The design and synthesis of novel SGLT2 inhibitors: C-glycosides with benzyltriazolopyridinone and phenylhydantoin as the aglycone moieties

Article abstract of DOI:10.1016/j.bmc.2014.04.036

The sodium glucose co-transporter 2 (SGLT2) has received considerable attention in recent years as a target for the treatment of type 2 diabetes mellitus. This report describes the design, synthesis and structure-activity relationship (SAR) of C-glycosides with benzyltriazolopyridinone and phenylhydantoin as the aglycone moieties as novel SGLT2 inhibitors. Compounds 5p and 33b demonstrated high potency in inhibiting SGLT2 and high selectivity against SGLT1. The in vitro ADMET properties of these compounds will also be discussed.

Full text of DOI:10.1016/j.bmc.2014.04.036

Accepted Manuscript
The design and synthesis of novel SGLT2 inhibitors: C-glycosides with ben-
zyltriazolopyridinone and phenylhydantoin as the aglycone moieties
Cheng Guo, Min Hu, Russell J. DeOrazio, Alex Usyatinsky, Kevin Fitzpatrick,
Jun-Ho Maeng, Douglas B. Kitchen, Susan Tom, Michele Luche, Yuri
Khmelnitsky, Drew J. Mhyre, Peter R. Guzzo, Shuang Liu
PII:
S0968-0896(14)00301-0
DOI:
http://dx.doi.org/10.1016/j.bmc.2014.04.036
BMC 11531
Reference:
Bioorganic & Medicinal Chemistry
To appear in:
Received Date:
Revised Date:
Accepted Date:
24 February 2014
11 April 2014
20 April 2014
Please cite this article as: Guo, C., Hu, M., DeOrazio, R.J., Usyatinsky, A., Fitzpatrick, K., Maeng, J-H., Kitchen,
D.B., Tom, S., Luche, M., Khmelnitsky, Y., Mhyre, D.J., Guzzo, P.R., Liu, S., The design and synthesis of novel
SGLT2 inhibitors: C-glycosides with benzyltriazolopyridinone and phenylhydantoin as the aglycone moieties,
Bioorganic & Medicinal Chemistry (2014), doi: http://dx.doi.org/10.1016/j.bmc.2014.04.036
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Bioorganic & Medicinal Chemistry
journal homepage: www.els evier.com
The design and synthesis of novel SGLT2 inhibitors: C-glycosides with benzyltriazolopyridinone and
phenylhydantoin as the aglycone moieties
Cheng Guo, Min Hu, Russell J. DeOrazio, Alex Usyatinsky, Kevin Fitzpatrick, Jun-Ho Maeng, Douglas B.
Kitchen, Susan Tom, Michele Luche, Yuri Khmelnitsky, Drew J. Mhyre, Peter R. Guzzo, Shuang Liu*
AMRI, 26 Corporate Circle, PO Box 15098, Albany, NY 12212-5098, USA
ARTICLE INFO
ABSTRACT
Article history:
Received
The sodium glucose co-transporter 2 (SGLT2) has received considerable attention in recent
years as a target for the treatment of type 2 diabetes mellitus. This report describes the design,
Received in revised form
Accepted
synthesis
and
structure-activity
relationship
(SAR)
of
C-glycosides
with
Available online
benzyltriazolopyridinone and phenylhydantoin as the aglycone moieties as novel SGLT2
inhibitors. Compounds 5p and 33b demonstrated high potency in inhibiting SGLT-2 and high
selectivity against SGLT-1. The in vitro ADMET properties of these compounds will also be
discussed.
Keywords:
triazolopyridinone
hydantoin
SGLT2
canagliflozin
dapagliflozin
glucoside
2011 Elsevier Ltd. All rights reserved.
1. Introduction
The recent approval of dapagliflozin (1) and canagliflozin (2)
Diabetes mellitus is a prevalent disease. It is estimated that the
patient population has reached 285 million and is expected to
increase to 438 million by 2030.1a Type 2 diabetes is the most
common disorder of glucose homeostasis, accounting for nearly
90–95% of all cases of diabetes.1b Hyperglycemia, the
characterization of type 2 diabetes mellitus, is a major risk factor
for microvascular and macrovascular complications including
retinopathy, nephropathy, neuropathy, and accelerated
cardiovascular disease. Despite various therapeutic options,
many patients demonstrate inadequate glycemic control and
remain at risk for chronic complications.
validated the approach of utilizing SGLT2 as a drug target.2m
Examination of the structures of 1 and 2 and two other C-
glucosides (3 and 4) in clinical development stage (Figure 1)
revealed the close resemblance and suggested room for
identifying novel functional groups as the distal ring of the
aglycone. Thus our research program focused on the design,
modification and characterization of distal ring analogues.3
Herein, we report the results from our effort.
2. Results and discussion
2.1 Triazolopyridinone series
Recently, inhibitors of sodium glucose co-transporter 2 (SGLT2)
have received considerable attention for the treatment of type 2
diabetes mellitus. Sodium-dependent glucose co-transporters
(SGLTs) couple the transport of glucose against a concentration
gradient with the simultaneous transport of Na+ down a
concentration gradient.2a Two important SGLT isoforms have
been cloned and identified as SGLT1 and SGLT2.2b SGLT1 is a
low capacity, high affinity transporter that is expressed in the
small intestine, heart and kidney;2c,2d whereas, SGLT2 is a high
capacity, low affinity transporter expressed predominantly in the
proximal convoluted tubule of the nephron,2e,2f where it is
responsible for 90% of renal glucose reabsorption. Inhibition of
SGLT2 is expected to be a safe approach to lowering the blood
sugar level. This is supported by the fact that human SGLT2 gene
mutations lead to renal glucosuria in individuals who are
otherwise asymptomatic.2g-k On the other hand, inhibition of
SGLT1 may lead to undesirable gastrointestinal effects.2l
Therefore, the selectivity over SGLT1 is important for a viable
SGLT2 inhibitor.
The structural features of several known SGLT-2 inhibitors
(Figure 1) prompted us to replace the distal phenyl ring in
dapagliflozin with a novel bicyclic heterocycle. Among our
attempts on a number of different bicyclic heterocycles, we
discovered that the [1,2,4]triazolo[4,3-a]pyridin-3(2H)-one group
as depicted in 5 of Figure 2 (referred as triazolopyridone
hereinafter) was the best for the SGLT-2 activity; therefore, we
decided to explore various substitutions on this heterocycle to
achieve the SGLT-2 activity and drug properties.
The preparation of the triazolopyridone analogues is shown in
Scheme 1. Tetra-TMS protected gluconolactone 8 was prepared
from gluconolactone.4 Bromide 9 was prepared in 97% yield
from 5-bromo-2-chlorobenzoic acid through a borane reduction
and TBDPS protection.3 Treatment of a mixture of 9 and 8 with
tert-butyllithium at –78 °C generated the corresponding lithium
reagent of 9 in situ, which underwent addition reaction with 8.
The reaction mixture was quenched with a methanolic solution of
methanesulfonic acid to give the de-protected C-glucoside 10 as a
∗ Corresponding author. Tel.: +1-518-512-2131; fax: +1-518-512-2430; e-mail: shuang.Liu@amriglobal.com

mixture of two diastereoisomers, which was treated with
triethylsilane and boron trifluoride in dichloromethane at 0 °C to
provide C-glucoside 11 in a 41% yield from 8, with the desired
β-anomer as the major product (~3:2 β-anomer : α- anomer).
Per-acylation of 11 using acetic anhydride and pyridine provided
tetra-acetate 12, which was treated with TBAF in THF/HOAc to
generate benzyl alcohol 13 in a 62% yield. Mitsunobu reactions
between alcohol 13 and various substituted triazolopyridinones
145 then gave compounds 15 in 20 to 60% yields. Finally, all the
acetate groups were removed by either basic or acidic conditions
to give the final products 5 in good yields.
primary alcohol gave 19. The bromide 20 was obtained in high
yield by reacting of the crude mesylate of 19 with lithium
bromide.
Scheme 3 shows our initial efforts to prepare compound 29 as the
common intermediate for the 3-alkyl hydantoin series. 4-
Bromoaniline (21) was treated with cyanogen bromide to provide
the crude cyanamide 229 which was then alkylated with methyl
bromoacetate to afford 23.10 Subsequent hydrolysis-cyclization
afforded hydantoin 24.10 Upon protection of the hydantoin
nitrogen with a trityl group, the bromide 2511 was converted to
the pinacol diborate 26. Suzuki coupling of 26 with the key
intermediate 20 at the benzylic sp3 carbon8 generated the fully
protected C-glucoside 27 in 57% yield. Although removal of the
MOM protecting groups in 27 was achieved readily, various
attempts to remove the trityl group were fruitless. We decided to
test compound 28 in the SGLT2 assay although the size of the
trityl group is larger than desired. To our delight compound 28
showed promising SGLT2 activity (IC50 = 328 nM), which
prompted us to examine smaller alkyl groups on the 3- nitrogen.
We decided to introduce the 3-alkyl group earlier in the
synthesis.
A number of triazolopyridinone analogues were prepared to
explore the structure activity relationship (SAR). The in vitro
inhibitory activities against SGLT-2 are summarized in Table 1.
The potency of dapagliflozin (1) is also included for comparison.
All compounds listed in Table 1 were tested to be inactive in the
SGLT-1 assay (IC50 > 90 µM, except dapagliflozin IC50 = 891
nM ). Among the 4 different positions on the triazolopyridinone,
C-6 and C-7 are the most tolerated positions for substitutions.
Generally, compounds with small substitution groups (5b to 5e)
at C-6 showed similar activity as the parent compound 5a.
Strong electron withdrawing groups (5f and 5g) at C-6 led to
reduced activities. Substitution at C-7 position showed similar
SAR trend as at C-6, where smaller groups are more tolerated
than larger and electron withdrawing groups (5h to 5j). We also
found that strong electron donating groups are not tolerated at C-
7 position (5k and 5l). Substitutions at C-8 or C-5 position are
not tolerated as shown by the weak activities of 5m – 5o. To our
delight, we found out that compound 5p, which is substituted at
both 6- and 7- positions (6-Cl, 7-Me), is more potent than either
the 6-Cl (5b) or 7-Me (5i) analogue. It showed a synergistic
effect of the “hybrid” of 5b and 5i.
Scheme 4 depicts the synthesis of hydantoin analogues 33a-c.
The alkylation of compound 24 was performed using sodium
hydride and alkyl iodide. However, in the case of methyl iodide,
the N-methylation was accompanied by the C-methylation at 5-
position. The attempt to obtain the selective N-methylated
product was not successful. Conversion of bromide 3012 to
pinacol diborate 31 and a Suzuki coupling reaction with the key
intermediate 20 provided the protected C-glucosides 32 in good
yield. Removal of MOM groups afforded the C-glucosides 33.
The hydantoin analogue 39 in which the hydantoin group
connects to the phenyl ring through N-3 was synthesized from 4-
bromoaniline 21 (Scheme 5). Reaction of 21 with ethyl 2-
isocyanatoacetate gave urea 34, which cyclized upon treatment
with acid to provide the hydantoin 35.13 Methylation on 3-
nitrogen gave 36.11 Installation of the pinacol diborate group
afforded 37. Suzuki coupling of 37 with bromide 20 produced
protected C-glucoside 38. Subsequent deprotection provided 39.
Compound 5p not only showed high binding affinity toward
SGLT2, it also exhibited very high selectivity over the
undesirable SGLT-1 transporter (IC50 > 90 µM). It did not
significantly inhibit a panel of cytochrome P450 enzymes (IC50
>
11 µM for 1A2, 2B6, 2C9, 2C19, 2D6, 3A4) which indicates low
liability for drug-drug interactions. Compound 5p also showed
good metabolic stability in a liver microsome assay (HLM Clint
3.6 µL/min/mg; RLM Clint 2.8 µL/min/mg). However, it
exhibited low permeability when tested in the PAMPA assay
(below quantifiable limit), perhaps reflecting the relative high
total polar surface area (tPSA) for this compound (calculated
tPSA = 126).6
Table 2 summarizes the potency data of the five hydantoin
analogues prepared. Compounds 33b and 33c, with the
hydantoin moiety connected to the diphenylmethane at the N-1
position, are more potent than the one with connection at N-3
(39). Hydantoin 33a with the methyl as R’ has lower potency vs
33b and 33c. Both 33b and 33c showed excellent selectivity
(>300 fold) for SGLT2 over SGLT1. Compound 33b was found
to exhibit good metabolic stability in liver microsomes (HLM
Clint 1.3 µL/min/mg; RLM Clint 1.9 µL/min/mg), and low CYP
inhibition against the same panel described previously (IC50 > 11
µM). To our satisfaction, compound 33b showed similar
permeability to that of dapagliflozin (PAMPA LogPe -6.2 cm/s)
despite a higher calculated tPSA (calculated tPSA for 33b = 130
versus dapagliflozin = 99). However, 33b was found to have a
low bioavailability of 4% and short half-life of 35 minutes in the
rat. Since 33b was predicted to be permeable and metabolically
stable based on the PAMPA and microsomal stability data, we
suspect that the low observed bioavailability might be due to a
clearance mechanism other than cytochrome P450 enzymes.
2.2 Hydantoin series
Based on the report by Washburn, the SGLT2 potency could be
further enhanced by addition of
a small para lipophilic
substitutent at C4 of the distal ring;7 we envisioned that a small
heterocycle at C4 could serve as a bioisostere of the ethoxy group
in dapagliflozin. After examining published SGLT2 inhibitors,
we decided to test a few hydantoin derivatives in order to identify
novel SGLT-2 inhibitors (Figure 2, 6 and 7).
We decided to employ a Suzuki coupling reaction of a benzylic
sp3 carbon8a as the key step in our synthetic strategy because: (1)
the synthetic route would be more convergent; and, (2) the mild
coupling condition could better accommodate the hydantoin
moiety in the molecule (Figure 3).
4. Conclusion
Scheme 2 depicts the preparation of the key intermediate 20.
Protection of the hydroxyl groups in 11 with MOMCl provided
18. Removal of the silyl protecting group on the benzylic
Two novel and potent SGLT2 inhibitors have been designed and
efficiently synthesized in both the triazolopyridinone and

hydantoin series. Compounds 5p and 33b showed good potency
for SGLT2 and high selectivity against SGLT1. Although 33b
exhibited promising in vitro ADME properties, it was found to
have low bioavailability in rat.
NMR (CD3OD, 500 MHz) δ 7.81 (s, 1H), 7.71–7.69 (m, 4H),
7.45–7.39 (m, 6H), 7.34–7.26 (m, 2H), 4.81 (d, J = 8.0 Hz, 2H),
4.16 (d, J = 9.5 Hz, 1H), 3.91 (dd, J = 11.5, 2.0 Hz, 1H), 3.69
(dd, J = 12.0, 6.0 Hz, 1H), 3.50 (t, J = 9.0 Hz, 1H), 3.47–3.42 (m,
1H), 3.39 (d, J = 9.0 Hz, 1H), 3.37–3.32 (m, 1H), 1.11 (s, 9H).
5. Experimental Section
5.4. Preparation of (2R,3R,4R,5S,6S)-2-(acetoxymethyl)-6-(4-
chloro-3-(hydroxymethyl)phenyl)tetrahydro-2H-pyran-3,4,5-triyl
triacetate (13):
5.1 General:
Unless otherwise noted, reagents and solvents were used as
received from commercial suppliers. All reactions involving dry
solvents or air-sensitive agents were performed under a nitrogen
or argon atmosphere and glassware was dried prior to use.
Solvents were dried according to standard procedures. Reactions
were monitored by analytical thin-layer chromatography (TLC)
analysis and analytical LC–MS. Flash chromatography was
performed using a CombiFlash Rf System (Teledyne Isco, Inc.)
on RediSep columns. Eluent systems are given in volume/volume
concentrations. Proton nuclear magnetic resonance spectra were
obtained on a Bruker AVANCE 300 spectrometer at 300 MHz or
Bruker AVANCE 500 spectrometer at 500 MHz. Chemical
shifts (δ) are given in parts per million (ppm) and coupling
constants J values are reported in hertz (Hz). Tetramethylsilane
was used as an internal standard for 1H nuclear magnetic
resonance. The following abbreviations
To a solution of C-glucoside 11 (2.0 g, 3.7 mmol) in chloroform
(35 mL) were added acetic anhydride (3.5 mL, 36.8 mmol),
pyridine (3.0 mL, 36.8 mmol), and DMAP (22 mg, 0.18 mmol) at
room temperature. The reaction solution was stirred overnight,
and then it was concentrated under reduced pressure. The residue
obtained was dissolved in EtOAc (50 mL), washed with 10%
aqueous HCl, water, and brine. The solution was dried over
sodium sulfate, filtered, and concentrated to give the per-acylated
glucoside 12 (2.6 g, crude) as a white foam. This crude material
was dissolved in THF (30 mL), cooled at 0 °C, and treated with
acetic acid (0.66 mL) and TBAF (4.0 mL, 1.0 M in THF). The
reaction solution was slowly warmed to room temperature and
stirred overnight, then it was diluted with EtOAc, washed with
0.5 N aqueous HCl and brine. The organic solution was dried
over sodium sulfate and concentrated under reduced pressure.
The crude material obtained was purified by flash column
chromatography (eluent: 10% to 50% EtOAc in hexanes) to give
are used: br = broad, s = singlet, d = doublet, dd = doublet of
doublet, t = triplet, q = quartet, m = multiplet. Mass spectra
analyses were performed on Agilent 6130A Mass Spectrometer
in ESI, APCI, or MultiMode mode when appropriate or Applied
Biosystems API-150EX Spectrometer in ESI or APCI mode
when appropriate.
1
the title compound as a white foam (0.83 g, 48% from 11): H
NMR (CD3OD, 500 MHz) δ 7.51 (d, J = 2.0 Hz, 1H), 7.33 (d, J =
8.5 Hz, 1H), 7.23 (dd, J = 8.0, 2.0 Hz, 1H), 5.32 (t, J = 9.5 Hz,
1H), 5.22 (t, J = 9.5 Hz, 1H), 5.11 (t, J = 9.5 Hz, 1H), 4.78 (s,
1H), 4.41 (d, J = 10.0 Hz, 1H), 4.28 (dd, J = 12.5, 5.0 Hz, 1H),
4.16 (dd, J = 12.0, 2.0 Hz, 1H), 3.85–3.82 (m, 1H), 2.09 (s, 3H),
2.06 (s, 3H), 2.00 (s, 3H), 1.84 (s, 3H).
5.2
butyldiphenylsilyloxy)methyl)-4-chlorophenyl)-6-
Preparation
of
(3S,4S,5S)-2-(3-((tert-
(hydroxymethyl)-2-methoxytetrahydro-2H-pyran-3,4,5-triol (10):
5.5 Typical procedure for preparing compound 5a-p as
2-(2-chloro-5-
To a solution of (3R,4S,5R,6R)-3,4,5-tris(trimethylsilyloxy)-6-
((trimethylsilyloxy)methyl)tetrahydro-2H-pyran-2-one (3.0 g, 6.5
exemplified
by
the
preparation
((2S,3R,4R,5S,6R)-3,4,5-trihydroxy-6-
of
mmol)
(8)
and
(5-bromo-2-chlorobenzyloxy)(tert-
(hydroxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)-
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one (5a):
butyl)diphenylsilane (3.7 g, 7.8 mmol) (9) in tetrahydrofuran
(105 mL) at –78 °C under nitrogen was added tert-BuLi (8.0 mL,
13.7 mmol) dropwise. Reaction was stirred at –78 °C for 5 hours
and then a cold (–78 °C) solution of methanesulfonic acid (1.6
mL) in methanol (54 mL) was added to it via cannulation. The
cold bath was then removed and the reaction mixture was stirred
at room temperature overnight. The reaction solution was
quenched with aqueous sodium bicarbonate and extracted with
EtOAc (3x). The combined organic extract was washed with
brine, dried over sodium sulfate and concentrated in vacuo to
give the title compound as a white foam (4.0 g, crude, mixture
of two anomers at 2-position), which was used in the next step
without purification.
To a solution of alcohol 13 (0.21 g, 0.43 mmol) and
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one (14, R = H, 67.4 mg,
0.50 mmol) in tetrahydrofuran (20 mL) were added
triphenylphosphine (0.17 g, 0.65 mmol) and diethyl
azodicarboxylate (0.11 g, 0.65 mmol) under nitrogen. The
reaction solution was stirred at room temperature for 15 hours,
then it was quenched with aqueous ammonium chloride solution
and extracted with EtOAc. The organic extract was washed with
brine, dried over sodium sulfate and concentrated in vacuo. The
crude material was first purified by flash column chromatography
(eluent: hexanes/EtOAc 95:5 to 25:75). The partially purified
material was then dissolved in methanol (25 mL) and treated with
potassium carbonate (0.17 g, 1.2 mmol). The reaction solution
was stirred at room temperature for 18 hours, then it was
concentrated in vacuo. The material obtained was purified by
5.3 (2S,3R,4R,5S,6R)-2-(3-((tert-butyldiphenylsilyloxy)methyl)-
4-chlorophenyl)-6-(hydroxymethyl)tetrahydro-2H-pyran-3,4,5-
triol (11)
flash
column
chromatography
(eluent:
To a solution of compound 10 (3.5 g, crude) in dichloromethane
(60 mL) at 0 °C was added triethylsilane (3.1 mL, 19.4 mmol),
followed by dropwise addition of boron trifluoride diethyl
etherate (2.5 mL, 20.3 mmol). The reaction mixture was stirred
at 0 °C for 2 hours and then it was quenched with aqueous
sodium bicarbonate and extracted with EtOAc (3x). The
combined organic extract was washed with brine, dried over
sodium sulfate and concentrated in vacuo. The crude material
obtained was purified by flash column chromatography (eluent:
dichloromethane/methanol 99:1 to 93:7) to give the title
dichloromethane/methanol/concentrated ammonium hydroxide
the title compound as a white foam (0.11 g, 55% over two steps
o
from 13). Mp 116-120 C; 1H NMR (CD3OD, 500 MHz) δ7.86–
7.84 (m, 1H), 7.41 (d, J = 1.0 Hz, 2H), 7.37 (s, 1H), 7.25 (ddd, J
= 9.5, 6.5, 1.0 Hz, 1H), 7.15–7.12 (m, 1H), 6.68 (td, J = 7.5, 1.0
Hz, 1H), 5.28 (s, 2H), 4.10 (d, J = 9.5 Hz, 1H), 3.85 (dd, J =
12.0, 1.5 Hz, 1H), 3.67 (dd, J = 12.0, 5.5 Hz, 1H), 3.44–3.25 (m,
4H); ESI MS m/z 422 [M+H]+. Anal. Calcd. for
C19H20ClN3O6•1.25H2O: C, 51.36; H, 5.10; N, 9.46. Found: C,
51.23; H, 5.10; N, 9.48.
1
compound as a white foam (1.45 g, 41% over two steps): H

7.87 (s, 1H), 7.41 (s, 2H), 7.37 (s, 1H), 7.30–7.21 (m, 2H), 5.28
(s, 2H), 4.10 (d, J = 9.5 Hz, 1H), 3.86 (dd, J = 12.0, 2.0 Hz, 1H),
3.61 (dd, J = 12.0, 2.0 Hz, 1H), 3.46–3.24 (m, 4H); ESI MS m/z
440 [M+H]+.
5.5.1 6-chloro-2-(2-chloro-5-((2S,3R,4R,5S,6R)-3,4,5-trihydroxy-
6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)-
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one (5b):
This compound was synthesized according to compound 5a but
employing 6-chloro-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one as
14 to give the title compound as a white solid (40% over 2
5.5.6 2-(2-chloro-5-((2S,3R,4R,5S,6R)-3,4,5-trihydroxy-6-
(hydroxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)-6-
(trifluoromethyl)-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one (5g)
1
steps). H NMR (CD3OD, 500 MHz) δ 7.97 (s, 1H), 7.41 (s, 2H),
This compound was synthesized according to compound 5a but
employing
7.36 (s, 1H), 7.22 (dd, J = 9.5, 1.5 Hz, 1H), 7.18 (dd, J = 9.5, 1.5
Hz, 1H), 5.28 (s, 2H), 4.10 (d, J = 9.5 Hz, 1H), 3.86 (dd, J =
12.0, 2.0 Hz, 1H), 3.68 (dd, J = 12.0, 2.5 Hz, 1H), 3.45–3.24 (m,
4H); ESI MS m/z 456 [M+H]+.
6-(trifluoromethyl)-[1,2,4]triazolo[4,3-a]pyridin-
3(2H)-one as 14 to give the title compound as a white solid
(50%). Mp 185 oC; 1H NMR (CD3OD, 500 MHz) δ 8.31 (q, J =
1.5 Hz, 1H), 7.41 (s, 2H), 3.38 (s, 1H), 7.35 (dd, J = 9.5, 1.5 Hz,
1H), 7.31 (d, J = 9.5 Hz, 1H), 5.29 (s, 2H), 4.10 (d, J = 9.5 Hz,
1H), 3.85 (dd, J = 12.0, 2.0 Hz, 1H), 3.68 (dd, J = 12.0, 5.5 Hz,
1H), 3.44–3.25 (m, 4H); ESI MS m/z 490 [M+H]+.
5.5.2 6-bromo-2-(2-chloro-5-((2S,3R,4R,5S,6R)-3,4,5-trihydroxy-
6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)-
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one (5c)
This compound was synthesized according to compound 5a but
employing 6-bromo-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one as
14 to give the title compound as a white solid (6% over 2 steps).
1H NMR (CD3OD, 500 MHz) δ 8.06 (dd, J = 2.0, 1.0 Hz, 1H),
7.41 (s, 2H), 7.36 (s, 1H), 7.30 (dd, J = 10.0, 2.0 Hz, 1H), 7.12
(dd, J = 10.0, 1.0 Hz, 1H), 5.24 (s, 2H), 4.10 (d, J = 9.5 Hz, 1H),
3.86 (dd, J = 12.0, 2.0 Hz, 1H), 3.68 (dd, J = 12.0, 5.0 Hz, 1H),
3.44–3.24 (m, 4H); ESI MS m/z 500 [M+H]+.
5.5.7 7-chloro-2-(2-chloro-5-((2S,3R,4R,5S,6R)-3,4,5-trihydroxy-
6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)-
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one (5h)
This compound was synthesized according to compound 5a but
employing 7-chloro-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one as
14 to give the title compound as a white solid (18% over 2
1
steps). H NMR (CD3OD, 300 MHz) δ 7.86 (d, J = 7.2 Hz, 1H),
7.40 (app s, 2H), 7.36 (s, 1H), 7.25 (d, J = 0.9 Hz, 1H), 6.67 (dd,
J = 7.5, 1.8 Hz, 1H), 5.25 (s, 2H), 4.10 (d, J = 9.3 Hz, 1H), 3.86
(d, J = 11.1 Hz, 1H), 3.67 (dd, J = 12.0, 4.8 Hz, 1H), 3.44–3.22
(m, 4H); ESI MS m/z 457 [M+H]+.
5.5.3
2-(2-chloro-5-((2S,3R,4R,5S,6R)-3,4,5-trihydroxy-6-
(hydroxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)-6-methyl-
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one (5d)
This compound was synthesized according to compound 5a but
employing 6-methyl-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one as
14 to give the title compound as a white solid (68% over 2
5.5.8.
2-(2-chloro-5-((2S,3R,4R,5S,6R)-3,4,5-trihydroxy-6-
(hydroxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)-7-methyl-
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one (5i)
1
steps). Mp 140-145 oC; H NMR (CD3OD, 300 MHz) δ 7.63 (q,
This compound was synthesized according to compound 5a but
employing 7-methyl-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one as
14 to give the title compound as a white solid (30% over 2
J = 1.2 Hz, 1H), 7.41–7.40 (m, 2H), 7.35 (s, 1H), 7.16 (dd, J =
9.6, 1.8 Hz, 1H), 7.08 (dd, J = 9.6, 0.6 Hz, 1H), 5.27 (s, 2H), 4.10
(d, J = 9.6 Hz, 1H), 3.85 (dd, J = 12.0, 1.5 Hz, 1H), 3.67 (dd, J =
12.0, 5.7 Hz, 1H), 3.44–3.23 (m, 4H), 2.23 (d, J = 1.2 Hz, 3H);
ESI MS m/z 436 [M+H]+.
1
steps). H NMR (CD3OD, 500 MHz) δ 7.75 (dd, J = 7.5, 0.5 Hz,
1H), 7.40 (s, 2H), 7.35 (s, 1H), 6.89 (d, J = 0.5 Hz, 1H), 6.55 (d,
J = 7.0, 0.5 Hz, 1H), 5.24 (s, 2H), 4.10 (d, J = 9.5 Hz, 1H), 3.85
(dd, J = 12.5, 1.5 Hz, 1H), 3.67 (dd, J = 12.0, 5.0 Hz, 1H), 3.46–
3.24 (m, 4H), 2.30 (s, 3H); ESI MS m/z 436 [M+H]+.
5.5.4 2-(2-chloro-5-((2S,3R,4R,5S,6R)-3,4,5-trihydroxy-6-
(hydroxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)-6-
(hydroxymethyl)-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one (5e)
5.5.9. 2-(2-chloro-5-((2S,3R,4R,5S,6R)-3,4,5-trihydroxy-6-
(hydroxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)-7-
(trifluoromethyl)-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one (5j)
This compound was synthesized via the Mitsunobu reaction
according to compound 5a but employing 6-(((tert-
butyldiphenylsilyl)oxy)methyl)-[1,2,4]triazolo[4,3-a]pyridin-
3(2H)-one, then the removal of the TBDPS group by TBAF in
THF, followed by the removal of the acetate protecting groups
using 6N HCl in MeOH to give the title compound as a white
This compound was synthesized according to compound 5a but
employing
7-(trifluoromethyl)-[1,2,4]triazolo[4,3-a]pyridin-
3(2H)-one as 14 to give the title compound as a white solid
(38%). Mp 200 oC dec.; 1H NMR (CD3OD, 300 MHz) δ 8.02 (d,
J = 7.5 Hz, 1H), 7.59 (q, J = 1.2 Hz, 1H), 7.41–7.40 (m, 2H),
7.37 (s, 1H), 6.79 (dd, J = 7.5, 1.5 Hz, 1H), 5.32 (s, 2H), 4.10 (d,
J = 9.3 Hz, 1H), 3.85 (dd, J = 12.9, 1.8 Hz, 1H), 3.80 (dd, J =
12.0, 5.1 Hz, 1H), 3.44–3.25 (m, 4H); ESI MS m/z 490 [M+H]+.
1
solid over 3-step (40%). Mp 150-154 oC; H NMR (CD3OD, 500
MHz) δ 7.80 (t, J = 1.5 Hz, 1H), 7.41 (d, J = 1.0 Hz, 2H), 7.37 (s,
1H), 7.26 (dd, J = 9.5, 6.5 Hz, 1H), 7.14 (dd, J = 9.5, 1.0 Hz,
1H), 5.28 (s, 2H), 4.51 (d, J = 1.0 Hz, 1H), 4.10 (d, J = 9.5 Hz,
1H), 3.86 (dd, J = 12.0, 1.5 Hz, 1H), 3.67 (dd, J = 12.0, 5.5 Hz,
1H), 3.44–3.28 (m, 4H); ESI MS m/z 452 [M+H]+.
5.5.10.
2-(2-chloro-5-((2S,3R,4R,5S,6R)-3,4,5-trihydroxy-6-
5.5.5
2-(2-chloro-5-((2S,3R,4R,5S,6R)-3,4,5-trihydroxy-6-
(hydroxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)-7-methoxy-
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one (5k)
(hydroxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)-6-fluoro-
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one (5f)
This compound was synthesized according to compound 5a but
employing methyl 7-methoxy-[1,2,4]triazolo[4,3-a]pyridin-
3(2H)-one as 14 to give the title compound as a white solid
This compound was synthesized according to compound 5a but
employing 6-fluoro-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one as
14 to give the title compound as a white solid over 2 steps (34%
o
(55% over 2-step). Mp 220 C dec.; 1H NMR (CD3OD, 500
o
over 2 steps). Mp 116-120 C; 1H NMR (CD3OD, 500 MHz) δ
MHz) δ 7.75 (dd, J = 7.0, 1.0 Hz, 1H), 7.40 (app s, 2H), 7.35 (s,

1H), 6.41 (dd, J = 8.0, 2.5 Hz, 1H), 6.36 (d, J = 1.5 Hz, 1H), 5.21
(s, 2H), 4.10 (d, J = 9.5 Hz, 1H), 3.87–3.84 (m, 1H), 3.85 (s, 3H),
3.67 (dd, J = 12.0, 5.5 Hz, 1H), 3.46–3.25 (m, 4H); APCI MS
m/z 452 [M+H]+.
4.10 (d, J = 9.5 Hz, 1H), 3.85 (dd, J = 12.5, 2.0 Hz, 1H), 3.67
(dd, J = 12.0, 5.5 Hz, 1H), 3.45–3.24 (m, 4H), 2.35 (s, 3H); ESI
MS m/z 470 [M+H]+. Anal. Calcd. for C20H21Cl2N3O6: C, 51.08;
H, 4.50; N, 8.93. Found: C, 50.96; H, 4.35; N, 8.80.
5.5.11.
2-(2-chloro-5-((2S,3R,4R,5S,6R)-3,4,5-trihydroxy-6-
5.6.
tris(methoxymethoxy)-6-((methoxymethoxy)methyl)tetrahydro-
2H-pyran-2-yl)benzyloxy)diphenylsilane (18): To stirred
solution of (2S,3R,4R,5S,6R)-2-(3-(((tert-
tert-Butyl(2-chloro-5-((2S,3S,4R,5R,6R)-3,4,5-
(hydroxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)-7-(2,2,2-
trifluoroethoxy)-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one (5l)
a
This compound was synthesized according to compound 5a but
employing methyl 7-(2,2,2-trifluoroethoxy)-[1,2,4]triazolo[4,3-
a]pyridin-3(2H)-one as 14 to give the title compound as a white
butyldiphenylsilyl)oxy)methyl)-4-chlorophenyl)-6-
(hydroxymethyl)tetrahydro-2H-pyran-3,4,5-triol (11) (1.0 g, 1.8
mmol) in dichloromethane (20 mL) at 0 °C was added dropwise
N,N-diisopropylethylamine (2.4 mL, 14.7 mmol) followed by
o
solid (43% over 2 steps). Mp 200 C dec.; 1H NMR (CD3OD,
500 MHz) δ 7.82 (d, J = 7.5 Hz, 1H), 7.40 (app s, 2H), 7.35 (s,
1H), 6.53 (d, J = 2.0 Hz, 1H), 6.50 (dd, J = 8.0, 2.0 Hz, 1H), 5.22
(s, 2H), 4.64 (q, J = 8.0 Hz, 2H), 4.12 (d, J = 8.5 Hz, 1H), 3.86
(d, J = 12.0, 1.5 Hz, 1H), 3.68 (dd, J = 12.0, 5.5 Hz, 1H), 3.46–
3.30 (m, 4H); ESI MS m/z 520 [M+H]+.
chloromethyl methyl ether (2.1 mL, 27.6 mmol).
Then
tetrabutylammonium iodide (2.2 g, 5.9 mmol) was added. The
reaction mixture was warmed to room temperature and stirred for
24 h. The reaction was quenched with saturated sodium
bicarbonate solution at 0 °C and extracted with dichloromethane
(3x). The combined extracts were dried over sodium sulfate,
filtered, and concentrated. The crude material obtained was
purified by flash column chromatography (eluent: hexanes/ethyl
acetate 100:0 to 65:35) to give compound 18 (1.3 g, 98%) as a
colorless syrup:1H NMR (CDCl3, 500 MHz) δ 7.66 (br d, J = 1.3
Hz, 1H), 7.70–7.69 (m, 4H), 7.45–7.42 (m, 2H), 7.40–7.37 (m,
4H), 7.27–7.24 (m, 2H), 4.92 (d, J = 6.4 Hz, 1H), 4.92 (d, J = 6.2
Hz, 1H), 4.88 (d, J = 6.2 Hz, 1H), 4.80 (s, 2H), 4.78 (d, J = 6.4
Hz, 1H), 4.65 (d, J = 6.5 Hz, 1H), 4.63 (d, J = 6.4 Hz, 1H), 4.44
(d, J = 6.4 Hz, 1H), 4.20 (d, J = 9.4 Hz, 1H), 4.10 (d, J = 6.4 Hz,
1H), 3.93 (dd, J = 10.6, 1.2 Hz, 1H), 3.78 (t, J = 8.8 Hz, 1H),
3.69 (dd, J = 11.1, 5.3 Hz, 1H), 3.61–3.59 (m, 2H), 3.52 (t, J =
9.3 Hz, 1H), 3.462 (s, 3H), 3.460 (s, 3H), 3.32 (s, 3H), 2.83 (s,
3H), 1.12 (s, 9H); ESI MS m/z 741 [M+Na]+.
5.5.12
2-(2-chloro-5-((2S,3R,4R,5S,6R)-3,4,5-trihydroxy-6-
(hydroxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)-5-methyl-
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one (5m)
This compound was synthesized according to compound 5a but
employing 5-methyl-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one as
14 to give the title compound as a white solid (40% over 2
steps). 1H NMR (CD3OD, 500 MHz) δ 7.41 (d, J = 1.0 Hz, 2H),
7.34 (s, 1H), 7.04 (dd, J = 9.5, 6.5 Hz, 1H), 6.90 (d, J = 9.5 Hz,
1H), 6.26–6.24 (m, 1H), 5.21 (s, 2H), 4.10 (d, J = 9.5 Hz, 1H),
3.86 (dd, J = 12.0, 2.0 Hz, 1H), 3.67 (dd, J = 12.0, 5.0 Hz, 1H),
3.44–3.25 (m, 4H), 2.78 (s, 3H); ESI MS m/z 436 [M+H]+.
5.5.13
8-chloro-2-(2-chloro-5-((2S,3R,4R,5S,6R)-3,4,5-
trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)-
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one (5n)
5.7. (2-Chloro-5-((2S,3S,4S,5R,6R)-3,4,5-tris(methoxymethoxy)-
6-((methoxymethoxy)methyl)tetrahydro-2H-pyran-2-
yl)phenyl)methanol (19): To a stirred solution of 18 (1.3 g, 1.8
mmol) in tetrahydrofuran (16 mL) at 0 °C was added dropwise
tetrabutylammonium fluoride (1.0 M solution in tetrahydrofuran;
2.2 mL, 2.2 mmol). The reaction mixture was warmed to room
temperature and stirred for 4 h. Then it was concentrated and the
crude material obtained was purified by flash column
chromatography (eluent: hexanes/ethyl acetate 100:0 to 75:25) to
give compound 19 (0.81 g, 94%) as a colorless syrup: 1H NMR
(CDCl3, 500 MHz) δ 7.54 (br d, J = 2.0 Hz, 1H), 7.33 (d, J = 8.2
Hz, 1H), 7.28 (dd, J = 8.2, 2.0 Hz, 1H), 4.91 (d, J = 6.4 Hz, 1H),
4.89 (d, J = 6.3 Hz, 1H), 4.87 (d, J = 6.3 Hz, 1H), 4.78–4.76 (m,
3H), 4.65 (s, 2H), 4.47 (d, J = 6.5 Hz, 1H), 4.19 (d, J = 9.5 Hz,
1H), 4.14–4.10 (m, 2H), 3.92 (dd, J = 11.3, 1.6 Hz, 1H), 3.76 (t, J
= 8.8 Hz, 1H), 3.71 (dd, J = 11.2, 5.2 Hz, 1H), 3.63–3.58 (m,
2H), 3.53 (t, J = 9.4 Hz, 1H), 3.452 (s, 3H), 3.448 (s, 3H), 3.34
(s, 3H), 2.82 (s, 3H); ESI MS m/z 481 [M+H]+.
This compound was synthesized according to compound 5a but
employing 8-chloro-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one as
14 to give the title compound as a white solid (51% over 2
1
steps). Mp 122-130 oC; H NMR (CD3OD, 500 MHz) δ 7.85 (dd,
J = 7.0, 1.0 Hz, 1H), 7.42 (s, 2H), 7.39 (dd, J = 7.5, 1.0 Hz, 1H),
7.36 (s, 1H), 6.66 (t, J = 7.0 Hz, 1H), 5.32 (s, 2H), 4.11 (d, J =
9.5 Hz, 1H), 3.85 (dd, J = 7.3, 1.0 Hz, 1H), 3.67 (dd, J = 8.5, 2.5
Hz, 1H), 3.45–3.24 (m, 4H); ESI MS m/z 456 [M+H]+.
5.5.14.
2-(2-chloro-5-((2S,3R,4R,5S,6R)-3,4,5-trihydroxy-6-
(hydroxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)-8-fluoro-
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one (5o)
This compound was synthesized according to compound 5a but
employing methyl 8-fluoro-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-
one 14 to give the title compound as a white solid (29% over 2
1
steps). Mp 117-121 oC; H NMR (CD3OD, 500 MHz) δ 7.73 (d,
5.8.
(2S,3S,4S,5R,6R)-2-(3-(Bromomethyl)-4-chlorophenyl)-
J = 7.0 Hz, 1H), 7.42 (s, 2H), 7.39 (s, 1H), 7.03 (dd, J = 11.5, 7.5
Hz, 1H), 6.63 (dd, J = 11.5, 7.0 Hz, 1H), 5.31 (s, 2H), 4.11 (d, J
= 9.0 Hz, 1H), 3.86 (dd, J = 12.5, 2.0 Hz, 1H), 3.68 (dd, J = 12.0,
5.0 Hz, 1H), 3.46–3.25 (m, 4H); ESI MS m/z 440 [M+H]+.
3,4,5-tris(methoxymethoxy)-6-((methoxymethoxy)methyl)-
tetrahydro-2H-pyran (20): To a stirred solution of 19 (470 mg,
0.98 mmol) and triethylamine (0.54 mL, 3.90 mmol) in
toluene/ethyl acetate (1:1, 12 mL) at 0 °C was added dropwise
methanesulfonyl chloride (0.15 mL, 1.95 mmol). The reaction
mixture was stirred at 0 °C for 2 h. The white precipitate formed
during the reaction was filtered off and washed with ethyl
acetate. The combined filtrate and washing were concentrated.
The residual oil was dissolved in acetone (6 mL) and treated with
lithium bromide (850 mg, 10.0 mmol) at 0 °C. After stirring at
room temperature for 1 h, the reaction was quenched with water
(25 mL) and extracted with ethyl acetate (4x). The combined
5.5.15
6-chloro-2-(2-chloro-5-((2S,3R,4R,5S,6R)-3,4,5-
trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)-
7-methyl-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one (5p)
This compound was synthesized according to compound 5a but
employing
6-chloro-7-methyl-[1,2,4]triazolo[4,3-a]pyridin-
3(2H)-one 14 to give the title compound as a white solid (43%
over 2 steps). Mp 124-131oC; 1H NMR (CD3OD, 500 MHz) δ
7.98 (s, 1H), 7.40 (s, 2H), 7.34 (s, 1H), 7.08 (s, 1H), 5.25 (s, 2H),

extracts were dried over sodium sulfate, filtered, and
concentrated to give compound 20 (517 mg, 97%) as a white
solid: 1H NMR (CDCl3, 500 MHz) δ 7.46 (d, J = 2.0 Hz, 1H),
7.37 (d, J = 8.3 Hz, 1H), 7.30 (dd, J = 8.3, 2.0 Hz, 1H), 4.91 (d, J
= 6.4 Hz, 1H), 4.89–4.86 (m, 2H), 4.77 (d, J = 6.4 Hz, 1H), 4.66
(s, 2H), 4.60–4.55 (m, 2H), 4.54 (d, J = 6.4 Hz, 1H), 4.17 (d, J =
9.4 Hz, 1H), 4.13 (d, J = 6.5 Hz, 1H), 3.92 (dd, J = 11.2, 1.6 Hz,
1H), 3.75 (t, J = 8.8 Hz, 1H), 3.71 (dd, J = 11.2, 5.2 Hz, 1H),
3.63–3.58 (m, 2H), 3.52 (t, J = 9.3 Hz, 1H), 3.450 (s, 3H), 3.446
(s, 3H), 3.34 (s, 3H), 2.79 (s, 3H); ESI MS m/z 543 [M+H]+.
extracts were dried over sodium sulfate, passed through a short
pad of silica gel, and concentrated. The coupling product
obtained was then stirred overnight with 6 N HCl/methanol (20:1
v/v) at room temperature. The reaction mixture was concentrated
to dryness and the residual material was purified by flash column
chromatography (eluent: dichloromethane/methanol 100:0 to
90:10) to provide the C-glycoside 33b as an off-white solid (26
o
mg, 36% over 2 steps). Mp 150-156 C; 1H NMR (CD3OD, 500
MHz) δ 7.52 (br d, J = 8.7 Hz, 2H), 7.36 (d, J = 2.1 Hz, 1H), 7.34
(dd, J = 8.3, 2.1 Hz, 1H), 7.29 (dd, J = 8.3, 2.1 Hz, 1H), 7.22 (br
d, J = 8.7 Hz, 2H), 4.38 (s, 2H), 4.10–4.08 (m, 3H), 3.86 (dd, J =
11.9, 1.7 Hz, 1H), 3.68 (dd, J = 11.9, 5.3 Hz, 1H), 3.60 (q, J =
7.2 Hz, 2H), 3.44–3.37 (m, 3H), 3.27 (d, J = 9.0 Hz, 1H), 1.22 (t,
J = 7.2 Hz, 3H); ESI MS m/z 491 [M+H]+.
5.9. Typical procedure for preparation of boronic esters 31a-c as
exemplified by the preparation of 3-ethyl-1-(4-(4,4,5,5-
tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)imidazolidine-2,4-
dione (31b).
5.10.1. 1-(4-(2-Chloro-5-((2S,3R,4R,5S,6R)-3,4,5-trihydroxy-6-
(hydroxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)phenyl)-3-
tritylimidazolidine-2,4-dione (28)
A mixture of 1-(4-bromophenyl)-3-ethylimidazolidine-2,4-dione
(30b; 278 mg, 0.98 mmol), bis(pinacolato)diboron (274 mg, 1.08
mmol), KOAc (289 mg, 2.95 mmol), and Pd(dppf)Cl2 (80 mg,
0.098 mmol) in DMSO (5 mL) was heated at 80 °C under
nitrogen for 14 h, cooled to room temperature and poured into
water (25 mL). The precipitate was collected, washed with water
and dissolved in dichloromethane. The resulting solution was
dried over sodium sulfate, filtered, and concentrated. The crude
material obtained was purified by flash column chromatography
(eluent: hexanes/ethyl acetate 100:0 to 65:35) to give compound
31b (161 mg, 50%) as a light yellow solid: 1H NMR (CDCl3, 500
MHz) δ 7.83 (d, J = 8.6 Hz, 2H), 7.58 (d, J = 8.6 Hz, 2H), 4.30
(s, 2H), 3.67 (q, J = 7.2 Hz, 2H), 1.35 (s, 12H), 1.28 (t, J = 7.2
Hz, 3H); ESI MS m/z 331 [M+H]+.
This compound was synthesized according to compound 33b but
employing 26 to give the title compound as a yellow solid (40
1
mg, 44% over 2 steps). H NMR (CD3OD, 500 MHz) δ 7.71–
7.49 (m, 6H), 7.40 (br d, J = 8.7 Hz, 2H), 7.33 (d, J = 8.2 Hz,
1H), 7.32 (d, J = 1.9 Hz, 1H), 7.28 (dd, J = 8.2, 1.9 Hz, 1H),
7.25–7.22 (m, 6H), 7.18–7.16 (m, 5H), 4.35 (s, 2H), 4.12–4.02
(m, 3H), 3.86 (dd, J = 12.0, 1.8 Hz, 1H), 3.68 (dd, J = 12.0, 5.1
Hz, 1H), 3.45–3.25 (m, 4H); ESI MS m/z 727 [M+Na]+.
5.10.2. 1-(4-(2-Chloro-5-((2S,3R,4R,5S,6R)-3,4,5-trihydroxy-6-
(hydroxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)phenyl)-3,5,5-
trimethylimidazolidine-2,4-dione (33a)
This compound was synthesized according to compound 33b but
employing 31a to give the title compound as an off-white solid
5.9.1. 3,5,5-Trimethyl-1-(4-(4,4,5,5-tetramethyl-1,3,2-
dioxaborolan-2-yl)phenyl)imidazolidine-2,4-dione (31a)
o
(16 mg, 48% over 2 steps). Mp 110-121 C; 1H NMR (CD3OD,
500 MHz) δ 7.42 (d, J = 2.0 Hz, 1H), 7.36 (d, J = 8.2 Hz, 1H),
7.33–7.30 (m, 3H), 7.21 (br d, J = 8.4 Hz, 2H), 4.17–4.10 (m,
3H), 3.86 (dd, J = 12.0, 1.6 Hz, 1H), 3.69 (dd, J = 12.0, 5.3 Hz,
1H), 3.48–3.39 (m, 3H), 3.28 (d, J = 9.0 Hz, 1H), 3.04 (s, 3H),
1.38 (s, 6H); ESI MS m/z 505 [M+H]+.
This compound was synthesized according to compound 31b but
employing 30a to give the title compound as a yellow solid (61
1
mg, 82%). H NMR δ 7.89–7.87 (m, 2H), 7.28–7.23 (m, 2H),
3.12 (s, 3H), 1.44 (s, 6H), 1.35 (s, 12H); ESI MS m/z 345
[M+H]+.
5.10.3. 1-(4-(2-Chloro-5-((2S,3R,4R,5S,6R)-3,4,5-trihydroxy-6-
(hydroxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)phenyl)-3-
isopropylimidazolidine-2,4-dione (33c)
5.9.2. 3-Isopropyl-1-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-
2-yl)phenyl)imidazolidine-2,4-dione (31c)
This compound was synthesized according to compound 31b but
employing 30c to give the title compound as an off-white solid
This compound was synthesized according to compound 33b but
employing 31c to give the title compound as a yellow solid (17
1
(34 mg, 63%). H NMR 7.83–7.81 (m, 2H), 7.58–7.56 (m, 2H)
o
mg, 49% over 2 steps). Mp 125-134 C; 1H NMR (CD3OD, 500
4.44 (Septet, J = 7.0 Hz, 1H), 4.23 (s, 2H), 1.48 (d, J = 7.0 Hz,
6H), 1.35 (s, 12H); ESI MS m/z 345 [M+H]+.
MHz) δ 7.50 (d, J = 8.5 Hz, 2H), 7.36–7.34 (m, 2H), 7.29 (dd, J
= 8.2, 1.6 Hz, 1H), 7.22 (d, J = 8.5 Hz, 2H), 4.36 (7, J = 6.9 Hz,
1H), 4.32 (s, 2H), 4.12–4.04 (m, 3H), 3.88 (d, J = 11.7 Hz, 1H),
3.69 (dd, J = 11.9, 4.8 Hz, 1H), 3.45–3.39 (m, 3H), 3.27 (d, J =
9.1 Hz, 1H), 1.44 (d, J = 6.9 Hz, 6H); ESI MS m/z 505 [M+H]+.
Anal. Calcd. for C24H27ClN2O7: C, 58.72; H, 5.54; N, 5.71.
Found: C, 58.64; H, 5.44; N, 5.55.
5.10. Typical procedure for the synthesis of 28, 33a-c, and 39 via
Suzuki coupling and deprotection of MOM groups as
exemplified by the preparation of 1-(4-(2-Chloro-5-
((2S,3R,4R,5S,6R)-3,4,5-trihydroxy-6-
(hydroxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)phenyl)-3-
ethylimidazolidine-2,4-dione (33b)
5.10.4. 3-(4-(2-Chloro-5-((2S,3R,4R,5S,6R)-3,4,5-trihydroxy-6-
(hydroxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)phenyl)-1-
methylimidazolidine-2,4-dione (39)
A mixture of 20 (82 mg, 0.15 mmol), the boronic ester 31b (0.18
mmol, 1.2 equiv), sodium carbonate (48 mg, 0.45 mmol), and
Pd(dppf)Cl2
(12.2
mg,
0.015
mmol)
in
N,N-
This compound was synthesized according to compound 33b but
employing 37 to give the title compound as an off-white solid (25
dimethylformamide/water (2:1, 2.1 mL) was heated at 80 °C
under nitrogen for 4 h. The reaction was quenched with water
(10 mL) and extracted with ethyl acetate (4x). The combined
1
mg, 47%). Mp 136-151 oC; H NMR (CD3OD, 500 MHz) δ 7.40
(d, J = 2.0 Hz, 1H), 7.36 (d, J = 8.3 Hz, 1H), 7.33–7.29 (m, 3H),

2. (a) Mackenzie, B.; Loo, D. D. J. Biol. Chem. 1996, 20, 32678. (b)
Wright, E. M. Am. J. Physiol. 2001, 280, F10. (c) Wright, E. M.;
Turk, E.; Hager, K.; Lescale-Matys, L.; Hirayama, B.; Supplisson,
S.; Loo, D. D. F. Acta Physiol. Scand. Suppl. 1992, 607, 201. (d)
Wright, E. M.; Hirayama, B.; Hazama, A.; Loo, D. D. F.;
Supplisson, S.; Turk, E.; Hager, K. M. Soc. Gen. Physiol. Ser.
1993, 48, 229. (e) Wells, R. G.; Pajor, A. M.; Kanai, Y.; Turk, E.;
Wright, E. M.; Hediger, M. A. Am. J. Physiol. 1992, 263, F459. (f)
Kanai, Y.; Lee, W.-S.; You, G.; Brown, D.; Hediger, M. A. J.
Clin. Invest. 1994, 93, 397. (g) Van den Heuvel, L. P.; Assink, K.;
Willemsen, M.; Monnens, L. Hum. Genet. 2002, 111, 544; (h)
Santer, R.; Kinner, M.; Lassen, C. L.; Schneppenheim, R.; Eggert,
P.; Bald, M.; Brodehl, J.; Daschner, M.; Ehrich, J. H. H.; Kemper,
M.; Volti, S. L.; Neuhaus, T.; Skovby, F.; Swift, P. G. F.; Schaub,
J.; Klaerke, D. J. Am. Soc. Nephrol. 2003, 14, 2873; (i) Francis, J.;
Zhang, J.; Farhi, A.; Carey, H.; Geller, D. S. Nephrol. Dial.
Transplant. 2004, 19, 2893; (j) Kleta, R.; Stuart, C.; Gill, F. A.;
Gahl, W. A. Mol. Genet. Metab. 2004, 82, 56; (k) Magen, D.;
Sprecher, E.; Zelikovic, I.; Skorecki, K. Kidney Int. 2005, 67, 34.
(l) Lam, J. T.; Martín, M. G.; Turk, E.; Hirayama, B. A.;
Bosshard, N. U.; Steinmann, B.; Wright, E. M. Biochim. Biophys.
Acta 1999, 1453, 297. (m) Washburn, W. N. In: Jones, R.M.;
Thurston, D. E.; Rotella, D.; Guccione, S.; Martinez, A.; Fox, D.;
Ganellin, R (Eds.). New Therapeutic Strategies for Type 2
Diabetes: Small Molecule Approaches. Royal Society of
Chemistry Press; 2012. p 29-87.
7.26 (dt, J = 8.5, 2.0 Hz, 2H), 4.20–4.14 (m, 2H), 4.11 (d, J = 9.5
Hz, 1H), 4.08 (s, 2H), 3.87 (dd, J = 12.0, 1.8 Hz, 1H), 3.69 (dd, J
= 12.0, 5.3 Hz, 1H), 3.48–3.36 (m, 3H), 3.28 (d, J = 8.9 Hz, 1H),
3.02 (s, 3H); ESI MS m/z 477 [M+H]+.
5.11. In Vitro Human SGLT Uptake Assays. The cDNAs for the
human genes of SGLT-1 (SLC5A1 – solute carrier family 5
sodium/glucose co-transporter member 1; Accession
#NM_000343.1) or SGLT-2 (SLC5A2 – member 2; Accession
#NM_003041.2) were synthesized (OriGene Technologies, Inc.)
and sub-cloned into the mammalian expression vector,
pcDNA3.1 (Invitrogen Corp., Carlsbad, CA) using standard
molecular biology techniques. CHO-K1 cells transfected with
pcDNA3.1 (Invitrogen Corp., Carlsbad, CA) containing either
the full-length hSGLT-1 or hSGLT-2 using Lipofectamine 2000
(Invitrogen Corp., Carlsbad, CA) were selected for stable
incorporation of the construct by resistance to the selective
pressure of Geneticin (450 µg/ml; Invitrogen Corp., Carlsbad,
CA). Monoclonal cell lines isolated by minimal dilution were
screened for uptake activity of radiolabled methyl α-D-
glucopyranoside ([14C]AMG), a non-metabolizable glucose
analogue, and a single clone for each transporter was selected for
maximal transporter activity to be used for evaluating the
inhibitory activity of the compounds of this invention. In brief,
35,000 cells (CHO-K1/hSGLT-1 or CHO-K1/hSGLT-2) were
plated per well of a black tissue culture treated 96-well plate in
Ham’s F12 media supplemented with 10% heat inactivated FBS
and allowed to attached overnight at 37°C and 5% CO2.
Compounds were serially diluted 3-fold in DMSO generating a
nine (9) data point dose response curve for each compound. Two
replicates were performed per determination. The compounds
were then diluted into Uptake Buffer (10mM Hepes, 5mM Tris,
137mM NaCl, 5.4mM KCl, 2.8mM CaCl2, and 1.2 mM MgSO4,
pH 7.4) with a final DMSO concentration of 0.9% (v/v). After
the overnight incubation and prior to compound treatment, the
cells were washed twice with Sodium Free Buffer in which the
sodium chloride was replaced with 137mM Choline Chloride,
and then incubated with 4µM [14C]AMG in Uptake Buffer in the
presence or absence of diluted compound. Following a 3-hr
incubation at 37°C and 5% CO2, the uptake reaction was stopped
by washing the cells three (3) times with ice-cold D-PBS and
then lysing the cells with 50µl of Microscint-20. After 15-min,
the amount of radioactivity that was incorporated into the cells
was quantified using a Microbeta reader. Data were fit to an
empirical four-parameter model to determine the inhibitor
concentration at half-maximal response (IC50). The assay
window was established by control wells incubated with
[14C]AMG in the presence or absence of sodium. A dose
response curve for phlorizin was generated on every plate as a
positive control.
3. Liu, S.; Guo, C.; Hu, M.; Kitchen, D. B.; Guzzo, P. R.; Deorazio,
R. U.S. Pat. Appl. Publ., 2011, US 20110237527.
4. Meng, W.; Ellsworth, B. A.; Nirschl, A. A.; McCann, P. J.; Patel,
M.; Girotra, R. N.; Wu, G.; Sher, P. M.; Morrison, E. P.; Biller, S.
A.; Zahler, R.; Deshpande, P. P.; Pullockaran, A.; Hagan, D. L.;
Morgan, N.; Taylor, J. R.; Obermeier, M. T.; Humphreys, W. G.;
Khanna, A.; Discenza, L.; Robertson, J. G.; Wang, A.; Han, S.;
Wetterau, J. R.; Janovitz, E. B.; Flint, O. P.; Whaley, J. M.;
Washburn, W. N. J. Med. Chem. 2008, 51, 1145.
5. Substituted triazolopyridones 14 were prepared from the
corresponding 2-halogen pyridine 16 by first subjecting to
hydrazine at 70°C to give 2-pyridyl hydrazine 17, followed by
cyclization using 1,1’-carbonyldiimidazole. Alternatively, it could
be prepared in one step by heating a 2-halogenated pyridine with
semicarbazide in ethoxyethanol.
6. By Smith, D. A. Edited by Lyubimov, A. V.; Rodrigues, A.; Sinz,
M. A. Encyclopedia of Drug Metabolism and Interactions. Vol 3,
3-22. John Wiley & Sons, Inc. 2012.
7.
8.
Washburn, W. N. J. Med. Chem. 2009, 52, 1785.
(a) Langle, S.; Abarbri, M.; Duchene, A. Tetrahedron. Lett. 2003,
44, 9255. (b) For a recent report on application of this strategy to
synthesis of C-glucosides, see: Lee, J.; Kim, J. Y.; Choi, J.; Lee,
S.-H.; Kim, J.; Lee, J. Bioorg. Med. Chem. Lett. 2010, 20, 7046.
9. Renodon-Corniere, A.; Dijols, S.; Perollier, C.; Lefevre-
Groboillot, D.; Boucher, J.-L.; Attias, R.; Sari, M.-A.; Stuehr, D.;
Mansuy, D. J. Med. Chem. 2002, 45, 944.
10. Kumar, L. V.; Kaushik, M. P.; Mazumdar, A. Eur. J. Org. Chem.
2008, 1910.
11. Cowan, D. J.; Larkin, A. L.; Zhang, C.; Musso, D. L.; Green, G.
M.; Cadilla, R.; Spearing, P. K.; Bishop, M. J.; Speake, J. D. PCT
Int. Appl., 2008, WO2008021849.
References and notes
12. Milcent, R.; Akhnazarian, A.; Lensen, N. J. Heterocyclic Chem.
1996, 33, 1829.
13. Ryczek, J. J. Heterocyclic Chem. 2002, 39, 997.
1. (a) Norman, P. Diabetes Pipeline: Intense Activity to Meet Unmet
Need, Insight Pharma Reports, Cambridge Health Institute,
September 2010. (b) Dwarakanathan, A. J. Insur. Med. 2006, 38,
20.

Figure 1. Structures of C-aryl glucoside SGLT2 inhibitors.
R
R
1
3
O
3
O
1
8
7
R
6
N
N
Cl
OH
O
O
N
N
Cl
N
Cl
N
OH
O
OH
O
HO
HO
N
5
HO
HO
HO
HO
O
OH
O
OH
OH
5
6
7
Figure 2. Triazolopyridine analogues (5) and hydantoin
analogues (6 and 7).
Hydantoin
Hydantoin
OMOM
O
Cl
Cl
OH
O
O
MOMO
MOMO
HO
HO
B
O
Br
+
MOMO
HO
Figure 3. Synthetic strategy of hydantoin analogues.
Scheme 1. a. tert-BuLi, THF, –78 °C; MsOH/MeOH; b. Et3SiH,
BF3•OEt2, CH2Cl2, 0 °C; c. Ac2O, pyridine, DMAP (cat.), CHCl3;
d. TBAF, HOAc, THF; e. 145, PPh3, DEAD, THF, rt; f. K2CO3,
MeOH; or HCl, MeOH

Scheme 2. Reagents and conditions: (a) MOMCl, i-Pr2NEt, n-
Bu4NI, CH2Cl2, 0 ° C then rt, 98%; (b) TBAF, THF, 0 °C then rt,
94%; (c) i. MeSO2Cl, Et3N, toluene/EtOAc, 0 °C; ii. LiBr,
acetone, 0 °C to rt, 97%.
O
O
NH2
NH
NTr
CN
N
OMe
O
NHCN
b
a
c
O
d
O
N
N
Br
Br
Br
Br
Br
21
22
23
24
25
O
NTr
O
NTr
O
N
f
e
O
Cl
N
OMOM
O
Cl
O
OMOM
O
B
O
MOMO
MOMO
MOMO
MOMO
Br
MOMO
26
27
MOMO
20
O
NH
O
NTr
O
Cl
N
OH
O
g
O
Cl
N
X
OH
HO
HO
O
HO
HO
HO
HO
29
28
Scheme 3. Reagents and conditions: (a) BrCN, NaOAc, MeOH,
0 °C to rt, 59%; (b) BrCH2CO2Me, NaH, DMF, 0 °C; (c) 50%
H2SO4, THF, 0 °C to rt, 89% over 2 steps; (d) TrCl, Et3N, CH2Cl2,
0 °C to rt, 91%; (e) bis(pinacolato)diboron, Pd(dppf)Cl2, KOAc,
DMSO, 80 °C, 58%; (f) 20, Pd(dppf)Cl2, Na2CO3, DMF/H2O, 80
°C, 57%; (g) 6 N HCl, MeOH, rt, 77%.
R
O
R
N
O
O
N
NH
O
N
c
b
a
O
N
O
N
R'
R'
R'
O
Cl
OMOM
O
R'
B
Br
MOMO
MOMO
Br
O
Br
MOMO
20
31a R = R' = Me
31b R = Et, R' = H
31c
30a R = R' = Me
30b
30c R - i-Pr, R' = H
24
R = Et, R' = H
R - i-Pr, R' = H
R
R
O
O
N
N
O
d
Cl
N
OMOM
O
O
Cl
N
OH
R'
MOMO
MOMO
R'
O
R'
R'
HO
HO
MOMO
HO
32a R = R' = Me
32b R = Et, R' = H
32c R - i-Pr, R' = H
33a R = R' = Me
33b
R = Et, R' = H
33c R - i-Pr, R' = H
Scheme 4. Reagents and conditions: (a) NaH, RI, DMF, 0 °C to
rt, 45-61%; (b) bis(pinacolato)diboron, Pd(dppf)Cl2, KOAc,
DMSO, 80 °C, 63-82%; (c) 20, Pd(dppf)Cl2, Na2CO3, DMF/H2O,
80 °C, 58-67%; (d) 6 N HCl, MeOH, rt, 70-77%.

Me
O
Me
N
O
O
O
NH
O
N
H
N
H
N
N
NH2
a
N
b
c
N
d
OEt
O
O
O
Br
B
O
O
Br
Br
Br
34
35
36
37
21
Me
Me
O
O
N
N
e
f
Cl
N
Cl
N
OMOM
O
OH
O
OMOM
O
Cl
HO
HO
O
MOMO
MOMO
O
MOMO
Br
MOMO
HO
MOMO
MOMO
39
38
20
Scheme 5. Reagents and conditions: (a) OCNCH2CO2Et,
CH2Cl2, rt, 91%; (b) 6 N HCl, EtOH, reflux, 79%; (c) MeI,
K2CO3, DMF, 0 °C to rt, 75%; (d) bis(pinacolato)diboron,
Pd(dppf)Cl2, KOAc, DMSO, 80 °C, 18%; (e) 20, Pd(dppf)Cl2,
Na2CO3, DMF/H2O, 80 °C 57%; (f) 6 N HCl, MeOH, rt, 70%.
Table 1. In vitro inhibitory activity of triazolopyridone analogues
a
SGLT2 IC50
Compound
R
(nM)
1
83
1
5a
5b
5c
5d
5e
5f
5g
5h
5i
5j
5k
5l
5m
5n
5o
5p
H
6-Cl
6-Br
6-Me
6-CH2OH
6-F
6-CF3
7-Cl
7-Me
7-CF3
7-OMe
7-OCH2CF3
5-Me
80
107
120
141
222
762
89
110
252
5478
5699
9916
9000
3296
33
8-Cl
8-F
6-Cl, 7-Me
a
The data were obtained from at least two independent
experiments
Table 2. In vitro inhibitory activity of hydantoin analogues
a
SGLT2 IC50
(nM)
328
SGLT1 IC50
(nM)
6252
Compound
28
33a
33b
33c
39
248
10.9
23.6
489
83060
17500
35308
90000
a The data were obtained from at least two independent
experiments.

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The design and synthesis of novel SGLT2
inhibitors: C-glycosides with
benzyltriazolopyridinone and
phenylhydantoin as the aglycone moieties
Cheng Guo, Min Hu, Russell J. DeOrazio, Alex Usyatinsky, Kevin Fitzpatrick, Jun-Ho Maeng, Douglas B.
Kitchen, Susan Tom, Michele Luche, Yuri Khmelnitsky, Drew J. Mhyre, Peter R. Guzzo, Shuang Liu*
AMRI, 26 Corporate Circle, PO Box 15098, Albany, NY 12212-5098, USA