Small molecule disruptors of the glucokinase-glucokinase regulatory protein interaction: 3. Structure-activity relationships within the aryl carbinol region of the N-arylsulfonamido-N′-arylpiperazine series

Article abstract of DOI:10.1021/jm5000497

We have recently reported a novel approach to increase cytosolic glucokinase (GK) levels through the binding of a small molecule to its endogenous inhibitor, glucokinase regulatory protein (GKRP) these initial investigations culminated in the identification of 2-(4-((2S)-4-((6-amino-3- pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-1-piperazinyl)phenyl)-1,1,1,3,3, 3-hexafluoro-2-propanol (1, AMG-3969), a compound that effectively enhanced GK translocation and reduced blood glucose levels in diabetic animals. Herein we report the results of our expanded SAR investigations that focused on modifications to the aryl carbinol group of this series. Guided by the X-ray cocrystal structure of compound 1 bound to hGKRP, we identified several potent GK-GKRP disruptors bearing a diverse set of functionalities in the aryl carbinol region. Among them, sulfoximine and pyridinyl derivatives 24 and 29 possessed excellent potency as well as favorable PK properties. When dosed orally in db/db mice, both compounds significantly lowered fed blood glucose levels (up to 58%).

Full text of DOI:10.1021/jm5000497

Article
pubs.acs.org/jmc
Small Molecule Disruptors of the Glucokinase−Glucokinase
Regulatory Protein Interaction: 3. Structure−Activity Relationships
within the Aryl Carbinol Region of the
N‑Arylsulfonamido‑N′‑arylpiperazine Series
Nobuko Nishimura,*,† Mark H. Norman,*,† Longbin Liu,† Kevin C. Yang,† Kate S. Ashton,†
Michael D. Bartberger,‡ Samer Chmait,‡ Jie Chen,∥ Rod Cupples,§ Christopher Fotsch,† Joan Helmering,§
Steven R. Jordan,‡ Roxanne K. Kunz,† Lewis D. Pennington,† Steve F. Poon,† Aaron Siegmund,†
Glenn Sivits,§ David J. Lloyd,§ Clarence Hale,§ and David J. St. Jean, Jr.†
‡
†Department of Therapeutic DiscoveryMedicinal Chemistry, Department of Therapeutic DiscoveryMolecular Structure and
§
∥
Characterization, Department of Metabolic Disorders, and Department of Pharmacokinetics and Drug Metabolism, Amgen Inc.,
One Amgen Center Drive, Thousand Oaks, California 91320-1799, United States
S
* Supporting Information
ABSTRACT: We have recently reported a novel approach to
increase cytosolic glucokinase (GK) levels through the binding
of a small molecule to its endogenous inhibitor, glucokinase
regulatory protein (GKRP). These initial investigations
culminated in the identification of 2-(4-((2S)-4-((6-amino-3-
pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-1-piperazinyl)phenyl)-
1,1,1,3,3,3-hexafluoro-2-propanol (1, AMG-3969), a compound that effectively enhanced GK translocation and reduced blood
glucose levels in diabetic animals. Herein we report the results of our expanded SAR investigations that focused on modifications
to the aryl carbinol group of this series. Guided by the X-ray cocrystal structure of compound 1 bound to hGKRP, we identified
several potent GK−GKRP disruptors bearing a diverse set of functionalities in the aryl carbinol region. Among them, sulfoximine
and pyridinyl derivatives 24 and 29 possessed excellent potency as well as favorable PK properties. When dosed orally in db/db
mice, both compounds significantly lowered fed blood glucose levels (up to 58%).
GK and sequestering it inside the nucleus when the glucose
level is low.6 By disrupting the GK−GKRP interaction, we
postulated that more unbound GK would be available to
regulate glucose levels, and since the kinetic parameters of GK
(Vmax and S0.5) would not be altered by this mechanism, the risk
of hypoglycemia would be reduced.
INTRODUCTION
■
Diabetes affects ∼370 million people worldwide, and the health
expenditures related to diabetes have been estimated to be over
471 billion dollars per year.1 Current treatments for diabetes
include patient education (lifestyle changes), insulin injections,
and antidiabetic drugs (to control blood glucose levels).
Despite many years of efforts to effectively manage diabetes,
there is still a great unmet medical need for orally available, safe,
and effective drugs for the treatment of diabetes.2 Allosteric
activation of glucokinase (GK) by small molecules has recently
been targeted by several pharmaceutical companies for the
potential treatment of diabetes.3 Even though this approach has
had some initial success (glucose lowering effect in animals and
in phase I clinical trials), undesirable side effects (e.g.,
hypoglycemia) and loss of efficacy in longer term phase II
clinical trials have hindered the advancement of this class of
antidiabetic agents.4 Other strategies to minimize hypoglycemic
risk have included designing GK activators that are exclusively
taken up by the liver.5 These molecules are substrates for
organic anion transporters and therefore result in selective
activation of hepatic GK.
In our previous publications, we described the identification
of a series of piperazine-based small molecule GK−GKRP
disruptors.7,8 These investigations led to the development of
metabolically stable GK−GKRP disruptors that were potent
and efficacious, culminating in the identification of compound 1
(AMG-3969) and its close analogue 2.9 Both compounds were
potent (IC50 < 10 nM) in the biochemical assay (AlphaScreen),
which measured the compound’s abilities to disrupt the GK−
GKRP interaction.10 They were also effective (EC50 ≈ 100−
200 nM) in the functional mouse hepatocyte assay that
measured the translocation of GK from the nucleus to the
cytoplasm.11 Compounds 1 and 2 also had good in vivo
pharmacokinetic (PK) properties in rats (F of 75% and 82%,
respectively) and were found to significantly lower blood
glucose levels in db/db mice.
Glucokinase regulatory protein (GKRP) plays a key role in
controlling GK levels in hepatocytes by releasing GK from the
nucleus when the blood glucose level is high and by binding to
Received: January 21, 2014
Published: March 10, 2014
© 2014 American Chemical Society
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In our preliminary SAR studies, the sulfonamide (region A in
Figure 1) and the central core piperazine (region B in Figure 1)
areas were extensively investigated; however, the SAR around
the phenyl carbinol (region C in Figure 1) was very limited.8,9
In these initial investigations, the C region was restricted to
only phenyl-bis-trifluoromethyl carbinol (e.g., 1) and
phenylmethyltrifluoromethyl carbinol (e.g., 2), which had
comparable potencies. Therefore, we wanted to explore the
SAR around the C region in more detail. Toward that end, we
first examined the X-ray structure of compound 1 bound to
hGKRP (Figure 2).9 To focus better in this area, only the
residues in proximity to the C region of compound 1 are
highlighted in the structures of Figure 2.12 As can be seen from
each of the four views, the phenyl C-ring of compound 1 sits
deep within the binding pocket and occupies a hydrophobic
area of the protein. This C-ring is sandwiched between Ala521
on the top and Val28 on the bottom with Glu32 and Tyr24
residues on either side (top and bottom views). The carbinol
oxygen forms a strong hydrogen bond with Arg525, while the
two trifluoromethyl groups occupy two channels, one
projecting toward Phe526, Met522, and His504 and the
other projecting toward Lys33 and Ser34 (side and end views).
To further expand the SAR in this region and increase the
chemical diversity within this series, we set out with three main
goals (as illustrated in general structure 3 in Figure 3): (1) to
probe the channels occupied by the two trifluoromethyl groups
Figure 1. Region representation of compounds 1 and 2.
́
Figure 2. X-ray cocrystal structure of compound 1 bound to full-length hGKRP. Note that only the residues within ∼5.5 Å of the C-region of
compound 1 are illustrated.
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with small hydrophobic and hydrophilic substituents; (2) to
evaluate non-carbinol functional groups that could engage in
with Arg525; (3) to examine the effect of various five- and six-
membered heterocyclic replacements to the phenyl C-ring.
by treating with sulfuric acid in chloroform. In the case of N-
benzyl intermediates 7, the compounds were treated with 1-
chloroethyl chlorocarbonate followed by heating in methanol to
provide the corresponding deprotected intermediates 8.15 N-
Arylpiperazines 8 were reacted with tert-butyl (5-
(chlorosulfonyl)pyridin-2-yl)carbamate (9)13 and triethylamine
or diisopropylethylamine in dichloromethane. Subsequent
cleavage of the tert-butyloxycarbonyl (Boc) group with
trifluoroacetic acid afforded the target sulfonamides 10−19
and 25−28. The methylsulfone and isopropylsulfonamide
derivatives (20 and 21, respectively) were obtained by
separation of the corresponding racemic intermediates by
chiral supercritical fluid chromatography (SFC) (these
derivatives were prepared from the racemic 2-alkynylpiperazine,
6). Compounds 22 and 28 were also subjected to chiral SFC
purification to afford the pure diastereomers 23 and 24 as well
as 29 and 30, respectively.16
Scheme 2 outlines the synthesis of compounds that required
further modifications to the C-ring substituent after they were
coupled with the 2-alkynylpiperazine (4 or 5). The synthesis of
(S)-cyclopropylsulfoximine 47 started by coupling 2-alkynylpi-
perazine 5 with 1-bromo-4-(cyclopropylsulfanyl)benzene13 to
obtain intermediate 31. The coupled product was then
debenzylated and reacted with sulfonyl chloride 9 to give 41,
which was oxidized with hydrogen peroxide in acetic acid to
afford sulfoxide 42. Treatment of compound 42 with sodium
azide and sulfuric acid in chloroform provided the targeted
sulfoximine 47.17 The corresponding methylsulfoximine
derivative, 48, was prepared by the analogous method from
1-bromo-4-(methylsulfinyl)benzene13 and 2-alkynylpiperazine
Figure 3. Area of SAR in a general structure 3.
CHEMISTRY
■
Because of the structural diversity of this series, several
synthetic approaches were necessary to prepare the desired
analogues. These methods are summarized in Schemes 1−5.
The most general method used to prepare C-ring analogues of
compounds 1 and 2 is outlined in Scheme 1. N-Carboxybenzyl
(Cbz) and N-benzyl (Bn) protected 2-alkynylpiperazine13 4, 5,
or 6 were coupled with the appropriate aryl halides (ArX)
utilizing palladium catalyzed amination conditions14 to afford
arylpiperazine intermediates 7. The requisite aryl halides
employed in the coupling reactions were either commercially
available or prepared as described in the Supporting
Information. For the majority of the cases, deprotection of
the Cbz group was achieved by treatment with triflic acid in
trifluoroacetic acid. Alternatively, the Cbz group was removed
a
Scheme 1. Synthesis of C-Ring Analogues 10−30
a
Reagents and conditions: (a) RuPhos/RuPhos first generation catalyst, RuPhos/Pd2(dba)3, DavePhos/Pd2(dba)3, X-Phos/Pd2(dba)3, JohnPhos/
Pd2(dba)3, or BINAP/Pd(OAc)2, NaO-t-Bu, 1,4-dioxane or toluene; (b) TfOH, TFA or conc H2SO4, CHCl3; (c) (i) 1-chloroethyl chlorocarbonate,
K2CO3, DCM; (ii) MeOH, reflux; (d) TEA or DIPEA, DCM; (e) TFA, DCM; (f) chiral SFC separation (for compounds starting from intermediate
6); (g) chiral SFC separation.16
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a
Scheme 2. Synthesis of C-ring Analogues 47−55
a
Reagents and conditions: (a) ArX, RuPhos/RuPhos first generation catalyst, DavePhos/Pd2(dba)3, or JohnPhos/Pd2(dba)3, NaO-t-Bu, 1,4-dioxane
or toluene; (b) (i) 1-chloroethyl chlorocarbonate, K2CO3, DCM; (ii) MeOH reflux; (c) H2SO4, CHCl3; (d) TfOH, TFA; (e) TEA or DIPEA,
DCM; (f) H2O2, AcOH; (g) TFA, DCM; (h) NaN3, H2SO4, CHCl3; (i) chiral SFC purification (the absolute stereochemistries of compounds 51
and 52 were established based on X-ray cocrystal structures with hGKRP, and the stereochemistries of compounds 54 and 55 were arbitrarily
assigned).
a
Scheme 3. Synthesis of Trifluoromethyl Carbinol Analogues 62−68
a
Reagents and conditions: (a) TsCl, TEA, DCM. (b) For 57: KCN, water, DMF. For 58: NaOMe, DMF, MeOH. For 59: (i) n-BuLi,
ethynyltrimethylsilane, THF; (ii) K2CO3, MeOH. For 61: NH4OH, DMF. (c) n-BuLi, MeI, THF; (d) TFA, DCM; (e) chiral SFC purification (the
absolute stereochemistries of compounds 67 and 68 were arbitrarily assigned).
4. For the compound with the primary sulfonamide substituent,
49, the synthesis began with the coupling of 2-alkynylpiperazine
4 with 4-bromo-N-(cyclopropylmethyl)benzenesulfonamide13
to obtain 35. Under strongly acidic conditions, the Cbz group
and the cyclopropylmethyl group were removed to give 36.
Subsequent sulfonamide formation with tert-butyl (5-
(chlorosulfonyl)pyridin-2-yl)carbamate (9) followed by depro-
tection of the Boc group afforded the primary sulfonamide 49.
The compounds bearing trifluoromethyldiol substituents with
either a phenyl or pyridine C-ring (50 or 53, respectively) were
constructed in a similar manner to each other. Coupling
reactions of 2-alkynylpiperazine 4 with the appropriate aryl
bromides13 containing the protected diols afforded 37 for the
phenyl derivative and 39 for the pyridine analogue. Removing
the Cbz groups with triflic acid in trifluoroacetic acid also
served to deprotect the acetonide to provide intermediates 38
and 40, respectively. Subsequent sulfonamide formation and
Boc removal afforded the diols 50 and 53, respectively. The
diastereomeric diols were resolved by chiral SFC purification to
obtain the pure epimers. From diol 50, epimers 51 and 52 were
obtained in >98% de, and the absolute stereochemistry was
assigned from X-ray crystallographic data from the ligand−
protein (hGKRP) complex. Similarly, epimers 54 and 55 were
separated from diol 53. However, in this case, the stereo-
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a
Scheme 4. Synthesis of Thiazole C-Ring Analogues 74 and 80
a
Reagents and conditions: (a) oxalyl chloride, cat. DMF, DCM; (b) TMSCF3, TMAF, DME; (c) TBSOTf, DIPEA, DCM; (d) RuPhos, RuPhos first
generation catalyst, NaO-t-Bu, 1,4-dioxane; (e) TFA, DCM; (f) 9, TEA, DCM; (g) HF−pyridine, ACN, TFA; (h) N,O-dimethylhydroxylamine−
HCl, DIPEA, DCM; (i) 6, DIPEA, DMF; (j) MeMgBr, THF; (k) TMSCF3, TMAF, THF; (l) TfOH, TFA; (m) TEA, DCM; (n) NH4OH, EtOH.
a
Scheme 5. Synthesis of Pyrimidine 88
a
Reagents and conditions: (a) 78, TEA, DCM; (b) (Boc)2O, TEA, DMAP, DCM; (c) (i) bromo(1-propy-1-yl)magnesium, THF; (ii) TFA, DCM;
(iii) NaBH(OAc)3; (d) 86, DIPEA, NMP; (e) (i) NH4OH, EtOH; (ii) NaBH4, MeOH;20 (f) chiral SFC purification.
chemistries at the carbinol stereocenters of 54 and 55 were
assigned based on their order of elution compared to that of the
phenyl analogues (51 and 52) and the absolute stereo-
chemistries were not unambiguously determined.
Both thiazole C-ring analogues 74 and 80 were prepared
from commercially available 2-chloro-1,3-thiazole-5-carboxylic
acid (69), and their syntheses are outlined in Scheme 4. For the
bis-trifluoromethyl carbinol derivative, the trifluoromethyl
group was installed first by converting acid 69 to acid chloride
70 followed by treatment with Ruppert’s reagent
(trimethylsilyltrifluoromethane) and tetramethylammonium
fluoride.18 The resulting hydroxyl group was then protected
as the tert-butyldimethylsilyl ether to afford 71. Subsequent
amination with Boc-protected piperazine 7213 afforded 73,
which was carried through the sequence of Boc removal,
sulfonamide formation (with sulfonyl chloride 9), and a one-
pot removal of both the tert-butyldimethylsilyl and Boc groups
to obtain thiazole 74. For the monotrifluoromethyl derivative
80, acid 69 was converted to Weinreb amide 75 that was then
coupled with piperazine 6 via nucleophilic substitution
condition to form 76. The amide moiety of 76 was converted
to the monotrifluoromethyl carbinol via ketone formation with
methylmagnesium bromide followed by trifluoromethylation to
obtain 77.18 Deprotection of the Cbz group followed by
Compounds with additional modifications to the trifluor-
omethyl carbinol center were synthesized by opening the
epoxide of intermediate 56 (prepared from the diol
intermediate 45) with various nucleophiles (Scheme 3). For
example, treatment of 56 with potassium cyanide, sodium
methoxide, lithiated ethynyltrimethylsilane (followed by
removal of TMS group), or ammonium hydroxide gave
intermediates 57, 58, 59, or 61, respectively. The methylalkyne
derivative 60 was obtained by methylation of compound 59
with methyl iodide. Removal of the Boc groups of compounds
57−61 with trifluoroacetic acid yielded the final products 62−
66. The diastereomeric amine compound 66 was subjected to
chiral SFC chromatography to provide diastereomers 67 and
68 with >98% diastereomeric excess. The absolute stereo-
chemistries at the carbinol carbons 67 and 68 were arbitrarily
assigned.
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sulfonamide formation with sulfonyl chloride 78 provided
chloropyridine sulfonamide 79. The requisite aminopyridine 80
was obtained by treatment of 79 with ammonium hydroxide in
ethanol.
Table 1. Biochemical and Cellular Assay Results with Rat
Liver Microsomal (RLM) Stability of Compounds with
Modifications to the Trifluoromethyl Carbinol Center
The synthesis of the final analogue, pyrimidine 88, is
illustrated in Scheme 5. Commercially available ketopiperazine
81 was reacted with sulfonyl chloride 7819 to form the
corresponding sulfonamide, 82. The amide NH of 82 was
protected as the tert-butyl carbamate to give 83. Treatment of
83 with the bromo(1-propy-1-yl)magnesium initially gave the
opened methyl ketone 84. Removal of the Boc group,
cyclization to the corresponding imine, and subsequent
reduction with sodium triacetoxyborohydride afforded the
piperazine 85. Compound 85 was coupled with chloropyr-
imidine 8613 via nucleophilic aromatic substitution, and the
resulting chloropyridine was converted to aminopyridine 87.
Chiral SFC purification of the racemate 87 gave the pure
enantiomers. The absolute stereochemistry of the carbon
bearing the propargyl group of the more active enantiomer
(88) was assigned to be (S) configuration, since we have
established from our previous SAR studies that compounds
with the (S) configuration at this center were significantly more
potent than their corresponding (R) epimers.8,9
RESULTS AND DISCUSSION
■
The compounds prepared in this study were tested in a hGK−
hGKRP binding assay (IC50, μM) and a GK translocation assay
(EC50, μM) in mouse hepatocytes.10,11 In addition to the two
primary assays, the analogues were evaluated for their metabolic
stability in rat liver microsomes (RLM) as measured by the
intrinsic clearance, CLint (μL min−1 mg−1).21,22 The current
structure−activity relationship (SAR) investigation focused on
two general areas of the molecule: the type of substituent on
the 4 position of the C-ring, which we refer to as the “tail
region” (Tables 1 and 2), and the nature of the aromatic C-ring
itself (Table 3).
Table 1 summarizes the results for compounds with either
small hydrophilic or hydrophobic groups in the tail region of
the molecule or with no substituent at all. The importance of
the carbinol functionality is clearly illustrated by compounds 10
and 11. No activity was observed for compound 10 where no
tail group was present, and only micromolar activity was
obtained for compound 11 where the alcohol moiety was
absent, despite the presence of the hydrophobic trifluorometh-
yl/methyl groups. Since removal of the trifluoromethyl carbinol
functionality resulted in more than a 100-fold decrease in
potency (presumably due to the loss of the hydrogen bond to
Arg525), we maintained the trifluoromethyl carbinol function-
ality and explored additional substitutions on the methyl group
in the remaining analogues reported in Table 1. These
additional substituents were selected to probe the two narrow
channels observed in this area of the GKRP protein. The upper
channel projects toward residues Phe526, Met522, and His504,
and the lower channel is flanked by residues Ser34, Lys33, and
Val28 (see Figure 1, end view). An additional hydroxyl group
adjacent to the tertiary carbinol was well tolerated, as shown by
the diols 51 and 52. Isomer 51 also exhibited improved in vitro
stability with liver microsomal clearance of <14 μL min−1 mg−1.
Interestingly, the amino analogues (67 and 68) were less
potent compared to compound 2, suggesting that basic groups
are not as tolerated in the region of the protein. In the X-ray
structure of diol 51 bound to GKRP (Figure 4A, orange),23 the
primary hydroxyl group forms hydrogen bonds with the
a
AlphaScreen data reported as an average (n ≥ 3). Compounds with
activities of >12.5 μM, n = 1. For all others, standard deviations are
reported in the Supporting Information. Mouse hepatocyte trans-
location data reported as an average (n ≥ 3). Standard deviations (n ≥
3) are reported in the Supporting Information. Average of two
experimental values. The stereochemistry at the carbinol carbon was
arbitrarily assigned.
b
c
d
imidazole N of His504 (N···OH) and the NH of Arg525
(NH···O); however, the NH2 groups of 67 and 68 would be
partially charged and unable to serve as hydrogen-bond
acceptors for His504. Both cyano (62) and methoxy (63)
groups were well tolerated when compared to compound 2,
although the cell potency suffered slightly. When small
hydrophobic groups such as ethynal and propargyl were
introduced next to the carbinol group (64 and 65), the
analogues showed potent activities similar to those of
compounds 1 and 2. In the X-ray structure of propargyl
derivative 65 bound to GKRP (Figure 4B, purple),23 the
configuration of the trifluorocarbinol was very similar to that of
compound 1 (Figure 4B, light-green lines). The alcohol moiety
forms a hydrogen bond to Arg525, and the propargyl group
projects up into the narrow channel near Phe526, Met522, and
His504. In addition, one of the hydrogens of the propargyl
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Figure 4. (A) X-ray cocrystal structure of compound 51 (orange sticks) bound to hGKRP determined at 2.4 Å resolution. (B) X-ray cocrystal
structure of compound 65 (purple sticks) bound to hGKRP determined at 2.8 Å resolution. The X-ray crystal structure of compound 1 (light-green
lines) is superimposed in both (A) and (B), and the gray surface indicates the van der Waals surface area.
methyl group engages in an edge-to-face interaction with
Phe526. Overall, the data reveal that small groups capable of
forming either hydrogen-bond interactions or hydrophobic
interactions with protein residues near the tail region were
tolerated and the trifluoropropanediol group (compounds 51
and 52) offered the best potency and metabolic stability profile
from this initial set of analogues.
GKRP protein (Figure 5A) showed that the two oxygens on C-
ring sulfonamide were engaged in hydrogen-bonding inter-
actions with the Arg525 and the sulfonamide methyl group
extended toward the lower Ser34/Lys33/Val28 channel;
however, there seemed to be no additional interaction between
the sulfonamide NH and the protein. Unfortunately, attempts
to gain additional activity by extending further into the lower
channel by increasing the size of the substituent on the nitrogen
of the sulfonamide were unsuccessful. As the size of the
hydrophobic group increased (from methyl to cyclopropyl,
isopropyl, methylcyclopropyl, and phenyl; compounds 16, 21,
17, and 18, respectively), activity decreased. These sulfonamide
analogues also exhibited reduced microsomal stability in rat
liver microsomes.
Lastly, sulfoximines were examined, as they offer certain
unique properties compared to sulfones and sulfonamides.24,25
For example, sulfoximines have been successfully employed as
alcohol isosteres.26 In addition, while being isosteric with
sulfones, they also introduced a mildly basic nitrogen that could
be alkylated to give an added substituent. Since the sulfur
center is chiral, we postulated that the sulfoximine could also
resemble the chiral trifluoromethyl carbinol group in
compound 2. Both methyl- and cyclopropylsulfoximines 48
and 47 showed modest biochemical activities, with the latter
also exhibiting good cellular activity (EC50 = 0.208 μM). The
trifluoromethylsulfoximine 22 was approximately 7 times more
potent than the methyl analogue 48 in the biochemical assay.
The two diastereomers of sulfoximine 22 (23 and 24) showed
10-fold differential activities, with the (S)-isomer 24 being the
most potent sulfoximine analogue. Notably, the sulfoximines
also exhibited marked microsomal stability overall; however,
when the nitrogen of sulfoximine 24 was methylated
(compound 19), both the potency and the microsomal stability
suffered. In this phase of the investigation we were able to
replace the carbinol function with either a sulfonamide or a
sulfoximine group while maintaining good potency and
stability. Furthermore, our design hypothesis was supported
by the X-ray structures of sulfonamide 15 and sulfoximine 24
Table 2 summarizes our efforts to identify suitable
bioisosteric replacements for the trifluoromethyl carbinol
functionality. As discussed previously, the C-ring carbinol
engages in a key hydrogen-bonding interaction with Arg525.
Since the basic Arg525 side chain normally exists as the
protonated form at neutral pH, the C-ring carbinol most likely
plays the role of a hydrogen-bond acceptor through the lone
pairs of electrons on the oxygen atom. Therefore, we explored
the effect of other oxygen containing groups. Simple carbonyl
compounds such as ketone 12 and amide 13 were
approximately 100-fold less potent in the biochemical assay
when compared to compounds 1 and 2. It is likely that these
carbonyl compounds lacked the three-dimensional feature of
our lead compounds that was important in filling the
hydrophobic pocket adjacent to Arg525. For this reason, we
turned our attention to sulfur-based oxygen functionalities as
alternative tail group moieties. Although the simple sulfoxide
and sulfone derivatives (14 and 20, respectively) were only
weak to moderate disruptors, we were encouraged by the
potent activity of sulfonamide 49 (binding IC50 = 61 nM and
cellular EC50 = 37 nM). The potent activity of compound 49
was somewhat surprising, since the sulfonamide tail region
lacked any hydrophobic groups that had been shown earlier to
be essential for the carbinol series. Therefore, we examined
derivatives with N-substitution on the sulfonamide, postulating
that potency might be enhanced by adding hydrophobic groups
in this region to gain additional van der Waals contacts to either
the upper or lower channel of the GKRP protein.
Methylsulfonamide 15 showed a modest improvement in the
biochemical assay; however, cellular potency was not improved.
The X-ray crystal structure of compound 15 bound to the
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Table 2. Biochemical and Cellular Assay Results with Rat
Liver Microsomal (RLM) Stability of Compounds with
Carbinol Replacements
Table 3. Biochemical and Cellular Assay Results with Rat
Liver Microsomal (RLM) Stability of Compounds with
Heterocycle C-Rings
a
AlphaScreen data reported as an average (n ≥ 3). Standard deviations
b
are reported in the Supporting Information. Mouse hepatocyte
translocation data reported as an average (n ≥ 3). Compounds with
activities of >12.5 μM, n = 1. For all others, standard deviations (n ≥
c
3) are reported in the Supporting Information. Average of two
d
experimental values. The stereochemistry at carbinol carbon was
e
arbitrarily assigned. This compound is a mixture of four stereo-
isomers.
that of the lower trifluoromethyl group of compound 1 (Figure
5B, light-green).
a
AlphaScreen data reported as an average (n ≥ 3). Standard deviations
b
are reported in the Supporting Information. Mouse hepatocyte
The SAR results for compounds bearing a heterocyclic C-
ring are summarized in Table 3. Compared to the
monotrifluoromethyl carbinol, 2, the 2-pyridinyl derivative 25
was 7-fold less potent in the biochemical assay and 10-fold less
potent in the cellular assay; however, the 3-pyridyl analogue 28
showed comparable biochemical potency. The two diaster-
eomers of pyridine 28 (29 and 30) were equipotent, with
diastereomer 29 showing similar cellular potency as that of
compound 2. When the 3-pyridyl C-ring was combined with
the bis-trifluoromethyl carbinol, the cellular potency dropped 2-
fold compared to compound 1, even though potency of the
binding assay was preserved (compound 26). A further drop in
translocation data reported as an average (n ≥ 2). Compounds with
activities of >12.5 μM, n = 1. For all others, standard deviations (n ≥
c
2) are reported in the Supporting Information. Average of two
experimental values.
bound to the GKRP protein (Figure 5A and Figure 5B).23 Both
structures show a bifurcated interaction between Arg525 and
either the OSO or the OSN functional group in
sulfonamide 15 or sulfoximine 24, respectively. In the case of
sulfoximine 24 (Figure 5B, light-blue), the trifluoromethyl
group projects toward Ser34 and resides in a position similar to
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Figure 5. (A) X-ray cocrystal structure of compound 15 (magenta sticks) bound to hGKRP determined at 2.4 Å resolution. (B) X-ray cocrystal
structure of compound 24 (light-blue sticks) bound to hGKRP determined at 2.58 Å resolution. The X-ray crystal structure of compound 1 (light-
green lines) is superimposed in both (A) and (B), and the gray surface indicates the van der Waals surface area.
cellular potency (∼5-fold) was observed when an additional
nitrogen was added in the C-ring (i.e., pyrimidine 88). In
general, analogues with the bis-trifluoromethyl carbinol tail
group showed a steeper shift in biochemical to cellular potency
when compared to the monotrifluoromethyl carbinol series. We
hypothesize that the higher logP of the former might be the
underlying factor. For example, the bis-trifluoromethyl
analogue 26 has a higher clogP value (2.8) and larger cell
shift (42-fold) than the corresponding methyltrifluoromethyl
analogue, 28 (clogP = 2.2 and a cell shift of 16-fold).27 This
trend was also observed between compounds 1 and 2, where
compound 1 (clogP = 3.7) showed a 49-fold cell shift and
compound 2 (clogP = 3.2) had only a 12-fold cell shift.
With the promising results obtained with 3-pyridyl C-ring
derivatives 26 and 28−30 (good cellular potencies and good
metabolic stabilities in RLM), we combined the pyridyl C-ring
with two of the better tail groups identified previously to give
methylsulfonamide pyridine 27 and trifluoropropanediol
pyridine 53. The two diastereomers of diol 53 were also
separated and evaluated (54 and 55). Overall, addition of the
pyridine nitrogen was well tolerated; however, small losses in
potencies were observed when the 3-pyridine C-ring replaced
the phenyl ring (i.e., methylsulfonamides (27 vs 15) and
trifluoropropanediols (54 and 55 vs 51 and 52). Finally, both
of the two five-membered C-ring analogues that were examined
showed reduced biochemical and cellular potencies (thiazoles
74 and 80). It is likely that the orientation of the carbinol group
in the five-membered heterocycle is not optimal to provide as
strong of a hydrogen-bonding interaction with Arg525,
compared with compounds 1 and 2.
methylsulfonamide 15, trifluoromethylsulfoximine 24, and
pyridinetrifluoromethyl carbinol 29). The results are shown
in Table 4, and the pharmacokinetic profile of compound 1 is
included for comparison. Despite their relatively low in vitro
microsomal clearance values, sulfonamides 49 and 15 showed
high in vivo clearance in rats (2.8 and 3.7 L kg−1 h−1,
respectively) as well as low oral bioavailabilities (F of 5% and
1.5%, respectively). Trifluoropropanediol 51 also gave low
exposures when administered orally (AUC = 7.1 μM·h) and
showed relatively high clearance (1.2 L kg−1 h−1) considering
its stability in RLM (<14 μL min−1 mg−1). On the other hand,
sulfoximine 24 and pyridine 29 were found to have favorable
pharmacokinetic profiles in rats with low clearance values, good
oral bioavailabilities, and high exposures. Therefore, sulfoximine
24 and pyridine 29 were also tested in mouse pharmacokinetic
experiments to determine if these derivatives would be suitable
for efficacy studies in mice. The clearance of sulfoximine 24 was
very low (0.025 L kg−1 h−1) resulting in even higher exposures
in mice than in rats (362 vs 25 μM·h at 10 mg/kg,
respectively). The pharmacokinetic profile of pyridine 29 was
found to be similar in both mice and rats.
Given their potent cellular activities and their favorable
pharmacokinetic profiles, we evaluated the efficacy of
sulfoximine 24 and pyridine 29 in db/db mice. The results of
these studies are shown in Figure 6A and Figure 6B,
respectively. Both compounds were found to lower blood
glucose levels when orally administered to db/db mice. As
shown in Figure 6A, compound 24 caused statistically
significant reductions (up to 58%) at all doses (10, 30, 100
mg/kg) at both 3 and 6 h time points. Like pyridine 24,
sulfoximine 29 (Figure 6B) also caused significant decreases in
fed blood glucose levels at both the early (3 and 6 h) time
points. With the exception of the 100 mg/kg dose of 24,
glucose levels had returned to normal 24 h postdose.
The SAR studies described above, which focused on the C-
ring modifications to compounds 1 and 2, resulted in the
identification of several potent GK−GKRP disruptors with
good metabolic stability in rat liver microsomes. To evaluate
these derivatives further, several of the potent analogues were
selected for additional pharmacokinetic studies. A variety of
structural differences were represented in the selected
compounds (i.e., trifluoropropanediol 51, sulfonamide 49,
CONCLUSION
We have described the synthesis and biological evaluation of a
series of N-arylsulfonamido-N′-arylpiperazine GK−GKRP
■
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Table 4. Pharmacokinetic Properties of Selected Compounds
a
d
in vivo rat PK
in vivo mouse PK
b
c
b
c
iv
po
iv
po
compd
CL (L kg−1 h−1
)
t1/2 (h)
F (%)
AUC (μM·h)
CL (L kg−1 h−1
0.11
)
t1/2 (h)
F (%)
AUC (μM·h)
Cmax (μM)
Tmax (h)
1
0.75
2.82
6.68
1.26
0.42
0.35
3.6
1.6
4.1
3.9
2.8
3.2
75
5
20.0
0.26
0.03
7.1
6.7
40
64.8
5.82
5.0
49
15
51
24
29
1.5
48
51
47
25.3
28.4
0.025
0.28
3.1
2.4
53
47
362
46.6
9.71
1.0
37.0
0.25
a
b
Pharmacokinetic parameters following administration in male Sprague−Dawley rats: n = 3 for each time point, 3 animals per study. Dosed at 2
c
mg/kg as a solution in DMSO. Dosed orally at 10 mg/kg (for 49, 1% Tween 80, 2% hydroxypropyl methylcellulose (HPMC); all others, 1% Tween
80, 2% HPMC, pH 2.2 with methanesulfonic acid (MSA). Pharmacokinetic parameters following administration in male C57BL/6 mice: n = 3 for
d
each time point, 9 animals per study.
Figure 6. (A) Blood glucose measurements after oral administration of 24 (10, 30, 100, mg/kg) to db/db mice. (B) Blood glucose measurements
after oral administration of 29 (10, 30, 100, mg/kg) to db/db mice. The statistical significance of the blood glucose measurements were based on
comparison to the individual vehicle control groups (n ≥ 6, ∗ = p < 0.05, ∗∗ = p < 0.01, ∗∗∗ = p < 0.001) calculated by ANOVA.
atmosphere. Silica gel chromatography was performed using either
glass columns packed with silica gel (200−400 mesh, Aldrich
Chemical) or prepacked silica gel cartridges (Biotage or Redisep).
NMR spectra were determined with a Bruker 300 MHz or DRX 400
MHz spectrometer. Chemical shifts are reported in parts per million
(ppm, δ units). All final compounds were purified to >95% purity
unless otherwise noted as determined by LC/MS obtained on an
Agilent 1100 or 1200 spectrometer using the following methods: [A]
Agilent SB-C18 column (50 mm × 3.0 mm, 2.5 μm) at 40 °C with a
1.5 mL/min flow rate using a gradient of 5−95% [0.1% TFA in
acetonitrile] in [0.1% TFA in water] over 3.5 min; [B] Waters XBridge
C18 column (50 mm × 3.0 mm, 3 μm) at 40 °C with a 1.5 mL/min
flow rate using a gradient of 5−95% [0.1% formic acid in acetonitrile]
in [0.1% formic acid in water] over 3.5 min. Low-resolution mass
spectrometry (MS) data were obtained at the same time of the purity
determination on the LC/MS instrument using ES ionization mode
(positive).
General Amination Method. To a reaction vessel were added
benzyl (3S)-3-(1-propyn-1-yl)-1-piperazinecarboxylate (4), (3S)-1-
benzyl-3-(1-propyn-1-yl)piperazine (5), or benzyl 3-(1-propyn-1-yl)-
1-piperazinecarboxylate (6),13 an aryl halide (1.1−1.5 equiv), ligand
(RuPhos, DavePhos, X-Phos JohnPhos, or BINAP, 5−10 mol %), Pd
source (RuPhos first generation precatalyst, Pd2(dba)3, or Pd(OAc)2,
10 mol %), NaO-t-Bu (2−3 equiv), and 1,4-dioxane or toluene. The
mixture was deoxygenated by bubbling argon gas through it and was
then heated at 80−100 °C until the starting material was consumed.
The mixture was allowed to cool to room temperature and partitioned
between EtOAc and water. The aqueous phase was extracted with
EtOAc. The combined organic phases were washed with saturated
aqueous NaCl, dried over Na2SO4 or MgSO4, filtered, and
disruptors with modifications to the phenyl carbinol C-ring.
Guided by structure-based design utilizing the X-ray cocrystal
structure of compound 1 bound to hGKRP, we explored three
main aspects of the C-ring SAR including exploration of the
two channels accessed by the terminal C-ring substituent (tail
region), assessment of various carbinol isosteres designed to
engage Arg525, and evaluation of heterocyclic replacements to
the phenyl C-ring. Through these investigations we were able
to identify several diverse and potent C-region analogues,
including diols (51 and 52), alkynes (64 and 65), sulfonamides
(49 and 15), sulfoximine (24), and pyridines (29, 30, 54, and
55). Among these derivatives, compound 24 (trifluoromethyl-
sulfoximine as the carbinol bioisostere) and compound 29
(pyridine replacement for the phenyl C-ring) were found to
possess favorable in vivo pharmacokinetic properties in rodents
(Foral = 47−53% in both rat and mouse), and when dosed orally
in db/db mice, they produced significant reductions in blood
glucose levels (∼40−58% 6 h postdose at 100 mg/kg). These
novel compounds will be evaluated further to assess their
potential as therapeutic antidiabetic agents.
EXPERIMENTAL SECTION
■
Chemistry. General. Unless otherwise noted, all materials were
obtained from commercial suppliers and used without further
purification. Anhydrous solvents were obtained from Aldrich, Acros,
or EM Science and used directly. All reactions involving air- or
moisture-sensitive reagents were performed under a nitrogen or argon
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concentrated. The material was purified by silica gel column
chromatography.
step without any purification. MS (ESI positive ion) m/z: calcd for
C13H16N2, 200.131; found, 201.1 (M + 1).
General N-Carboxylbenzyl (Cbz) Deprotection: Method A. A
Cbz-protected amine was dissolved in TFA. Trifluoromethanesulfonic
acid (3 equiv) was added slowly at room temperature, and the mixture
was stirred for 2−5 min. The reaction mixture was concentrated and
subjected to the next reaction directly or quenched as follows: Solid
NaHCO3 was added to the reaction mixture slowly followed by
aqueous saturated NaHCO3. The aqueous phase was extracted with
EtOAc, and the combined organic phases were washed with water and
aqueous saturated NaCl. The organic phase was dried over Na2SO4 or
MgSO4, filtered, and concentrated. The crude product was used
directly in the next step or purified by silica gel column
chromatography.
General N-Carboxylbenzyl (Cbz) Deprotection: Method B.
To a reaction vessel was added a Cbz-protected amine and CHCl3, and
the mixture was cooled to 0 °C. Excess concentrated H2SO4 was
added, and the mixture was stirred at room temperature until the
starting material was consumed. The reaction mixture was basified by
the addition of 10% NaOH and then extracted with EtOAc. The
organic extract was washed with water, aqueous saturated NaCl, then
dried over anhydrous Na2SO4 and filtered. The filtrate was
concentrated under reduced pressure. The crude product was used
directly in the next step or purified by silica gel column
chromatography.
(2S)-1-Phenyl-2-(1-propyn-1-yl)piperazine (0.150 g, 0.75 mmol)
was treated with tert-butyl (5-(chlorosulfonyl)-2-pyridinyl)carbamate
(9) (0.260 g, 0.9 mmol) according to the general sulfonamide
formation method using Et3N (0.2 mL, 1.5 mmol) to give tert-butyl
(5-(((3S)-4-phenyl-3-(1-propyn-1-yl)-1-piperazinyl)sulfonyl)-2-
pyridinyl)carbamate (0.120 g, 35%) as a white solid. MS (ESI positive
ion) m/z: calcd for C23H28N4O4S, 456.183; found, 457.1 (M + 1).
tert-Butyl (5-(((3S)-4-phenyl-3-(1-propyn-1-yl)-1-piperazinyl)-
sulfonyl)-2-pyridinyl)carbamate (0.120 g, 0.305 mmol) was depro-
tected according to the general Boc-deprotection method to give 5-
(((3S)-4-phenyl-3-(1-propyn-1-yl)-1-piperazinyl)sulfonyl)-2-pyridin-
amine (10) (0.020 g, 19%) as a white solid. MS (ESI positive ion) m/
1
z: calcd for C18H20N4O2S, 356.131; found, 356.9 (M + 1). H NMR
(400 MHz, DMSO-d6) δ 8.23 (d, J = 2.5 Hz, 1 H), 7.64 (dd, J = 2.5,
8.8 Hz, 1 H), 7.26−7.18 (m, 2 H), 7.03 (s, 2 H), 6.94 (d, J = 8.0 Hz, 2
H), 6.83 (t, J = 7.3 Hz, 1 H), 6.54 (d, J = 8.8 Hz, 1 H), 4.72 (br s, 1
H), 3.63−3.53 (m, 2 H), 3.47−3.41 (m, 1 H), 3.13−3.03 (m, J = 8.8,
11.9 Hz, 1 H), 2.56 (dd, J = 3.3, 11.3 Hz, 1 H), 2.42−2.34 (m, 1 H),
1.73 (d, J = 1.9 Hz, 3 H).
5-(((3S)-3-(1-Propyn-1-yl)-4-(4-(2,2,2-trifluoro-1-
methylethyl)phenyl)-1-piperazinyl)sulfonyl)-2-pyridinamine
(11). Benzyl (3S)-3-(1-propyn-1-yl)-1-piperazinecarboxylate (4)
(0.520 g, 2.01 mmol) and 1-bromo-4-(2,2,2-trifluoro-1-methylethyl)-
benzene13 (0.470 g, 1.86 mmol) were coupled according to the general
amination method using RuPhos first generation precatalyst (65 mg,
0.080 mmol) and 1,4-dioxane to afford benzyl (3S)-3-(1-propyn-1-yl)-
4-(4-(2,2,2-trifluoro-1-methylethyl)phenyl)-1-piperazinecarboxylate
(0.38 g, 47%) as a clear oil. MS (ESI positive ion) m/z: calcd for
General N-Benzyl (Bn) Deprotection Method. To a reaction
vessel were added a Bn-protected amine, 1-chloroethyl chlorocar-
bonate (5 equiv), K2CO3 (3 equiv), and DCM. The mixture was
stirred at room temperature until the starting material was consumed.
The solid was removed by filtration, and the filtrate was concentrated.
MeOH was added to the residue, and the mixture was heated at reflux
for 2 h. The mixture was allowed to cool to room temperature and
concentrated. The crude product was used directly in the next step or
purified by silica gel column chromatography.
1
C24H25F3N2O2, 430.187; found, 431.3 (M + 1). H NMR (400 MHz,
CDCl3) δ 7.27−7.44 (m, 5 H), 7.22 (d, J = 7.43 Hz, 2 H), 6.94 (d, J =
7.82 Hz, 2 H), 5.05−5.33 (m, 2 H), 4.10−4.40 (m, 3 H), 3.02−3.43
(m, 5 H), 1.68 (br s, 3 H), 1.47 (d, J = 6.85 Hz, 3 H).
Benzyl (3S)-3-(1-propyn-1-yl)-4-(4-(2,2,2-trifluoro-1-methylethyl)-
phenyl)-1-piperazinecarboxylate (0.38 g, 0.88 mmol) was deprotected
according to the general Cbz-deprotection method A to afford (2S)-2-
(1-propyn-1-yl)-1-(4-(2,2,2-trifluoro-1-methylethyl)phenyl)piperazine
as a crude product. This material was used for the next reaction
without further purification.
General Sulfonamide Formation Method. To a reaction vessel
was added a deprotected piperazine, Et3N, DIPEA or pyridine (3−10
equiv), and DCM. After the mixture was stirred for 5 min, appropriate
sulfonyl chloride (1.1 equiv) was added. The mixture was stirred at
room temperature until the starting material was consumed. The
mixture was concentrated in vacuo and used directly in the next
deprotection step or purified by silica gel chromatography.
(2S)-2-(1-Propyn-1-yl)-1-(4-(2,2,2-trifluoro-1-methylethyl)phenyl)-
piperazine (0.26 g, crude) was treated with tert-butyl (5-(chlor-
osulfonyl)-2-pyridinyl)carbamate (9) (0.300 g, 1.03 mmol) according
to the general sulfonamide formation method using Et3N (0.600 mL,
4.30 mmol) aand then deprotected by the general Boc-deprotection
method to afford 5-(((3S)-3-(1-propyn-1-yl)-4-(4-(2,2,2-trifluoro-1-
methylethyl)phenyl)-1-piperazinyl)sulfonyl)-2-pyridinamine (11)
(0.315 g, 79% over three steps) as a light-yellow foam. MS (ESI
positive ion) m/z: calcd for C21H23F3N4O2S, 452.149; found, 453.2
(M + 1). 1H NMR (400 MHz, CDCl3) δ 8.49 (br s, 1 H), 7.78 (d, J =
9.19 Hz, 1 H), 7.21 (d, J = 7.24 Hz, 2 H), 6.91 (d, J = 7.04 Hz, 2 H),
6.54 (d, J = 7.24 Hz, 1 H), 5.03 (br s, 2 H), 4.37 (br s, 1 H), 3.72 (t, J
= 11.83 Hz, 2 H), 3.27−3.43 (m, 3 H), 2.86 (d, J = 11.35 Hz, 1 H),
2.71 (t, J = 10.56 Hz, 1 H), 1.78 (br s, 3 H), 1.46 (d, J = 6.06 Hz, 3 H).
1-(4-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-
yl)-1-piperazinyl)phenyl)ethanone (12). (3S)-1-Benzyl-3-(1-pro-
pyn-1-yl)piperazine (5) (0.500 g, 2.52 mmol) and 1-(4-bromophenyl)-
ethanone (0.540 g, 2.52 mmol) were coupled according to the general
amination method using RuPhos (0.059 g, 0.13 mmol), RuPhos first
generation precatalyst (0.061 g, 0.075 mmol), and 1,4-dioxane to
afford 1-(4-((2S)-4-benzyl-2-(1-propyn-1-yl)-1-piperazinyl)phenyl)-
ethanone (0.120 g, 16%) as an off-white solid. MS (ESI positive
General N-tert-Butyl Carbamate (Boc) Deprotection Method.
To a reaction vessel was added a Boc protected aminopyridine
sulfonamide, TFA (20−50 equiv), and DCM. The mixture was stirred
at room temperature until the reaction was complete. The reaction
mixture was concentrated and then neutralized by the addition of
saturated aqueous NaHCO3. The aqueous phase was extracted with
EtOAc, and the combined organic phases were washed with saturated
aqueous NaHCO3, water, and saturated aqueous NaCl. The organic
phase was dried over Na2SO4 or MgSO4, filtered, and concentrated.
The crude product was purified by silica gel column chromatography
unless otherwise noted.
5-(((3S)-4-Phenyl-3-(1-propyn-1-yl)-1-piperazinyl)sulfonyl)-
2-pyridinamine (10). Benzyl (3S)-3-(1-propyn-1-yl)-1-piperazine-
carboxylate (4) (0.250 g, 0.96 mmol) and bromobenzene (0.304 g,
1.93 mmol) were coupled according to the general amination method
using 2′-(diphenylphosphino)-N,N-dimethyl-[1,1′-biphenyl]-2-amine
(DavePhos) (0.038 g, 0.097 mmol), Pd2(dba)3 (0.044 g, 0.048
mmol), and toluene to give benzyl (3S)-4-phenyl-3-(1-propyn-1-yl)-1-
piperazinecarboxylate (0.200 g, 46%) as a yellow solid. MS (ESI
positive ion) m/z: calcd for C21H22N2O2, 334.168; found, 335.1 (M +
1). 1H NMR (400 MHz, DMSO-d6) δ 7.52−7.33 (m, 5 H), 7.29 (t, J =
7.9 Hz, 2 H), 7.03 (d, J = 8.3 Hz, 2 H), 6.89 (t, J = 7.2 Hz, 1 H), 5.30−
5.06 (m, 2 H), 4.68 (br s, 1 H), 4.14 (d, J = 12.2 Hz, 2 H), 3.04 (br s, 2
H), 1.69 (d, J = 1.7 Hz, 3 H). Two protons were obscured by the
water peak.
1
ion) m/z: calcd for C22H24N2O, 332.189; found, 333.1 (M + 1). H
NMR (400 MHz, CDCl3) δ 7.91 (d, J = 8.8 Hz, 2 H), 7.44−7.27 (m, 5
H), 6.94 (d, J = 8.8 Hz, 2 H), 4.53 (s, 1 H), 3.74 (d, J = 13.4 Hz, 1 H),
3.58−3.51 (m, 2 H), 3.36−3.67 (m, 1 H), 3.04−2.98 (m, 2 H), 2.53
(s, 3 H), 2.38−2.33 (m, 2 H), 1.80 (d, J = 2.2 Hz, 3 H).
1-(4-((2S)-4-Benzyl-2-(1-propyn-1-yl)-1-piperazinyl)phenyl)-
ethanone (0.130 g, 0.39 mmol) was deprotected according to the
general Bn-deprotection method to afford 1-(4-((2S)-2-(1-propyn-1-
Benzyl (3S)-4-phenyl-3-(1-propyn-1-yl)-1-piperazinecarboxylate
(0.250 g, 0.749 mmol) was deprotected according to the general
Cbz-deprotection method B to give (2S)-1-phenyl-2-(1-propyn-1-
yl)piperazine (0.150 g, crude). The crude product was used in the next
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yl)-1-piperazinyl)phenyl)ethanone (0.090 g). This material was used
without further purification. MS (ESI positive ion) m/z: calcd for
C15H18N2O, 242.142; found, 243.0 (M + 1).
bromo-4-(methylsulfinyl)benzene13 (0.63 g, 2.9 mmol) were coupled
according to the general amination method using Pd2(dba)3 (0.089 g,
0.096 mmol), DavePhos (0.037 g, 0.096 mmol), and toluene to afford
benzyl (3S)-4-(4-(methylsulfinyl)phenyl)-3-(1-propyn-1-yl)-1-pipera-
zinecarboxylate (0.75 g, 65%) as a pale-brown gummy solid. MS (ESI
positive ion) m/z: calcd for C22H24N2O3S, 396.151; found, 397.0 (M +
1).
Benzyl (3S)-4-(4-(methylsulfinyl)phenyl)-3-(1-propyn-1-yl)-1-pi-
perazinecarboxylate (0.75 g, 1.9 mmol) was deprotected according
to the general Cbz-deprotection method B to give (2S)-1-(4-
(methylsulfinyl)phenyl)-2-(1-propyn-1-yl)piperazine (0.40 g, 80%) as
a brown gummy liquid. MS (ESI positive ion) m/z: calcd for
C14H18N2OS, 262.114; found, 263.1 (M + 1).
1-(4-((2S)-2-(1-Propyn-1-yl)-1-piperazinyl)phenyl)ethanone
(0.090 g, 0.37 mmol) was treated with tert-butyl (5-(chlorosulfonyl)-2-
pyridinyl)carbamate (9) (0.217 g, 0.74 mmol) according to the general
sulfonamide formation method using pyridine (0.15 mL, 1.85 mmol)
to afford tert-butyl (5-(((3S)-4-(4-acetylphenyl)-3-(1-propyn-1-yl)-1-
piperazinyl)sulfonyl)-2-pyridinyl)carbamate (0.075 g, 41%) as a white
solid. MS (ESI positive ion) m/z: calcd for C25H30N4O5S, 498.194;
found, 399.0 (M − Boc + 1). 1H NMR (400 MHz, CDCl3) δ 8.68 (d, J
= 2.4 Hz, 1 H), 8.15 (d, J = 8.9 Hz, 1 H), 8.05−7.99 (m, 2 H), 7.90 (d,
J = 8.8 Hz, 2 H), 6.92 (d, J = 8.8 Hz, 2 H), 4.57 (s, 1 H), 3.86−3.80
(m, 2 H), 3.54−3.56 (m, 1 H), 3.41−3.40 (m, 1 H), 2.82 (dd, J = 11.1,
3.4 Hz, 1 H), 2.68−2.66 (m, 1 H), 2.53 (s, 3 H), 1.78 (d, J = 2.1 Hz, 3
H), 1.55 (s, 9 H).
tert-Butyl (5-(((3S)-4-(4-acetylphenyl)-3-(1-propyn-1-yl)-1-
piperazinyl)sulfonyl)-2-pyridinyl)carbamate (0.075 g, 0.15 mmol)
was deprotected according to the general Boc-deprotection method
to afford 1-(4-((2S)-4-((6-amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-
yl)-1-piperazinyl)phenyl)ethanone (12) (0.030 g, 50%) as an off-white
solid. MS (ESI positive ion) m/z: calcd for C20H22N4O3S, 398.141;
found, 399.0 (M + 1). 1H NMR (400 MHz, CDCl3) δ 8.23 (d, J = 2.5
Hz, 1 H), 7.83−7.81 (m, 2 H), 7.64−7.61 (m, 1 H), 7.03−6.99 (m, 4
H), 6.53 (d, J = 8.9 Hz, 1 H), 4.96 (s, 1 H), 3.74 (d, J = 11.6 Hz, 1 H),
3.64−3.59 (m, 2 H), 3.12−3.11 (m, 1 H), 2.54 (d, J = 3.6 Hz, 1 H),
2.49 (s, 3 H), 2.39−2.37 (m, 1 H), 1.74 (d, J = 1.9 Hz, 3 H).
4-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-
1-piperazinyl)-N-methylbenzamide (13). Benzyl (3S)-3-(1-pro-
pyn-1-yl)-1-piperazinecarboxylate (4) (0.484 g, 1.87 mmol) and 4-
bromo-N-methylbenzamide13 (0.40 g, 1.9 mmol) were coupled
according to the general amination method using Pd2(dba)3 (0.034
g, 0.037 mmol), X-Phos (0.026 g, 0.056 mmol), and 1,4-dioxane to
afford benzyl (3S)-4-(4-(methylcarbamoyl)phenyl)-3-(1-propyn-1-yl)-
1-piperazinecarboxylate (0.22 g, 30%) as a white solid. MS (ESI
positive ion) m/z: calcd for C23H25N3O3, 391.190; found, 392.1 (M +
1).
Benzyl (3S)-4-(4-(methylcarbamoyl)phenyl)-3-(1-propyn-1-yl)-1-
piperazinecarboxylate (0.21 g, 0.54 mmol) was deprotected according
to the general Cbz-deprotection method B to obtain N-methyl-4-
((2S)-2-(1-propyn-1-yl)-1-piperazinyl)benzamide (0.13 g, crude) as a
yellow solid. The crude product was used in the next step without
purification. MS (ESI positive ion) m/z: calcd for C15H19N3O:
257.153; found, 258.1 (M + 1).
N-Methyl-4-((2S)-2-(1-propyn-1-yl)-1-piperazinyl)benzamide (0.13
g, 0.505 mmol) was treated with tert-butyl (5-(chlorosulfonyl)-2-
pyridinyl)carbamate (9) (0.147 g, 0.505 mmol) according to the
general sulfonamide formation method using Et3N (0.105 mL, 0.757
mmol) to afford tert-butyl (5-(((3S)-4-(4-(methylcarbamoyl)phenyl)-
3-(1-propyn-1-yl)-1-piperazinyl)sulfonyl)-2-pyridinyl)carbamate as an
off-white solid. The crude product was used in the next step without
purification. MS (ESI positive ion) m/z: calcd for C25H31N5O5S,
513.205; found, 514.1 (M + 1).
(2S)-1-(4-(Methylsulfinyl)phenyl)-2-(1-propyn-1-yl)piperazine
(0.40 g, 1.5 mmol) was treated with tert-butyl (5-(chlorosulfonyl)-2-
pyridinyl)carbamate (9) (0.67 g, 2.3 mmol) according to the general
sulfonamide formation method using Et3N (0.60 mL, 3.8 mmol) to
give tert-butyl (5-(((3S)-4-(4-(methylsulfinyl)phenyl)-3-(1-propyn-1-
yl)-1-piperazinyl)sulfonyl)-2-pyridinyl)carbamate (0.35 g, 44%) as a
brown solid. MS (ESI positive ion) m/z: calcd for C24H30N4O5S2,
1
518.166; found, 519.3 (M + 1). H NMR (300 MHz, CDCl3) δ 8.66
(s, 1 H), 8.13 (d, J = 6.6 Hz, 1 H), 8.03 (dd, J = 6.6, 1.5 Hz, 1 H), 7.65
(s, 1 H), 7.56 (d, J = 6.6 Hz, 2 H), 7.03 (d, J = 6.0 Hz, 2 H), 4.47 (s, 1
H), 3.84−3.77 (m, 2 H), 3.43−3.39 77 (m, 3 H), 2.84 (dd, J = 8.4, 2.7
Hz, 1 H), 2.70 (s, 3 H), 1.78 (s, 3 H), 1.58 (s, 9 H).
tert-Butyl (5-(((3S)-4-(4-(methylsulfinyl)phenyl)-3-(1-propyn-1-
yl)-1-piperazinyl)sulfonyl)-2-pyridinyl)carbamate (0.10 g, 0.19
mmol) was deprotected according to the general Boc-deprotection
method to afford 5-(((3S)-4-(4-(methylsulfinyl)phenyl)-3-(1-propyn-
1-yl)-1-piperazinyl)sulfonyl)-2-pyridinamine (14) (0.040 g, 50%) as a
pale-brown solid. MS (ESI positive ion) m/z: calcd for C19H22N4O3S2,
1
418.113; found, 419.0 (M + 1). H NMR (400 MHz, DMSO-d6) δ
8.24 (d, J = 2.5 Hz, 1 H), 7.64 (dd, J = 2.5, 8.8 Hz, 1 H), 7.54 (d, J =
8.8 Hz, 2 H), 7.11 (d, J = 8.8 Hz, 2 H), 7.05 (s, 2 H), 6.54 (d, J = 8.8
Hz, 1 H), 4.87 (br s, 1 H), 3.68−3.55 (m, 3 H), 3.15−3.06 (m, 1 H),
2.68 (s, 3 H), 2.43−2.30 (m, 2 H), 1.75 (d, J = 1.4 Hz, 3 H).
4-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-
1-piperazinyl)-N-methylbenzenesulfonamide (15). Benzyl (3S)-
3-(1-propyn-1-yl)-1-piperazinecarboxylate (4) (1.00 g, 3.87 mmol)
and 4-bromo-N-methylbenzenesulfonamide13 (1.45 g, 5.81 mmol)
were coupled according to the general amination method using
RuPhos (0.090 g, 0.194 mmol), RuPhos first generation precatalyst
(0.158 g, 0.194 mmol), and 1,4-dioxane to afford benzyl (3S)-4-(4-
(methylsulfamoyl)phenyl)-3-(1-propyn-1-yl)-1-piperazinecarboxylate
(0.235 g, 14%) as an amber oil. MS (ESI positive ion) m/z: calcd for
1
C22H25N3O4S, 427.157; found, 428.0 (M + 1). H NMR (400 MHz,
CDCl3) δ 7.75 (d, J = 8.8 Hz, 2 H), 7.29−7.43 (m, 5 H), 6.99 (d, J =
8.8 Hz, 2 H), 5.09−5.30 (m, 2 H), 4.38−4.52 (m, 1 H), 4.21 (br s, 1
H), 4.25−4.38 (m, 2 H), 3.24−3.53 (m, 3 H), 3.04−3.20 (m, 1 H),
2.65 (d, J = 5.38 Hz, 3 H), 1.69 (br s, 3 H).
Benzyl (3S)-4-(4-(methylsulfamoyl)phenyl)-3-(1-propyn-1-yl)-1-
piperazinecarboxylate (0.235 g, 0.550 mmol) was deprotected
according to the general Cbz-deprotection method A and then treated
with tert-butyl (5-(chlorosulfonyl)-2-pyridinyl)carbamate (9) (0.241 g,
0.825 mmol) according to the general sulfonamide formation method
using DIPEA (1.15 mL, 6.60 mmol) to afford tert-butyl (5-(((3S)-4-
(4-(methylsulfamoyl)phenyl)-3-(1-propyn-1-yl)-1-piperazinyl)-
sulfonyl)-2-pyridinyl)carbamate (0.160 g, 53% over two steps), as a
white solid. MS (ESI positive ion) m/z: calcd for C24H31N5O6S2,
549.172; found, 550.1 (M + 1).
tert-Butyl (5-(((3S)-4-(4-(methylcarbamoyl)phenyl)-3-(1-propyn-
1-yl)-1-piperazinyl)sulfonyl)-2-pyridinyl)carbamate (0.25 g,0.49
mmol) was deprotected according to the general Boc-deprotection
method. The crude product obtained was purified by preparative
HPLC (Zorbax-C18 XDB, 20−60% (1:1 acetonitrile/MeOH) in
(0.1% TFA in water) in 6 min, 20 mL/min) to afford 4-((2S)-4-((6-
amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-1-piperazinyl)-N-meth-
ylbenzamide (13) (0.060 g, 30%) as an off-white solid. MS (ESI
positive ion) m/z: calcd for C20H23N5O3S, 413.152; found, 414.1 (M +
tert-Butyl (5-(((3S)-4-(4-(methylsulfamoyl)phenyl)-3-(1-propyn-1-
yl)-1-piperazinyl)sulfonyl)-2-pyridinyl)carbamate (0.160 g, 0.291
mmol) was deprotected according to the general Boc-deprotection
method to afford 4-((2S)-4-((6-amino-3-pyridinyl)sulfonyl)-2-(1-
propyn-1-yl)-1-piperazinyl)-N-methylbenzenesulfonamide (15)
(0.062 g, 47%) as an off-white solid. MS (ESI positive ion) m/z:
1
1). H NMR (400 MHz, CD3OD) δ 8.23 (d, J = 2 Hz, 1 H), 7.86−
7.84 (dd, J = 2.4,9.2 Hz, 1 H), 7.62 (d, J = 8.8 Hz, 2 H), 6.91 (d, J =
8.8 Hz, 2 H), 6.78 (d, J = 8.8 Hz, 1 H), 4.64 (s, 1 H), 3.69 (d, J = 11.2
Hz, 2 H), 3.49 (d, J = 12.8 Hz 1 H), 2.78−2.74 (m, 5 H), 2.62−2.56
(m, 1 H), 1.65 (s, 3 H).
1
calcd for C19H23N5O6S2, 449.119; found, 450.0 (M + 1). H NMR
(400 MHz, DMSO-d6) δ 8.27 (d, J = 2.4 Hz, 1 H), 7.67 (dd, J = 8.8,
2.54 Hz, 1 H), 7.62 (d, J = 9.0 Hz, 2 H), 7.17 (q, J = 5.19 Hz, 1 H),
7.10 (d, J = 9.0 Hz, 4 H), 6.57 (d, J = 9.0 Hz, 1 H), 4.93 (br s, 1 H),
5-(((3S)-4-(4-(Methylsulfinyl)phenyl)-3-(1-propyn-1-yl)-1-
piperazinyl)sulfonyl)-2-pyridinamine (14). Benzyl (3S)-3-(1-
propyn-1-yl)-1-piperazinecarboxylate (4) (0.50 g, 1.9 mmol) and 1-
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3.72 (d, J = 12.1 Hz, 1 H), 3.59−3.69 (m, 2 H), 3.09−3.19 (m, 1 H),
2.58 (dd, J = 11.5, 3.33 Hz, 1 H), 2.32−2.46 (m, 4 H), 1.77 (d, J = 2.0
Hz, 3 H).
(4-((2S)-4-Benzyl-2-(1-propyn-1-yl)-1-piperazinyl)-N-
(cyclopropylmethyl)benzenesulfonamide (0.200 g, 0.47 mmol) was
deprotected according to the general Bn-deprotection method to
obtain N-(cyclopropylmethyl)-4-((2S)-2-(1-propyn-1-yl)-1-
piperazinyl)benzenesulfonamide (0.15 g, crude) as a pale-brown
residue. This material was used in the next step without purification.
MS (ESI positive ion) m/z: calcd for C17H23N3O2S, 333.151; found,
333.9 (M + 1).
N-(Cyclopropylmethyl)-4-((2S)-2-(1-propyn-1-yl)-1-piperazinyl)-
benzenesulfonamide (0.150 g, 0.45 mmol) was treated with tert-butyl
(5-(chlorosulfonyl)-2-pyridinyl)carbamate (9) (0.197 g, 0.67 mmol)
according to the general sulfonamide formation method using pyridine
(0.75 mL, 9.3 mmol) to give tert-butyl (5-(((3S)-4-(4-
((cyclopropylmethyl)sulfamoyl)phenyl)-3-(1-propyn-1-yl)-1-
piperazinyl)sulfonyl)-2-pyridinyl)carbamate (0.110 g, 41%) as a white
solid. MS (ESI positive ion) m/z: calcd for C27H35N5O6S2, 589.203;
found, 490.1 (M − Boc + 1). 1H NMR (400 MHz, DMSO-d6) δ 10.54
(s, 1 H), 8.62 (dd, J = 2.5, 0.8 Hz, 1 H), 8.13 (dd, J = 8.9, 2.5 Hz, 1 H),
8.06 (dd, J = 9.0, 0.8 Hz, 1 H), 7.68−7.59 (m, 2 H), 7.50 (t, J = 6.0 Hz,
1 H), 7.14−7.05 (m, 2 H), 4.95 (s, 1 H), 3.83−3.65 (m, 3 H), 3.13
(td, J = 12.3, 3.3 Hz, 1 H), 2.75−2.57 (m, 3 H), 1.76 (d, J = 2.1 Hz, 3
H), 1.50 (s, 9 H), 0.92−0.73 (m, 2 H), 0.41−0.29 (m, 2 H), 0.09−0.03
(m, 2 H).
4-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-
1-piperazinyl)-N-cyclopropylbenzenesulfonamide (16). (3S)-1-
Benzyl-3-(1-propyn-1-yl)piperazine (5) (0.460 g, 2.18 mmol) and 4-
bromo-N-cyclopropylbenzenesulfonamide13 (0.500 g, 1.81 mmol)
were coupled according to the general amination method using
RuPhos (0.042 g, 0.090 mmol), RuPhos first generation precatalyst
(0.042 g, 0.055 mmol), and 1,4-dioxane to give 4-((2S)-4-benzyl-2-(1-
propyn-1-yl)-1-piperazinyl)-N-cyclopropylbenzenesulfonamide (0.350
g, 47%) as a white solid. MS (ESI positive ion) m/z: calcd for
1
C23H27N3O2S, 409.182; found, 410.1 (M + 1). H NMR (300 MHz,
DMSO-d6) δ 7.66−7.57 (m, 3 H), 7.36 (d, J = 6.6 Hz, 4 H), 7.30−7.23
(m, 1 H), 7.08 (d, J = 8.8 Hz, 2 H), 4.78 (bs, 1 H), 3.63 (d, J = 13.6
Hz, 2 H), 3.51 (d, J = 13.6 Hz, 1 H), 3.09 (dd, J = 13.0, 10.0 Hz, 1 H),
2.92 (d, J = 11.0 Hz, 2 H), 2.33−2.12 (m, 2 H), 2.04 (dtt, J = 10.9, 7.5,
3.8 Hz, 1 H), 1.74 (d, J = 2.1 Hz, 3 H), 0.54−0.29 (m, 4 H).
4-((2S)-4-Benzyl-2-(1-propyn-1-yl)-1-piperazinyl)-N-cyclopropyl-
benzenesulfonamide (0.350 g, 0.855 mmol) was deprotected according
to the general Bn-deprotection method to afford N-cyclopropyl-4-
((2S)-2-(1-propyn-1-yl)-1-piperazinyl)benzenesulfonamide (0.25 g,
crude) as a pale-brown residue that was used in the next step without
purification. MS (ESI positive ion) m/z: calcd for C16H21N3O2S,
319.135; found, 319.8 (M + 1).
tert-Butyl (5-(((3S)-4-(4-((cyclopropylmethyl)sulfamoyl)phenyl)-
3-(1-propyn-1-yl)-1-piperazinyl)sulfonyl)-2-pyridinyl)carbamate
(0.110 g, 0.186 mmol) was deprotected according to the general Boc-
deprotection method to give 4-((2S)-4-benzyl-2-(1-propyn-1-yl)-1-
piperazinyl)-N-(cyclopropylmethyl)benzenesulfonamide (17) (0.050
g, 55%) as a white solid. MS (ESI positive ion) m/z: calcd for
N-Cyclopropyl-4-((2S)-2-(1-propyn-1-yl)-1-piperazinyl)-
benzenesulfonamide (0.250 g, 0.783 mmol) was treated with tert-butyl
(5-(chlorosulfonyl)-2-pyridinyl)carbamate (9) (0.340 g, 1.17 mmol)
according to the general sulfonamide formation method using pyridine
(1.2 mL, 14.8 mmol) to give tert-butyl (5-(((3S)-4-(4-
(cyclopropylsulfamoyl)phenyl)-3-(1-propyn-1-yl)-1-piperazinyl)-
sulfonyl)-2-pyridinyl)carbamate (0.200 g, 41% over two steps) as a
white solid. MS (ESI positive ion) m/z: calcd for C26H33N5O6S2,
1
C22H27N5O4S2, 489.150; found, 489.9 (M+1). H NMR (400 MHz,
DMSO-d6) δ 8.26 (d, J = 2.6 Hz, 1 H), 7.69−7.60 (m, 3 H), 7.48 (s, 1
H), 7.12−7.02 (m, 4 H), 6.61−6.52 (m, 1 H), 4.94 (s, 1 H), 3.77−3.56
(m, 3 H), 3.13 (td, J = 12.1, 3.0 Hz, 1 H), 2.59 (td, J = 6.7, 3.4 Hz, 2
H), 2.46−2.32 (m, 2 H), 1.77 (d, J = 2.1 Hz, 3 H), 0.84−0.72 (m, 1
H), 0.39−0.28 (m, 2 H), 0.08−0.03 (m, 2 H).
1
575.187; found, 576 (M + 1). H NMR (400 MHz, DMSO-d6) δ
10.53 (s, 1 H), 8.64−8.56 (m, 1 H), 8.11 (dd, J = 9.0, 2.5 Hz, 1 H),
8.04 (dd, J = 9.0, 0.8 Hz, 1 H), 7.71−7.58 (m, 3 H), 7.17−7.03 (m, 2
H), 4.99−4.87 (m, 1 H), 3.79−3.63 (m, 3 H), 3.13 (td, J = 12.2, 3.2
Hz, 1 H), 2.64 (dd, J = 11.5, 3.3 Hz, 1 H), 2.03−1.95 (m, 1 H), 1.75
(d, J = 2.1 Hz, 3 H), 1.48 (s, 9 H), 0.43 (dt, J = 7.9, 3.3 Hz, 2 H),
0.36−0.30 (m, 2 H). One proton was obscured by solvent peak.
tert-Butyl (5-(((3S)-4-(4-(cyclopropylsulfamoyl)phenyl)-3-(1-pro-
pyn-1-yl)-1-piperazinyl)sulfonyl)-2-pyridinyl)carbamate (0.200 g,
0.347 mmol) was deprotected according to the general Boc-
deprotection method to give 4-((2S)-4-((6-amino-3-pyridinyl)-
sulfonyl)-2-(1-propyn-1-yl)-1-piperazinyl)-N-cyclopropyl-
benzenesulfonamide (16) (0.100 g, 62%) as a white solid. MS (ESI
positive ion) m/z: calcd for C21H25N5O4S2, 475.135; found, 476.1 (M
4-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-
1-piperazinyl)-N-phenylbenzenesulfonamide (18). Benzyl (3S)-
3-(1-propyn-1-yl)-1-piperazinecarboxylate (4) (0.290 g, 1.12 mmol)
and 4-bromo-N-phenylbenzenesulfonamide13 (0.350 g, 1.12 mmol)
were coupled according to the general amination method using
JohnPhos (0.016 g, 0.056 mmol), Pd2(dba)3 (0.030 g, 0.033 mmol),
and toluene (5 mL) to give benzyl (3S)-4-(4-(phenylsulfamoyl)-
phenyl)-3-(1-propyn-1-yl)-1-piperazinecarboxylate (0.170 g, 31%) as a
white solid. MS (ESI positive ion) m/z: calcd for C27H27N3O4S,
1
489.172; found, 490.0 (M + 1). H NMR (300 MHz, DMSO-d6) δ
10.07 (s, 1 H), 7.63−7.54 (m, 2 H), 7.40−7.35 (m, 3 H), 7.29−7.17
(m, 4 H), 7.09−6.80 (m, 5 H), 5.2 5−5.05 (m, 2 H), 4.78 (s, 1 H),
4.12−3.95 (m, 2 H), 3.60 (s, 1 H), 2.98−3.1 (m, 2 H), 1.63 (d, J = 1.9
Hz, 3 H). One proton was obscured under solvent peak.
Benzyl (3S)-4-(4-(phenylsulfamoyl)phenyl)-3-(1-propyn-1-yl)-1-
piperazinecarboxylate (0.170 g, 0.34 mmol) was deprotected according
to the general Cbz-deprotection method A to give N-phenyl-4-((2S)-
2-(1-propyn-1-yl)-1-piperazinyl)benzenesulfonamide, the title com-
pound (0.100 g, crude), as a pale-brown solid. The material was used
in the next step without purification. MS (ESI positive ion) m/z: calcd
for C19H21N3O2S, 355.135; found, 356.1 (M + 1).
N-Phenyl-4-((2S)-2-(1-propyn-1-yl)-1-piperazinyl)-
benzenesulfonamide (0.100 g, 0.28 mmol) was treated with tert-butyl
(5-(chlorosulfonyl)-2-pyridinyl)carbamate (9) (0.120 g, 0.42 mmol)
according to the general sulfonamide formation method using pyridine
(0.5 mL, 6.2 mmol) to give tert-butyl (5-(((3S)-4-(4-
(phenylsulfamoyl)phenyl)-3-(1-propyn-1-yl)-1-piperazinyl)sulfonyl)-
2-pyridinyl)carbamate (0.060 g, 28% over two steps) as a white solid.
MS (ESI positive ion) m/z: calcd for C29H33N5O6S2, 611.187; found,
612.3 (M + 1). 1H NMR (300 MHz, CDCl3) δ 8.65 (d, J = 2.3 Hz, 1
H), 8.14 (d, J = 8.8 Hz, 1 H), 8.03 (dd, J = 8.9, 2.4 Hz, 1 H), 7.75−
7.58 (m, 2 H), 7.26 (m, 3 H), 7.13−7.04 (m, 2 H), 6.87 (d, J = 8.8 Hz,
2 H), 6.47 (s, 1 H), 4.49 (s, 1 H), 3.90−3.78 (m, 2 H), 3.50 (br d, J =
12.4 Hz, 1 H), 3.46−3.31 (m, 1 H), 2.79 (dd, J = 11.1, 3.0 Hz, 1 H),
1
+ 1). H NMR (400 MHz, DMSO-d6) δ 8.24 (d, J = 2.5 Hz, 1 H),
7.68−7.58 (m, 4 H), 7.12−7.02 (m, 4 H), 6.53 (d, J = 8.9 Hz, 1 H),
4.99−4.87 (m, 1 H), 3.76−3.53 (m, 3 H), 3.19−3.06 (m, 1 H), 2.37
(td, J = 11.9, 11.5, 3.0 Hz, 2 H), 2.02 (dq, J = 6.8, 3.4 Hz, 1 H), 1.75
(d, J = 2.1 Hz, 3 H), 0.43 (dt, J = 6.4, 3.1 Hz, 2 H), 0.37−0.28 (m, 2
H).
4-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-
1-piperazinyl)-N-(cyclopropylmethyl)benzenesulfonamide
(17). (3S)-1-Benzyl-3-(1-propyn-1-yl)piperazine (5) (0.440 g, 2.08
mmol) and 4-bromo-N-(cyclopropylmethyl)benzenesulfonamide13
(0.500 g, 1.73 mmol) were coupled according to the general
amination method using RuPhos (0.040 g, 0.086 mmol), RuPhos
first generation precatalyst (0.040 g, 0.051 mmol), and 1,4-dioxane to
give 4-((2S)-4-benzyl-2-(1-propyn-1-yl)-1-piperazinyl)-N-
(cyclopropylmethyl)benzenesulfonamide (0.300 g, 41%) as a white
solid. MS (ESI positive ion) m/z: calcd for C24H29N3O2S, 423.198;
found, 424.2 (M + 1). 1H NMR (300 MHz, CDCl3) δ 7.78−7.69 (m,
2 H), 7.46−7.25 (m, 4 H), 7.02−6.91 (m, 3 H), 4.53−4.35 (m, 2 H),
3.74 (d, J = 13.5 Hz, 1 H), 3.62−3.44 (m, 2 H), 3.35 (td, J = 11.7, 3.1
Hz, 1 H), 3.08−2.92 (m, 2 H), 2.87−2.72 (m, 2 H), 2.44−2.27 (m, 2
H), 1.80 (d, J = 2.2 Hz, 3 H), 1.28 (d, J = 8.4 Hz, 1 H), 0.89 (qd, J =
8.0, 3.2 Hz, 2 H), 0.53−0.40 (m, 2 H).
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2.72−2.58 (m, 1 H), 1.78 (d, J = 2.1 Hz, 3 H), 1.58 (s, 9 H). One
exchangeable proton was not observed.
0.05 mmol), Pd(OAc)2 (0.011 g, 0.04 mmol), and toluene to obtain
benzyl 4-(4-(methylsulfonyl)phenyl)-3-(1-propyn-1-yl)-1-piperazine-
carboxylate (0.220 g, 25%) as a white solid. MS (ESI positive ion)
m/z: calcd for C22H24N2O4S, 412.146; found, 413.1 (M + 1).
Benzyl 4-(4-(methylsulfonyl)phenyl)-3-(1-propyn-1-yl)-1-piperazi-
necarboxylate (0.22 g, 0.53 mmol) was deprotected according to the
general Cbz-deprotection method A to obtain 1-(4-(methylsulfonyl)-
phenyl)-2-(prop-1-yn-1-yl)piperazine (0.13 g, crude) as a pale-brown
solid. The material was used in the next step without purification. MS
(ESI positive ion) m/z: calcd for C14H18N2O2S, 278.109; found, 279.1
(M + 1).
tert-Butyl (5-(((3S)-4-(4-(phenylsulfamoyl)phenyl)-3-(1-propyn-1-
yl)-1-piperazinyl)sulfonyl)-2-pyridinyl)carbamate (0.060 g, 0.098
mmol) was deprotected according to the general Boc-deprotection
method to give 4-((2S)-4-((6-amino-3-pyridinyl)sulfonyl)-2-(1-pro-
pyn-1-yl)-1-piperazinyl)-N-phenylbenzenesulfonamide (18) (0.013 g,
18%) as a white solid. MS (ESI positive ion) m/z: calcd for
1
C24H25N5O4S2, 511.135; found, 512.1 (M + 1). H NMR (400 MHz,
CD3OD) δ 8.18 (d, J = 2.6 Hz, 1 H), 7.62 (dd, J = 8.9, 2.5 Hz, 1 H),
7.52−7.44 (m, 2 H), 7.09−7.05 (m, 2 H), 7.00−6.82 (m, 5 H), 6.51
(d, J = 9.0 Hz, 1 H), 4.61 (s, 1 H), 3.62 (br d, J = 11.2 Hz, 2 H), 3.49
(br d, J = 12.4 Hz, 1 H), 3.12 (td, J = 12.4, 3.2 Hz, 1 H), 2.58 (dd, J =
11.6, 3.2 Hz, 1 H), 2.42 (td, J = 11.6, 3.2 Hz, 1 H), 1.63 (d, J = 2.1 Hz,
3 H).
1-(4-(Methylsulfonyl)phenyl)-2-(1-propyn-1-yl)piperazine (0.12 g,
0.43 mmol) was treated with tert-butyl (5-(chlorosulfonyl)-2-
pyridinyl)carbamate (9) (0.127 g, 0.43 mmol) according to the
general sulfonamide formation method using Et3N (0.2 mL, 1.9
mmol) to afford tert-butyl (5-((4-(4-(methylsulfonyl)phenyl)-3-(1-
propyn-1-yl)-1-piperazinyl)sulfonyl)-2-pyridinyl)carbamate (0.080 g,
35%) as a white solid. MS (ESI positive ion) m/z: calcd for
5-(((3S)-4-(4-(N-Methyl-S-(trifluoromethyl)sulfonimidoyl)-
phenyl)-3-(1-propyn-1-yl)-1-piperazinyl)sulfonyl)-2-pyridin-
amine (19). (3S)-1-Benzyl-3-(1-propyn-1-yl)piperazine (5) (0.250 g,
1.15 mmol) and 1-bromo-4-(N-methyl-S-(trifluoromethyl)-
sulfonimidoyl)benzene13 (0.350 g, 1.15 mmol) were coupled
according to the general amination method using RuPhos (0.016 g,
0.034 mmol), Pd2(dba)3 (0.055 g, 0.058 mmol), and 1,4-dioxane to
give (2S)-4-benzyl-1-(4-(N-methyl-S-(trifluoromethyl)sulfonimidoyl)-
phenyl)-2-(1-propyn-1-yl)piperazine (0.300 g, 59%) as a white solid.
MS (ESI positive ion) m/z: calcd for C22H24F3N3OS, 435.159; found,
436.0 (M + 1). 1H NMR (300 MHz, CDCl3) δ 7.88 (d, J = 8.8 Hz, 2
H), 7.40 (d, J = 7.2 Hz, 2 H), 7.34 (dd, J = 7.2 Hz, 2 H), 7.28−7.26
(m, 1 H), 6.98 (d, J = 9.2 Hz, 2 H), 4.52 (s, 1 H), 3.72 (d, J = 13.2 Hz,
1 H), 3.60−3.53 (m, 2 H), 3.42−3.35 (m, 1 H), 3.06 (s, 3 H), 3.05−
2.98 (m, 2 H), 2.36−2.39 (m, 2 H), 1.81 (d, J = 1.5 Hz, 3 H).
(2S)-4-Benzyl-1-(4-(N-methyl-S-(trifluoromethyl)sulfonimidoyl)-
phenyl)-2-(1-propyn-1-yl)piperazine (0.300 g, 0.690 mmol) was
deprotected according to the general Bn-deprotection method to
afford (2S)-1-(4-(N-methyl-S-(trifluoromethyl)sulfonimidoyl)phenyl)-
2-(1-propyn-1-yl)piperazine (0.2 g, crude), which was used in the next
step without purification. MS (ESI positive ion) m/z: calcd for
C15H18F3N3OS, 345.112; found, 345.9 (M + 1).
1
C24H30N4O6S2, 534.161; found, 534.5 (M + 1). H NMR (400 MHz,
DMSO-d6) δ 8.59 (bs,1 H), 8.09−8.01 (m, 2 H), 7.72 (d, J = 6.6, 2.4
Hz, 2 H), 7.12 (d, J = 6.9 Hz, 2 H), 7.03 (s, 2 H), 4.96 (s, 1 H), 3.76−
3.67 (m, 3 H), 3.11 (m, 4 H), 2.62 (d, J = 7.8 Hz, 1 H), 1.74 (s, 3 H),
1.47 (s, 9 H).
tert-Butyl (5-((4-(4-(methylsulfonyl)phenyl)-3-(1-propyn-1-yl)-1-
piperazinyl)sulfonyl)-2-pyridinyl)carbamate (0.080 g, 0.15 mmol)
was deprotected according to the general Boc-deprotection method
to afford 5-4-(4-(methylsulfonyl)phenyl)-3-(1-propyn-1-yl)-1-
piperazinyl)sulfonyl)-2-pyridinamine (0.030 g, 46%) as a white solid.
MS (ESI positive ion) m/z: calcd for C19H22N3O4S2, 434.108; found,
435.3 (M + 1). 1H NMR (400 MHz, DMSO-d6) δ 8.24 (d, J = 2.5 Hz,
1 H), 7.72 (d, J = 8.8 Hz, 2 H), 7.64 (dd, J = 2.5, 8.8 Hz, 1 H), 7.12 (d,
J = 9.1 Hz, 2 H), 7.05 (s, 2 H), 6.53 (d, J = 8.8 Hz, 1 H), 4.97 (br s, 1
H), 3.76 (d, J = 12.2 Hz, 1 H), 3.63 (t, J = 10.1 Hz, 2 H), 3.17 (d, J =
5.3 Hz, 1 H), 3.12 (s, 3 H), 2.42−2.30 (m, 2 H), 1.76 (d, J = 1.4 Hz, 3
H).
The racemic 5-4-(4-(methylsulfonyl)phenyl)-3-(1-propyn-1-yl)-1-
piperazinyl)sulfonyl)-2-pyridinamine (0.030 g, 0.069 mmol) was
separated using chiral SFC as follows: Sepax OJH (5 μm, 21 mm ×
250 mm) column, using 70% carbon dioxide−30% MeOH containing
20 mM ammonia; flow rate was 80 mL/min. This procedure produced
5-(((3S)-4-(4-(methylsulfonyl)phenyl)-3-(1-propyn-1-yl)-1-
piperazinyl)sulfonyl)-2-pyridinamine (20). The absolute stereochem-
istry at the piperazine carbon next to the N−Ar was assigned to be (S)
configuration based on the result obtained in the biochemical assay.
MS (ESI positive ion) m/z: calcd for C19H22N3O4S2, 434.108; found,
434.9 (M + 1). 1H NMR (300 MHz, CDCl3) δ 8.49 (d, J = 1.9 Hz, 1
H), 7.86−7.76 (m, 3 H), 7.04−6.95 (m, 2 H), 6.59 (d, J = 8.8 Hz, 1
H), 5.32 (br s, 2 H), 4.55 (br s, 1 H), 3.90−3.76 (m, 2 H), 3.59 (br s,
1 H), 3.50−3.37 (m, J = 2.9, 11.7 Hz, 1 H), 3.03 (s, 3 H), 2.85 (dd, J =
3.4, 11.5 Hz, 1 H), 2.77−2.65 (m, 1 H), 1.80 (s, 3 H).
(2S)-1-(4-(N-Methyl-S-(trifluoromethyl)sulfonimidoyl)phenyl)-2-
(1-propyn-1-yl)piperazine (0.220 g, 0.636 mmol) was treated with tert-
butyl (5-(chlorosulfonyl)-2-pyridinyl)carbamate (9) (0.190 g, 0.636
mmol) according to the general sulfonamide formation method using
Et3N (0.2 mL, 2.5 mmol) in THF (15 mL) instead of DCM to afford
tert-butyl (5-(((3S)-4-(4-(N-methyl-S-(trifluoromethyl)-
sulfonimidoyl)phenyl)-3-(1-propyn-1-yl)-1-piperazinyl)sulfonyl)-2-
pyridinyl)carbamate (0.250 g, 60% over two steps) as a white solid.
MS (ESI positive ion) m/z: calcd for C25H30F3N5O5S2, 601.164;
1
found, 602.2 (M + 1). H NMR (300 MHz, DMSO-d6) δ 10.31 (s, 1
H), 8.59 (d, J = 1.8 Hz, 1 H), 8.13−8.08 (m, 1 H), 8.04−8.01 (d, J =
9.0 Hz, 1 H), 7.82 (d, J = 9.0 Hz, 2 H), 7.18 (d, J = 9.0 Hz. 2 H), 5.03
(bs, 1 H), 3.88 (bd, J = 12.3 Hz, 1 H), 3.75−3.67 (m, 2 H), 3.31−3.05
(m, 2 H), 2.93 (s, 3 H), 2.67−2.64 (m, 1 H), 1.76 (d, J = 1.5 Hz, 3 H),
1.47 (s, 9 H).
4-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-
1-piperazinyl)-N-(1-methylethyl)benzenesulfonamide (21).
Benzyl 3-(1-propyn-1-yl)-1-piperazinecarboxylate (6) (0.370 g, 1.44
mmol) and 4-bromo-N-(1-methylethyl)benzenesulfonamide13 (0.400
g, 1.44 mmol) were coupled according to the general amination
method using JohnPhos (0.021 g, 0.072 mmol), Pd2(dba)3 (0.040 g,
0.043 mmol), and toluene to give benzyl 4-(4-((1-methylethyl)-
sulfamoyl)phenyl)-3-(1-propyn-1-yl)-1-piperazinecarboxylate (0.300 g,
46%) as a white solid. MS (ESI positive ion) m/z: calcd for
tert-Butyl (5-(((3S)-4-(4-(N-methyl-S-(trifluoromethyl)-
sulfonimidoyl)phenyl)-3-(1-propyn-1-yl)-1-piperazinyl)sulfonyl)-2-
pyridinyl)carbamate (0.15 g, 0.25 mmol) was deprotected according to
the general Boc-deprotection method to give 5-(((3S)-4-(4-(N-
methyl-S-(trifluoromethyl)sulfonimidoyl)phenyl)-3-(1-propyn-1-yl)-1-
piperazinyl)sulfonyl)-2-pyridinamine (19) (0.045 g, 36%) as a white
solid. MS (ESI positive ion) m/z: calcd for C20H22F3N5O3S2, 501.112;
1
found, 502 (M + 1). H NMR (400 MHz, CDCl3) δ 8.51 (d, J = 2.4
1
C24H29N3O4S, 455.188; found, 456.1 (M + 1). H NMR (300 MHz,
Hz, 1 H), 7.91 (d, J = 8.8 Hz, 2 H), 7.78 (dd, J = 8.8, 2 Hz, 1 H), 6.99
(d, J = 8.0 Hz, 2 H), 6.55 (d, J = 8.8 Hz, 1 H), 5.03 (s, 2 H), 4.59 (bs,
1 H), 3.88−3.82 (m, 2 H), 3.7−3.63 (m, 1 H), 3.53−3.46 (m, 1 H),
3.07 (s, 3 H), 2.8 (dd, J = 11.2, 3.2 Hz, 1 H), 2.71−2.63 (m, 1 H), 1.81
(d, J = 2 Hz, 3 H).
CDCl3) δ 7.75 (br d, J = 8.7 Hz, 2 H), 7.42−7.33 (m, 4 H), 6.97 (br d,
J = 9 Hz, 3 H), 5.32−5.10 (m, 2 H), 4.55−4.20 (m, 4 H), 3.53−3.19
(m, 4 H), 3.18−3.03 (m, 1 H), 1.65 (d, J = 2.1 Hz, 3 H), 1.08 (d, J =
6.5 Hz, 6H).
Benzyl 4-(4-((1-methylethyl)sulfamoyl)phenyl)-3-(1-propyn-1-yl)-
1-piperazinecarboxylate (0.300 g, 0.65 mmol) was deprotected
according to the general Cbz-deprotection method A to give N-(1-
methylethyl)-4-(2-(1-propyn-1-yl)-1-piperazinyl)benzenesulfonamide
(0.2 g, crude) as a pale-brown solid. This material was used in the next
5-(((3S)-4-(4-(Methylsulfonyl)phenyl)-3-(1-propyn-1-yl)-1-
piperazinyl)sulfonyl)-2-pyridinamine (20). Benzyl 3-(1-propyn-1-
yl)-1-piperazinecarboxylate (6) (0.450 g, 1.74 mmol) and 1-bromo-4-
(methylsulfonyl)benzene (0.500 g, 2.12 mmol) were coupled
according to the general amination method using BINAP (0.032 g,
3107
dx.doi.org/10.1021/jm5000497 | J. Med. Chem. 2014, 57, 3094−3116

Journal of Medicinal Chemistry
Article
1
step without purification. MS (ESI positive ion) m/z: calcd for
C16H23N3O2S, 321.151; found, 322.1 (M + 1).
calcd for C19H20F3N5O3S2, 487.096; found, 488.1 (M + 1). H NMR
(300 MHz, CDCl3) δ 8.48 (d, J = 2.2 Hz, 1 H), 7.95 (d, J = 9.1 Hz, 2
H), 7.76 (dd, J = 2.3, 8.8 Hz, 1 H), 6.99 (d, J = 9.1 Hz, 2 H), 6.52 (d, J
= 8.8 Hz, 1 H), 5.03 (s, 2 H), 4.58 (br s, 1 H), 3.90−3.75 (m, 2 H),
3.66 (br s, 1 H), 3.54−3.37 (m, 2 H), 2.78 (dd, J = 3.4, 11.5 Hz, 1 H),
2.66 (dt, J = 3.0, 11.6 Hz, 1 H), 1.79 (d, J = 1.8 Hz, 3 H).
N-(1-Methylethyl)-4-(2-(1-propyn-1-yl)-1-piperazinyl)-
benzenesulfonamide (0.200 g, 0.623 mmol) was treated with tert-butyl
(5-(chlorosulfonyl)-2-pyridinyl)carbamate (9) (0.200 g, 0.68 mmol)
according to the general sulfonamide formation method using pyridine
(1.0 mL, 12 mmol) to give tert-butyl (5-((4-(4-((1-methylethyl)-
sulfamoyl)phenyl)-3-(1-propyn-1-yl)-1-piperazinyl)sulfonyl)-2-
pyridinyl)carbamate (0.150 g, 40% over two steps) as a white solid.
MS (ESI positive ion) m/z: calcd for C26H35N5O6S2, 577.203; found,
5-(((3S)-3-(1-Propyn-1-yl)-4-(4-(R)-(S-(trifluoromethyl)-
sulfonimidoyl)phenyl)-1-piperazinyl)sulfonyl)-2-pyridinamine
(23) and 5-(((3S)-3-(1-Propyn-1-yl)-4-(4-(S)-(S-(trifluoromethyl)-
sulfonimidoyl)phenyl)-1-piperazinyl)sulfonyl)-2-pyridinamine
(24). The individual diastereomers were isolated using chiral SFC. The
method used was as follows: Chiralpak AS-H column (21 mm × 250
mm, 5 μm) using 30% (240 mM NH3 in methanol) in supercritical
CO2 (total flow was 70 mL/min). This produced the two
diastereomers with diastereomeric and enanteomeric excesses greater
than 98%. The absolute stereochemistry around the sulfur in
sulfoximine moiety was determined using enantiomeric pure 1-
bromo-4-(S-(trifluoromethyl)sulfonimidoyl)benzene.16
5-(((3S)-3-(1-Propyn-1-yl)-4-(4-(R)-(S-(trifluoromethyl)-
sulfonimidoyl)phenyl)-1-piperazinyl)sulfonyl)-2-pyridinamine (23).
MS (ESI positive ion) m/z: calcd for C19H20F3N5O3S2, 487.096;
found, 488.1 (M + 1). 1H NMR (300 MHz, CDCl3) δ 8.48 (d, J = 2.2
Hz, 1 H), 7.95 (d, J = 9.1 Hz, 2 H), 7.77 (d, J = 2.5 Hz, 1 H), 6.99 (d, J
= 9.2 Hz, 2 H), 6.52 (d, J = 8.9 Hz, 1 H), 5.00 (s, 2 H), 4.57 (br s, 1
H), 3.91−3.76 (m, 2 H), 3.65 (d, J = 12.7 Hz, 1 H), 3.54−3.38 (m, 2
H), 2.78 (dd, J = 3.6, 11.5 Hz, 1 H), 2.66 (dt, J = 3.3, 11.6 Hz, 1 H),
1.79 (d, J = 2.0 Hz, 3 H).
5-(((3S)-3-(1-Propyn-1-yl)-4-(4-(S)-(S-(trifluoromethyl)-
sulfonimidoyl)phenyl)-1-piperazinyl)sulfonyl)-2-pyridinamine (24).
MS (ESI positive ion) m/z: calcd for C19H20F3N5O3S2, 487.096;
found, 488.1 (M + 1). 1H NMR (300 MHz, CDCl3) δ 8.51 (d, J = 2.2
Hz, 1 H), 7.97 (d, J = 9.1 Hz, 2 H), 7.78 (dd, J = 2.5, 8.8 Hz, 1 H),
7.01 (d, J = 9.2 Hz, 2 H), 6.54 (d, J = 8.8 Hz, 1 H), 5.02 (s, 2 H), 4.60
(br s, 1 H), 3.93−3.77 (m, 2 H), 3.72−3.60 (m, 1 H), 3.56−3.40 (m, 2
H), 2.80 (dd, J = 3.6, 11.5 Hz, 1 H), 2.68 (dt, J = 3.4, 11.6 Hz, 1 H),
1.81 (d, J = 2.2 Hz, 3 H).
2-(5-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-
yl)-1-piperazinyl)-2-pyridinyl)-1,1,1-trifluoro-2-propanol (25).
(3S)-1-Benzyl-3-(1-propyn-1-yl)piperazine (5) (0.180 g, 0.839
mmol) and 2-(5-bromo-2-pyridinyl)-1,1,1-trifluoro-2-propanol13
(0.232 g, 0.859 mmol) were coupled according to the general
amination method using RuPhos (0.040 g, 0.085 mmol), RuPhos first
generation precatalyst (0.072 g, 0.089 mmol), and 1,4-dioxane to
afford 2-(5-((2S)-4-benzyl-2-(1-propyn-1-yl)-1-piperazinyl)-2-pyridin-
yl)-1,1,1-trifluoro-2-propanol (0.289 g, 85%) as a light-brown oil. MS
(ESI positive ion) m/z: calcd for C22H24F3N3O, 403.187; found, 404.0
1
478.1 (M − Boc + 1). H NMR (300 MHz, DMSO-d6) δ 10.51 (s, 1
H), 8.60 (br s, 1 H), 8.16−7.99 (m, 2 H), 7.62 (br d, J = 8.4 Hz, 2 H),
7.32 (d, J = 7.0 Hz, 1 H), 7.07 (d, J = 8.4 Hz, 2 H), 4.93 (s, 1 H),
3.78−3.62 (m, 3 H), 3.20−3.05 (m, 2 H), 2.64 (br d, J = 8.7 Hz, 1 H),
1.73 (d, J = 1.9 Hz, 3 H), 1.48 (s, 9 H), 0.90 (d, J = 6.4 Hz, 6 H). One
proton was obscured under solvent peak.
tert-Butyl (5-((4-(4-((1-methylethyl)sulfamoyl)phenyl)-3-(1-pro-
pyn-1-yl)-1-piperazinyl)sulfonyl)-2-pyridinyl)carbamate (0.150 g,
0.25 mmol) was deprotected according to the general Boc-
deprotection method to give 4-(4-((6-amino-3-pyridinyl)sulfonyl)-2-
(1-propyn-1-yl)-1-piperazinyl)-N-(1-methylethyl)benzenesulfonamide
(0.080 g, 67%) as a white solid. MS (ESI positive ion) m/z: calcd for
1
C21H27N5O4S2, 477.150; found, 478.1 (M + 1). H NMR (400 MHz,
DMSO-d6) δ 8.24 (d, J = 2.5 Hz, 1 H), 7.68−7.57 (m, 3 H), 7.31 (d, J
= 7.1 Hz, 1 H), 7.11−7.02 (m, 4 H), 6.53 (d, J = 8.9 Hz, 1 H), 4.92 (br
s, 1 H), 3.73−3.56 (m, 3 H), 3.20−3.05 (m, 2 H), 2.45−2.35 (m, 1
H), 1.74 (d, J = 2.2 Hz, 3 H), 0.91 (d, J = 6.4 Hz, 6 H). One proton
was obscured under solvent peak.
The racemic 4-(4-((6-amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-
yl)-1-piperazinyl)-N-(1-methylethyl)benzenesulfonamide (0.030 g,
0.063 mmol) was separated using chiral SFC as follows: Chiralpak
AS-H (5 μm, 21 mm × 250 mm) column, using 70% carbon dioxide−
30% MeOH containing 20 mM ammonia; flow rate was 70 mL/min.
This procedure produced 4-((2S)-4-((6-amino-3-pyridinyl)sulfonyl)-
2-(1-propyn-1-yl)-1-piperazinyl)-N-(1-methylethyl)-
benzenesulfonamide (21). The absolute stereochemistry at the
piperazine carbon next to the N−Ar was assigned to be (S)
configuration based on the result obtained in the biochemical assay.
MS (ESI positive ion) m/z: calcd for C21H27N5O4S2, 477.150; found,
477.9 (M + 1). 1H NMR (300 MHz, CDCl3) δ 8.50 (d, J = 2.3 Hz, 1
H), 7.79 (dd, J = 2.3, 8.8 Hz, 1 H), 7.75 (d, J = 9.1 Hz, 2 H), 6.95 (d, J
= 9.1 Hz, 2 H), 6.55 (d, J = 8.8 Hz, 1 H), 5.12 (s, 2 H), 4.52 (br s, 1
H), 4.14 (d, J = 7.5 Hz, 1 H), 3.88−3.73 (m, 2 H), 3.59−3.35 (m, 3
H), 2.84 (dd, J = 3.4, 11.3 Hz, 1 H), 2.70 (dt, J = 3.5, 11.3 Hz, 1 H),
1.79 (d, J = 2.0 Hz, 3 H), 1.08 (d, J = 6.6 Hz, 6 H).
5-(((3S)-3-(1-Propyn-1-yl)-4-(4-(S-(trifluoromethyl)-
sulfonimidoyl)phenyl)-1-piperazinyl)sulfonyl)-2-pyridinamine
(22). Benzyl (3S)-3-(1-propyn-1-yl)-1-piperazinecarboxylate (4)
(0.684 g, 2.65 mmol) and 1-bromo-4-(S-(trifluoromethyl)-
sulfonimidoyl)benzene13 (0.758 g, 2.63 mmol) were coupled
according to the general amination method using RuPhos (0.123 g,
0.263 mmol), RuPhos first generation precatalyst (0.214 g, 0.262
mmol), and 1,4-dioxane to afford benzyl (3S)-3-(1-propyn-1-yl)-4-(4-
(S-(trifluoromethyl)sulfonimidoyl)phenyl)-1-piperazinecarboxylate
(0.891 g, 73%) as a light-yellow foam. MS (ESI positive ion) m/z:
1
(M + 1). H NMR (300 MHz, CDCl3) δ 8.26 (t, J = 2.5 Hz, 1 H),
7.45−7.27 (m, 7 H), 6.23 (s, 1 H), 4.38 (br s, 1 H), 3.73 (d, J = 10.7
Hz, 1 H), 3.58 (s, 1 H), 3.47−3.30 (m, 2 H), 3.06−2.92 (m, 2 H),
2.50−2.32 (m, 2 H), 1.81 (d, J = 2.0 Hz, 3 H), 1.70 (s, 3 H).
2-(5-((2S)-4-Benzyl-2-(1-propyn-1-yl)-1-piperazinyl)-2-pyridinyl)-
1,1,1-trifluoro-2-propanol (0.289 g, 0.716 mmol) was deprotected
according to the general Bn-deprotection method. The crude product
was treated with tert-butyl (5-(chlorosulfonyl)-2-pyridinyl)carbamate
(9) (0.238 g, 0.813 mmol) according to the general sulfonamide
formation method using Et3N (1.0 mL, 7.2 mmol) to afford tert-butyl
(5-(((3S)-3-(1-propyn-1-yl)-4-(6-(2,2,2-trifluoro-1-hydroxy-1-methyl-
ethyl)-3-pyridinyl)-1-piperazinyl)sulfonyl)-2-pyridinyl)carbamate
(0.347 g, 85%) as a white solid. MS (ESI positive ion) m/z: calcd for
C25H30F3N5O5S, 569.192; found, 570.0 (M + 1). 1H NMR (300 MHz,
CDCl3) δ 8.67 (dd, J = 0.7, 2.3 Hz, 1 H), 8.23 (t, J = 2.6 Hz, 1 H),
8.18−8.11 (m, 1 H), 8.07−8.00 (m, 1 H), 7.84 (s, 1 H), 7.42−7.35
(m, 1 H), 7.35−7.28 (m, 1 H), 6.10 (s, 1 H), 4.39 (br s, 1 H), 3.87−
3.72 (m, 2 H), 3.48−3.32 (m, 2 H), 2.96−2.86 (m, J = 3.2 Hz, 1 H),
2.82−2.69 (m, 1 H), 1.79 (s, 3 H), 1.68 (s, 3 H), 1.55 (s, 9 H).
tert-Butyl (5-(((3S)-3-(1-propyn-1-yl)-4-(6-(2,2,2-trifluoro-1-hy-
droxy-1-methylethyl)-3-pyridinyl)-1-piperazinyl)sulfonyl)-2-
pyridinyl)carbamate (0.347 g, 0.609 mmol) was deprotected according
to the general Boc-deprotection method to afford 2-(5-((2S)-4-((6-
amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-1-piperazinyl)-2-pyri-
1
calcd for C22H22F3N3O3S, 465.133; found, 466.1 (M + 1). H NMR
(300 MHz, CDCl3) δ 7.98 (d, J = 9.1 Hz, 2 H), 7.45−7.29 (m, 5 H),
7.03 (d, J = 9.2 Hz, 2 H), 5.21 (d, J = 17.0 Hz, 2 H), 4.50 (br s, 1 H),
4.33 (d, J = 11.4 Hz, 2 H), 3.61 (d, J = 11.3 Hz, 1 H), 3.50−3.08 (m, 4
H), 1.72 (br s, 3 H).
Benzyl (3S)-3-(1-propyn-1-yl)-4-(4-(S-(trifluoromethyl)-
sulfonimidoyl)phenyl)-1-piperazinecarboxylate (0.890 g, 1.91 mmol)
was deprotected according to the general Cbz-deprotection method A,
then treated with tert-butyl (5-(chlorosulfonyl)-2-pyridinyl)carbamate
(9) (0.627 g, 2.14 mmol) according to the general sulfonamide
formation method using Et3N (2.7 mL, 19.4 mmol), and finally
deprotected according to the general Boc-deprotection method to
afford 5-(((3S)-3-(1-propyn-1-yl)-4-(4-(S-(trifluoromethyl)-
sulfonimidoyl)phenyl)-1-piperazinyl)sulfonyl)-2-pyridinamine (22)
(0.886 g, 95%) as an off-white foam. MS (ESI positive ion) m/z:
3108
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dinyl)-1,1,1-trifluoro-2-propanol (25) (0.225 g, 79%) as a white solid.
MS (ESI positive ion) m/z: calcd for C20H22F3N5O3S, 469.140; found,
469.9 (M + 1). 1H NMR (300 MHz, CDCl3) δ 8.49 (d, J = 2.0 Hz, 1
H), 8.23 (t, J = 2.6 Hz, 1 H), 7.77 (dd, J = 2.5, 8.8 Hz, 1 H), 7.41−7.28
(m, 2 H), 6.53 (d, J = 8.8 Hz, 1 H), 6.10 (s, 1 H), 5.00 (s, 2 H), 4.38
(br s, 1 H), 3.81−3.68 (m, 2 H), 3.44−3.33 (m, 2 H), 2.88 (dd, J =
3.4, 11.4 Hz, 1 H), 2.79−2.67 (m, 1 H), 1.78 (d, J = 2.2 Hz, 3 H), 1.68
(s, 3 H).
(300 MHz, DMSO-d6) δ 8.44 (d, J = 2.3 Hz, 1 H), 8.23 (d, J = 2.3 Hz,
1 H), 7.86 (dd, J = 2.5, 9.1 Hz, 1 H), 7.63 (dd, J = 2.5, 8.9 Hz, 1 H),
7.30 (d, J = 3.4 Hz, 1 H), 6.99 (t, J = 4.4 Hz, 3 H), 6.52 (d, J = 8.9 Hz,
1 H), 5.48 (br s, 1 H), 4.29 (d, J = 12.3 Hz, 1 H), 3.65 (d, J = 11.1 Hz,
2 H), 3.27−3.13 (m, 2 H), 2.44−2.24 (m, 4 H), 1.78 (d, J = 2.0 Hz, 3
H).
2-(6-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-
yl)-1-piperazinyl)-3-pyridinyl)-1,1,1-trifluoro-2-propanol (28).
Benzyl (3S)-3-(1-propyn-1-yl)-1-piperazinecarboxylate (4) (1.04 g,
4.03 mmol) and 2-(6-bromo-3-pyridinyl)-1,1,1-trifluoro-2-propanol13
(1.39 g, 5.15 mmol) were coupled according to the general amination
method using RuPhos and RuPhos first generation precatalyst premix
(1:1) (0.245 g, 0.205 mmol) and 1,4-dioxane to afford benzyl (3S)-3-
(1-propyn-1-yl)-4-(5-(2,2,2-trifluoro-1-hydroxy-1-methylethyl)-2-pyri-
dinyl)-1-piperazinecarboxylate (1.63 g, 90%) as a light-yellow foam.
MS (ESI positive ion) m/z: calcd for C23H24F3N3O3, 447.177; found,
448.2 (M + 1). 1H NMR (300 MHz, CDCl3) δ 8.41 (s, 1 H), 7.74 (d, J
= 9.1 Hz, 1 H), 7.47−7.29 (m, 5 H), 6.68 (d, J = 8.9 Hz, 1 H), 5.37−
5.05 (m, 3 H), 4.33 (d, J = 10.8 Hz, 2 H), 3.97 (d, J = 9.9 Hz, 1 H),
3.46−2.92 (m, 3 H), 2.42 (s, 1 H), 1.77 (s, 3 H), 1.70 (br s, 3 H).
Benzyl (3S)-3-(1-propyn-1-yl)-4-(5-(2,2,2-trifluoro-1-hydroxy-1-
methylethyl)-2-pyridinyl)-1-piperazinecarboxylate (1.55 g, 3.46
mmol) was deprotected according to the general Cbz-deprotection
method A. The crude product was treated with tert-butyl (5-
(chlorosulfonyl)-2-pyridinyl)carbamate (9) (1.20 g, 4.11 mmol)
according to the general sulfonamide formation method using Et3N
(5.0 mL, 36 mmol) and then deprotected according to the general
Boc-deprotection method to afford 2-(6-((2S)-4-((6-amino-3-
pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-1-piperazinyl)-3-pyridinyl)-
1,1,1-trifluoro-2-propanol (28) (1.42 g, 87% for three steps) as an off-
white foam. MS (ESI positive ion) m/z: calcd for C20H22F3N5O3S,
2-(6-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-
yl)-1-piperazinyl)-3-pyridinyl)-1,1,1,3,3,3-hexafluoro-2-propa-
nol (26). Benzyl (3S)-3-(1-propyn-1-yl)-1-piperazinecarboxylate (4)
(0.129 g, 0.500 mmol) and a mixture of 2-(6-bromo-3-pyridinyl)-
1,1,1,3,3,3-hexafluoro-2-propanol and 2-(6-chloro-3-pyridinyl)-
1,1,1,3,3,3-hexafluoro-2-propanol13 (∼1:1, 0.160 g, 0.53 mmol) were
coupled according to the general amination method using RuPhos and
RuPhos first generation precatalyst premix (1:1) (0.041 g, 0.034
mmol) and 1,4-dioxane to afford benzyl (3S)-3-(1-propyn-1-yl)-4-(5-
(2,2,2-trifluoro-1-hydroxy-1-(trifluoromethyl)ethyl)-2-pyridinyl)-1-pi-
perazinecarboxylate (0.135 g, 55%) as a pale-yellow foam. MS (ESI
positive ion) m/z: calcd for C23H21F6N3O3: 501.149; found, 502.1 (M
1
+ 1). H NMR (300 MHz, CDCl3) δ 8.54 (d, J = 2.0 Hz, 1 H), 7.80
(dd, J = 2.1, 9.3 Hz, 1 H), 7.46−7.30 (m, 5 H), 6.71 (d, J = 9.1 Hz, 1
H), 5.22 (d, J = 17.8 Hz, 3 H), 4.44−4.18 (m, 2 H), 4.03 (br s, 1 H),
3.48 (s, 1 H), 3.45−3.30 (m, 1 H), 3.29−2.92 (m, 2 H), 1.71 (br s, 3
H).
Benzyl (3S)-3-(1-propyn-1-yl)-4-(5-(2,2,2-trifluoro-1-hydroxy-1-
(trifluoromethyl)ethyl)-2-pyridinyl)-1-piperazinecarboxylate (0.135 g,
0.269 mmol) was deprotected according to the general Cbz-
deprotection method A. The crude product was treated with tert-
butyl (5-(chlorosulfonyl)-2-pyridinyl)carbamate (9) (0.086 g, 0.29
mmol) according to the general sulfonamide formation method using
Et3N (0.40 mL, 2.9 mmol) and then deprotected according to the
general Boc-deprotection method to afford 2-(6-((2S)-4-((6-amino-3-
pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-1-piperazinyl)-3-pyridinyl)-
1,1,1,3,3,3-hexafluoro-2-propanol (26) (0.125 g, 89%) as a white solid.
MS (ESI positive ion) m/z: calcd for C20H19F6N5O3S, 523.111; found,
1
469.140; found, 470.1 (M + 1). H NMR (300 MHz, CDCl3) δ 8.49
(d, J = 1.9 Hz, 1 H), 8.38 (s, 1 H), 7.83−7.68 (m, 2 H), 6.67 (s, 1 H),
6.56−6.47 (m, 1 H), 5.22 (br s, 1 H), 4.95 (s, 2 H), 4.11−4.03 (m, 1
H), 3.92−3.77 (m, 2 H), 3.47−3.34 (m, 1 H), 2.70 (dd, J = 3.7, 11.3
Hz, 1 H), 2.57 (dt, J = 3.2, 11.6 Hz, 1 H), 2.44 (s, 1 H), 1.84−1.72 (m,
6 H).
1
524.1 (M + 1). H NMR (300 MHz, CDCl3) δ 8.49 (dd, J = 2.0, 9.6
Hz, 2 H), 7.79 (dd, J = 2.3, 8.8 Hz, 2 H), 6.68 (d, J = 9.1 Hz, 1 H),
6.54 (d, J = 8.8 Hz, 1 H), 5.25 (br s, 1 H), 5.09 (s, 2 H), 4.21−4.10
(m, 1 H), 3.92−3.77 (m, 2 H), 3.71−3.36 (m, 2 H), 2.71 (dd, J = 3.7,
11.3 Hz, 1 H), 2.58 (dt, J = 3.2, 11.8 Hz, 1 H), 1.81 (d, J = 2.0 Hz, 3
H).
(2R)-2-(6-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-pro-
pyn-1-yl)-1-piperazinyl)-3-pyridinyl)-1,1,1-trifluoro-2-propanol
(29) and (2S)-2-(6-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-
propyn-1-yl)-1-piperazinyl)-3-pyridinyl)-1,1,1-trifluoro-2-prop-
anol (30). The individual diastereomers were isolated using chiral
SFC from 2-(6-((2S)-4-((6-amino-3-pyridinyl)sulfonyl)-2-(1-propyn-
1-yl)-1-piperazinyl)-3-pyridinyl)-1,1,1-trifluoro-2-propanol. The meth-
od used was as follows: Chiralpak AS-H column (21 mm × 250 mm, 5
μm) using 25% (40 mM NH3 in methanol) in supercritical CO2 (total
flow was 75 mL/min). This produced the following two diastereomers
with diastereomeric and enantiomeric excesses greater than 98%. The
absolute stereochemistry around the sulfur in the sulfoximine moiety
was determined using enantiomeric pure 2-(6-bromo-3-pyridinyl)-
1,1,1-trifluoro-2-propanol.16
(2R)-2-(6-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-
yl)-1-piperazinyl)-3-pyridinyl)-1,1,1-trifluoro-2-propanol (29). MS
(ESI positive ion) m/z: calcd for C20H22F3N5O3S, 469.140; found,
470.1 (M + 1). 1H NMR (300 MHz, CDCl3) δ 8.47 (d, J = 1.8 Hz, 1
H), 8.37 (d, J = 2.3 Hz, 1 H), 7.80−7.67 (m, 2 H), 6.64 (d, J = 8.9 Hz,
1 H), 6.51 (d, J = 8.8 Hz, 1 H), 5.19 (br s, 1 H), 4.98 (s, 2 H), 4.08 (d,
J = 12.9 Hz, 1 H), 3.89−3.74 (m, 2 H), 3.39 (dt, J = 3.2, 12.4 Hz, 1
H), 2.69 (dd, J = 3.5, 11.3 Hz, 1 H), 2.62−2.49 (m, 1 H), 2.40 (br s, 1
H), 1.83−1.68 (m, 6 H).
(2S)-2-(6-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-
yl)-1-piperazinyl)-3-pyridinyl)-1,1,1-trifluoro-2-propanol (30). MS
(ESI positive ion) m/z: calcd for C20H22F3N5O3S, 469.140; found,
470.1 (M + 1). 1H NMR (300 MHz, CDCl3) δ 8.47 (d, J = 1.9 Hz, 1
H), 8.36 (d, J = 2.5 Hz, 1 H), 7.82−7.66 (m, 2 H), 6.64 (d, J = 8.9 Hz,
1 H), 6.50 (d, J = 8.8 Hz, 1 H), 5.20 (br s, 1 H), 4.97 (s, 2 H), 4.07 (d,
J = 13.4 Hz, 1 H), 3.91−3.73 (m, 2 H), 3.39 (dt, J = 3.1, 12.3 Hz, 1
H), 2.69 (dd, J = 3.5, 11.3 Hz, 1 H), 2.55 (dt, J = 3.3, 11.7 Hz, 1 H),
2.39 (br s, 1 H), 1.83−1.69 (m, 6 H).
6-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-
1-piperazinyl)-N-methyl-3-pyridinesulfonamide (27). Benzyl
(3S)-3-(1-propyn-1-yl)-1-piperazinecarboxylate (4) (0.507 g, 1.96
mmol) and 6-chloro-N-methyl-3-pyridinesulfonamide13 (0.501 g,
2.42 mmol) were coupled according to the general amination
procedure using RuPhos and RuPhos first generation precatalyst
premix (1:1) (0.235 g, 0.196 mmol) and 1,4-dioxane to afford benzyl
(3S)-4-(5-(methylsulfamoyl)-2-pyridinyl)-3-(1-propyn-1-yl)-1-pipera-
zinecarboxylate (0.309 g, 37%) as a white solid. MS (ESI positive ion)
m/z: calcd for C21H24N4O4S, 428.152; found, 429.2 (M + 1). 1H
NMR (300 MHz, DMSO-d6) δ 8.44 (d, J = 2.3 Hz, 1 H), 8.23 (d, J =
2.3 Hz, 1 H), 7.86 (dd, J = 2.5, 9.1 Hz, 1 H), 7.63 (dd, J = 2.5, 8.9 Hz,
1 H), 7.30 (d, J = 3.4 Hz, 1 H), 6.99 (t, J = 4.4 Hz, 3 H), 6.52 (d, J =
8.9 Hz, 1 H), 5.48 (br s, 1 H), 4.29 (d, J = 12.3 Hz, 1 H), 3.65 (d, J =
11.1 Hz, 2 H), 3.27−3.13 (m, 2 H), 2.44−2.24 (m, 4 H), 1.78 (d, J =
2.0 Hz, 3 H). One exchangeable proton was not observed, and another
proton was obscured by the solvent peak.
Benzyl (3S)-4-(5-(methylsulfamoyl)-2-pyridinyl)-3-(1-propyn-1-
yl)-1-piperazinecarboxylate (0.157 g, 0.366 mmol) was deprotected
according to the general Cbz-deprotection method A. The crude
product was treated with tert-butyl (5-(chlorosulfonyl)-2-pyridinyl)-
carbamate (9) (0.0865 g, 0.295 mmol) according to the general
sulfonamide formation using Et3N (0.50 mL, 3.6 mmol) and then
deprotected according to the general Boc-deprotection method to
afford 6-((2S)-4-((6-amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-1-
piperazinyl)-N-methyl-3-pyridinesulfonamide (27) (0.0247 g, 15%
over three steps) as an off-white solid. MS (ESI positive ion) m/z:
1
calcd for C18H22N6O4S2, 450.114; found, 451.1 (M + 1). H NMR
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5-(((3S)-4-(4-(S-Cyclopropylsulfonimidoyl)phenyl)-3-(1-pro-
pyn-1-yl)-1-piperazinyl)sulfonyl)-2-pyridinamine (47). (3S)-1-
Benzyl-3-(1-propyn-1-yl)piperazine (5) (0.510 g, 2.41 mmol) and 1-
bromo-4-(cyclopropylsulfanyl)benzene13 (0.500 g, 2.19 mmol) were
coupled according to the general amination method using RuPhos
(0.051 g, 0.109 mmol), Pd2(dba)3 (0.060 g, 0.066 mmol), and 1,4-
dioxane to give (2S)-4-benzyl-1-(4-(cyclopropylsulfanyl)phenyl)-2-(1-
propyn-1-yl)piperazine (31) (0.350 g, 47%) as a white solid. MS (ESI
positive ion) m/z: calcd for C23H26N2S, 362.182; found, 363.2 (M +
1).
0.096 mmol), DavePhos (0.037 g, 0.096 mmol), and toluene to afford
benzyl (3S)-4-(4-(methylsulfinyl)phenyl)-3-(1-propyn-1-yl)-1-pipera-
zinecarboxylate (33) (0.75 g, 65%) as a pale-brown gummy solid. MS
(ESI positive ion) m/z: calcd for C22H24N2O3S, 396.151; found, 397.0
(M + 1).
Compound 33 (0.75 g, 1.9 mmol) was deprotected according to the
general Cbz-deprotection method
B to give (2S)-1-(4-
(methylsulfinyl)phenyl)-2-(1-propyn-1-yl)piperazine (34) (0.40 g,
80%) as a brown gummy liquid. MS (ESI positive ion) m/z: calcd
for C14H18N2OS, 262.114; found, 263.1 (M + 1).
Compound 31 (0.350 g, 0.690 mmol) was deprotected according to
the general Bn-deprotection method to afford (2S)-1-(4-
(cyclopropylsulfanyl)phenyl)-2-(1-propyn-1-yl)piperazine (32) (0.40
g, crude) as a pale-brown residue, which was carried forward to the
next step without further purification. MS (ESI positive ion) m/z:
calcd for C16H20N2S, 272.135; found, 273.1 (M + 1).
Compound 34 (0.40 g, 1.5 mmol) was treated with tert-butyl (5-
(chlorosulfonyl)-2-pyridinyl)carbamate (9) (0.67 g, 2.3 mmol)
according to the general sulfonamide formation method using Et3N
(0.6 mL, 3.8 mmol) to give tert-butyl (5-(((3S)-4-(4-(methylsulfinyl)-
phenyl)-3-(1-propyn-1-yl)-1-piperazinyl)sulfonyl)-2-pyridinyl)-
carbamate (43) (0.35 g, 44%) as a brown solid. MS (ESI positive ion)
1
Compound 32 (0.400 g, 1.47 mmol) was treated with tert-butyl (5-
(chlorosulfonyl)-2-pyridinyl)carbamate (9) (0.510 g, 1.76 mmol)
according to the general sulfonamide formation method using pyridine
(2.0 mL, 25 mmol) to give tert-butyl (5-(((3S)-4-(4-
(cyclopropylsulfanyl)phenyl)-3-(1-propyn-1-yl)-1-piperazinyl)-
sulfonyl)-2-pyridinyl)carbamate (41) (0.260 g, 50% over two steps) as
a white solid. MS (ESI positive ion) m/z: calcd for C26H32N4O4S2,
m/z: calcd for C24H30N4O5S2, 518.166; found, 519.3 (M + 1). H
NMR (300 MHz, CDCl3) δ 8.66 (s, 1 H), 8.13 (d, J = 6.6 Hz, 1 H),
8.03 (dd, J = 6.6, 1.5 Hz, 1 H), 7.65 (s, 1 H), 7.56 (d, J = 6.6 Hz, 2 H),
7.03 (d, J= 6.0 Hz, 2 H), 4.47 (s, 1 H), 3.84−3.77 (m, 2 H), 3.43−3.39
77 (m, 3 H), 2.84 (dd, J = 8.4, 2.7 Hz, 1 H), 2.70 (s, 3 H), 1.78 (s, 3
H), 1.58 (s, 9 H).
A 100 mL round-bottomed flask was charged with compound 43
(0.25 g, 0.48 mmol) and CHCl3 (20 mL) and treated with NaN3
(0.035 g, 0.53 mmol) at room temperature. The resulting mixture was
cooled to 0 °C, and concentrated H2SO4 (0.530 g, 5.3 mmol) was
added dropwise to the above solution. The reaction mixture was
allowed to warm to room temperature and stirred at room temperature
for 6 h. The reaction mixture was diluted with ice-cold water (20 mL)
and neutralized with Na2CO3 solution (10%, 10 mL) before extracting
with CHCl3 (3 × 50 mL). The combined organic extracts were washed
with water and saturated aqueous NaCl, dried over anhydrous Na2SO4,
filtered, and concentrated under reduced pressure. The residue
obtained was purified by silica gel preparative TLC (eluent 3%
MeOH−DCM) to give 5-(((3S)-4-(4-(S-methylsulfonimidoyl)-
phenyl)-3-(1-propyn-1-yl)-1-piperazinyl)sulfonyl)-2-pyridinamine
(48) (0.075 g, 36%) as a white solid. MS (ESI positive ion) m/z: calcd
1
528.186; found, 528.7 (M + 1). H NMR (300 MHz, DMSO-d6) δ
10.50 (s, 1 H), 8.59 (d, J = 2.4 Hz, 1 H), 8.15−7.98 (m, 2 H), 7.25 (d,
J = 8.3 Hz, 2 H), 6.93 (d, J = 8.4 Hz, 2 H), 4.70 (s, 1 H), 3.66 (m, 2
H), 3.42 (d, J = 12.1 Hz, 2 H), 3.17−2.96 (m, 1 H), 2.71−2.58 (m, 1
H), 2.22 (m, 1 H), 1.74 (d, J = 2.0 Hz, 3 H), 1.49 (d, J = 4.1 Hz, 9 H),
0.99 (td, J = 6.7, 4.4 Hz, 2 H), 0.58−0.49 (m, 2 H).
A 100 mL round-bottomed flask was charged with compound 41
(0.26 g, 0.49 mmol) and acetic acid (2.6 mL). The mixture was cooled
to 0 °C, and H2O2 (30%, 0.075 g, 0.74 mmol) was added dropwise
over a period of 5 min. The resulting reaction mixture was stirred at 0
°C for 30 min and at room temperature for 1 h. The reaction mixture
was diluted with saturated aqueous NaHCO3 solution (30 mL) and
EtOAc (30 mL). The organic layer was separated, washed with water
and saturated aqueous NaCl, dried over anhydrous Na2SO4, and
filtered. The filtrate was concentrated under reduced pressure and the
residue was purified by silica gel column chromatography (eluent, 70%
EtOAc−hexanes) to give tert-butyl (5-(((3S)-4-(4-
(cyclopropylsulfinyl)phenyl)-3-(1-propyn-1-yl)-1-piperazinyl)-
sulfonyl)-2-pyridinyl)carbamate (42) (0.150 g, 56%) as a pale-brown
viscous solid. MS (ESI positive ion) m/z: calcd for C26H32N4O5S2,
544.181; found, 545.0 (M + 1).
1
for C19H23N5O3S2, 433.124; found, 434.1 (M + 1). H NMR (400
MHz, DMSO-d6) δ 8.24 (d, J = 2.4 Hz 1 H), 7.74 (d, J = 8.8 Hz, 2 H),
7.64 (dd, J = 8.8, 2.4 Hz, 1H), 7.08 (d, J = 8.8 Hz, 2 H), 7.04 (s, 2 H),
6.53 (d, J = 8.8 Hz, 1 H), 4.93 (s, 1 H), 3.96 (d, J = 4.8 Hz, 1 H),
3.72−3.60 (m, 3 H), 3.17−3.12 (m, 2 H), 2.99 (s, 3 H), 2.40−2.33
(m, 1 H), 1.76 (d, J = 1.6 Hz, 3 H).
4-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-
1-piperazinyl)benzenesulfonamide (49). Benzyl (3S)-3-(1-pro-
pyn-1-yl)-1-piperazinecarboxylate (4) (0.440 g, 1.73 mmol) and 4-
bromo-N-(cyclopropylmethyl)benzenesulfonamide13 (0.500 g, 1.73
mmol) were coupled according to the general amination method using
JohnPhos (0.025 g, 0.086 mmol), Pd2(dba)3 (0.047 g, 0.051 mmol),
and 1,4-dioxane to obtain benzyl (3S)-4-(4-((cyclopropylmethyl)-
sulfamoyl)phenyl)-3-(1-propyn-1-yl)-1-piperazinecarboxylate (35)
(0.270 g, 33%) as a white solid. MS (ESI positive ion) m/z: calcd
for C25H29N3O4S, 467.188; found, 468.0 (M + 1).
Compound 35 (0.270 g, 0.58 mmol) was globally deprotected
according to the general Cbz-deprotection method B to give 4-((2S)-
2-(1-propyn-1-yl)-1-piperazinyl)benzenesulfonamide (36) as a pale-
brown solid (0.19 g, crude), which was used in the next step without
purification.
Compound 36 (0.100 g, 0.35 mmol) was treated with tert-butyl (5-
(chlorosulfonyl)-2-pyridinyl)carbamate (9) (0.156 g, 0.53 mmol)
according to the general sulfonamide formation method using pyridine
(1.0 mL, 12 mmol) to afford tert-butyl (5-(((3S)-3-(1-propyn-1-yl)-4-
(4-sulfamoylphenyl)-1-piperazinyl)sulfonyl)-2-pyridinyl)carbamate
(44) (0.060 g, 28% over two steps) as a white solid. MS (ESI positive
ion) m/z: calcd for C23H29N5O6S2, 535.156; found, 558.1 (M + Na).
1H NMR (300 MHz, CDCl3) δ 8.66 (d, J = 2.4 Hz, 1 H), 8.14 (d, J = 9
A 100 mL round-bottomed flask was charged with compound 42
(0.1 g, 0.2 mmol), CHCl3 (2 mL), and NaN3 (0.020 g, 0.29 mmol).
The resulting mixture was cooled to 0 °C, and concentrated H2SO4
(0.095 g, 0.97 mmol) was added dropwise. The reaction mixture was
allowed to warm to room temperature and stirred at room temperature
for 6 h. The reaction mixture was diluted with ice-cold water (20 mL)
and neutralized with Na2CO3 solution (10%, 10 mL) before extracting
with EtOAc (3 × 50 mL). The combined organic extracts were washed
with water and saturated aqueous NaCl, dried over anhydrous Na2SO4,
filtered, and concentrated under reduced pressure. The residue
obtained was purified by silica gel column chromatography (eluent,
1 0 % M e O H − D C M ) t o g i v e 5 - ( ( ( 3 S ) - 4 - ( 4 - ( S -
cyclopropylsulfonimidoyl)phenyl)-3-(1-propyn-1-yl)-1-piperazinyl)-
sulfonyl)-2-pyridinamine (47) (0.010 g, 11%). MS (ESI positive ion)
1
m/z: calcd for C21H22N5O3S2, 459.140; found, 459.9 (M + 1). H
NMR (300 MHz, CD3OD) δ 8.20 (d, J = 2.4 Hz, 1 H), 7.72−7.57 (m,
3 H), 7.01 (d, J = 8.8 Hz, 2 H), 6.52 (d, J = 9.0 Hz, 1 H), 4.71 (s, 1 H),
3.67 (bd, J = 11.2 Hz, 2 H), 3.57 (d, J = 12.4 Hz, 1 H), 2.69−2.38 (m,
3 H), 1.66 (dd, J = 2.2, 0.9 Hz, 3 H), 1.13 (q, J = 6.5 Hz, 2 H), 0.96 (tt,
J = 9.5, 4.7 Hz, 2 H). One proton is obscured under the solvent peak.
HPLC purity at 254 nm, 90.3%; at 215 nm, 91.5%.
5-(((3S)-4-(4-(S-Methylsulfonimidoyl)phenyl)-3-(1-propyn-1-
yl)-1-piperazinyl)sulfonyl)-2-pyridinamine (48). Benzyl (3S)-3-
(1-propyn-1-yl)-1-piperazinecarboxylate (4) (0.50 g, 1.9 mmol) and 1-
bromo-4-(methylsulfinyl)benzene13 (0.63 g, 2.9 mmol) were coupled
according to the general amination method using Pd2(dba)3 (0.089 g,
Hz, 1 H), 8.03 (dd, J = 9.0, 2.4 Hz, 1 H), 7.80 (d, J = 9 Hz, 3 H), 6.95
(d, J = 9 Hz, 2 H), 4.74 (s, 2 H), 4.52 (s, 1 H), 3.91−3.75 (m, 2 H),
3.57−3.33 (m, 2 H), 2.81 (dd, J = 11.4, 3.5 Hz, 1 H), 2.67 (td, J =
11.4, 3.6 Hz, 1 H), 1.78 (d, J = 2.1 Hz, 3 H), 1.54 (s, 9 H).
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Compound 44 was deprotected according to the general Boc-
deprotection method to afford 4-((2S)-4-((6-amino-3-pyridinyl)-
sulfonyl)-2-(1-propyn-1-yl)-1-piperazinyl)benzenesulfonamide (49)
(0.010 g, 12%) as a white solid. MS (ESI positive ion) m/z: calcd
2-(6-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-
yl)-1-piperazinyl)-3-pyridinyl)-3,3,3-trifluoro-1,2-propanediol
(53). Benzyl (3S)-3-(1-propyn-1-yl)-1-piperazinecarboxylate (4)
(0.100 g, 0.387 mmol) and 2-bromo-5-(2,2-dimethyl-4-(trifluorometh-
yl)-1,3-dioxolan-4-yl)pyridine13(0.140 g, 0.429 mmol) were coupled
according to the general amination method using RuPhos (0.009 g,
0.020 mmol), RuPhos first generation precatalyst (0.016 g, 0.019
mmol), and 1,4-dioxane to afford benzyl (3S)-4-(5-(2,2-dimethyl-4-
(trifluoromethyl)-1,3-dioxolan-4-yl)-2-pyridinyl)-3-(1-propyn-1-yl)-1-
piperazinecarboxylate (39) (0.045 g, 23%) as a yellow paste. MS (ESI
positive ion) m/z: calcd for C26H28F3N3O4S, 503.203; found, 504.2
(M + 1). 1H NMR (300 MHz, CDCl3) δ 8.29 (s, 1 H), 7.61 (d, J = 9.1
Hz, 1 H), 7.45−7.30 (m, 5 H), 6.68 (d, J = 8.9 Hz, 1 H), 5.28−5.08
(m, 3 H), 4.73−4.62 (m, 1 H), 4.35 (br s, 2 H), 4.26−4.17 (m, 1 H),
3.99 (br s, 1 H), 3.34 (t, J = 11.5 Hz, 1 H), 3.21 (br s, 1 H), 3.06 (d, J
= 14.2 Hz, 1 H), 1.71 (br s, 3 H), 1.63−1.57 (m, 3 H), 1.34 (s, 3 H).
Compound 39 (0.100 g, 0.199 mmol) was globally deprotected
according to the general Cbz-deprotection method A. The crude
product was treated with tert-butyl (5-(chlorosulfonyl)-2-pyridinyl)-
carbamate (9) (0.065 g, 0.222 mmol) according to the general
sulfonamide formation method using Et3N (0.14 mL, 0.99 mmol) and
then deprotected according to the general Boc-deprotection method
to afford 2-(6-((2S)-4-((6-amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-
yl)-1-piperazinyl)-3-pyridinyl)-3,3,3-trifluoro-1,2-propanediol (53)
(0.060 g, 62% over three steps) as a light-brown foam. MS (ESI
positive ion) m/z: calcd for C20H22F3N5O4S, 485.134; found, 508.1
1
for C18H21N5O4S2, 435.103; found, 436.1 (M + 1). H NMR (400
MHz, DMSO-d6) δ 8.26 (d, J = 2.5 Hz, 1 H), 7.70−7.63 (m, 3 H),
7.16 (s, 2 H), 7.08 (d, J = 8.8 Hz, 2 H), 6.56 (d, J = 8.9 Hz, 1 H), 4.94
(s, 1 H), 3.72−3.59 (m, 4 H), 3.17−3.04 (m, 1 H), 2.45−2.32 (m, 2
H), 1.77 (d, J = 2.1 Hz, 3 H). One proton was obscured under the
solvent peak.
(2S)-2-(4-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-pro-
pyn-1-yl)-1-piperazinyl)phenyl)-3,3,3-trifluoro-1,2-propane-
diol (51) and (2R)-2-(4-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-
2-(1-propyn-1-yl)-1-piperazinyl)phenyl)-3,3,3-trifluoro-1,2-
propanediol (52). Benzyl (3S)-3-(1-propyn-1-yl)-1-piperazinecar-
boxylate (4) (5.0 g, 19 mmol) and 4-(4-bromophenyl)-2,2-dimethyl-4-
(trifluoromethyl)-1,3-dioxolane13 (6.0 g, 20 mmol) were coupled
according to the general amination method using RuPhos (0.45 g, 0.97
mmol), RuPhos first generation precatalyst (0.79 g, 0.97 mmol), and
1,4-dioxane to afford benzyl (3S)-4-(4-(2,2-dimethyl-4-(trifluorometh-
yl)-1,3-dioxolan-4-yl)phenyl)-3-(1-propyn-1-yl)-1-piperazinecarboxy-
late (37) (5.0 g, 51%). MS (ESI positive ion) m/z: calcd for
1
C27H29F3N2O4, 502.208; found, 503.2 (M + 1). H NMR (300 MHz,
CDCl3) δ 7.44−7.31 (m, 7 H), 6.96 (d, J = 8.6 Hz, 2 H), 5.35−5.09
(m, 2 H), 4.74−4.63 (m, 1 H), 4.43−4.18 (m, 4 H), 3.44−3.21 (m, 3
H), 3.12 (d, J = 13.2 Hz, 1 H), 1.77−1.68 (m, 3 H), 1.63−1.58 (m, 3
H), 1.37−1.30 (m, 3 H).
1
(M + Na). H NMR (300 MHz, CDCl3) δ 8.48 (d, J = 2.2 Hz, 1 H),
8.34 (br s, 1 H), 7.86−7.63 (m, 2 H), 6.67 (d, J = 8.9 Hz, 1 H), 6.52
(d, J = 8.8 Hz, 1 H), 5.20 (br s, 1 H), 4.96 (s, 2 H), 4.28 (d, J = 11.8
Hz, 1 H), 4.10 (d, J = 12.4 Hz, 1 H), 3.96−3.75 (m, 3 H), 3.67 (br s, 1
H), 3.49−3.28 (m, 1 H), 2.72 (d, J = 8.2 Hz, 1 H), 2.66−2.45 (m, 1
H), 1.80 (d, J = 1.8 Hz, 3 H). One exchangeable proton was not
observed.
(2S)-2-(6-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-pro-
pyn-1-yl)-1-piperazinyl)-3-pyridinyl)-3,3,3-trifluoro-1,2-pro-
panediol (54) and (2R)-2-(6-((2S)-4-((6-Amino-3-pyridinyl)-
sulfonyl)-2-(1-propyn-1-yl)-1-piperazinyl)-3-pyridinyl)-3,3,3-
trifluoro-1,2-propanediol (55). The diastereomeric mixture of 2-(6-
((2S)-4-((6-amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-1-pipera-
zinyl)-3-pyridinyl)-3,3,3-trifluoro-1,2-propanediol (53) was separated
by chiral SFC method (ODH (21 mm × 250 mm, 5 μm), 20% MeOH
with 0.2% diethylamine in CO2, flow rate of 70 mL/min) to afford
each diastereomer. The stereochemistry at the carbinol center was
assigned arbitrarily.
Compound 37 (5.0 g, 9.9 mmol) was globally deprotected
according to the general Cbz-deprotection method A. The crude
product obtained was treated with tert-butyl (5-(chlorosulfonyl)-2-
pyridinyl)carbamate (9) (3.50 g, 12.0 mmol) according to the general
sulfonamide formation using Et3N (7.42 mL, 53.4 mmol) and then
deprotected according to the general Boc-deprotection method to
afford 2-(4-((2S)-4-((6-amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-
yl)-1-piperazinyl)phenyl)-3,3,3-trifluoro-1,2-propanediol (50) (4.7 g,
91% over three steps) as a light-brown foam. MS (ESI positive ion) m/
z: calcd for C21H23F3N4O4S, 484.139; found, 485.1 (M + 1). 1H NMR
(300 MHz, CDCl3) δ 8.50 (d, J = 2.3 Hz, 1 H), 7.78 (dd, J = 2.4, 8.7
Hz, 1 H), 7.45 (d, J = 8.6 Hz, 2 H), 6.96 (d, J = 8.9 Hz, 2 H), 6.53 (d, J
= 8.8 Hz, 1 H), 4.97 (s, 2 H), 4.41 (br s, 1 H), 4.26 (d, J = 9.2 Hz, 1
H), 3.90 (d, J = 12.9 Hz, 1 H), 3.81−3.59 (m, 3 H), 3.45−3.30 (m, 2
H), 2.85 (dd, J = 3.4, 11.1 Hz, 1 H), 2.70 (td, J = 7.3, 11.1 Hz, 1 H),
1.92 (br s, 1 H), 1.79 (d, J = 1.9 Hz, 3 H).
The diastereomeric mixture 50 was resolved using preparative SFC
(Chiralpak AS-H (250 mm × 21 mm, 5 μm, using 30% (20 mM NH3
in methanol) in super critical CO2 (total flow was 75 mL/min). This
produced the following two compounds with diastereomeric excess
values greater than 99%, each. The absolute chemistry of each
compound was established by X-ray crystallography of cocrystals of
these molecules to hGKRP protein.
(2S)-2-(4-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-
yl)-1-piperazinyl)phenyl)-3,3,3-trifluoro-1,2-propanediol (51). MS
(ESI positive ion) m/z: calcd for C21H23F3N4O4S, 484.139; found,
485.1 (M + 1). 1H NMR (300 MHz, CDCl3) δ 8.48 (d, J = 2.2 Hz, 1
H), 7.77 (dd, J = 2.3, 8.8 Hz, 1 H), 7.44 (d, J = 8.8 Hz, 2 H), 6.95 (d, J
= 8.9 Hz, 2 H), 6.52 (d, J = 8.6 Hz, 1 H), 4.98 (s, 2 H), 4.41 (d, J = 2.0
Hz, 1 H), 4.25 (d, J = 11.8 Hz, 1 H), 3.89 (d, J = 11.3 Hz, 1 H), 3.80−
3.58 (m, 3 H), 3.43−3.34 (m, J = 2.8 Hz, 2 H), 2.84 (dd, J = 3.4, 11.2
Hz, 1 H), 2.74−2.63 (m, 1 H), 1.77 (d, J = 2.0 Hz, 3 H). One
exchangeable proton was not observed.
(2R)-2-(4-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-
yl)-1-piperazinyl)phenyl)-3,3,3-trifluoro-1,2-propanediol (52). MS
(ESI positive ion) m/z: calcd for C21H23F3N4O4S, 484.139; found,
485.1 (M + 1). 1H NMR (300 MHz, CDCl3) δ 8.50 (d, J = 2.2 Hz, 1
H), 7.78 (dd, J = 2.4, 8.8 Hz, 1 H), 7.45 (d, J = 8.6 Hz, 2 H), 6.96 (d, J
= 8.9 Hz, 2 H), 6.54 (d, J = 8.8 Hz, 1 H), 4.98 (s, 2 H), 4.41 (br s, 1
H), 4.26 (d, J = 11.8 Hz, 1 H), 3.90 (d, J = 12.1 Hz, 1 H), 3.75 (t, J =
10.1 Hz, 2 H), 3.64 (br s, 1 H), 3.44−3.32 (m, 2 H), 2.85 (dd, J = 3.1,
11.1 Hz, 1 H), 2.77−2.60 (m, 1 H), 1.79 (d, J = 1.9 Hz, 3 H). One
exchangeable proton was not observed.
(2S)-2-(6-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-
yl)-1-piperazinyl)-3-pyridinyl)-3,3,3-trifluoro-1,2-propanediol (54).
MS (ESI positive ion) m/z: calcd for C20H22F3N5O4S, 485.134;
1
found, 508.1 (M + Na). H NMR (300 MHz, CDCl3) δ 8.48 (d, J =
1.9 Hz, 1 H), 8.34 (s, 1 H), 7.83−7.66 (m, 2 H), 6.67 (d, J = 9.1 Hz, 1
H), 6.52 (d, J = 8.9 Hz, 1 H), 5.20 (br s, 1 H), 4.97 (s, 2 H), 4.28 (d, J
= 12.0 Hz, 1 H), 4.10 (d, J = 13.6 Hz, 1 H), 3.94−3.76 (m, 3 H), 3.67
(br s, 1 H), 3.53−3.34 (m, 1 H), 2.73 (dd, J = 3.7, 11.4 Hz, 1 H),
2.66−2.50 (m, 1 H), 1.80 (d, J = 2.0 Hz, 3 H). One exchangeable
proton was not observed.
(2R)-2-(6-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-
yl)-1-piperazinyl)-3-pyridinyl)-3,3,3-trifluoro-1,2-propanediol (55).
MS (ESI positive ion) m/z: calcd for C20H22F3N5O4S, 485.134;
found, 508.1 (M + Na). 1H NMR (300 MHz, DMSO-d6) δ 8.28 (m, 1
H), 8.23 (d, J = 2.2 Hz, 1 H), 7.73 (dd, J = 2.2, 8.9 Hz, 1 H), 7.63 (dd,
J = 2.5, 8.9 Hz, 1 H), 6.99 (s, 2 H), 6.84 (d, J = 9.1 Hz, 1 H), 6.52 (d, J
= 8.9 Hz, 1 H), 6.43 (s, 1 H), 5.34 (br s, 1 H), 5.16 (t, J = 5.8 Hz, 1
H), 4.15 (d, J = 12.6 Hz, 1 H), 3.97−3.76 (m, 2 H), 3.64 (d, J = 10.1
Hz, 2 H), 3.14−3.05 (m, 1 H), 2.45 (d, J = 3.1 Hz, 1 H), 2.37−2.21
(m, 1 H), 1.75 (d, J = 2.0 Hz, 3 H).
3-(4-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-
yl)-1-piperazinyl)phenyl)-4,4,4-trifluoro-3-hydroxy-
butanenitrile (62). Compound 37 (1.60 g, 3.18 mmol) was globally
deprotected according to the general Cbz-deprotection method. The
crude product was treated with tert-butyl (5-(chlorosulfonyl)-2-
pyridinyl)carbamate (9) (1.04 g, 3.60 mmol) according to the general
sulfonamide formation method using Et3N (2.20 mL, 16.0 mmol) to
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afford tert-butyl(5-(((3S)-3-(1-propyn-1-yl)-4-(4-(2,2,2-trifluoro-1-hy-
droxy-1-(hydroxymethyl)ethyl)phenyl)-1-piperazinyl)sulfonyl)-2-
pyridinyl)carbamate (45) (1.0 g, 54%) as a yellow foam. MS (ESI
positive ion) m/z: calcd for C26H31F3N4O6S, 584.192; found, 585.2
(0.024 mL, 0.33 mmol). The mixture was stirred at room temperature
for 1 h. The reaction mixture was partitioned between saturated
NaHCO3 (15 mL) and DCM (40 mL), and the aqueous layer was
extracted with DCM (2 × 30 mL). The combined organic layers were
dried over MgSO4, filtered, and concentrated. The crude product was
purified by silica column chromatography (0−5% MeOH in DCM) to
afford 2-(4-((2S)-4-((6-amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-
yl)-1-piperazinyl)phenyl)-1,1,1-trifluoro-3-methoxy-2-propanol (63)
(0.030 g, 43% over two steps) as an off-white solid. MS (ESI positive
ion) m/z: calcd for C22H25F3N4O4S, 498.155; found, 499.1 (M + 1).
1H NMR (300 MHz, CDCl3) δ 8.49 (d, J = 2.0 Hz, 1 H), 7.82 (dd, J =
1
(M + 1). H NMR (300 MHz, CDCl3) δ 8.67 (d, J = 2.3 Hz, 1 H),
8.15 (d, J = 8.8 Hz, 1 H), 8.04 (dd, J = 2.3, 8.8 Hz, 1 H), 7.94 (s, 1 H),
7.45 (d, J = 8.6 Hz, 2 H), 6.95 (d, J = 8.8 Hz, 2 H), 4.42 (br s, 1 H),
4.26 (dd, J = 6.5, 11.9 Hz, 1 H), 3.95−3.85 (m, 1 H), 3.84−3.69 (m, 2
H), 3.63 (s, 1 H), 3.43−3.33 (m, 2 H), 2.85 (dd, J = 3.3, 11.2 Hz, 1
H), 2.77−2.63 (m, 1 H), 1.86 (dt, J = 2.4, 6.8 Hz, 1 H), 1.78 (d, J = 2.0
Hz, 3 H), 1.56 (s, 9 H).
To a solution of compound 45 (0.300 g, 0.513 mmol) in DCM (5
mL) were added Et3N (0.400 mL, 2.88 mmol) and p-toluenesulfonyl
chloride (0.108 g, 0.564 mmol). The resulting mixture was heated at
reflux (50 °C) under N2 for 2 h. The reaction mixture was allowed to
cool to room temperature and partitioned between saturated NaHCO3
(30 mL) and DCM (70 mL). The aqueous layer was extracted with
DCM (2 × 40 mL). The combined organic layers were dried over
MgSO4, filtered, and concentrated. The crude product was purified by
silica gel column chromatography (10−40% acetone in hexanes) to
afford tert-butyl (5-(((3S)-3-(1-propyn-1-yl)-4-(4-(2-(trifluorometh-
yl)-2-oxiranyl)phenyl)-1-piperazinyl)sulfonyl)-2-pyridinyl)carbamate
(56) (0.240 g, 83%) as an off-white solid. MS (ESI positive ion) m/z:
2.4, 8.8 Hz, 1 H), 7.44 (d, J = 8.8 Hz, 2 H), 6.95 (d, J = 8.9 Hz, 2 H),
6.59 (d, J = 8.9 Hz, 1 H), 5.27 (br s, 2 H), 4.42 (br s, 1 H), 4.02 (d, J =
9.9 Hz, 1 H), 3.82−3.68 (m, 2 H), 3.69−3.57 (m, 2 H), 3.45 (s, 3 H),
3.41−3.33 (m, 2 H), 2.87 (dd, J = 3.4, 11.1 Hz, 1 H), 2.72 (td, J = 7.1,
11.4 Hz, 1 H), 1.79 (d, J = 2.0 Hz, 3 H).
2-(4-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-
yl)-1-piperazinyl)phenyl)-1,1,1-trifluoro-4-pentyn-2-ol (64). A
flame-dried, 50 mL, three-necked round-bottomed flask was charged
with THF (8 mL) and ethynyltrimethylsilane (0.075 mL, 0.530
mmol). The reaction mixture was cooled to −78 °C, and n-
butyllithium (2.5 M in hexanes, 0.220 mL, 0.530 mmol) was added
at that temperature. The resulting mixture was stirred for 30 min at
−78 °C. tert-Butyl (5-(((3S)-3-(1-propyn-1-yl)-4-(4-(2-(trifluoro-
methyl)-2-oxiranyl)phenyl)-1-piperazinyl)sulfonyl)-2-pyridinyl)-
carbamate (56) (0.150 g, 0.265 mmol) in THF (5 mL) was added
dropwise via an addition funnel. After the addition was complete, the
reaction mixture was stirred at −78 °C for 10 min and then allowed to
warm to room temperature and stirred at room temperature for an
additional 20 h. The reaction was quenched with saturated aqueous
NH4Cl (3 mL). The reaction mixture was concentrated, and the
residue was dissolved in MeOH (10 mL) and then treated with 2 M
K2CO3 (3 mL) at room temperature for 2 h. The resulting mixture was
partitioned between EtOAc (60 mL) and water (30 mL). The aqueous
layer was extracted with EtOAc (50 mL). The combined organic layers
were dried over MgSO4, filtered, and concentrated. The crude product
was purified by silica gel column chromatography (10−40% acetone in
hexanes) to obtain tert-butyl (5-(((3S)-4-(4-(1-hydroxy-1-(trifluoro-
methyl)-3-butyn-1-yl)phenyl)-3-(1-propyn-1-yl)-1-piperazinyl)-
sulfonyl)-2-pyridinyl)carbamate (59) (0.090 g, 57%) as an off-white
solid. MS (ESI positive ion) m/z: calcd for C28H31F3N4O5S, 592.197;
1
calcd for C26H29F3N4O5S, 566.181; found, 567.2 (M + 1). H NMR
(400 MHz, CDCl3) δ 8.66 (dd, J = 0.6, 2.3 Hz, 1 H), 8.20−8.10 (m, 1
H), 8.04 (dd, J = 2.2, 8.9 Hz, 1 H), 7.63 (s, 1 H), 7.41 (d, J = 8.6 Hz, 2
H), 6.94 (d, J = 8.8 Hz, 2 H), 4.42 (d, J = 2.2 Hz, 1 H), 3.89−3.67 (m,
2 H), 3.38 (d, J = 5.3 Hz, 3 H), 2.97−2.83 (m, 2 H), 2.80−2.60 (m, 1
H), 1.78 (dd, J = 0.8, 2.0 Hz, 3 H), 1.55 (s, 9 H).
To a solution of compound 56 (0.030 g, 0.053 mmol) in DMF (2
mL) were added water (0.3 mL) and KCN (10 mg, 0.154 mmol). The
mixture was stirred at room temperature for 20 min and then
partitioned between EtOAc (30 mL) and water (10 mL). The organic
layer was washed with water (3×), saturated NaCl, dried over Na2SO4,
filtered, and concentrated to give a crystalline solid. This solid was
dissolved in DCM (2.5 mL) and was treated with TFA (0.300 mL,
3.89 mmol). After 1 h, the mixture was concentrated and the residue
was diluted with EtOAc (20 mL) and washed with 1 N aqueous
NaOH (5 mL), water (5 mL), and saturated NaCl (5 mL). The
organic layer was dried over Na2SO4, filtered, and concentrated. The
residue was purified by chromatography on silica gel using EtOAc in
hexanes (30−80%) as eluent to give 3-(4-((2S)-4-((6-amino-3-
pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-1-piperazinyl)phenyl)-4,4,4-tri-
fluoro-3-hydroxybutanenitrile (62) (0.020 g, 77%) as a light-pink
foam. MS (ESI positive ion) m/z: calcd for C22H22F3N5O3S, 493.140;
found, 494.3 (M + 1). 1H NMR (400 MHz, CDCl3) δ 8.48 (br s, 1 H),
7.79 (d, J = 8.8 Hz, 1 H), 7.44 (d, J = 7.6 Hz, 2 H), 6.97 (d, J = 7.4 Hz,
2 H), 6.54 (d, J = 8.2 Hz, 1 H), 5.10 (br s, 2 H), 4.44 (br s, 1 H),
4.07−4.18 (m, 1 H), 3.34−3.49 (m, 2 H), 3.17 (br s, 2 H), 2.95−3.07
(m, 1 H), 2.85 (d, J = 11.0 Hz, 1 H), 2.70 (t, J = 13.1 Hz, 1 H), 1.79
(br s, 3 H). One exchangeable proton was not observed.
2-(4-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-
yl)-1-piperazinyl)phenyl)-1,1,1-trifluoro-3-methoxy-2-propa-
nol (63). A flame-dried 50 mL two-necked round-bottomed flask was
charged with sodium methoxide (0.045 g, 0.85 mmol) and anhydrous
MeOH (3 mL). To this solution was added the suspension of tert-
butyl (5-(((3S)-3-(1-propyn-1-yl)-4-(4-(2-(trifluoromethyl)-2-
oxiranyl)phenyl)-1-piperazinyl)sulfonyl)-2-pyridinyl)carbamate (56)
(0.080 g, 0.14 mmol) in MeOH (3 mL). The resulting mixture was
heated at 70 °C for 1 h, and 3 mL of DMF was added. The stirring at
70 °C was resumed for 24 h. The reaction mixture was allowed to cool
to room temperature and concentrated. The residue was partitioned
between EtOAc (60 mL) and water (30 mL), and the aqueous layer
was extracted with EtOAc (30 mL). The combined organic layers were
dried over MgSO4, filtered, and concentrated. The crude product was
purified by silica gel column chromatography (10−40% EtOAc in
hexanes) to afford the crude tert-butyl (5-(((3S)-3-(1-propyn-1-yl)-4-
(4-(2,2,2-trifluoro-1-hydroxy-1-(methoxymethyl)ethyl)phenyl)-1-
piperazinyl)sulfonyl)-2-pyridinyl)carbamate (58) (0.045 g). This
material was dissolved in DCM (3.0 mL) and treated with TFA
1
found, 615.1 (M + Na). H NMR (300 MHz, CDCl3) δ 8.66 (d, J =
1.6 Hz, 1 H), 8.17−8.09 (m, 1 H), 8.08−7.96 (m, 1 H), 7.63 (s, 1 H),
7.46 (d, J = 8.8 Hz, 2 H), 6.95 (d, J = 9.1 Hz, 2 H), 4.43 (br s, 1 H),
3.79 (t, J = 11.1 Hz, 2 H), 3.48−3.31 (m, 2 H), 3.07 (dd, J = 2.3, 5.6
Hz, 2 H), 3.02−2.94 (m, 1 H), 2.87 (dd, J = 3.4, 11.1 Hz, 1 H), 2.78−
2.62 (m, 1 H), 2.07 (t, J = 2.3 Hz, 1 H), 1.79 (d, J = 1.9 Hz, 3 H), 1.55
(s, 9 H).
A 20 mL vial was charged with compound 59 (0.025 g, 0.042
mmol), DCM (3.0 mL), and TFA (0.030 mL, 0.42 mmol). The vial
was capped, and the mixture was stirred at room temperature for 2 h.
The reaction mixture was partitioned between saturated aqueous
NaHCO3 (15 mL) and DCM (40 mL). The aqueous layer was
extracted with DCM (2 × 30 mL), and the combined organic layers
were dried over MgSO4, filtered, and concentrated. The crude product
was purified by silica gel column chromatography (0−5% MeOH in
DCM) to afford 2-(4-((2S)-4-((6-amino-3-pyridinyl)sulfonyl)-2-(1-
propyn-1-yl)-1-piperazinyl)phenyl)-1,1,1-trifluoro-4-pentyn-2-ol (64)
(0.020 g, 96%) as an off-white solid. MS (ESI positive ion) m/z:
1
calcd for C23H23F3N4O3S, 492.114; found, 493.1 (M + 1). H NMR
(300 MHz, CDCl3) δ 8.50 (d, J = 2.2 Hz, 1 H), 7.80 (dd, J = 2.3, 8.8
Hz, 1 H), 7.46 (d, J = 8.8 Hz, 2 H), 7.04−6.87 (m, 2 H), 6.56 (d, J =
8.8 Hz, 1 H), 5.15 (s, 2 H), 4.44 (br s, 1 H), 3.84−3.63 (m, 2 H),
3.47−3.33 (m, 2 H), 3.17−2.99 (m, 3 H), 2.85 (dd, J = 3.4, 11.2 Hz, 1
H), 2.79−2.62 (m, 1 H), 2.13−2.01 (m, 1 H), 1.79 (d, J = 1.9 Hz, 3
H).
2-(4-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-
yl)-1-piperazinyl)phenyl)-1,1,1-trifluoro-4-hexyn-2-ol (65). A
flame-dried, 50 mL, three-necked round-bottomed flask was charged
with tert-butyl (5-(((3S)-4-(4-(1-hydroxy-1-(trifluoromethyl)-3-butyn-
3112
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Article
1-yl)phenyl)-3-(1-propyn-1-yl)-1-piperazinyl)sulfonyl)-2-pyridinyl)-
carbamate (59) (0.060 g, 0.10 mmol) and THF (5.0 mL). The
reaction mixture was cooled to 0 °C, and n-butyllithium (2.5 M in
hexanes, 0.10 mL, 0.25 mmol) was added. The resulting mixture was
stirred for 20 min, and then iodomethane (0.020 mL, 0.29 mmol) was
added. The reaction mixture was allowed to warm to room
temperature and stirred for an additional 2 h and then quenched
with saturated aqueous NH4Cl (3 mL), concentrated, and then
partitioned between EtOAc (60 mL) and water (20 mL). The aqueous
layer was extracted with EtOAc (2 × 30 mL), and the combined
organic layers were dried over MgSO4, filtered, and concentrated. The
crude product was purified by silica gel column chromatography (0−
40% EtOAc in hexanes) to afford tert-butyl (5-(((3S)-4-(4-(1-hydroxy-
1-(trifluoromethyl)-3-pentyn-1-yl)phenyl)-3-(1-propyn-1-yl)-1-
piperazinyl)sulfonyl)-2-pyridinyl)carbamate (60) (0.020 g, 33%) as an
off-white solid. MS (ESI positive ion) m/z: calcd for C29H33F3N4O5S,
606.212; found, 629.2 (M + Na). 1H NMR (300 MHz, CDCl3) δ 8.68
(d, J = 1.9 Hz, 1 H), 8.19−8.11 (m, 1 H), 8.08−7.99 (m, 1 H), 7.94 (s,
1 H), 7.45 (d, J = 8.8 Hz, 2 H), 6.93 (d, J = 8.9 Hz, 2 H), 4.43 (br s, 1
H), 3.78 (t, J = 10.9 Hz, 2 H), 3.47−3.32 (m, 2 H), 3.14−3.02 (m, 2
H), 3.01−2.83 (m, 2 H), 2.79−2.66 (m, 1 H), 1.78 (d, J = 1.9 Hz, 3
H), 1.75 (t, J = 2.3 Hz, 3 H), 1.56 (s, 9 H).
A 20 mL vial was charged with compound 60 (0.020 g, 0.03 mmol),
DCM (2.0 mL), and TFA (0.030 mL, 0.33 mmol). The vial was
capped and stirred at room temperature for 1 h. The reaction mixture
was partitioned between saturated aqueous NaHCO3 (15 mL) and
DCM (40 mL). The aqueous layer was extracted with DCM (2 × 30
mL), and the combined organic layers were dried over MgSO4,
filtered, and concentrated. The crude product was purified by silica
column chromatography (0−5% MeOH in DCM) to obtain 2-(4-
((2S)-4-((6-amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-1-
piperazinyl)phenyl)-1,1,1-trifluoro-4-hexyn-2-ol (65) (0.015 g, 90%)
as an off-white solid. MS (ESI positive ion) m/z: calcd for
C24H25F3N4O3S, 506.160; found, 507.1 (M + 1). 1H NMR (300
MHz, CDCl3) δ 8.44 (s, 1 H), 7.87 (d, J = 7.2 Hz, 1 H), 7.46 (d, J =
8.6 Hz, 2 H), 6.95 (d, J = 8.8 Hz, 2 H), 6.76 (d, J = 8.9 Hz, 1 H), 6.11
(br s, 2 H), 4.45 (br s, 1 H), 3.76 (t, J = 10.3 Hz, 2 H), 3.46−3.33 (m,
2 H), 3.08 (dd, J = 2.5, 17.0 Hz, 2 H), 3.01−2.88 (m, 2 H), 2.78 (dd, J
= 5.7, 10.4 Hz, 1 H), 1.79 (d, J = 1.8 Hz, 3 H), 1.75 (t, J = 2.3 Hz, 3
H).
(2S)-3-Amino-2-(4-((2S)-4-((6-amino-3-pyridinyl)sulfonyl)-2-
(1-propyn-1-yl)-1-piperazinyl)phenyl)-1,1,1-trifluoro-2-propa-
nol (67) and (2R)-3-Amino-2-(4-((2S)-4-((6-amino-3-pyridinyl)-
sulfonyl)-2-(1-propyn-1-yl)-1-piperazinyl)phenyl)-1,1,1-tri-
fluoro-2-propanol (68). A 20 mL vial was charged with tert-butyl(5-
(((3S)-3-(1-propyn-1-yl)-4-(4-(2-(trifluoromethyl)-2-oxiranyl)-
phenyl)-1-piperazinyl)sulfonyl)-2-pyridinyl)carbamate (56) (0.120 g,
0.212 mmol), DMF (3.0 mL), and ammonium hydroxide (0.165 mL,
1.23 mmol). The vial was sealed, and the reaction mixture was stirred
at room temperature for 24 h. The reaction mixture was partitioned
between EtOAc (60 mL) and water (30 mL), and the organic layer
was washed with water (2 × 30 mL), dried over MgSO4, filtered, and
concentrated. To this crude intermediate were added DCM (10 mL)
and TFA (0.160 mL, 2.12 mmol). The resulting mixture was stirred at
room temperature for 2 h and then concentrated. The residue was
partitioned between EtOAc (60 mL) and saturated NaHCO3 (40 mL),
and the aqueous layer was extracted with EtOAc (2 × 30 mL). The
combined organic layers were dried over MgSO4, filtered, and
concentrated to afford 3-amino-2-(4-((2S)-4-((6-amino-3-pyridinyl)-
sulfonyl)-2-(1-propyn-1-yl)-1-piperazinyl)phenyl)-1,1,1-trifluoro-2-
propanol (66) (0.095 g) as a mixture of two diastereomers. The
individual diastereomers were isolated using chiral SFC (Chiralpak
AD-H Sepax column (150 mm × 21 mm, 5 μm)) using 45% (20 mM
NH3 in ethanol) in supercritical CO2 (total flow was 75 mL/min).
This produced the two compounds (67 and 68) with diastereomeric
excess greater than 98%. The stereochemistry at carbinol was
arbitrarily assigned.
found, 484.1 (M + 1). 1H NMR (300 MHz, CDCl3) δ 8.49 (br s, 1 H),
7.76 (d, J = 7.5 Hz, 1 H), 7.44 (d, J = 7.6 Hz, 2 H), 6.92 (d, J = 8.3 Hz,
2 H), 6.51 (d, J = 8.8 Hz, 1 H), 4.93 (br s, 2 H), 4.39 (br s, 1 H), 3.72
(t, J = 9.3 Hz, 2 H), 3.60−3.42 (m, 1 H), 3.35 (br s, 2 H), 3.01 (br s, 1
H), 2.83 (d, J = 8.9 Hz, 1 H), 2.75−2.59 (m, J = 10.5 Hz, 1 H). Three
exchangeable protons were not observed.
(2R)-3-Amino-2-(4-((2S)-4-((6-amino-3-pyridinyl)sulfonyl)-2-(1-
propyn-1-yl)-1-piperazinyl)phenyl)-1,1,1-trifluoro-2-propanol (68).
MS (ESI positive ion) m/z: calcd for C21H24F3N5O3S, 483.155;
found, 484.1 (M + 1). 1H NMR (300 MHz, CDCl3) δ 8.49 (br s, 1 H),
7.76 (d, J = 7.5 Hz, 1 H), 7.44 (d, J = 7.6 Hz, 2 H), 6.92 (d, J = 8.3 Hz,
2 H), 6.51 (d, J = 8.8 Hz, 1 H), 4.93 (br s, 2 H), 4.39 (br s, 1 H), 3.72
(t, J = 9.3 Hz, 2 H), 3.60−3.42 (m, 1 H), 3.35 (br s, 2 H), 3.01 (br s, 1
H), 2.83 (d, J = 8.9 Hz, 1 H), 2.75−2.59 (m, 1 H), 1.77 (s, 3 H).
Three exchangeable protons were not observed.
2-(2-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-
yl)-1-piperazinyl)-1,3-thiazol-5-yl)-1,1,1,3,3,3-hexafluoro-2-
propanol (74). To a stirring suspension of 2-chloro-1,3-thiazole-5-
carboxylic acid (69) (5.0 g, 31 mmol) in DCM (30 mL) at 0 °C under
nitrogen was added oxalyl chloride (8.14 mL, 92 mmol) followed by
DMF (0.118 mL, 1.53 mmol). The suspension was stirred for 3 h
warming to 20 °C. The solvents were removed under reduced pressure
and the residue was purified by silica gel chromatography (80 g),
eluting with 0−20% EtOAc/hexanes to afford 2-chloro-1,3-thiazole-5-
1
carbonyl chloride (70) (4.9 g, 88%) as a colorless oil. H NMR (400
MHz, CDCl3) δ 8.35 (s, 1 H). 13C NMR (101 MHz, CDCl3) δ 135.07,
150.76, 157.50, 161.45.
To a stirring solution of compound 70 (2.7 g, 15 mmol) and
(trifluoromethyl)trimethylsilane (4.82 mL, 32.6 mmol) in 1,2-
dimethoxyethane at −65 °C under argon was added tetramethylam-
monium fluoride (3.04 g, 32.6 mmol). The suspension had an
exotherm to −52 °C and then stabilized. After the mixture was cooled
to −60 °C, the cooling bath was removed. After the mixture was
stirred for 20 h at room temperature, the reaction was quenched with 1
N HCl (50 mL) and the aqueous portion was extracted with EtOAc
(50 mL). The separated organic layer was dried over MgSO4, filtered,
and concentrated under reduced pressure. The crude product was
purified by silica gel chromatography (120 g), eluting with 0−30%
EtOAc/Hex to afford 2-(2-chloro-1,3-thiazol-5-yl)-1,1,1,3,3,3-hexa-
fluoro-2-propanol (2.23 g, 52.6%) as a white solid. MS (ESI positive
ion) m/z: calcd for C6H2ClF6NOS, 284.945; found, 286.0 (M + 1).
To a stirring solution of 2-(2-chloro-1,3-thiazol-5-yl)-1,1,1,3,3,3-
hexafluoro-2-propanol (2.23 g, 7.81 mmol) and DIPEA (3.00 mL, 17.2
mmol) in DCM (20 mL) at 0 °C under nitrogen was added (1,1-
dimethylethyl)dimethylsilyl trifluoromethanesulfonate (2.15 mL, 9.37
mmol) over a 1 min period. After 30 min the reaction mixture was
washed with 1 M KH2PO4 (20 mL). The organic phase was
concentrated onto silica (15 g) under reduced pressure and then
purified by silica gel chromatography (120 g), eluting with 0−20%
EtOAc/Hex to afford 5-(1-((tert-butyl(dimethyl)silyl)oxy)-2,2,2-tri-
fluoro-1-(trifluoromethyl)ethyl)-2-chloro-1,3-thiazole (71) (2.60 g,
83%) as a colorless oil. MS (ESI positive ion) m/z: calcd for
C12H16ClF6NOSSi, 399.031; found, 400.0 (M + 1).
tert-Butyl (3S)-3-(1-propyn-1-yl)-1-piperazinecarboxylate13 (72,
0.701 g, 3.13 mmol) and compound 71 (1.0 g, 2.5 mmol) were
coupled according to the general amination method using RuPhos
(0.058 g, 0.125 mmol), RuPhos first generation precatalyst (0.102 g,
0.125 mmol), and 1,4-dioxane to afford tert-butyl (3S)-4-(5-(1-((tert-
butyl(dimethyl)silyl)oxy)-2,2,2-trifluoro-1-(trifluoromethyl)ethyl)-1,3-
thiazol-2-yl)-3-(1-propyn-1-yl)-1-piperazinecarboxylate (73) (0.64 g,
44%) as a colorless oil. MS (ESI positive ion) m/z: calcd for
1
C24H35F6N3O3SSi, 587.207; found, 588.0 (M + 1). H NMR (400
MHz, CDCl3) δ 7.12 (s, 1 H), 4.64 (br s, 1 H), 3.94−4.18 (m, 2 H),
3.38 (br s, 1 H), 3.24−3.36 (m, 1 H), 3.03 (br s, 1 H), 2.82 (br s, 1
H), 1.64 (d, J = 1.76 Hz, 3 H), 1.35 (s, 9 H), 0.81 (s, 9 H), 0.00 (s, 6
H).
Compound 73 (0.64 g, 1.1 mmol) was deprotected according to the
general Boc-deprotection method. The crude product was treated with
tert-butyl (5-(chlorosulfonyl)-2-pyridinyl)carbamate (9) (0.398 g, 1.36
mmol) according to the general sulfonamide formation method using
(2S)-3-Amino-2-(4-((2S)-4-((6-amino-3-pyridinyl)sulfonyl)-2-(1-
propyn-1-yl)-1-piperazinyl)phenyl)-1,1,1-trifluoro-2-propanol (67).
MS (ESI positive ion) m/z: calcd for C21H24F3N5O3S, 483.155;
3113
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1
DIPEA (1.9 mL, 11 mmol) to afford tert-butyl (5-(((3S)-4-(5-(1-
((tert-butyl(dimethyl)silyl)oxy)-2,2,2-trifluoro-1-(trifluoromethyl)-
ethyl)-1,3-thiazol-2-yl)-3-(1-propyn-1-yl)-1-piperazinyl)sulfonyl)-2-
pyridinyl)carbamate (0.40 g, 49%) as a colorless oil. MS (ESI positive
ion) m/z: calcd for C29H39F6N5O5S2Si, 743.207; found, 744.0 (M + 1).
To a stirring solution of tert-butyl (5-(((3S)-4-(5-(1-((tert-butyl-
(dimethyl)silyl)oxy)-2,2,2-trifluoro-1-(trifluoromethyl)ethyl)-1,3-thia-
zol-2-yl)-3-(1-propyn-1-yl)-1-piperazinyl)sulfonyl)-2-pyridinyl)-
carbamate (0.400 g, 0.538 mmol) in MeCN (4 mL) at 20 °C under
argon was added HF−pyridine complex (70% HF, 301 μL, 2.42
mmol). The solution was stirred overnight at 20 °C. To the mixture
was added TFA (5 mL), and the mixture was stirred for 24 h at 20 °C.
The solvents were removed under reduced pressure, and the residue
was partitioned between 9:1 CHCl3/IPA (30 mL) and 1 M KH2PO4
(pH 5). The separated organic layer was then dried over MgSO4,
filtered, and concentrated under reduced pressure. The crude material
was purified by silica gel chromatography (12 g), eluting with 0−8% 2
M NH3 in MeOH/DCM to afford 2-(2-((2S)-4-((6-amino-3-
pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-1-piperazinyl)-1,3-thiazol-5-yl)-
1,1,1,3,3,3-hexafluoro-2-propanol (74) (0.220 g, 77%) as a white foam.
MS (ESI positive ion) m/z: calcd for C17H18F6N5O3S2, 529.068;
384.0 (M + 1). H NMR (400 MHz, CDCl3) δ 7.83 (s, 1 H), 7.29−
7.42 (m, 5 H), 5.10−5.29 (m, 2 H), 4.92−5.02 (m, 1 H), 4.24−4.41
(m, 2 H), 3.64−3.72 (m, 1 H), 3.49−3.62 (m, 1 H), 2.96−3.30 (m, 2
H), 2.45 (s, 3 H), 1.70 (br s, 3 H).
To a stirring solution of benzyl 4-(5-acetyl-1,3-thiazol-2-yl)-3-(1-
propyn-1-yl)-1-piperazinecarboxylate (0.380 g, 0.991 mmol) and
trifluoromethyltrimethylsilane (220 μL, 1.49 mmol) in THF (3 mL)
under nitrogen at 0 °C was added tetramethylammonium fluoride
(0.111 g, 1.19 mmol) at once. After the mixture was stirred for 30 min
at 0 °C, the reaction was quenched with 10% citric acid (20 mL) and
the aqueous portion was extracted with EtOAc (30 mL). The organic
phase was dried over MgSO4, filtered, concentrated onto silica (15 g),
and then purified by silica gel chromatography (40 g), eluting with
20−60% EtOAc in hexanes to afford benzyl 3-(1-propyn-1-yl)-4-(5-
(2,2,2-trifluoro-1-hydroxy-1-methylethyl)-1,3-thiazol-2-yl)-1-piperazi-
necarboxylate (77) (0.068 g, 15%) as a colorless oil. MS (ESI positive
ion) m/z: calcd for C21H22F3N3O3S, 453.133; found, 454.1 (M + 1).
Compound 77 (0.070 g, 0.154 mmol) was deprotected according to
the general Cbz-deprotection method A. The crude product was
treated with 6-chloro-3-pyridinesulfonyl chloride7819 (0.0491 g, 0.232
mmol) according to the general sulfonamide formation method using
DIPEA (0.27 mL, 1.5 mmol) to afford 2-(2-(4-((6-chloro-3-
pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-1-piperazinyl)-1,3-thiazol-5-yl)-
1,1,1-trifluoro-2-propanol (79) (0.058 g, 76%) as a colorless film. MS
(ESI positive ion) m/z: calcd for C18H18ClF3N4O3S2, 494.046; found,
494.9 (M + 1).
1
found, 530.0 (M + 1). H NMR (400 MHz, DMSO-d6) δ 9.12 (s, 1
H), 8.23 (d, J = 2.4 Hz, 1 H), 7.63 (dd, J = 9.0, 2.5 Hz, 1 H), 7.38 (s, 1
H), 7.05 (br s, 2 H), 6.54 (d, J = 8.8 Hz, 1 H), 4.99 (br s, 1 H), 3.75
(d, J = 12.3 Hz, 1 H), 3.56−3.69 (m, 2 H), 3.26−3.37 (m, 1 H), 2.59
(dd, J = 11.6, 3.4 Hz, 1 H), 2.37−2.49 (m, 1 H), 1.80 (d, J = 2.2 Hz, 3
H).
A solution of compound 79 (0.058 g, 0.117 mmol) in EtOH (1.5
mL) and NH4OH (28% in water, 1 mL) was heated to 120 °C with
microwave apparatus for 3 h. The reaction mixture was allowed to cool
to room temperature and partitioned between 9:1 CHCl3/IPA (15
mL) and 5% NaHCO3 (7 mL). The aqueous layer was further
extracted with 9:1 CHCl3/IPA (10 mL). The combined organics were
dried over MgSO4, filtered, concentrated under reduced pressure, and
then purified by silica gel chromatography (4 g), eluting with 0−6% (2
M NH3 in MeOH) in DCM to afford 2-(2-(4-((6-amino-3-
pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-1-piperazinyl)-1,3-thiazol-5-yl)-
1,1,1-trifluoro-2-propanol (80) (0.013 g, 23%) as a colorless film. MS
(ESI positive ion) m/z: calcd for C18H20F3N5O3S2, 475.096; found,
476.0 (M + 1). 1H NMR (400 MHz, DMSO-d6) δ 8.22 (d, J = 2.5 Hz,
1 H), 7.60 (s, 1 H), 7.21 (d, J = 3.9 Hz, 1 H), 7.01 (s, 2 H), 6.97 (d, J
= 1.2 Hz, 1 H), 6.52 (d, J = 8.8 Hz, 1 H), 4.87−4.99 (m, 1 H), 3.62 (br
s, 3 H), 3.31 (m, 1 H), 2.52−2.60 (m, 1 H), 2.31−2.46 (m, 1 H), 1.79
(t, J = 2.4 Hz, 3 H), 1.66 (s, 3 H). HPLC purity at 254 nm, 89.0%
2-(2-((2S)-4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-
yl)-1-piperazinyl)-5-pyrimidinyl)-1,1,1,3,3,3-hexafluoro-2-
propanol (88). A 1 L round-bottomed flask was charged with 2-
piperazinone (81) (10.2 g, 102 mmol) and DCM (250 mL). 6-Chloro-
3-pyridinesulfonyl chloride (78)19 (21.8 g, 103 mmol) was added in
portions at 0 °C under argon stream. Then Et3N (32.0 mL, 230
mmol) in DCM (50 mL) was added via an additional funnel over 30
min at 0 °C. The ice−water bath was removed, and the milky mixture
was stirred at room temperature for 30 min. The mixture was
concentrated, and the residue was taken into saturated aqueous
NaHCO3 (200 mL). The mixture was stirred at room temperature for
30 min. The white precipitate was collected via filtration. The filter
cake was washed with water (3 × 200 mL), air-dried, and then dried in
a vacuum oven (60 °C, 50 mmHg) for 18 h to afford 4-((6-chloro-3-
pyridinyl)sulfonyl)-2-piperazinone (82) (27.5 g, 97%) as an off-white
solid. MS (ESI positive ion) m/z: calcd for C9H10ClN3O3S, 275.013;
found, 276.0 (M + 1). 1H NMR (400 MHz, DMSO-d6) δ 8.81 (d, J =
2.2 Hz, 1 H), 8.24 (dd, J = 2.5, 8.4 Hz, 1 H), 8.05 (br s, 1 H), 7.79 (d,
J = 8.4 Hz, 1 H), 3.59 (s, 2 H), 3.31−3.25 (m, 2 H), 3.21−3.15 (m, 2
H).
2-(2-(4-((6-Amino-3-pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-1-
piperazinyl)-1,3-thiazol-5-yl)-1,1,1-trifluoro-2-propanol (80).
To a stirring suspension of 2-chloro-1,3-thiazole-5-carboxylic acid
(69) (5.0 g, 31 mmol) in DCM (30 mL) at 0 °C under nitrogen were
added oxalyl chloride (8.1 mL, 92 mmol) and DMF (0.118 mL, 1.53
mmol). The suspension was stirred for 5 h warming to 20 °C to create
a solution. The solvents were then removed under reduced pressure
and redissolved in DCM (30 mL). To the solution was added DIPEA
(16 mL, 92 mmol), and then the mixture was cooled to 0 °C under
nitrogen. To the reaction mixture N,O-dimethylhydroxylamine
hydrochloride (2.98 g, 30.6 mmol) was added at once. After 15 min
the reaction mixture was diluted with 1 M KH2PO4 (75 mL). The
organic phase was dried over MgSO4, filtered, and concentrated under
reduced pressure. The crude material was purified by silica gel
chromatography (120 g), eluting with 20−50% EtOAc/Hex to afford
2-chloro-N-methoxy-N-methyl-1,3-thiazole-5-carboxamide (75) (5.31
g, 84%) as a yellow solid. MS (ESI positive ion) m/z: calcd for
C6H7ClN2O2S, 205.992; found, 206.9 (M + 1).
A suspension of benzyl 3-(1-propyn-1-yl)-1-piperazinecarboxylate
(6)13 (1.0 g, 3.9 mmol), compound 75 (1.20 g, 5.81 mmol), and
DIPEA (1.01 mL, 5.81 mmol) in DMF (5 mL) was heated to 100 °C
with stirring for 20 h. The reaction mixture was allowed to cool to
room temperature and partitioned between EtOAc (50 mL) and 1 M
KH2PO4 (80 mL). The organic phase was then dried over MgSO4,
filtered, concentrated under reduced pressure, and then purified by
silica gel chromatography (80 g), eluting with 0−30% acetonitrile in
DCM to afford benzyl 4-(5-(methoxy(methyl)carbamoyl)-1,3-thiazol-
2-yl)-3-(1-propyn-1-yl)-1-piperazinecarboxylate (76) (0.58 g, 35%) as
a colorless oil. MS (ESI positive ion) m/z: calcd for C21H24N4O4S,
1
428.152; found, 429.0 (M + 1). H NMR (400 MHz, CDCl3) δ 8.06
(s, 1 H), 7.28−7.43 (m, 5 H), 5.08−5.29 (m, 2 H), 4.95 (br s, 1 H),
4.17−4.43 (m, 2 H), 3.75 (s, 3 H), 3.61−3.72 (m, 1 H), 3.44−3.58
(m, 1 H), 3.32 (s, 3 H), 3.01−3.29 (m, 2 H), 1.71 (br s, 3 H).
To a solution of compound 76 (0.550 g, 1.28 mmol) in THF (5
mL) at 0 °C under nitrogen was added methylmagnesium bromide
(3.0 M in diethyl ether, 1.28 mL, 3.85 mmol) dropwise. The reaction
mixture was stirred for 30 min, then slowly quenched with saturated
NH4Cl (20 mL) and EtOAc (30 mL). The organic phase was dried
over MgSO4, filtered, concentrated under reduced pressure, and then
purified by silica gel chromatography (40 g), eluting with 0−40%
EtOAc in hexanes to afford benzyl 4-(5-acetyl-1,3-thiazol-2-yl)-3-(1-
propyn-1-yl)-1-piperazinecarboxylate (0.392 g, 80%) as a colorless oil.
MS (ESI positive ion) m/z: calcd for C20H21N3O3S, 383.130; found,
A 1 L round-bottomed flask was charged with compound 82 (27.5
g, 100 mmol), DMAP (1.49 g, 12.2 mmol), TEA (30.0 mL, 215
mmol), and DCM (300 mL). Di-tert-butyl dicarbonate (44.01 g, 202
mmol) was added in portions at room temperature. The mixture was
stirred at room temperature for 1.5 h. Additional DMAP (1.57 g, 12.8
mmol) was added, and stirring was resumed for 1.5 h (3 h total). The
reaction mixture was concentrated, and the residue was taken into
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EtOAc (500 mL). The slurry was washed with 1 N HCl (2 × 200 mL),
water (200 mL), and saturated aqueous NaCl (200 mL). The EtOAc
phase was filtered to collect a white solid. The solid was washed with
EtOAc (2 × 100 mL). The filtrate and washes were combined and
concentrated. EtOAc (100 mL) was added to the residue to induce the
second crop of the product. The resulting white precipitate was
collected via filtration, and the filter cake was washed with EtOAc (2 ×
50 mL). The two crops were combined to give tert-butyl 4-((6-chloro-
3-pyridinyl)sulfonyl)-2-oxo-1-piperazinecarboxylate (83) (32.0 g,
85%) as a white solid. MS (ESI positive ion) m/z: calcd for
(400 MHz, CDCl3) δ 8.59 (s, 2 H), 8.43 (d, J = 2.15 Hz, 1 H), 7.77
(dd, J = 2.25, 8.71 Hz, 1 H), 6.54 (d, J = 8.80 Hz, 1 H), 5.75 (br s, 1
H), 5.05−5.18 (m, 2 H), 4.69 (d, J = 13.30 Hz, 1 H), 3.75−3.91 (m, 2
H), 3.43−3.58 (m, 1 H), 2.63 (dd, J = 3.72, 11.15 Hz, 1 H), 2.49 (dt, J
= 3.03, 11.69 Hz, 1 H), 1.82 (d, J = 2.15 Hz, 3 H). One exchangeable
proton was not observed.
ASSOCIATED CONTENT
* Supporting Information
■
S
Standard deviations for the in vitro data listed in Tables 1−3;
VCD data for compounds 89 and 90; and synthetic procedures
for the preparation of piperazine intermediates 4, 5, 6, and 72,
sulfonyl chloride 9, and aryl halides intermediates that were not
commercially available. This material is available free of charge
via the Internet at http://pubs.acs.org.
1
C14H18ClN3O5S, 375.066; found, 398.0 (M + Na). H NMR (400
MHz, CDCl3) δ 8.81 (d, J = 2.0 Hz, 1 H), 8.03 (dd, J = 2.3, 8.4 Hz, 1
H), 7.55 (d, J = 8.4 Hz, 1 H), 3.94−3.80 (m, 4 H), 3.44 (t, J = 5.5 Hz,
2 H), 1.52 (s, 9 H).
A 1 L round-bottomed flask was charged with compound 83 (11.05
g, 29.4 mmol) and 100 mL of THF. After the mixture was cooled to 0
°C, bromo(1-propyn-1-yl)magnesium (0.5 M in THF, 88 mL, 44.1
mmol) was added. Soon after the finish of the addition, the reaction
was quenched with saturated aqueous NH4Cl and the aqueous portion
was extracted with EtOAc. The combined extracts were dried over
MgSO4, filtered, and concentrated to give an oil. To this was added
DCM (30 mL). After the mixture was cooled to 0 °C, TFA (33.5 g,
294 mmol) was added. After 15 min, sodium triacetoxyhydroborate
(24.9 g, 118 mmol) was added portionwise at 0 °C. The mixture was
stirred at room temperature for 1.5 h, and then the mixture was
concentrated. To this oil was added DCM (100 mL), and then the
mixture was neutralized with 5 N NaOH to pH 6−7. The layers were
separated, and the organics were dried over MgSO4, filtered, and
concentrated. The resulting oil was purified by silica gel column
chromatography (10−100% EtOAc in hexanes) to give 1-((6-chloro-3-
pyridinyl)sulfonyl)-3-(1-propyn-1-yl)piperazine (85) (7.13 g, 23.8
mmol, 81%) as a brown brittle foam. MS (ESI positive ion) m/z:
calcd for C12H14ClN3O2S, 299.050; found, 300.1(M + 1).
Accession Codes
The cocrystal structures of hGKRP + compounds 51, 65, 15,
and 24 have been deposited in the Protein Data Bank with
PDB codes 4OHM, 4OHK, 4OHP, and 4OHO, respectively.
AUTHOR INFORMATION
Corresponding Authors
*N.N.: phone, 805-447-0339; e-mail, nobukon@amgen.com.
*M.H.N.: phone, 805-447-1552; e-mail, markn@amgen.com.
■
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
The authors acknowledge Kyung Gahm, Wesley Barnhart, and
Samuel Thomas for conducting the SFC separations, Robert
Kurzeja for providing the purified proteins, and Robert Wahl
and Kathy Chen for assay development. Additionally, the
A 350 mL pressure tube was charged with compound 85 (7.13 g,
23.8 mmol), 2-(2-chloro-5-pyrimidinyl)-1,1,1,3,3,3-hexafluoro-2-prop-
anol (86),13 (7.34 g, 26.2 mmol), NMP (30 mL), and DIPEA (8.27
mL, 47.6 mmol). The tube was sealed and heated at 130 °C for 8 h.
The mixture was allowed to cool to room temperature and then
diluted with water (100 mL) and EtOAc (200 mL). The biphasic
mixture was transferred to a separatory funnel, and the aqueous layer
was removed. The remaining organics were washed with water (2 ×
150 mL), saturated aqueous NaCl (150 mL), dried over MgSO4,
filtered, and concentrated to give a brown oil. Purification via silica gel
column chromatography (0−50% EtOAc in hexanes) gave crude 2-(2-
(4-((6-chloro-3-pyridinyl)sulfonyl)-2-(1-propyn-1-yl)-1-piperazinyl)-
5-pyrimidinyl)-1,1,1,3,3,3-hexafluoro-2-propanol (∼7.5 g) as an off-
white brittle foam. To this was added concentrated NH4OH (20 mL)
and EtOH (30 mL). The mixture was heated in a sealed tube at 135
°C for 8 h. The mixture was allowed to cool to room temperature and
then concentrated. To this solution was added MeOH (40 mL) and
sodium borohydride (0.900 g, 23.8 mmol) to reduce the methyl
ketone byproduct formed via hydration of the triple bond, thereby
facilitating the removal of this byproduct in the purification process.
After 5 min, the reaction mixture was concentrated. The residue was
dissolved in EtOAc and washed with water. The organics were
separated, dried over MgSO4, filtered, and concentrated. The resulting
oil was purified by silica gel column chromatography (0−50% EtOAc
in hexanes) to give 2-(2-(4-((6-amino-3-pyridinyl)sulfonyl)-2-(1-
propyn-1-yl)-1-piperazinyl)-5-pyrimidinyl)-1,1,1,3,3,3-hexafluoro-2-
propanol (87) (4.15 g, 33%) as an off-white foam. MS (ESI positive
ion) m/z: calcd for C19H18F6N6O3S, 524.107; found, 525.1 (M + 1).
The racemate 87 (0.082 g, 0.16 mmol) was separated using chiral
SFC as follows: AD-H (5 μm, 21 mm × 250 mm) column, using 70%
carbon dioxide−30% MeOH; flow rate was 70 mL/min. This
procedure produced 2-(2-((2S)-4-((6-amino-3-pyridinyl)sulfonyl)-2-
(1-propyn-1-yl)-1-piperazinyl)-5-pyrimidinyl)-1,1,1,3,3,3-hexafluoro-2-
propanol (88). The absolute stereochemistry at the piperazine carbon
next to the N−Ar was assigned to be (S) configuration based on the
result obtained in the biochemical assay. MS (ESI positive ion) m/z:
́
authors thank Scott Simonet, Murielle Veniant, Dean Hickman,
Philip Tagari, and Randall Hungate for their support of this
research.
ABBREVIATIONS USED
■
Ac, acetyl; BINAP, 2,2′-bis(diphenylphosphino)-1,1′-binaphth-
yl; Bn, benzyl; Boc, tert-butyloxycarbonyl; Cbz, carboxybenzyl;
CL, clearance; DavePhos, 2′-(biphenylphosphino)- N,N-
dimethyl-[1,1′-biphenyl]-2-amine; dba, 1,5-diphenylpenta-1,4-
dien-3-one; DCM, dichloromethane; DIPEA, diisopropylethyl-
amine; DMAP, 4-dimethylaminopyridine; DME, 1,2-dime-
thoxyethane; DMF, N,N-dimethylformamide; DMSO, dimethyl
sulfoxide; Et3N, triethylamine; EtOAc, ethyl acetate; EtOH,
ethyl alcohol; GK, glucokinase; GKA, glucokinase activator;
GKRP, glucokinase regulatory protein; IPA, isopropyl alcohol;
iv, intravenous; JohnPhos, 2-biphenylyl(di-tert-butyl)-
phosphane; MeOH, methyl alcohol; NMP, 1-methyl-2-
pyrrolidinone; PD, pharmacodynamic; po, orally; RLM, rat
liver microsome; RuPhos, 2-dicyclohexyl(2′,6′-diisopropoxybi-
phenyl-2-yl)phosphine; RuPhos first generation precatalyst,
chloro(2-dicyclohexylphosphino-2′,6′-diisopropoxy-1,1′-
biphenyl)[2-(2-aminoethylphenyl)]palladium(II); SFC, super-
critical fluid chromatography; TBAF, tetrabutylammonium
fluoride; TBS, tert-butyldimethylsilyl; Tf, trifluoromethanesul-
fonyl; TFA, trifluoroacetic acid; THF, tetrahydrofuran; Ts, p-
toluenesulfonyl; X-Phos, 2-dicyclohexylphosphino-2′,4′,6′-trii-
sopropyl-1,1′-biphenyl
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1
calcd for C19H18F6N6O3S, 524.107; found, 525.0 (M + 1). H NMR
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