Synthesis and pharmacological profile of a new selective G protein-coupled receptor 119 agonist; 6-((2-Fluoro-3-(1-(3-isopropyl-1,2,4-oxadiazol-5-yl) piperidin-4-yl)propyl)amino)-2,3-dihydro-1H-inden-1-one

Article abstract of DOI:10.1248/cpb.c12-00484

6-((2-Fluoro-3-(1-(3-isopropyl-1,2,4-oxadiazol-5-yl)piperid-in-4-yl)propyl) amino)-2,3-dihydro-1 H -inden-1-one is a potent drug-like G protein-coupled receptor 119 (GPR119) agonist. It is hoped that this compound would be instrumental in probing the pharmacological potential of GPR119 agonists.

Full text of DOI:10.1248/cpb.c12-00484

September 2012
Communication to the Editor
Chem. Pharm. Bull. 60(9) 1093–1095 (2012)
1093
of early-stage development also suggest that the potential of
GPR119 agonists for treatment of T2DM is still elusive.9,10)
Apparently, drug-like, selective GPR119 agonists provide a
useful tool for probing the physiological roles and pharmaco-
logical potential of GPR119 agonists. Recently, we reported
synthesis and pharmacological profiles of a new series of
GPR119 agonists having high potency.11) This series of ago-
nists (e.g. 6, 7) feature small species difference in the in vitro
potency between mouse and human, and good physical prop-
erties such as water solubility and molecular weight. Further
investigation has been carried out to improve these profiles. In
this communication, we are pleased to report the synthesis and
pharmacological profile of a new, selective GPR119 agonist,
6-((2-fluoro-3-(1-(3-isopropyl-1,2,4-oxadiazol-5-yl)piperidin-4-
yl)propyl)amino)-2,3-dihydro-1H-inden-1-one (5).12)
Synthesis and Pharmacological Profile
of a New Selective G Protein-Coupled
Receptor 119 Agonist; 6-((2-Fluoro-
3-(1-(3-isopropyl-1,2,4-oxadiazol-5-
yl)piperidin-4-yl)propyl)amino)-2,3-
dihydro-1H-inden-1-one
Masao Sakairi, Masakazu Kogami, Masafumi Torii,
Mitsuhiro Makino, Daisuke Kataoka, Ryuji Okamoto,
Toshiyuki Miyazawa, Megumi Inoue, Naoki Takahashi,
Satoko Harada, and Nobuhide Watanabe*
Synthesis of 5 is shown in Chart 1. The piperidine-3-pro-
panol 3 was prepared in 79% yield via Horner–Wadsworth–
Emmons type reaction of the commercially available aldehyde
1. 1,2,4-Oxadiazole ring was introduced in 80% yield by a
two-step sequence according to a reported protocol.13) Oxida-
tion of 4 with Dess–Martin reagent followed by reductive am-
ination with the commercially available 6-aminoindan-1-one
gave 5 in 46% yield after recrystallization.
Compound 5 in vitro potency was determined using
GPR119 homogeneous time resolved fluorescence (HTRF)
cAMP activation assay, and its GPR119 agonistic activity was
determined as percentage of maximum activation (100%) pro-
duced by the reference AR231453. As shown in Table 1, com-
Drug Discovery Laboratories, Sanwa Kagaku Kenkyusho Co.,
Ltd.; 363 Shiosaki, Hokusei-cho, Inabe, Mie 511–0406, Japan.
Received May 28, 2012; accepted June 19, 2012
6-((2-Fluoro-3-(1-(3-isopropyl-1,2,4-oxadiazol-5-yl)piperid-
in-4-yl)propyl)amino)-2,3-dihydro-1H-inden-1-one is a potent
drug-like G protein-coupled receptor 119 (GPR119) agonist. It
is hoped that this compound would be instrumental in prob-
ing the pharmacological potential of GPR119 agonists.
Key words glucagon-like peptide-1; G protein-coupled recep-
tor 119 agonist; glucose-dependent insulin secretagogue; gastric
emptying
pound 5 exhibited good in vitro potency (hEC50: 33nM; hEmax
;
Obesity is strongly associated with insulin resistance and 100%) across the tested species, although its rat EC50 was
can therefore be problematic in the management of type 2 lower than that in human or mouse. Pharmacokinetic (PK)
diabetes mellitus (T2DM).1,2) Ironically, treatment of T2DM studies showed that compound 5 has low clearance (0.89L/h/
also targets obesity, although oral medications, such as sulfo- kg) and good oral bioavailability (58%) in rats, and relatively
nylureas and thiazolidinediones are known to hardly achieve high clearance (1.71L/h/kg) and good oral bioavailability
weight loss. Glucose-dependent insulin secretagogues, such (68%) in mice (Table 2). Next, we decided to conduct oral glu-
as glucagon-like peptide-1 (GLP-1) analogs and dipeptidyl cose tolerance test (OGTT) with compound 5 and the selected
peptidase-IV (DPP-4) inhibitors have recently emerged as new data are shown in Table 3. As shown in Table 3, compound 5
agents for the treatment of T2DM.3) Although both GLP-1 (30, 10mg/kg, per os (p.o.)) significantly reduced AUC0–120min
analogs and DPP-4 inhibitors improve glycemic control and by 27 and 37% in rats and mice, respectively. On the other
minimize hypoglycemia, GLP-1 analogs can produce weight hand, administration of 5 to overnight-fasted normal rats
loss, while DPP-4 inhibitors merely suppress body weight produced no reduction in blood glucose level even at a dose
gain. Very recently, G protein-coupled receptor 119 (GPCR
119, or GPR119) agonists have received considerable attention
as a promising therapeutics for the treatment of T2DM.4,5)
GPR119 is a membrane receptor expressed in pancreatic islet
β-cells, and its activation enhances insulin secretion in glu-
cose-dependent manner. GPR119 expression has also been
detected in murine intestinal L- and K-cell lines. In fact, treat-
ment with AR231453, a GPR119 agonist has been reported
to enhance secretion of both GLP-1 and gastric inhibitory
polypeptide (GIP) in glucose-challenged mice.6) It is therefore
expected that GPR119 agonists would improve glucose tol-
erance with minimum hypoglycemia in T2DM patients and
produce weight loss by reducing food intake. Based on this
hypothesis, a large number of patents and publications regard-
ing GPR119 have been disclosed and several GPR119 agonists
such as APD668,7) MBX-2982 and GSK-1292263A have been
Reagents and conditions: a) (EtO)2POCHFCO2Et, n-BuLi, THF, 0°C; b)
H2, 10% Pd–C, EtOH, rt; c) LiAlH4, THF, 0°C; d) 4N HCl/dioxane, 0°C; e)
BrCN, aq. NaHCO3, CH2Cl2; f) ZnCl2, amidine, AcOEt–THF, reflux then
HCl–EtOH, reflux; g) Dess–Martin reagent, CH2Cl2, rt; h) 6-aminoindan-1-one,
under development.5,8) However, there are some conflicting
results from the recent publication, and the high attrition rates
NaBH(OAc)3, CH2Cl2, rt.
The authors declare no conflict of interest.
Chart 1. Synthesis of Compound 5 and Related Compounds 6 and 7
*To whom correspondence should be addressed. e-mail: no_watanabe@skk-net.com
© 2012 The Pharmaceutical Society of Japan

1094
Vol. 60, No. 9
Fig. 1. GPR119 Agonists in Clinical Trials and AR231453
Fig. 2. Effect of 5 on Fasting Normoglycemia in Rats
Table 1. Properties of Compound 5
Male Wistar/ST rats (8 weeks old) were used. Compounds were adminis-
GPR119 activity (EC50; nM)
Solubility (µM)c)
pH 1.2
tered orally at time 0min to overnight-fasted animals (n=8/group). The plasma
glucose levels were measured using
a portable glucometer (GLUTEST ProR;
Human
Rat
33 (100%)a)
80.5
40.7
Sanwa Kagaku Kenkyusho, Japan). Statistical significance was tested using a
one-way ANOVA and the Dunnett multiple comparison test. *p<0.05, **p<0.01,
***p<0.001 vs. vehicle control. Data are expressed as the mean S.E.M.
125
47 (116%)a)
pH 6.5
Mouse
Protein binding (%)b)
Permeability (×10-6cm/s)d)
pH 6.2
CLint (L/h/kg)e)
RLM
50
Table 3. OGTT of Compound 5 in Rats and Micea)
Human
Rat
99.5
98.6
99.2
10
4.6
Species, dose
(mg/kg)
ΔAUC0–120min of
cntl (mg/dL·min) (mg/dL·min)
ΔAUC0–120min
Mouse
HLM
% reduction
a) Values in parentheses indicate % maximum (the max. response of AR231453
was defined as 100% activation). b) Assayed using Rapid Equilibrium Dialysis
(Thermo Fisher Scientific, Waltham, MA, U.S.A.). c) Measured using dimethyl sul-
foxide (DMSO) solution precipitation method. d) Assayed using PAMPA Explorer™
(pION, Woburn, MA, U.S.A.). e) Calculated from substrate disappearance rate in
liver microsomes as L/h/kg body weight. The assay was carried out by incubation of
5µM test compound with human (HLM) or rat (RLM) liver microsomes (Xenotech,
Lenexa, KS, U.S.A.), NADPH and buffer at 37°C for 30min and measurement of per-
cent compound remaining by precipitation method followed by LC-MS-MS analysis.
Rat, 30
9762 477
7156 464**
7668 321***
27
37
Mouse, 10
12116 843
a) Male Wistar/ST rats (8 weeks old) and male C57BL/6J mice (8 weeks old) were
used. 5 was administered orally (vehicle; 10% DMSO–5% hydroxypropyl-β-cyclodex-
trin (HPbCD)/H2O) to overnight-fasted animals (n=8/group) 30min before glucose
loading (2g/kg). Plasma glucose levels were measured using a portable glucometer
(GLUTEST ProR; Sanwa Kagaku Kenkyusho, Japan). Statistical significance was de-
termined using one-way ANOVA and Dunnett multiple comparison test. **p<0.01,
***p<0.001 vs. vehicle control. ΔAUC are expressed as mean S.E.M.
as high as 100mg/kg, while other insulin secretagogues, such
as nateglinide and glimepiride significantly reduced blood
glucose levels below normal, suggesting that 5 induces a glu-
cose-dependent effect on insulin secretion (Fig. 2). In order
to see if compound 5 has beneficial effect on gastric empty-
ing, acetaminophen (APAP) absorption test was conducted.10)
Fasted mice were orally treated with 10mg/kg of 5 followed
0.5h later by APAP (100mg/kg, p.o.) in a 2g/kg glucose-con-
taining aqueous solution. Plasma APAP concentrations were
determined 10 and 20min after APAP administration. As ex-
pected, compound 5 produced a significant decrease in plasma
APAP, indicating delay of gastric emptying (Table 4). Of par-
ticular interest, closely related compound 7 showed no effect
on gastric emptying in APAP absorption test at a dose as high
Table 4. Effect of Compound 5 on Gastric Emptyinga)
Plasma APAP conc. (mM)
AUC0–20min
(mM·min)
10min
20min
Control
5
0.362 0.015
0.312 0.008*
0.389 0.014
0.336 0.012*
5.57 0.21
4.80 0.12*
a) Male C57BL/6J mice (8 weeks old) were used. Statistical significance was de-
termined using one-way ANOVA and Dunnett multiple comparison test. *p<0.05 vs.
vehicle control. Data are expressed as mean S.E.M.
From a safety point of view, compound 5 was found to have
as 30mg/kg, p.o. (data not shown), although compound 7 pro- excellent preclinical safety profile with no inhibition of liver
duced almost equal GLP-1 secretion compared to that reported metabolic enzymes, such as CYP3A4, CYP2C9, and CYP2D6
for MBX-2982.11) In addition, another related compound 6 (IC50 >10µM), and no induction of CYP3A4 and CYP1A2 at
produced no significant reduction in OGTT in mice at a dose a concentration of 50µM. Compound 5 also showed no sig-
of 10mg/kg, p.o. Evidently, these data show superiority of nificant inhibition of the human ether-à-go-go related gene
compound 5 over compounds 6 and 7 for oral efficacy.
channel in patch clamp using human embryonic kidney 293
Table 2. Selected PK Parameter of Compound 5a)
Dose, i.v./oral
Species
i.v. t1/2 (h)
CLp (L/h/kg)
Vdss (L/kg)
Oral t1/2 (h)
Cmax (ng/mL)
Tmax (h)
BA (%)
(mg/kg)
Rat
Mouse
0.5/3.0
1.0/5.0
2.24
1.16
0.89
1.71
2.31
1.87
3.67
1.07
315
2.11
0.17
58
68
1090
a) Male Wister/ST rats (9 weeks old) and male CD-1 (ICR) mice (7 weeks old) were acclimated to experimental conditions 7–14d before use, and had free access to food
and water throughout the acclimatization period. The animals were fasted overnight, and 5 was administered intravenously via the tail vein or orally (by gavage) at the indicated
doses (n=3 in rats, n=2 in mice) as a solution in 10% DMSO and 5% HPbC in H2O. Blood samples were taken periodically and the plasma was analyzed by LC-MS-MS with
quantitation against a standard curve.

September 2012
1095
Y., Demarest K. T., Jones R. M., Bioorg. Med. Chem. Lett., 21,
3134–3141 (2011).
cells (IC50; 27.4µM). Finally, compound 5 was negative in
Ames mutagenicity test and showed low toxicity in cell tox-
icity assay using Chinese hamster ovary cells (CC50 value of
31µM). In a panel of 68 receptor binding/ion channel assays,
compound 5 (10µM) showed no specific binding greater
than 50% in any of the 68 assays, except for the assay with
5-hydroxytryptamine2B (97% inhibition at 10µM).14) In a cal-
cium mobilization assay, compound 5 showed no agonist/an-
tagonist activity towards other human pancreatic islet GPCRs,
including GPR40, GPR41, GPR43, and GPR120.15)
8) Mascitti V., Stevens B. D., Choi C., McClure K. F., Guimarães C.
R., Farley K. A., Munchhof M. J., Robinson R. P., Futatsugi K.,
Lavergne S. Y., Lefker B. A., Cornelius P., Bonin P. D., Kalgutkar
A. S., Sharma R., Chen Y., Bioorg. Med. Chem. Lett. 21, 1306–1309
(2011), and the current status of development of MBX-2982 and
GSK-1292263 are cited therein.
9) Drug reports are available from Thomson Pharm®.
10) Flock G., Holland D., Seino Y., Drucker D. J., Endocrinology, 152,
374–383 (2011).
11) Sakairi M., Kogami M., Torii M., Kataoka H., Fujieda H., Makino
M., Kataoka D., Okamoto R., Miyazawa T., Okabe M., Inoue M.,
Takahashi N., Harada S., Watanabe N., Bioorg. Med. Chem. Lett.,
22, 5123–5128 (2012).
In conclusion, we have demonstrated that compound 5 has
drug-like properties and improves glucose tolerance without
affecting fasting normoglycemia. It is therefore hoped that
compound 5 can play an instrumental role in probing the
pharmacological potential of GPR119 agonists.
12) 5: Pale yellow needles. mp 88–90°C. IR (KBr) 3402, 2926, 1699,
1598, 1505, 1406, 1263, 837cm−1
.
1H-NMR (400MHz, CDCl3) δ:
7.27 (1H, d, J=8.1Hz, Ph), 6.93 (1H, dd, J=8.1, 2.4Hz, Ph), 6.89
(1H, d, J=2.4Hz, Ph), 4.84 (1H, dddd, J=50.4, 10.5, 6.9, 2.9Hz,
CHF), 4.14 (3H, dd, J=12.6, 2.0Hz, CH2N and NH), 3.46–3.21 (2H,
m, N(H)CH2), 3.07 (2H, ddd, J=12.6, 3.9, 2.9Hz, CH2N), 3.02 (2H,
t, J=5.5Hz, CH2Ph), 2.88 (1H, sep, J=6.9Hz, CH from iPr), 2.68
(2H, t, J=5.5Hz, COCH2), 1.94–1.68 (4H, m, CH2 and CH from
piperidine and CFCH2), 1.61–1.20 (9H, m, CH3 from iPr, CH2 from
piperidine and CFCH2). 13C-NMR (100MHz, CDCl3) δ: 207.4, 175.7,
170.8, 147.2, 145.5, 138.1, 127.16, 122.5, 104.2, 90.4 (d, J=169.9Hz),
48.4 (d, J=21.2Hz), 46.1, 46.0, 3.92 (d, J=20.1Hz), 36.9, 31.94,
31.92, 30.94, 27.0, 24.9, 20.4. HR-MS Calcd for C20H29FN4O2
(M++1), 401.2347; Found, 401.2352.
References and Notes
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14) http://www.ricerca.com/
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369–385 (2009), Assay services are available, see; http://www.multi-
spaninc.com/