at 0 °C for 15 min. To
the mixture was added KI (489 mg, 2.94 mmol) in H2O (4.0 mL) at
0 °C, and the mixture was stirred at 10 °C for 10 min. Et2O (10 mL)
was added to the mixture at 10 °C, and the mixture was stirred at
room temperature for 2 h. The reaction was quenched with KHSO4
solution and extracted with EtOAc. The organic phase was washed
with NH4Cl solution and brine, dried over MgSO4, and evaporated.
Log D values were measured using reported methods.18–20
6.3. Solubility
Solubility data were measured using HPLC-UV method. To 1 mg
of sample was added 1 ml of 200 mM phosphate buffer (pH 7.4),
and the mixture was stirred at 25 °C for 1 h and left 25 °C for
24 h without stirring. After centrifugation, UV area of the skim-
ming was measured and calculated using HPLC-UV method based
on standard curve prepared previously.

T. Iino et al. / Bioorg. Med. Chem. 17 (2009) 3800–3809
3809
6.4. Biology
Sekine-Satoh and Hiroshi Takehana for the PK study in rats. We
would also like to thank Dr. J. Sakaki and Dr. N. Ohtake for critical
reading of the manuscript.
6.4.1. In vitro GK assay
The recombinant human liver GK used in this assay was ex-
pressed in E. coli as a FLAG fusion protein. GK activity was mea-
sured by the glucose-6-phosphate dehydrogenase coupled
continuous spectrophotometric assay. GK was incubated with
DMSO solution in assay buffer containing 25 mM Hepes, pH 7.2,
1 mM dithiothreitol, 0.5 mM thionicotinamide adenine dinucleo-
tide, 2 mM MgCl2, 1 mM ATP, 2 U/mL glucose-6-phosphate dehy-
drogenase and 2.5 or 10 mM glucose at 30 °C. Reaction velocities
were obtained from the rate of increase in absorbance at 405 nm
after 5 min of reaction. The OD values were measured at each con-
centration of the evaluated compound, using the OD value of the
Supplementary data
Supplementary data associated with this article can be found, in
the online version, at doi:10.1016/j.bmc.2009.04.040.
References and notes
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The authors are grateful to Hirokazu Ohsawa and Miyoko
Miyashita for the analytical and spectral studies and to Hiromi