Discovery and biological evaluation of novel 4-amino-2-phenylpyrimidine derivatives as potent and orally active GPR119 agonists

Article abstract of DOI:10.1016/j.bmc.2012.06.049

Novel 4-amino-2-phenylpyrimidine derivatives were synthesized and evaluated as GPR119 agonists. Optimization of the substituents on the phenyl ring at the 2-position and the amino group at the 4-position led to the identification of 3,4-dihalogenated and

Full text of DOI:10.1016/j.bmc.2012.06.049

Bioorganic & Medicinal Chemistry 20 (2012) 5235–5246
Contents lists available at SciVerse ScienceDirect
Bioorganic & Medicinal Chemistry
journal homepage: www.elsevier.com/locate/bmc
Discovery and biological evaluation of novel 4-amino-2-phenylpyrimidine
derivatives as potent and orally active GPR119 agonists
⇑
Kenji Negoro , Yasuhiro Yonetoku, Hana Misawa-Mukai, Wataru Hamaguchi, Tatsuya Maruyama,
Shigeru Yoshida, Makoto Takeuchi, Mitsuaki Ohta
Drug Discovery Research, Astellas Pharma Inc., 21 Miyukigaoka, Tsukuba, Ibaraki 305-8585, Japan
a r t i c l e i n f o
a b s t r a c t
Article history:
Novel 4-amino-2-phenylpyrimidine derivatives were synthesized and evaluated as GPR119 agonists.
Optimization of the substituents on the phenyl ring at the 2-position and the amino group at the 4-posi-
tion led to the identification of 3,4-dihalogenated and 2,4,5-trihalogenated phenyl derivatives showing
potent GPR119 agonistic activity. The advanced analog (2R)-3-{[2-(4-chloro-2,5-difluorophenyl)-6-ethyl-
pyrimidin-4-yl]amino}propane-1,2-diol (24g) was found to improve glucose tolerance at 1 mg/kg po in
mice and to show excellent pharmacokinetic profiles in mice and monkeys. Compound 24g also showed
an excellent antidiabetic effect in diabetic kk/Ay mice after one week of single daily treatment. These
results demonstrate that novel GPR119 agonist 24g improves glucose tolerance not only by enhancing
glucose-dependent insulin secretion but also by preserving pancreatic b-cell function.
Received 8 June 2012
Revised 27 June 2012
Accepted 28 June 2012
Available online 6 July 2012
Keywords:
Type 2 diabetes mellitus
Glucose-dependent insulin secretion
G-protein-coupled receptor 119
GPR119 agonist
Ó 2012 Elsevier Ltd. All rights reserved.
1. Introduction
of small molecule GPR119 agonists, such as AR231453 (1) and
PSN632408 (2) (Fig. 1), have been reported to show insulinotropic
Depletion of glucose-dependent insulin secretion (GDIS) and
particularly the loss of the first phase of GDIS are characteristic fea-
tures in the pathology of type 2 diabetes mellitus (T2DM), which
results in postprandial hyperglycemia.1 For the clinical manage-
ment of T2DM patients, sulfonylureas (SUs) are the most widely
used hypoglycemic agents,2 despite reports that these compounds
can cause severe hypoglycemia due to their glucose-independent
mode of action.3 Recent strategies for promoting normoglycemia
have focused on enhancing GDIS through G protein-coupled recep-
tors such as the glucagon-like peptide 1 (GLP-1) receptor. Although
GLP-1 analogs such as exendin-4 have been shown to effectively
stimulate GDIS and preserve pancreatic b cells, these analogs can
cause gastrointestinal side effects and pancreatitis and require par-
enteral administration.4 Such limitations for SUs and GLP-1 ana-
logs underscore the need for oral insulin secretagogues that
preserve the first phase of GDIS and induce normoglycemia in
T2DM patients.
and antiobesity effects,6 and several clinical trials of GPR119 ago-
nists are currently ongoing.6
We have identified distinct structures that function as GPR119
agonists.7 For example, high-throughput screening of the Astellas
corporate compound library revealed the 4-amino-2-phenylpyrim-
idine derivative
published initial structure–activity relationship (SAR) studies of
4-amino-2-phenylpyrimidine derivatives, finding compound
5 as a novel GPR119 agonist. We recently
6
has moderate GPR119 agonistic activity, good potency in an oral
glucose tolerance test (OGTT) in vivo and favorable pharmacoki-
netic (PK) profiles.8
Here, we describe further optimization of 6 as a GPR119 agonist
including SAR studies and evaluations of in vivo efficacy in diabetic
kk/Ay mice.
2. Chemistry
The G-protein-coupled receptor 119 (GPR119) is predominantly
expressed in pancreatic b cells and intestinal L-cells, and its activa-
tion directly promotes GDIS and indirectly increases GLP-1 levels
through the accumulation of the intracellular cAMP, followed by
a decrease in blood glucose levels,5 suggesting GPR119 as an
attractive drug target for treating T2DM. To date, several classes
The synthesis of commercially unavailable benzonitrile inter-
mediates is described in Scheme 1. Rosenmund-von Braun reaction
of commercially available 4-bromo-2,6-difluoroaniline 7, followed
by Sandmayer reaction in the presence of CuBr gave 4-bromo-3,5-
difluorobenzonitrile 9g9 in moderate yield. Benzonitrile 9h was
readily prepared from 1,4-dibromo-2,5-difluorobenzene 10 in four
steps. Lithium halogen exchange of 10, followed by trapping with
dry ice yielded carboxylic acid 11a,10 which was transformed to
benzonitrile 9h via acid chloride and carboxamide intermediates
⇑
Corresponding author. Tel.: +81 0 29 847 6631; fax: +81 0 29 847 1519.
E-mail address: kenji.negoro@astellas.com (K. Negoro).
0968-0896/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.bmc.2012.06.049

5236
K. Negoro et al. / Bioorg. Med. Chem. 20 (2012) 5235–5246
O O
S
N
O
Me
N
N
O
Me
Me
O
N
H
N
N
N
N
Me
Me
F
NO2
Me
N
O
1, AR231453
2, PSN632408
O
N
N
Me
O
S
N
O
Me
O
S
N
N
N
N
N
N
N
N
N
O
O
N
Me
Et
3, MBX-2982
4, GSK1292263
Me
N
Me
N
OH
N+
N
N
H
N
N
H
O
Br
Br
5
6
Figure 1. Structures of GPR119 agonists (AR231453 [1], PSN632408 [2], MBX-2982 [3], GSK1292263 [4], 5 and 6).
diate 16 in high yield. The foregoing 4-chloropyrimidines 14a–i
were subjected to substitution with amine 16 to obtain the desired
17a–i.
F
Br
F
CN
F
CN
a
b
H
H
2N
2N
Br
The synthesis of the 2-pyridone derivatives 23a–d is outlined in
Scheme 4. The intermediate amine 21 was prepared from methyl
2-chloroisonicotinate 18 in five steps. Substitution of 18 with
sodium methoxide, followed by reduction with lithium aluminum
hydride gave 2-methoxypyridin-4-ylmethanol 19 in good yield.
Chlorination of 19 with thionylchloride, followed by substitution
with potassium cyanide and catalytic hydrogenation with
RaneyÒ-nickel gave 21. Substitution of the 4-chroropyrimidines
14d, 14h, 14i, and 14m with amine 21, followed by demethylation
with hydrobromic acid gave the desired 2-pyridone derivatives
23a–d.
F
F
F
7
8
9g
F
Br
F
F
CO2H
F
F
CN
F
c
d, e, f
Br
R
R
10
11a (R = Br)
11b (R = Cl)
9h (R = Br)
9i (R = Cl)
Scheme 1. Synthesis of benzonitriles 9g–i. Reagents and conditions: (a) CuCN,
NMP, reflux; (b) NaNO2, concd H2SO4, 47% HBr, CuBr, AcOH, rt; (c) n-BuLi/hexane,
Et2O, dry ice, À78 °C to rt; (d) SOCl2, cat. DMF, 80 °C; (e) 28% aq NH3, CHCl3, 5 °C; (f)
POCl3, 80 °C.
As outlined in Scheme 5, the diol derivatives 24a–g were easily
prepared from the 4-chroropyrimidines 14d and 14j–m by substi-
tution with chiral 3-amino-1,2-propanediols.
in good yield. In the same manner, 4-chloro-2,5-difluorobenzonit-
rile 9i was prepared from the corresponding carboxylic acid 11b in
high yield.
The key intermediates 14b–m were prepared via a procedure
similar to that described in our previous report (Scheme 2). Benzo-
nitriles 9b–i were first converted into amidines 12b–i in two steps,
and condensation of 12b–i and the corresponding ketoesters under
basic conditions gave pyrimidones 13b–m, which were treated
with phosphorous oxychloride to afford 4-chloropyrimidines
14b–m.
3. Results and discussion
The synthesized compounds were evaluated for their agonistic
activities toward GPR119 using a cAMP reporter assay system in
which HEK293 cells were transfected with human GPR119 and
cAMP responsive element (pCRE)-luciferase expression plasmids.11
In this assay system, we relatively evaluated our compounds by
comparing their EC and IA values with those of lead compound
5. The EC values refer to the concentration of the tested com-
pounds in this assay system at which they showed as potent effi-
The synthesis of the pyridine N-oxide derivatives 17a–i listed in
Table 1 is shown in Scheme 3. Protection of the amino group in 15
by a Boc group followed by oxidation with m-chloroperbenzoic
acid (m-CPBA) and deprotection of the Boc group gave the interme-
cacy as compound 5 did at 10 lM. The IA values refer to the
relative activity (%) of the tested compounds compared to the effi-
cacy of compound 5 at 10
l
M in the same assay system.8,12
R2
R2
NH
NH2
CN
N
N
a, b
c
d
R1
R1
N
H
O
N
Cl
R1
R1
9b-i
12b-i
13b-m
14b-m
Scheme 2. Synthesis of 4-chloro-2-phenylpyrimidine derivatives 14b–m. Reagents and conditions: (a) HCl, EtOH, rt; (b) (NH4)2CO3, EtOH, rt; (c) R2COCH2CO2Me, NaOMe,
MeOH, rt; (d) POCl3, 80 °C.

K. Negoro et al. / Bioorg. Med. Chem. 20 (2012) 5235–5246
5237
Table 1
Because the halogen group at the 4-position in the phenyl moiety
was found to be important for agonistic activity, introduction of
additional halogen groups was investigated. Introduction of a flu-
oro group at the 2-position (compound 17c) was found to have
no effect on the agonistic activity. In contrast, the 3-fluoro deriva-
tives 17d and 17e showed improved agonistic activity over com-
pounds 6 and 17b, respectively. These results indicated that the
introduction of an additional fluoro group at the 3-position in the
phenyl moiety should be particularly preferred for agonistic activ-
ity. Introduction of an additional chloro group to compound 17b at
the 3-position (compound 17f) reduced the agonistic activity, indi-
cating that a small halogen group at the 3-position in the phenyl
moiety would be favorable for agonistic activity.
In vitro SARs and in vivo antihyperglycemic effects for analogs with substitution of
halogen groups in the phenyl moiety
Me
N
N+
O
N
N
Ar
H
Compound
Ar-
GPR119/pCRE
M)
IAb (%)
OGTT (3 mg/kg po)c
% Decrease
ECa
1.2
(l
6
325
NEf
Br
(38 at 10 mg/kg po)
NTg
Based on the above results, the trihalogenated compounds 17g
and 17h were designed and their agonistic activities towards
GPR119 were evaluated. The 4-bromo-3,5-difluorophenyl deriva-
tive 17g was found to be slightly less active than the 4-bromo-3-
fluorophenyl derivative 17d. In contrast, a two-fold enhancement
in activity was confirmed in the 4-bromo-2,5-difluorophenyl deriv-
ative 17h. From these observations, we concluded that the intro-
17a
NEd
NDe
376
17b
17c
0.70
1.5
NTg
19
Cl
268
573
duction of 2,5-difluoro groups to compound
6 was more
Br
F
F
favorable than that of 3,5-difluoro groups, and the 4-bromo-2,5-
difluorophenyl derivative 17h showed an approximately 10-fold
improvement in GPR119 agonistic activity over compound 6. In a
similar fashion, the 4-chloro-2,5-difluorophenyl derivative (com-
pound 17i) was found to show in vitro activity almost equal in po-
tency to that of 17h.
We also evaluated the antihyperglycemic effects of 6 and 17c–i
via OGTT in male ICR mice. Although no antihyperglycemic effects
of the parent compound 6 were observed at 3 mg/kg po, the 3,4-
dihalogenated (17d and 17e) and the 2,4,5-trihalogenated (17h
and 17i) phenyl derivatives all demonstrated clear effects at this
dose as a result of the improved in vitro agonistic activities.
As described above, modification of the phenyl moiety in the
pyridine N-oxide derivative 6 led to the identification of com-
pounds with potent in vitro and in vivo activities. However, these
compounds also showed CYP1A2 inhibitory activity (17h/17i:
17d
17e
17f
0.22
0.33
0.72
30
25
15
Br
F
450
430
Cl
Cl
Cl
F
17g
0.34
493
15
Br
F
F
17h
17i
0.11
0.21
588
536
23
27
Br
F
F
F
IC50 = 7.2/3.7 lM). We attributed this inhibition to a 4-amino
group8 and therefore considered replacing the pyridine N-oxide
structure of compounds 17d, 17e, 17h, and 17i, with the goal of
reducing the CYP1A2 inhibitory activity but preserving the potent
GPR119 agonistic activity.
Cl
a
Concentration of tested compounds equipotent to the efficacy of 5 at 10
human recombinant cell-based assays. See Section 5.
lM in
To this end, we introduced a 2-pyridone structure that mimics
pyridine N-oxide into the above compounds. As can be seen in Ta-
ble 2, the 2-(2-oxo-1,2-dihydropyridin-4-yl)ethylamino derivative
23a showed 10 times more potent activity than corresponding pyr-
idine N-oxide 17d. The 2,4,5-trihalogenated phenyl derivatives
23b–d further improved the agonistic activity of 23a, especially
compound 23c, which had the most potent activity and an EC value
in the nano molar range. Compounds 23a–d were evaluated for
their antihyperglycemic effects via OGTT. While we did not
observe significant effects for the 3,4-dihalogenated phenyl deriv-
ative 23a at 3 mg/kg po, the 2,4,5-trihalogenated phenyl deriva-
tives 23b–d all demonstrated antihyperglycemic effects at this
dose. These results indicated that the introduction of a fluoro group
onto the 2-position in the phenyl moiety is important for instilling
in vivo activity and may contribute to the improved PK profiles. In
b
Relative efficacy of tested compounds at 10
lM. See Section 5.
lM compared with efficacy of 5 at
10
c
Antihyperglycemic effects of tested compounds in male ICR mice at 3 mg/kg po.
See Section 5.
d
Not effective at 10 lM.
Not determined.
Not effective at 3 mg/kg po.
Not tested.
e
f
g
First, we carried out the optimization of substituents in the phe-
nyl moiety of compound 6 (Table 1). Preliminary conversion of the
bromo group in 6 indicated that the SARs information in the phenyl
moiety obtained by a previous study of lead compound 58 is appli-
cable to the pyridine N-oxide derivative 6. That is, removal of the
bromo group (compound 17a) resulted in a loss of activity,
whereas the chloro derivative 17b retained potent activity.
Me
2HCl
H2N
a, b, c
N
d
N+
N+
N
O
H2N
N
N
H
O
R1
15
16
17a-i
Scheme 3. Synthesis of compounds 17a–i. Reagents and conditions: (a) (Boc)2O, THF, rt; (b) m-CPBA, CHCl3, rt; (c) 4 M HCl/EtOAc, Et2O, rt; (d) 14a–i, K2CO3, DMI, 80 °C.

5238
K. Negoro et al. / Bioorg. Med. Chem. 20 (2012) 5235–5246
N
a, b
c, d
e
N
N
N
HO
NC
MeO2C
Cl
H2N
OMe
OMe
OMe
R2
18
19
20
21
R2
f
g
N
N
N
NH
N
N
H
N
N
OMe
O
R1
R1
H
22a-d
23a-d
Scheme 4. Synthesis of compounds 23a–d. Reagents and conditions: (a) NaOMe, dioxane, reflux; (b) LiAlH4, THF, 0 °C; (c) SOCl2, 0 °C; (d) KCN, 18-crown-6, MeCN, rt; (e)
1 atm H2, RaneyÒ-Ni, 28% aq NH3, EtOH, rt; (f) 14d, 14h, 14i or 14m, K2CO3, DMI, 80 °C; (g) 48% HBr, 80 °C.
to have potent agonistic activity with an EC value in the 10À7 molar
range. These results indicated that the ethyl group was more favor-
able than the methyl group as the substituent at the 6-position in
the pyrimidine ring for GPR119 agonistic activity. The 4-chloro-3-
fluorophenyl derivative 24e and the 2,4,5-trihalogenated phenyl
derivatives 24f and 24g showed potent GPR119 agonistic activities
R2
N
a
14d or 14j-m
*
N
N
OH
R1
H
OH
24a-g
with respective EC values of 0.39 lM, 0.22 lM, and 0.28 lM.
Scheme 5. Synthesis of compounds 24a–g. Reagents and conditions: (a) (S or R)-3-
amino-1,2-propanediol, i-Pr2NEt, MeCN, 70 °C.
We then evaluated the antihyperglycemic effects at a lower
dose of the five compounds 24c–g that showed potent agonistic
activities. Surprisingly, the 2,3-dihydroxypropylamino derivatives
24d, 24e, and 24g demonstrated excellent potency in vivo as as-
sessed via OGTT at 1 mg/kg po, and their activity was found to
be more potent than that of pyridine N-oxide derivatives despite
showing equipotent in vitro activity. From these observations, we
speculated that the improved PK profiles of 24d, 24e, and 24g
could result in potent in vivo activity compared with those of pyr-
idine N-oxide derivatives. On evaluation of the CYP1A2 inhibitory
activities of the compounds listed in Table 3, the 3,4-dihalogenated
phenyl derivatives 24b–e inhibited CYP1A2 with IC50 values in the
10À6 molar range. In contrast, the 2,4,5-trihalogenated phenyl
derivatives 24f and 24g were found to be 10- to 20 times less po-
tent than the 3,4-dihalogenated phenyl derivatives for CYP1A2
inhibitory activity. Examination of the in vitro metabolic stability
for the 2,3-dihydroxypropylamino derivatives 24d, 24e and 24g
found that the 3,4-dihalogenated phenyl derivatives 24d and 24e
were relatively unstable in human liver microsomes (168 and
236 mL/min/kg, respectively). Introducing a 2,4,5-trihalogenated
phenyl group (compound 24g), however, significantly improved
contrast, despite their potent in vitro activity, the 2-pyridone
derivatives 23a–d showed only moderate in vivo activity, compa-
rable to activity achieved with the pyridine N-oxide derivatives
17d, 17h, and 17i. We therefore speculated that 23a–d have rela-
tively poor PK profiles compared with 17d, 17h, and 17i.
We previously found that 4-(substituted)ethylamino deriva-
tives such as hydroxy, 1-oxidopyridyl and 2-oxo-1,2-dihydropyr-
idyl derivatives show potent GPR119 agonistic activity,8 implying
that some oxy functional group in this region could stimulate po-
tent GPR119 agonistic activity. Therefore, the introduction of a
1,2-diol structure to the 4-ethylamino group was examined (Ta-
ble 3). Compound 24a showed about 10-fold less activity than
17d. However, (R)-isomer 24b showed approximately two times
more potent activity than 24a, indicating that the (R)-configuration
of the 2,3-dihydroxypropylamino group demonstrated superior
GPR119 agonistic activity to the (S)-configuration. In addition,
the 6-ethyl derivatives 24c and 24d showed approximately
five-fold improved GPR119 agonistic activity over the 6-methyl
derivatives 24a and 24b, and (R)-isomer 24d in particular was found
Table 2
In vitro SARs and in vivo antihyperglycemic effects for 2-(2-oxo-1,2-dihydropyridin-4-yl)ethylamino derivatives
R
NH
N
O
N
N
H
Ar
c
Compound
Ar-
R-
GPR119/pCRE
OGTT (3 mg/kg po)
% Decrease
ECa
(l
M)
IAb (%)
617
F
23a
23b
Me-
Me-
0.021
0.017
10
23
Br
F
1077
Br
F
F
F
23c
23d
Me-
Et-
0.0069
0.013
722
578
21
25
Cl
a–c
See the corresponding footnotes to Table 1.

K. Negoro et al. / Bioorg. Med. Chem. 20 (2012) 5235–5246
5239
Table 3
In vitro SARs, in vivo antihyperglycemic effects and CYP1A2 inhibitory activities for 2,3-dihydroxypropylamino derivatives
R
N
*
OH
N
N
Ar
H
OH
Compound
Ar-
R-
Configuratione
GPR119/pCRE
M)
OGTT (1 mg/kg po)c
% Decrease
CYP 1A2
IC50 (lM)
ECa
(
l
IAb (%)
24a
24b
Me-
Me-
S
R
2.3
1.2
257
346
NTd
NTd
1.7
F
NTd
24c
24d
Et-
Et-
S
R
0.59
0.19
283
284
16
23
1.6
1.5
Br
F
24e
24f
24g
Et-
Et-
Et-
R
R
R
0.39
0.22
0.28
266
391
497
24
19
25
2.1
25
35
Cl
F
Br
F
F
F
Cl
a–b
c
See the corresponding footnotes to Table 1.
Antihyperglycemic effects of tested compounds in male ICR mice at 1 mg/kg po. See experimental section.
Not tested.
d
e
Configuration of the chiral 2,3-dihydroxypropylamino group.
Table 4
Pharmacokinetic data for compound 24g in mice and monkeys
Species
Mice
Route
Dose (mg/kg)
Tmax (h)
0.1
t1/2 (h)
Vdss (L/kg)
CLtot (mL/min/kg)
Bioavailability (%)
iv
po
1
3
2.2
6.9
35.9
86
51
Monkeys
iv
po
1
3
4.6
4.7
12.0
2.2
400
300
200
100
0
75
**
50
25
0
**
**
**
Vehicle
24g
Pioglitazone
Vehicle
24g
*
Pioglitazone
500
400
300
200
100
0
500
400
300
200
100
0
**
**
Vehicle
24g
Pioglitazone
Vehicle
24g
Pioglitazone
Figure 2. Effect of repeated administration in male kk/Ay mice (3 mg/kg po, 1 week once daily treatment, n = 8). Data are presented as the mean SE. ⁄p <0.05, ⁄⁄p <0.01
versus vehicle group, as determined using the Dunnett’s multiple comparison test.
the metabolic stability (<20 mL/min/kg). From these findings, we
speculated that the phenyl moiety at the 2-position in the pyrim-
idine ring played important roles in both the recognition and
metabolism of compounds by CYP enzymes, and lowering the elec-
tron density of this phenyl moiety contributed to the reduction in
CYP1A2 inhibitory activity and improvement of the metabolic sta-
bility of the given compounds. In addition, the improved in vitro
GPR119 agonistic activity and metabolic stability of compound
24g was considered to contribute to its potent antihyperglycemic
effect in vivo in the OGTT.

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K. Negoro et al. / Bioorg. Med. Chem. 20 (2012) 5235–5246
The PK profiles of compound 24g in mice and monkeys are shown
stirred at reflux temperature for 1.5 h and then cooled down to
room temperature. To the mixture was added 1,2-diaminoethane
(23 mL) and the mixture was poured into water (150 mL). The mix-
ture was extracted with ethyl acetate and the organic layer was
washed with 10 wt % 1,2-diaminoethane solution in water and
water, and then dried. The desiccant was removed by filtration
and the filtrate was evaporated in vacuo. The resulting residue
was purified by silica gel column chromatography (hexane–ethyl
acetate) to obtain 8 (16.54 g, 86%) as a pale yellow solid: 1H NMR
(DMSO-d6) d 6.36 (2H, s), 7.50 (2H, dd, J = 2.7, 6.7 Hz); EI-MS m/z
154 [(M)+].
in Table 4. This compound showed moderate total clearance, high
volume of distribution, good half-life after oral dosing, and excellent
oral bioavailability in both animals, and was therefore selected for
further in vivo studies using animal models of T2DM.
To evaluate the effects of chronic treatment with GPR119 agonist,
eight-week-old male diabetic kk/Ay mice were treated once daily at
3 mg/kg with compound 24g, pioglitazone and vehicle for a week.
After the treatment period, the blood glucose, plasma insulin, plas-
ma triglyceride (TG) and pancreatic insulin levels were measured
(Fig. 2). Compound 24g significantly reduced blood glucose, plasma
insulin and TG levels at potencies equal to or exceeding that of piog-
litazone. Further, unlike pioglitazone, compound 24g also improved
pancreatic insulin levels. These results demonstrate that novel
GPR119 agonist 24g not only effectively controls glucose and lipid
levels to a similar degree as pioglitazone, the compound also
preserves pancreatic b-cell function in diabetic kk/Ay mice.
5.3. 4-Bromo-3,5-difluorobenzonitrile (9g)
To concentrated sulfuric acid (25 mL) was added sodium nitrite
(3.20 g) portionwise at 5 °C, and the mixture was stirred at room
temperature for 0.5 h. The mixture was cooled down to 5 °C, and
then acetic acid (40 mL) was added dropwise to the mixture. The
mixture was stirred at 5 °C for 5 min. To the mixture was added
4-amino-3,5-difluorobenzonitrile (8, 6.50 g) portionwise, and then
the mixture was stirred at room temperature for 1 h. The mixture
was transferred into a dropping funnel, and was added dropwise
to a solution of copper(I) bromide (9.07 g) in 47 wt % hydrobromic
acid (25 mL) over 0.5 h. The mixture was stirred at room tempera-
ture for 13 h. Water (300 mL) was added to the mixture, and the
mixture was extracted with ethyl acetate. The organic layer was
washed with brine, and then dried. The desiccant was removed
by filtration and the filtrate was evaporated in vacuo. The resulting
residue was purified by silica gel column chromatography (hexane–
ethyl acetate) to obtain 9g (5.00 g, 54%) as a white solid: 1H NMR
(DMSO-d6) d 7.98 (2H, d, J = 6.3 Hz); EI-MS m/z 217, 219 [(M)+].
4. Conclusion
We optimized the 4-amino-2-phenylpyrimidine derivative 6 to
develop a novel and potent GPR119 agonist for use in treating
T2DM. Optimization of the substituents in the phenyl moiety of
compound 6 led to the identification of the 2,4,5-trihalogenated
phenyl derivatives and an approximately 10-fold improvement in
GPR119 agonistic activity. Subsequent replacement of the amino
group at the 4-position in the pyrimidine ring gave novel com-
pound 23c, which contains
a 2-(2-oxo-1,2-dihydropyridin-4-
yl)ethylamino group and possesses highly potent agonistic activity
with an EC value of 6.9 nM. Further replacement of the amino group
with a 2,3-dihydroxypropylamino group led to the identification of
(2R)-3-{[2-(4-chloro-2,5-difluorophenyl)-6-ethylpyrimidin-4-
yl]amino}propane-1,2-diol (24g) as an advanced analog. Com-
pound 24g was found to improve glucose tolerance at 1 mg/kg po
in mice, showed excellent PK profiles in mice and monkeys, and
improved blood glucose, plasma insulin, triglyceride levels and
pancreatic insulin content in diabetic kk/Ay mice after one week
of single daily treatment. These results suggest that novel GPR119
agonist 24g not only improves glucose tolerance through enhancing
GDIS, but also preserves pancreatic b-cell function. We therefore
propose that 24g represents a new type of antihyperglycemic agent
with promising potential for the effective treatment of T2DM.
5.4. 4-Bromo-2,5-difluorobenzoic acid (11a)
Under an argon atmosphere, to a solution of 1,4-dibromo-2,5-
difluorobenzene (10, 70.00 g) in diethyl ether (500 mL) was added
dropwise 1.58 M n-butyl lithium solution in hexane (171 mL) at
À78 °C, and the mixture was stirred at same temperature for
2 min. The mixture was added quickly to the mixture of dry ice
(about 300 g) and diethyl ether (600 mL), and the mixture was
warmed up to room temperature. The precipitate was collected
by filtration, and washed with diethyl ether. The obtained solid
was treated with water (100 mL) and 1 M hydrochloric acid
(500 mL), and extracted with diethyl ether. The organic layer
was washed with brine and dried. The desiccant was removed
by filtration and the filtrate was evaporated in vacuo. The
resulting residue was washed with hexane, dried in vacuo to
5. Experimental
5.1. Chemistry
obtain 11a (53.29 g, 83%) as
a
pale yellow solid: 1H NMR
1H NMR and 13C NMR spectra were recorded on a JEOL JNM-
LA300 or a JEOL JNM-EX400 spectrometer and were referenced to
an internal standard, tetramethylsilane. The abbreviations of 1H
NMR signal patterns are as follows: s, singlet; br, broad; d,
doublet; t, triplet; q, quartet; dd, double doublet; m, multiplet. Mass
spectra were recorded on a JEOL LX-2000, a Hitachi M-80 or a Waters
ZQ-2000 mass spectrometer. The elemental analyses were per-
formed with a Yanako MT-5 microanalyzer (C, H, N) and a Yokogawa
IC-7000S ion chromatographic analyzer (halogens). Where analyses
are indicated by symbols, the analytical results are within 0.4% of
the theoretical values. Drying of organic solutions during workup
was done over anhydrous MgSO4. Column chromatography was per-
formed with Wakogel C-200 or Merck silica gel 60.
(DMSO-d6) d 7.78 (1H, dd, J = 6.4, 8.3 Hz), 7.89 (1H, dd, J = 5.9,
9.8 Hz); FAB-MS m/z 235, 237 [(MÀH)À].
5.5. 4-Bromo-2,5-difluorobenzonitrile (9h)
A mixture of 4-bromo-2,5-difluorobenzoic acid (11a, 53.28 g),
thionyl chloride (165 mL) and DMF (0.87 mL) was stirred at 80 °C
for 1.5 h, and cooled down to room temperature. The mixture
was evaporated in vacuo, and the resulting residue was dissolved
in chloroform (300 mL). To the solution was added dropwise
28 wt % aqueous ammonia (300 mL) at 5 °C, and the mixture was
stirred at 5 °C for 0.5 h. The mixture was extracted with chloro-
form, and the organic layer was dried. The desiccant was removed
by filtration and the filtrate was evaporated in vacuo to obtain a
pale yellow solid. The mixture of the obtained solid and phos-
phoryl chloride (195 mL) was stirred at 80 °C for 2 h, and cooled
down to room temperature. The mixture was evaporated in vacuo,
and the resulting residue was treated with diethyl ether (500 mL)
5.2. 4-Amino-3,5-difluorobenzonitrile (8)
A
mixture suspension of 4-bromo-2,6-difluoroaniline (7,
25.85 g) and copper(I) cyanide (16.70 g) in NMP (60 mL) was

K. Negoro et al. / Bioorg. Med. Chem. 20 (2012) 5235–5246
5241
and ice-water (300 mL), then stirred at room temperature for 0.5 h.
5.13. 4-Bromo-2,5-difluorobenzamidine (12h)
The mixture was extracted with diethyl ether and the organic layer
was washed with saturated aqueous sodium hydrogen carbonate
and brine, and then dried. The desiccant was removed by filtration
and the filtrate was evaporated in vacuo to obtain 9h (41.57 g, 85%)
as a pale yellow solid: 1H NMR (DMSO-d6) d 8.15–8.25 (2H, m); EI-
MS m/z 217, 219 [(M)+].
Pale yellow solid (yield 47%); 1H NMR (DMSO-d6) d 5.80–7.20
(3H, br), 7.53 (1H, dd, J = 6.1, 9.0 Hz), 7.77 (1H, dd, J = 5.4,
9.3 Hz); EI-MS m/z 234, 236 [(M)+].
5.14. 4-Chloro-2,5-difluorobenzamidine (12i)
Pale yellow solid (yield 35%); 1H NMR (DMSO-d6) d 6.00–7.00
(3H, br), 7.58 (1H, dd, J = 6.1, 9.5 Hz), 7.69 (1H, dd, J = 6.1,
9.5 Hz); FAB-MS m/z 191, 193 [(M+H)+].
5.6. 4-Chloro-2,5-difluorobenzonitrile (9i)
This compound was prepared from commercially available 4-
chloro-2,5-difluorobenzoic acid 11b by a procedure similar to that
described for 9h.
5.15. 2-(4-Chlorophenyl)-6-methylpyrimidin-4-one (13b)
Light brown solid (yield 98%); 1H NMR (DMSO-d6) d 8.08 (1H,
dd, J = 6.3, 8.8 Hz), 8.25 (1H, dd, J = 5.6, 8.6 Hz); EI-MS m/z 173,
175 [(M)+].
To a solution of 4-chlorobenzamidine hydrochloride (12b,
1.12 g) in methanol (15 mL) were added sodium methoxide
(0.95 g) and methyl acetoacetate (0.73 g), and the reaction mixture
was stirred at room temperature for 5 days. To the mixture was
added 1 M hydrochloric acid (20 mL). The resulting precipitate
was collected by filtration, washed with water, and dried in vacuo
at 50 °C overnight to give 13b (0.72 g, 56%) as a white solid: 1H
5.7. 4-Chlorobenzamidine hydrochloride (12b)
Hydrogen chloride gas was passed through a solution of 4-chlo-
robenzonitrile (9b, 25.0 g) in chloroform (350 mL) and ethanol
(100 mL) at À78 °C for 0.5 h. Then the solution was warmed up
to room temperature, and stirred at room temperature overnight.
The solution was evaporated in vacuo, and the resulting residue
was dissolved with ethanol (500 mL). To the solution was added
ammonium carbonate (90.0 g), and the reaction mixture was stir-
red at room temperature for 3 days. To the mixture was added
water (300 mL), and ethanol was removed by concentration in va-
cuo. The resulting solid was collected by filtration, washed with
water and dried in vacuo to give 12b (25.4 g, 71%) as a white solid:
1H NMR (DMSO-d6) d 2.60–4.80 (2H, br), 7.53 (2H, d, J = 8.8 Hz),
7.81 (2H, d, J = 8.8 Hz), 7.50–9.50 (2H, br); FAB-MS m/z 155, 157
[(M+H)+].
NMR (DMSO-d6)
d 2.29 (3H, s), 6.26 (1H, s), 7.59 (2H, d,
J = 7.8 Hz), 8.14 (2H, d, J = 7.8 Hz), 12.40–12.90 (1H, br); FAB-MS
m/z 221, 223 [(M+H)+].
The following compounds (13c–m) were prepared by a proce-
dure similar to that described for 13b.
5.16. 2-(4-Bromo-2-fluorophenyl)-6-methylpyrimidin-4-one
(13c)
White solid (yield 83%); 1H NMR (DMSO-d6) d 2.25 (3H, s), 6.26
(1H, s), 7.57 (1H, dd, J = 1.8, 8.2 Hz), 7.67 (1H, t, J = 8.0 Hz), 7.75
(1H, dd, J = 1.8, 10.2 Hz); FAB-MS m/z 283, 285 [(M)+].
5.17. 2-(4-Bromo-3-fluorophenyl)-6-methylpyrimidin-4-one
(13d)
The following compounds (12c–i) were prepared by a proce-
dure similar to that described for 12b.
White solid (yield 92%); 1H NMR (DMSO-d6) d 2.31 (3H, s), 6.33
(1H, s), 7.86 (1H, dd, J = 7.3, 8.3 Hz), 7.95 (1H, dd, J = 2.0, 8.3 Hz),
8.07 (1H, dd, J = 2.0, 10.3 Hz); FAB-MS m/z 283, 285 [(M+H)+].
5.8. 4-Bromo-2-fluorobenzamidine (12c)
White solid (yield 48%); 1H NMR (DMSO-d6) d 3.17 (1H, s), 6.38
(2H, s), 7.40–7.55 (2H, m), 7.58 (1H, dd, J = 1.6, 10.0 Hz); FAB-MS
m/z 217,219 [(M)+].
5.18. 2-(4-Chloro-3-fluorophenyl)-6-methylpyrimidin-4-one
(13e)
White solid (yield 75%); 1H NMR (DMSO-d6) d 2.31 (3H, s), 6.32
(1H, s), 7.70–7.79 (1H, m), 7.99–8.07 (1H, m), 8.12 (1H, dd, J = 2.0,
10.3 Hz), 11.60–13.20 (1H, br); FAB-MS m/z 239, 241 [(M+H)+].
5.9. 4-Bromo-3-fluorobenzamidine (12d)
White solid (yield 60%); 1H NMR (DMSO-d6) d 6.00–7.00 (3H,
br), 7.60 (1H, dd, J = 1.5, 8.3 Hz), 7.70–7.80 (2H, m); EI-MS m/z
216, 218 [(M)+].
5.19. 2-(3,4-Dichlorophenyl)-6-methylpyrimidin-4-one (13f)
White solid (yield 55%); 1H NMR (CDCl3) d 2.40 (3H, s), 3.30–3.80
(1H, br), 6.32 (1H, s), 7.62 (1H, d, J = 8.3 Hz), 7.98 (1H, dd, J = 2.0,
8.3 Hz), 8.31 (1H, d, J = 2.0 Hz); FAB-MS m/z 255, 257 [(M+H)+].
5.10. 4-Chloro-3-fluorobenzamidine (12e)
Brown solid (yield 65%); 1H NMR (DMSO-d6) d 6.10–7.10 (3H,
br), 7.58–7.72 (2H, m), 7.79 (1H, dd, J = 2.0, 10.8 Hz); FAB-MS m/z
173, 175 [(M+H)+].
5.20. 2-(4-Bromo-3,5-difluorophenyl)-6-methylpyrimidin-4-
one (13g)
White solid (yield 88%); 1H NMR (DMSO-d6) d 2.33 (3H, s), 2.70–
4.50 (1H, br), 6.40 (1H, s), 7.97 (2H, d, J = 7.8 Hz); FAB-MS m/z 301,
303 [(M+H)+].
5.11. 3,4-Dichlorobenzamidine (12f)
White solid (yield 68%); 1H NMR (DMSO-d6) d 6.20–7.00 (3H,
br), 7.67 (1H, d, J = 8.8 Hz), 7.80 (1H, dd, J = 2.0, 8.8 Hz), 8.03 (1H,
d, J = 2.0 Hz); EI-MS m/z 188, 190 [(M)+].
5.21. 2-(4-Bromo-2,5-difluorophenyl)-6-methylpyrimidin-4-
one (13h)
5.12. 4-Bromo-3,5-difluorobenzamidine (12g)
Pale yellow solid (yield 97%); 1H NMR (DMSO-d6) d 2.27 (3H, s),
6.30 (1H, s), 7.76 (1H, dd, J = 5.9, 8.8 Hz), 7.94 (1H, dd, J = 5.6,
9.5 Hz), 12.20–13.10 (1H, br); FAB-MS m/z 301, 303 [(M)+].
Pale yellow solid (yield 98%); 1H NMR (DMSO-d6) d 6.20–6.90
(3H, br), 7.63–7.71 (2H, m); EI-MS m/z 234, 236 [(M)+].

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K. Negoro et al. / Bioorg. Med. Chem. 20 (2012) 5235–5246
5.22. 2-(4-Chloro-2,5-difluorophenyl)-6-methylpyrimidin-4-
one (13i)
5.30. 4-Chloro-2-(4-chloro-3-fluorophenyl)-6-methylpyr-
imidine (14e)
White solid (yield 91%); 1H NMR (DMSO-d6) d 2.27 (3H, s), 6.30
(1H, s), 7.81 (1H, dd, J = 6.4, 9.3 Hz), 7.86 (1H, dd, J = 6.1, 9.7 Hz),
12.10–13.20 (1H, br); FAB-MS m/z 257, 259 [(M+H)+].
Pale yellow solid (yield 104%); 1H NMR (DMSO-d6) d 2.56 (3H,
s), 7.61 (1H, s), 7.71–7.79 (1H, m), 8.11–8.18 (2H, m); FAB-MS m/
z 257, 259 [(M+H)+].
5.23. 2-(4-Bromo-3-fluorophenyl)-6-ethylpyrimidin-4-one (13j)
5.31. 4-Chloro-2-(3,4-dichlorophenyl)-6-methylpyrimidine (14f)
White solid (yield 91%); 1H NMR (DMSO-d6) d 1.21 (3H, t,
J = 7.9 Hz), 2.59 (2H, q, J = 7.9 Hz), 6.30 (1H, s), 7.82–7.91 (1H, m),
7.92–8.02 (1H, m), 8.09 (1H, dd, J = 1.7, 10.0 Hz), 11.90–13.00
(1H, br); FAB-MS m/z 297, 299 [(M+H)+].
White solid (yield 100%); 1H NMR (CDCl3) d 2.58 (3H, s), 7.13
(1H, s), 7.54 (1H, d, J = 8.3 Hz), 8.29 (1H, dd, J = 2.1, 8.3 Hz), 8.56
(1H, d, J = 2.1 Hz); FAB-MS m/z 273, 275 [(M+H)+].
5.32. 2-(4-Bromo-3,5-difluorophenyl)-4-chloro-6-
methylpyrimidine (14g)
5.24. 2-(4-Chloro-3-fluorophenyl)-6-ethylpyrimidin-4-one
(13k)
Pale yellow solid (yield 73%); 1H NMR (DMSO-d6) d 2.58 (3H, s),
7.68 (1H, s), 7.97–8.05 (2H, m); FAB-MS m/z 319, 321 [(M+H)+].
White solid (yield 107%); 1H NMR (DMSO-d6) d 1.21 (3H, t,
J = 7.5 Hz), 2.59 (2H, q, J = 7.5 Hz), 6.30 (1H, s), 7.70–7.80 (1H, m),
7.98–8.09 (1H, m), 8.14 (1H, dd, J = 2.0, 10.8 Hz), 11.70–13.10
(1H, br); FAB-MS m/z 253, 255 [(M+H)+].
5.33. 2-(4-Bromo-2,5-difluorophenyl)-4-chloro-6-methylpyr-
imidine (14h)
Pale yellow solid (yield 96%); 1H NMR (DMSO-d6) d 2.56 (3H, s),
7.67 (1H, s), 7.85–7.98 (2H, m); FAB-MS m/z 319, 321 [(M)+].
5.25. 2-(4-Bromo-2,5-difluorophenyl)-6-ethylpyrimidin-4-one
(13l)
Pale yellow solid (yield 82%); 1H NMR (DMSO-d6) d 1.18 (3H, t,
J = 7.6 Hz), 2.54 (2H, q, J = 7.6 Hz), 6.28 (1H, s), 7.77 (1H, d, J = 6.3,
8.8 Hz), 7.94 (1H, dd, J = 5.6, 9.5 Hz), 12.20–13.10 (1H, br); FAB-
MS m/z 315, 317 [(M)+].
5.34. 4-Chloro-2-(4-chloro-2,5-difluorophenyl)-6-methylpyr-
imidine (14i)
Pale yellow solid (yield 100%); 1H NMR (DMSO-d6) d 2.56 (3H,
s), 7.68 (1H, s), 7.74–7.89 (1H, m), 7.90–8.04 (1H, m); FAB-MS
m/z 275, 277 [(M)+].
5.26. 2-(4-Chloro-2,5-difluorophenyl)-6-ethylpyrimidin-4-one
(13m)
5.35. 2-(4-Bromo-3-fluorophenyl)-4-chloro-6-ethylpyrimidine
(14j)
Light brown solid (yield 67%); 1H NMR (DMSO-d6) d 1.18 (3H, t,
J = 7.6 Hz), 2.55 (2H, q, J = 7.6 Hz), 6.28 (1H, s), 7.82 (1H, d, J = 6.4,
9.3 Hz), 7.85 (1H, dd, J = 5.9, 9.8 Hz), 12.30–13.20 (1H, br); FAB-
MS m/z 271, 273 [(M+H)+].
Light brown solid (yield 103%); 1H NMR (DMSO-d6) d 1.30 (3H, t,
J = 7.6 Hz), 2.84 (2H, q, J = 7.6 Hz), 7.60 (1H, s), 7.87 (1H, dd, J = 7.3,
8.5 Hz), 8.04–8.14 (2H, m); FAB-MS m/z 315, 317 [(M+H)+].
5.27. 4-Chloro-2-(4-chlorophenyl)-6-methylpyrimidine (14b)
5.36. 4-Chloro-2-(4-chloro-3-fluorophenyl)-6-ethylpyrimidine
(14k)
A
mixture of 2-(4-chlorophenyl)-6-methylpyrimidin-4-one
Brown solid (yield 106%); 1H NMR NMR (DMSO-d6) d 1.30 (3H, t,
J = 7.6 Hz), 2.83 (2H, q, J = 7.6 Hz), 7.57 (1H, s), 7.66–7.75 (1H, m),
8.06–8.15 (2H, m); FAB-MS m/z 271, 273 [(M+H)+].
(13b, 0.71 g) and phosphorus oxychloride (10 mL) was stirred
at 80 °C for 2.5 h. The mixture was cooled down to room tem-
perature, and evaporated in vacuo. To the resulting residue
was added water, and the solid was collected by filtration,
washed with water and dried in vacuo to give 14b (0.81 g,
105%) as a white solid: 1H NMR (CDCl3) d 2.57 (3H, s), 7.11
(1H, s), 7.44 (2H, d, J = 8.8 Hz), 8.40 (2H, d, J = 8.8 Hz); FAB-MS
m/z 239, 241 [(M+H)+].
5.37. 2-(4-Bromo-2,5-difluorophenyl)-4-chloro-6-
ethylpyrimidine (14l)
Pale yellow oil (yield 99%); 1H NMR (DMSO-d6) d 1.29 (3H, t,
J = 7.5 Hz), 2.84 (2H, q, J = 7.5 Hz), 7.65 (1H, s), 7.87 (1H, d, J = 5.7,
10.1 Hz), 7.92 (1H, dd, J = 6.3, 9.3 Hz); FAB-MS m/z 333, 335 [(M)+].
The following compounds (14c–m) were prepared by a proce-
dure similar to that described for 14b.
5.28. 2-(4-Bromo-2-fluorophenyl)-4-chloro-6-methylpyr-
imidine (14c)
5.38. 4-Chloro-2-(4-chloro-2,5-difluorophenyl)-6-
ethylpyrimidine (14m)
White solid (yield 99%); 1H NMR (DMSO-d6) d 2.55 (3H, s), 7.59
(1H, d, J = 8.4 Hz), 7.64 (1H, s), 7.72 (1H, d, J = 10.8 Hz), 7.98 (1H, t,
J = 8.4 Hz); FAB-MS m/z 301, 303 [(M)+].
Dark brown oil (yield 97%); 1H NMR (DMSO-d6) d 1.28 (3H, t,
J = 7.5 Hz), 2.84 (2H, q, J = 7.5 Hz), 7.66 (1H, s), 7.80 (1H, d,
J = 6.1, 10.0 Hz), 7.98 (1H, dd, J = 6.9, 9.8 Hz); FAB-MS m/z 289,
291 [(M)+].
5.29. 2-(4-Bromo-3-fluorophenyl)-4-chloro-6-methylpyr-
imidine (14d)
5.39. 2-(1-oxidopyridin-3-yl)ethylamine hydrochloride (16)
Pale yellow solid (yield 111%); 1H NMR (DMSO-d6) d 2.55 (3H,
s), 7.60 (1H, s), 7.85 (1H, dd, J = 7.4, 8.6 Hz), 8.02–8.11 (2H, m);
FAB-MS m/z 301, 303 [(M+H)+].
To a solution of 2-(3-pyridyl)ethylamine (15, 50.22 g) in THF
(500 mL) was added di-tert-butyl dicarbonate (94.20 g) portion-
wise at 5 °C, and then the mixture was stirred at room temperature

K. Negoro et al. / Bioorg. Med. Chem. 20 (2012) 5235–5246
5243
for 3 h. The mixture was diluted with ethyl acetate, and then water
5.43. 2-(4-Bromo-3-fluorophenyl)-6-methyl-N-[2-(1-
and 1 M aqueous sodium hydroxide were added. The mixture was
extracted with ethyl acetate, and the organic layer was washed
with brine and dried. The desiccant was removed by filtration
and the filtrate was evaporated in vacuo to obtain a pale yellow
oil. The obtained oil was dissolved in chloroform (1000 mL) and
to the solution was added m-CPBA (about 65% purity, 111.47 g),
and the mixture was stirred at room temperature for 2.5 h. To
the reaction mixture were added a solution of sodium thiosulfate
(20.00 g) in water (100 mL) and 1 M aqueous sodium hydroxide
(600 mL), and extracted with a mixture of chloroform and 2-propa-
nol. The organic layer was dried and the desiccant was removed by
filtration, and then the solvent was evaporated in vacuo. The
resulting residue was dissolved with diethyl ether (500 mL), and
to the solution was added 4 M hydrochloride solution in ethyl ace-
tate (500 mL) at 5 °C. Then the mixture was stirred at room tem-
perature for 8 h. The precipitate was collected by filtration, and
dried in vacuo to obtain 16 (76.82 g, 89%) as a white solid: 1H
NMR (DMSO-d6) d 3.00–3.24 (4H, m), 7.72–7.83 (1H, m), 7.88–
7.98 (1H, m), 8.10–8.50 (3H, m), 8.60–8.70 (1H, m), 8.74 (1H, s),
9.50–11.50 (1H, br); FAB-MS m/z 139 [(M+H)+].
oxidopyridin-3-yl)ethyl]pyrimidin-4-amine oxalate (17d)
White solid (yield 56%); 1H NMR (DMSO-d6) d 2.35–2.56 (5H,
m), 2.80–3.00 (2H, m), 3.40–4.00 (2H, m), 6.51 (1H, s), 7.30–7.45
(2H, m), 7.94 (1H, t, J = 7.6 Hz), 8.00–8.19 (2H, m), 8.20–8.38 (2H,
m), 8.50–9.20 (1H, br); FAB-MS m/z 403, 405 [(M+H)+]. Anal.
(C18H16N4OBrFÁ1.5C2H2O4): C, H, N, Br, F.
5.44. 2-(4-Chloro-3-fluorophenyl)-6-methyl-N-[2-(1-oxido-
pyridin-3-yl)ethyl]pyrimidin-4-amine hydrochloride (17e)
Pale yellow solid (yield 52%); 1H NMR (DMSO-d6) d 2.45–2.60
(5H, m), 2.95–3.10 (2H, m), 3.80–4.00 (2H, m), 6.64 (1H, s), 7.62
(1H, t, J = 7.1 Hz), 7.70–7.83 (1H, m), 7.83–7.93 (1H, m), 8.21 (1H,
d, J = 7.9 Hz), 8.37–8.51 (2H, m), 8.63 (1H, s), 9.50–10.00 (1H, br);
FAB-MS
m/z
359,
361
[(M+H)+].
Anal.
(C18H16N4OClFÁ2HClÁ0.25H2O): C, H, N, Cl, F.
5.45. 2-(3,4-Dichlorophenyl)-6-methyl-N-[2-(1-oxidopyridin-3-
yl)ethyl]pyrimidin-4-amine oxalate (17f)
White solid (yield 76%); 1H NMR (DMSO-d6) d 2.30 (3H, s), 2.87
(2H, t, J = 6.6 Hz), 3.50–4.00 (2H, m), 6.30 (1H, s), 7.27 (1H, d,
J = 7.8 Hz), 7.33 (1H, t, J = 7.1 Hz), 7.50–7.68 (1H, br), 7.74 (1H, d,
J = 8.4 Hz), 8.07 (1H, d, J = 6.3 Hz), 8.19 (1H, s), 8.25 (1H, d,
J = 8.4 Hz), 8.44 (1H, d, J = 2.0 Hz); FAB-MS m/z 341, 343
[(M+H)+]. Anal. (C18H16N4OCl2Á1.7C2H2O4): C, H, N, Cl.
5.40. 6-Methyl-N-[2-(1-oxidopyridin-3-yl)ethyl]-2-
phenylpyrimidin-4-amine oxalate (17a)
To a solution of 4-chloro-6-methyl-2-phenylpyrimidine (14a,
160 mg) in DMI (5 mL) were added 2-(1-oxidopyridin-3-yl)ethyl-
amine hydrochloride (16, 480 mg) and potassium carbonate
(540 mg), and the mixture was stirred at 80 °C for 24 h. The
reaction mixture was cooled down to room temperature and
treated with water, then extracted with ethyl acetate. The organ-
ic layer was washed with brine, dried, filtered, and then the sol-
vent was evaporated in vacuo. The resulting residue was purified
by silica gel column chromatography (chloroform–methanol).
The obtained solid (90 mg) was treated with ethanol (5 mL)
and oxalic acid (53 mg), and the mixture was evaporated in va-
cuo and the resulting residue was washed with diethyl ether to
give 17a (70 mg, 19%) as a white solid: 1H NMR (DMSO-d6) d
2.31 (3H, s), 2.88 (2H, t, J = 6.6 Hz), 3.50–4.00 (2H, m), 6.30
(1H, s), 7.20–7.30 (1H, m), 7.30–7.40 (1H, m), 7.40–7.55 (3H,
m), 7.55–7.75 (1H, br), 8.07 (1H, d, J = 5.8 Hz), 8.19 (1H, s),
8.24–8.35 (2H, m); FAB-MS m/z 307 [(M)+]. Anal. (C18H18N4OÁ1.8-
C2H2O4Á0.4H2O): C, H, N, Br, F.
5.46. 2-(4-Bromo-3,5-difluorophenyl)-6-methyl-N-[2-(1-
oxidopyridin-3-yl)ethyl]pyrimidin-4-amine oxalate (17g)
Pale yellow solid (yield 69%); 1H NMR (DMSO-d6) d 2.29 (3H, s),
2.87 (2H, t, J = 6.6 Hz), 3.30–4.00 (3H, m), 6.32 (1H, s), 7.24–7.40
(2H, m), 7.50–7.70 (1H, br), 7.92–8.13 (3H, m), 8.21 (1H, s); FAB-
MS m/z 421, 423 [(M+H)+]. Anal. (C18H15N4OBrF2Á1.5-
C2H2O4Á0.3C2H5O): C, H, N, Br, F.
5.47. 2-(4-Bromo-2,5-difluorophenyl)-6-methyl-N-[2-(1-
oxidopyridin-3-yl)ethyl]pyrimidin-4-amine oxalate (17h)
White solid (yield 50%); 1H NMR NMR (DMSO-d6) d 2.28 (3H, s),
2.85 (2H, t, J = 6.8 Hz), 3.00–5.50 (3H, m), 6.31 (1H, s), 7.15–7.28
(1H, m), 7.28–7.38 (1H, m), 7.61 (1H, s), 7.80 (1H, dd, J = 5.9,
9.8 Hz), 7.81–8.00 (1H, br), 8.07 (1H, d, J = 6.4 Hz), 8.15 (1H, s);
FAB-MS m/z 421, 423 [(M+H)+]. Anal. (C18H15N4OBrF2ÁC2H2O4): C,
H, N, Br, F.
The following compounds (17b–i) were prepared by a proce-
dure similar to that described for 17a.
5.41. 2-(4-Chlorophenyl)-6-methyl-N-[2-(1-oxidopyridin-3-
yl)ethyl]pyrimidin-4-amine oxalate (17b)
5.48. 2-(4-Chloro-2,5-difluorophenyl)-6-methyl-N-[2-(1-
oxidopyridin-3-yl)ethyl]pyrimidin-4-amine oxalate (17i)
White solid (yield 63%); 1H NMR (DMSO-d6) d 2.29 (3H, s),
2.87 (2H, t, J = 6.9 Hz), 3.00–4.50 (2H, m), 6.29 (1H, s), 7.26
(1H, d, J = 7.8 Hz), 7.33 (1H, t, J = 7.1 Hz), 7.45–7.70 (3H, m),
8.06 (1H, d, J = 6.4 Hz), 8.19 (1H, s), 8.31 (2H, d, J = 8.3 Hz);
FAB-MS m/z 341, 343 [(M+H)+]. Anal. (C18H17N4OClÁ1.5-
C2H2O4ÁH2O): C, H, N, Cl.
Pale yellow solid (yield 28%); 1H NMR (DMSO-d6) d 2.28 (3H, s),
2.85 (2H, t, J = 6.8 Hz), 3.40–3.70 (2H, m), 6.31 (1H, s), 7.15–7.28
(1H, m), 7.29–7.37 (1H, m), 7.52–7.66 (1H, m), 7.71 (1H, dd,
J = 6.4, 10.3 Hz), 7.82–8.00 (1H, m), 8.08 (1H, d, J = 6.4 Hz), 8.10–
8.25 (1H, br); FAB-MS m/z 377, 379 [(M+H)+]. Anal.
(C18H15N4OClF2ÁC2H2O4): C, H, N, Cl, F.
5.42. 2-(4-Bromo-2-fluorophenyl)-6-methyl-N-[2-(1-
oxidopyridin-3-yl)ethyl]pyrimidin-4-amine oxalate (17c)
5.49. (2-Methoxypyridin-4-yl)methanol (19)
To methyl 2-chloroisonicotinate (18, 53.63 g) were added diox-
ane (150 mL) and sodium methoxide (25.32 g), and the mixture
was stirred at reflux temperature for 26 h and then cooled down
to room temperature. To the mixture was added acetic acid
(28 mL), and the mixture was evaporated in vacuo. To the resulting
residue were added ethyl acetate and water, and the mixture was
extracted with ethyl acetate. The organic layer was washed with
Colorless crystal (yield 32%); 1H NMR NMR (DMSO-d6) d 2.27
(3H, s), 2.85 (2H, t, J = 6.9 Hz), 3.00–4.50 (1H, m), 6.30 (1H, s),
7.15–7.26 (1H, m), 7.32 (1H, dd, J = 6.5, 7.5 Hz), 7.46–7.54 (1H,
m), 7.53–7.60 (1H, m), 7.61 (1H, dd, J = 1.9, 10.5 Hz), 7.78–7.96
(1H, m), 8.02–8.09 (1H, m), 8.09–8.23 (1H, br); FAB-MS m/z 403,
405 [(M)+]. Anal. (C18H16N4OBrFÁC2H2O4): C, H, N, Br, F.

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K. Negoro et al. / Bioorg. Med. Chem. 20 (2012) 5235–5246
water and brine, dried, filtered, and the filtrate was evaporated in
vacuo. The resulting residue was dissolved in THF (300 mL). Under
an argon atmosphere, the solution was added dropwise to a sus-
pension of lithium aluminum hydride (11.88 g) in THF (500 mL)
at 0 °C over 1 h. Then the reaction mixture was stirred at 0 °C for
2 h. To the mixture was added water (30 mL) dropwise at 0 °C,
and then THF (270 mL) was added. The mixture was filtered over
celite, and the filtrate was evaporated in vacuo to obtain 19
(33.55 g, 75%) as a orange oil: 1H NMR (DMSO-d6) d 3.83 (3H, s),
4.49 (2H, d, J = 5.3 Hz), 4.70 (1H, t, J = 5.3 Hz), 6.73 (1H, s), 6.90
(1H, d, J = 5.4 Hz), 8.07 (1H, d, J = 5.4 Hz); EI-MS m/z 139 [(M)+].
5.54. 2-(4-Chloro-2,5-difluorophenyl)-N-[2-(2-methoxypyridin-
4-yl)ethyl]-6-methylpyrimidin-4-amine (22c)
This compound was synthesized from 14i and 21, and used to
next reaction without purification by silica gel column
chromatography.
5.55. 2-(4-Chloro-2,5-difluorophenyl)-6-ethyl-N-[2-(2-
methoxypyridin-4-yl)ethyl]pyrimidin-4-amine (22d)
This compound was synthesized from 14m and 21, and used to
next reaction without purification by silica gel column
chromatography.
5.50. (2-Methoxypyridin-4-yl)acetonitrile (20)
5.56. 4-(2-{[2-(4-Bromo-3-fluorophenyl)-6-methylpyrimidin-4-
yl]amino}ethyl)pyridin-2(1H)-one (23a)
Thionyl chloride (170 mL) was added dropwise to (2-methoxy-
pyridin-4-yl)methanol (19, 34.53 g) at 0 °C over 15 min. The mixture
was stirred at 0 °C for 2 h and evaporated in vacuo. The residue was
dissolved in chloroform (400 mL) and treated with sat. aqueous so-
dium hydrogen carbonate (500 mL). The mixture was extracted with
chloroform. The organic layer was dried, filtered, and the filtrate was
evaporated in vacuo. To the residue were added acetonitrile
(700 mL), potassium cyanide (30.00 g) and 18-crown-6 ether
(61.03 g), and the reaction mixture was stirred at room temperature
for 13 h. The mixture was evaporated in vacuo, and to the residue
was added water (300 mL). The mixture was extracted with ethyl
acetate, and the organic layer was washed with brine, dried, filtered,
and the filtrate was evaporated in vacuo. The resulting residue was
purified by silica gel column chromatography (hexane–ethyl ace-
tate) to obtain 20 (12.12 g, 33%) as a pale yellow solid: 1H NMR
NMR (DMSO-d6) d 3.86 (3H, s), 4.09 (2H, s), 6.79 (1H, s), 6.97 (1H,
d, J = 5.4 Hz), 8.18 (1H, d, J = 5.4 Hz); FAB-MS m/z 149 [(M+H)+].
A
mixture of 2-(4-bromo-3-fluorophenyl)-N-[2-(6-methoxy-
pyridin-2-yl)ethyl]-6-methylpyrimidin-4-amine (22a, 206 mg)
and 48 wt % hydrobromic acid (2.0 mL) was stirred at 80 °C for
3 days. The mixture was cooled down to room temperature and
treated with saturated aqueous sodium hydrogen carbonate and
ethyl acetate. The organic layer was dried, filtered and evaporated
in vacuo. The resulting residue was washed with diethyl ether and
dried in vacuo to obtain 23a (82 mg, 41%) as a white solid: 1H NMR
(DMSO-d6) d 2.29 (3H, s), 2.70 (2H, t, J = 6.9 Hz), 3.50–3.80 (2H, m),
6.12 (1H, dd, J = 1.5, 6.9 Hz), 6.18 (1H, s), 6.30 (1H, s), 7.27 (1H, d,
J = 6.3 Hz), 7.36–7.52 (1H, br), 7.74–7.85 (1H, m), 8.00–8.20 (2H,
m), 11.10–11.50 (1H, br); ESI-MS m/z 403, 405 [(M+H)+]. Anal.
(C18H16N4OBrFÁ0.35H2O): C, H, N, Br, F.
The following compounds (23b–d) were prepared by a proce-
dure similar to that described for 23a.
5.51. 2-(2-Methoxypyridin-4-yl)ethylamine (21)
5.57. 4-(2-{[2-(4-Bromo-2,5-difluorophenyl)-6-
methylpyrimidin-4-yl]amino}ethyl)pyridin-2(1H)-one
hydrochloride (23b)
A mixture of (2-methoxypyridin-4-yl)acetonitrile (20, 12.12 g),
ethanol (100 mL), 28 wt % aqueous ammonia (25 mL) and Ra-
neyÒ-nickel (25 mL) was stirred at room temperature under hydro-
gen atmosphere for 22 h. The mixture was filtered over celite, and
the filtrate was evaporated in vacuo to obtain 21 (12.73 g, 102%) as
a brown oil.: 1H NMR (DMSO-d6) d 2.10–3.75 (6H, m), 3.82 (3H, s),
6.65 (1H, s), 6.84 (1H, d, J = 5.4 Hz), 8.04 (1H, d, J = 5.4 Hz); EI-MS
m/z 152 [(M)+].
White solid (yield 39% from 14h); 1H NMR (DMSO-d6) d 2.52 (3H,
s), 2.87 (2H, t, J = 6.6 Hz), 3.76–3.95 (2H, m), 5.00–7.50 (2H, m), 6.53
(1H, d, J = 6.4 Hz), 6.56 (1H, s), 6.66 (1H, s), 7.55 (1H, d, J = 6.4 Hz),
8.24–8.35 (2H, m), 9.60–9.90 (1H, br); FAB-MS m/z 421, 423
[(M+H)+]. Anal. (C18H15N4OBrF2Á1.8HClÁ0.5H2O): C, H, N, Br, Cl, F.
5.58. 4-(2-{[2-(4-Chloro-2,5-difluorophenyl)-6-
methylpyrimidin-4-yl]amino}ethyl)pyridin-2(1H)-one
hydrochloride (23c)
5.52. 2-(4-Bromo-3-fluorophenyl)-N-[2-(6-methoxypyridin-2-
yl)ethyl]-6-methylpyrimidin-4-amine (22a)
White solid (yield 58% from 14i); 1H NMR (DMSO-d6) d 2.46
(3H, s), 2.72–2.87 (2H, m), 3.50–3.80 (2H, m), 6.20–6.60 (2H, m),
6.68 (1H, s), 7.30–7.60 (1H, m), 7.90–8.10 (2H, m), 9.40–10.00
A mixture of 2-(4-bromo-3-fluorophenyl)-4-chloro-6-methyl-
pyrimidine (14d, 198 mg), DMI (2 mL), potassium carbonate
(454 mg) and 2-(6-methoxypyridin-2-yl)ethylamine (21, 200 mg)
was stirred at 95 °C overnight. The mixture was cooled down to
room temperature, and water was added to the mixture. The mix-
ture was extracted with toluene and the organic layer was dried,
filtered and evaporated in vacuo to obtain 22a (220 mg, 80%) as a
yellow oil: 1H NMR (DMSO-d6) d 2.28 (3H, s), 2.87 (2H, t,
J = 6.8 Hz), 3.50–3.75 (2H, m), 3.81 (3H, s), 6.30 (1H, s), 6.72 (1H,
s), 6.90 (1H, d, J = 5.3 Hz), 7.49 (1H, s), 7.74–7.85 (1H, m), 7.98–
8.20 (3H, m); FAB-MS m/z 417, 419 [(M+H)+].
(2H, m); FAB-MS m/z 377, 379 [(M+H)+]. Anal. (C18H15
N4OClF2Á2HClÁ0.25H2O): C, H, N, Cl, F.
-
5.59. 4-(2-{[2-(4-Chloro-2,5-difluorophenyl)-6-ethylpyrimidin-
4-yl]amino}ethyl)pyridin-2(1H)-one hydrochloride (23d)
Pale yellow solid (yield 78% from 14m); 1H NMR (DMSO-d6) d
1.24 (3H, t, J = 7.5 Hz), 2.70–2.87 (4H, m), 3.50–3.90 (2H, m),
6.20–6.60 (2H, m), 6.69 (1H, s), 7.35–7.55 (1H, m), 7.90–8.10 (2H,
m), 9.40–10.00 (2H, m); FAB-MS m/z 391, 393 [(M+H)+]. Anal.
(C19H17N4OClF2Á2HClÁH2O): C, H, N, Cl, F.
The following compounds (22b–d) were prepared by a proce-
dure similar to that described for 22a.
5.53. 2-(4-Bromo-2,5-difluorophenyl)-N-[2-(2-methoxypyridin-
5.60. (2S)-3-{[2-(4-Bromo-3-fluorophenyl)-6-methylpyrimidin-
4-yl)ethyl]-6-methylpyrimidin-4-amine (22b)
4-yl]amino}propane-1,2-diol oxalate (24a)
This compound was synthesized from 14h and 21, and used to
next reaction without purification by silica gel column
chromatography.
A mixture of 2-(4-bromo-3-fluorophenyl)-4-chloro-6-methyl-
pyrimidine (14d, 241 mg), (S)-3-amino-1,2-propanediol (366 mg),

K. Negoro et al. / Bioorg. Med. Chem. 20 (2012) 5235–5246
5245
N,N-diisopropylethylamine (0.14 mL) and acetonitrile (4 mL) was
stirred at 70 °C for 4 days. The reaction mixture was cooled down
to room temperature. To the mixture was added water, and ex-
tracted with chloroform. The organic layer was dried, and the desic-
cant was removed by filtration, and then the solvent was evaporated
in vacuo. The resulting residue was dissolved in ethanol (5 mL), and
to the solution was added oxalic acid (108 mg). The mixture was
evaporated in vacuo and the residue was recrystallized from aceto-
nitrile and ethanol, and the crystal was dried in vacuo to obtain 24a
(228 mg, 64%) as a colorless crystal: 1H NMR (DMSO-d6) d 2.29 (3H,
s), 3.20–3.75 (5H, m), 4.00–7.00 (4H, m), 6.38 (1H, s), 7.30–7.55 (1H,
br), 7.60–7.95 (1H, m), 8.00–8.22 (2H, m); FAB-MS m/z 356, 358
[(M+H)+]. Anal. (C14H15N3O2BrFÁ1.5C2H2O4): C, H, N, Br, F.
6.30 (3H, br), 6.40 (1H, s), 7.00–7.68 (1H, br), 7.71 (1H, dd, J = 6.1,
10.0 Hz), 7.80–8.05 (1H, m); 13C NMR (DMSO-d6) d 17.05, 30.75,
51.21, 57.67, 76.45, 105.49, 105.74, 106.31, 106.60, 139.63, 142.05,
146.66, 148.52, 152.02, 168.39, 183.80, 191.34; FAB-MS m/z 344,
346 [(M+H)+]. Anal. (C15H16N3O2ClF2ÁC2H2O4): C, H, N, Cl, F.
5.67. Human GPR119 cAMP reporter assay
Human GPR119 agonist activity was evaluated in HEK293 cells
stably expressing human GPR119 and pCRE-Luc. HEK293-hGPR119
cells were seeded in 96-well plates at 2.5 Â 104 cells/well, incu-
bated overnight at 37 °C in 5% CO2, and then exposed to the test
compound dissolved in DMSO at concentrations ranging from
The following compounds (24b–g) were prepared by a proce-
dure similar to that described for 24a.
0.01 to 10 lM. After 6 h incubation, cells were harvested using
0.2% Triton X-100 in phosphate-buffered saline (pH 7.4). Luciferase
activity was measured using a model ML-3000 Luminometer (Dy-
nex Tech, VA, USA). Three replicates for each concentration were
performed.
5.61. (2R)-3-{[2-(4-Bromo-3-fluorophenyl)-6-methylpyrimidin-
4-yl]amino}propane-1,2-diol oxalate (24b)
Colorless crystal (yield 41% from 14d); 1H NMR (DMSO-d6) d
2.29 (3H, s), 2.70–3.50 (3H, m), 3.50–3.80 (2H, m), 3.80–6.00 (3H,
m), 6.38 (1H, s), 7.00–7.60 (1H, br), 7.75–7.85 (1H, m), 8.09 (1H,
d, J = 8.3 Hz), 8.15 (1H, d, J = 10.3 Hz); FAB-MS m/z 356, 358
[(M+H)+]. Anal. (C14H15N3O2BrFÁC2H2O4Á0.25H2O): C, H, N, Br, F.
5.68. Oral glucose tolerance test (OGTT)
Eight-week-old male ICR mice were fasted overnight and then
orally administered 0.5% methyl-cellulose (vehicle) or 1–3 mg/kg
test compounds. After 10 min, glucose was given orally at a dose
of 2 g/kg/10 mL, and blood sample were collected from tail veins
after 30 min. Blood glucose levels were determined using the Glu-
cose CII test (Wako, Osaka, Japan).
5.62. (2S)-3-{[2-(4-Bromo-3-fluorophenyl)-6-ethylpyrimidin-4-
yl]amino}propane-1,2-diol oxalate (24c)
Colorless crystal (yield 61% from 14j); 1H NMR (DMSO-d6) d
1.21 (3H, t, J = 7.4 Hz), 2.57 (2H, q, J = 7.4 Hz), 2.70–3.50 (3H, m),
3.50–3.90 (2H, m), 3.90–6.00 (2H, br), 6.39 (1H, s), 7.00–7.70
(1H, br), 7.75–7.88 (1H, m), 8.00–8.25 (2H, m); FAB-MS m/z 370,
372 [(M)+]. Anal. (C15H17N3O2BrFÁC2H2O4Á0.25H2O): C, H, N, Br, F.
5.69. Efficacy of repeated administration in male kk/Ay mice
Male kk/Ay mice were purchased from Japan CLEA Inc. (Kanag-
awa, Japan). Eight-week-old male kk/Ay mice (n = 8) were orally
administered 0.5% methyl-cellulose (vehicle), 3 mg/kg compound
24g or 3 mg/kg Pioglitazone hydrochloride once daily for a week.
Blood samples were collected from tail veins under feeding condi-
tions for the measurement of blood glucose, insulin, and triglycer-
ide (TG) levels. Pancreatic tissue samples were also collected,
weighed, homogenized, extracted with 2 mL acid–ethanol solution
(concentrated HCl: ethanol: distilled H2O = 1.5: 75: 23.5), centri-
fuged for 10 min at 3000 g, and the insulin concentration in the
supernatant was then determined. Blood glucose levels were
determined using the Glucose CII test (Wako, Osaka, Japan). Plasma
triglyceride level was determined using the Triglyceride E-test
(Wako). Data are expressed as the mean SE. Significant differ-
ences between two groups and multiple groups were determined
using the Dunnett’s multiple comparison test. A value of p <0.05
was considered to represent statistical significance. All statistical
analyses were performed using the SAS 8.2 software package
(SAS Institute Japan, Ltd, Tokyo, Japan).
5.63. (2R)-3-{[2-(4-Bromo-3-fluorophenyl)-6-ethylpyrimidin-4-
yl]amino}propane-1,2-diol oxalate (24d)
Colorless crystal (yield 62% from 14j); 1H NMR (DMSO-d6) d
1.22 (3H, t, J = 7.4 Hz), 2.58 (2H, q, J = 7.4 Hz), 2.70–3.50 (3H, m),
3.50–3.90 (2H, m), 4.50–6.35 (2H, br), 6.40 (1H, s), 7.00–7.70
(1H, br), 7.75–7.88 (1H, m), 8.00–8.25 (2H, m); FAB-MS m/z 370,
372 [(M)+]. Anal. (C15H17N3O2BrFÁC2H2O4Á0.25H2O): C, H, N, Br, F.
5.64. (2R)-3-{[2-(4-Chloro-3-fluorophenyl)-6-ethylpyrimidin-4-
yl]amino}propane-1,2-diol oxalate (24e)
Colorless crystal (yield 64% from 14k); 1.22 (3H, t, J = 7.4 Hz),
2.58 (2H, q, J = 7.4 Hz), 2.70–3.50 (3H, m), 3.50–3.80 (2H, m),
6.39 (1H, s), 7.00–7.64 (1H, br), 7.64–7.74 (1H, m), 8.10–8.25
(2H, m); FAB-MS m/z 326, 328 [(M+H)+]. Anal. (C15H17N3O2ClFÁ-
C2H2O4Á0.5H2O): C, H, N, Cl, F.
Acknowledgments
5.65. (2R)-3-{[2-(4-Bromo-2,5-difluorophenyl)-6-
ethylpyrimidin-4-yl]amino}propane-1,2-diol oxalate (24f)
We are grateful to Dr. Masakazu Imamura, Dr. Tetsuo Matsui,
and Dr. Hirotsugu Tanaka for their useful advice, and to the staff
of the Division of Analysis & Pharmacokinetics Research Laborato-
ries for the elemental analysis and spectral measurements.
Slightly yellow crystal (yield 54% from 14l); 1H NMR (DMSO-d6)
d 1.19 (3H, t, J = 7.5 Hz), 2.55 (2H, q, J = 7.5 Hz), 2.80–3.75 (5H, m),
3.75–6.30 (3H, br), 6.40 (1H, s), 7.00–7.70 (1H, br), 7.79 (1H, dd,
J = 5.9, 9.8 Hz), 7.82–8.00 (1H, m); FAB-MS m/z 388, 390 [(M)+].
Anal. (C15H16N3O2BrF2ÁC2H2O4): C, H, N, Br, F.
References and notes
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2. Meece, J. Curr. Med. Res. Opin. 2007, 23, 933.
5.66. (2R)-3-{[2-(4-Chloro-2,5-difluorophenyl)-6-
ethylpyrimidin-4-yl]amino}propane-1,2-diol oxalate (24g)
3. Seino, Y.; Rasmussen, M. F.; Nishida, T.; Kaku, K. Curr. Med. Res. Opin. 2010, 26,
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Colorlesscrystal (yield 26% from14m); 1H NMR(DMSO-d6) d 1.19
(3H, t, J = 7.6 Hz), 2.55 (2H, q, J = 7.6 Hz), 2.70–3.75 (5H, m), 3.75–

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K. Negoro et al. / Bioorg. Med. Chem. 20 (2012) 5235–5246
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