Design and synthesis of carbazole carboxamides as promising inhibitors of Bruton's tyrosine kinase (BTK) and Janus kinase 2 (JAK2)

Article abstract of DOI:10.1016/j.bmcl.2015.07.102

Four series of disubstituted carbazole-1-carboxamides were designed and synthesised as inhibitors of Bruton's tyrosine kinase (BTK). 4,7- and 4,6-disubstituted carbazole-1-carboxamides were potent and selective inhibitors of BTK, while 3,7- and 3,6-disubs

Full text of DOI:10.1016/j.bmcl.2015.07.102

Accepted Manuscript
Design and Synthesis of Carbazole Carboxamides as Promising Inhibitors of
Bruton’s Tyrosine Kinase (BTK) and Janus Kinase 2 (JAK2)
Qingjie Liu, Douglas G. Batt, Jonathan S. Lippy, Neha Surti, Andrew J. Tebben,
Jodi K. Muckelbauer, Lin Chen, Yongmi An, Chiehying Chang, Matt Pokross,
Zheng Yang, Haiqing Wang, James R. Burke, Percy H. Carter, Joseph A. Tino
PII:
S0960-894X(15)00821-5
DOI:
http://dx.doi.org/10.1016/j.bmcl.2015.07.102
BMCL 22991
Reference:
Bioorganic & Medicinal Chemistry Letters
To appear in:
Received Date:
Revised Date:
Accepted Date:
4 June 2015
27 July 2015
29 July 2015
Please cite this article as: Liu, Q., Batt, D.G., Lippy, J.S., Surti, N., Tebben, A.J., Muckelbauer, J.K., Chen, L., An,
Y., Chang, C., Pokross, M., Yang, Z., Wang, H., Burke, J.R., Carter, P.H., Tino, J.A., Design and Synthesis of
Carbazole Carboxamides as Promising Inhibitors of Bruton’s Tyrosine Kinase (BTK) and Janus Kinase 2 (JAK2),
Bioorganic & Medicinal Chemistry Letters (2015), doi: http://dx.doi.org/10.1016/j.bmcl.2015.07.102
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers
we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and
review of the resulting proof before it is published in its final form. Please note that during the production process
errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Design and Synthesis of Carbazole Carboxamides as Promising
Inhibitors of Bruton’s Tyrosine Kinase (BTK) and Janus Kinase
2 (JAK2)
Qingjie Liu*, Douglas G. Batt, Jonathan S. Lippy, Neha Surti, Andrew J. Tebben, Jodi
K. Muckelbauer, Lin Chen, Yongmi An, Chiehying Chang, Matt Pokross, Zheng Yang,
Haiqing Wang, James R. Burke, Percy H. Carter, Joseph A. Tino
Bristol-Myers Squibb Pharmaceutical Research Institute, P. O .Box 4000, Princeton, NJ 08543-4000, USA
Received Month XX, 2015; Accepted Month XX, 2015
Abstract—Four series of disubstituted carbazole-1-carboxamides were designed and synthesized as inhibitors of Bruton’s tyrosine kinase
(BTK). 4,7- and 4,6-Disubstituted carbazole-1-carboxamides were potent and selective inhibitors of BTK, while 3,7- and 3,6-
disubstituted carbazole-1-carboxamides were potent and selective inhibitors of Janus kinase 2 (JAK2).
* Corresponding author: Tel: +1-609-252-4794; fax: +1-609-252-7410; email: qingjie.liu@bms.com
Bruton’s tyrosine kinase (BTK) is a member of the TEC
family of protein tyrosine kinases which is
predominantly expressed in B lymphocytes. The
expression and activity of BTK are critical to several
key steps in the life cycle of B-lineage cells including
proliferation, development, differentiation, survival, and
apoptosis.1,2 Following B cell receptor ligation, BTK is
recruited to a macromolecular complex at the cell
membrane where it is activated by phosphorylation on
two key tyrosine residues. Activated BTK then
phosphorylates PLCγ2, leading to the generation of
inositol-1,4,5-triphosphate and diacylglycerol, which in
turn cause calcium mobilization and protein kinase C
(PKC) activation.3,4
disease, relapsing-remitting multiple sclerosis, and
systemic lupus erythematosis has also been reported.7-9
Inhibitors of BTK may thus provide selective
modulation of B cell activity, and may be useful in
treating inflammatory and autoimmune conditions.
Researchers at Bristol-Myers Squibb have disclosed a
series of disubstituted nicotinamides which exhibit
potent inhibition of BTK (single-digit nanomolar
IC50).10,11 An x-ray crystal structure of one example,
(R)-6-(3-(4-tert-butylbenzamido)-piperidin-1-yl)-2-(4-
(morpholine-4-carbonyl)phenyl-amino)nicotinamide,
bound in the catalytic subunit of human BTK showed
typical binding to the hinge region in the ATP pocket
(PDB ID 5BPY) (Figure 1).11,12 The primary amide NH
formed a hydrogen bond with the backbone carbonyl of
Glu 475, the carbonyl oxygen interacted with the
backbone NH of Met 477, and the aniline NH formed a
weak hydrogen bond with the carbonyl of Met 477. The
morpholine amide was solvent-exposed, suggesting
toleration of a variety of substituents. A noteworthy
feature of this structure is the nearly co-planar
arrangement of the pyridine and aminophenyl rings. The
importance of this spatial arrangement is demonstrated
by the significant loss of BTK inhibitory potency
resulting from replacement of the pyridyl nitrogen with
Mutations in the human BTK gene are known to cause
X-linked agammaglobulinemia (XLA), a male immune
deficiency disorder characterized by a lack of mature,
immunoglobulin-producing B cells.5 There is strong
evidence that B cells can play a critical role in the
pathogenesis of rheumatoid arthritis and other
autoimmune diseases. Rituximab (Rituxan®), a chimeric
monoclonal antibody, was the first approved B cell
targeted therapy. Besides utility in the treatment of non-
Hodgkin’s lymphoma, clinical experience has shown
that B cell depletion with Rituximab is an effective and
generally well tolerated treatment option for rheumatoid
arthritis.6 Evidence for utility in chronic graft-vs.-host

carbon, whic
planarity through steric hinderance.
h w
oul
d b
e e
xpe
cted to dis
tort the ne
ar co-
Figure 2. Constraining the nicotinamide to form a carbazole.
A few carbazoles bearing a substituted phenyl at the 4-
positon, and N-methyl-piperazine amide at either the 6-
or 7- positions, were prepared (Table 1, entries 1-10).
Encouragingly, all of these initial compounds showed
good BTK inhibition. A pharmacokinetic study with
compound 6 demonstrated good oral exposure in the
mouse (AUC 25.6 μM⋅h at 10 mg/kg), a promising
improvement over the nicotinamide series.
Table 1. 4,6- and 4,7-Disubstituted carbazole-1-carboxamides.
Amide
Position
BTK
IC50, nM14
16
JAK215/
BTK
1
Compds
X
1
2
3
4
2-F
3-OMe
3-NHCOMe
4-OMe
4-NHCOMe
2-F
3-OMe
3-NHCOMe
4-OMe
4-NHCOMe
2-Me
2-OMe
2-Cl
3-Cl
3-CONHMe
4-Cl
4-t-butyl
4-CONHMe
4-OPh
6
6
6
6
6
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
28
88
29
39
1
1
1
1
5
Figure 1. X-ray crystal structure of (R)-6-(3-(4-tert-butylbenzamido)-
6
7
8
9
15
32
30
55
15
24
144
15
38
3
1
8
1
4
3
4
3
2
2
2
2
1
3
2
7
piperidin-1-yl)-2-(4-(morpholine-4-carbonyl)phenylamino)nicotinamide
12
bound to BTK. (PDB ID 5BPY)
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Unfortunately, compounds of this series have generally
shown poor metabolic stability. For the compound
shown in Figure 1, less than 3% was recovered after 10
minute incubation with human, rat or mouse liver
microsomes, and closely related compounds gave poor
oral exposure in mouse pharmacokinetic studies (AUC
generally <1 μM⋅h at 10 mg/kg). Seeking to address
71
59
103
44
127
101
13
these issues, we designed
a
carbazole series,
constraining the pyridine and aniline phenyl rings of the
nicotinamides (Figure 2).13 This tricyclic core would
lock the required co-planarity of the rings without
disturbing the hinge-binding motif, and also offer a
variety of substitution possibilities for exploration of
SAR. The substituents R and R' of the nicotinamide
series could be mimicked by either R3 or R4, and by
either R6 or R7, respectively, on the carbazole core.
3,4-di-Cl
2,3-di-Cl
2,3-di-F
2-Me, 3-Cl
2-Me, 3-NH2
2-Me, 3-NHCOMe
2,4-di-F
6.9
32
19
16
22
3
6
5
13
2
3
2,5-di-F
2,6-di-F
16
12
2
Unfortunately, selectivity of these compounds with
respect to inhibition of several other kinases was low (1-
to 8-fold). Notably, selectivity against JAK2, a member
of the Janus kinase family, was very poor. Activation of
JAK2, which functions as a mediator of cytokine
receptor signaling, stimulates cell proliferation,
differentiation, migration and apoptosis. These cellular
events are critical to hematpoiesis, immune
development and other biological functions. A mutation
in JAK2 has been identified in most patients with

toward solvent (Figure 3).20 The carbazole NH is
hydrogen bonded to the backbone carbonyl of Met 477,
an interaction not observed in the nicotinamide
polycythaemia vera, essential thrombocythaemia and
primary myelofibrosis. While JAK2 has emerged as an
interesting target for treatment of myeloproliferative
disorders,16-19 concomitant inhibition of JAK2 would be
undesirable for the treatment of B-cell mediated
disorders with a BTK inhibitor. We therefore needed to
improve the selectivity of BTK inhibition over that of
other kinases, particularly JAK2.
structure.
The conformation of the chlorophenyl
substituent in compound 13 differs significantly from
the aminopiperidine of the nicotinamide series (Figure
1). The chlorophenyl ring is nearly orthogonal to the
carbazole core and forms hydrophobic interactions with
Val 416 and Cys 481. These interactions, stabilized by
hindered rotation due to the ortho chloro substituent on
the 4-phenyl ring, may be responsible for improved
potency relative to analogs lacking an ortho-substituent.
This conformation may also contribute to selectivity
over other kinases, although reasons for this are not
apparent. (Note that the ortho-chloro group of
compound 13 was resolved in the x-ray structure into at
least 2 conformations. The two rotomers that best fit the
observed density are shown as yellow and orange
below. Both are free of steric clashes in the refined
structure.)
Paired compounds with either 6- (1-5) or 7-amide
substituents (6-10) showed similar BTK potency and
JAK2 selectivity. However, 7-substituted compounds
generally exhibited better metabolic stability than the
corresponding 6-substituted analogs. For example,
incubation of compound 6 (0.5 μM) with human, rat and
mouse liver microsomes for 10 minutes at 37 °C gave
78%, 59%, and 49% recoveries, respectively, of
unchanged compound, while the recoveries from similar
incubation of compound 1 were only 34%, 7%, and 8%.
Therefore, 4,7-disubstituted carbazole-1-carboxamides
were selected for further exploration of the SAR.
Additional variation of the substitution on the 4-phenyl
ring was examined in detail (Table 1, entries 11-28).
Compounds with small para-substituents (OMe, Cl,
NHCOMe, and CONHMe; entries 9, 16, 10, and 18)
showed similar BTK potency, with IC50 values in the
range of 15-59 nM, but without significant selectivity
over JAK2. Bulky para substituents (t-butyl and
phenoxy; entries 17 and 19) decreased BTK potency to
100 nM or greater.
Small ortho-substituents (F, Cl, and Me) on the 4-
phenyl group were well tolerated, with BTK IC50 values
of 15-24 nM (entries 6, 11, 13) while the larger ortho-
methoxy (entry 12) had somewhat reduced potency.
Compounds with meta-substituents (OMe, Cl,
CONHMe, and NHCOMe; entries 7, 14, 15, and 8) all
showed similar BTK potencies (30-71 nM). However,
the meta-acetamide 8 was more selective relative to
JAK2 than the others. Better JAK2 selectivities were
also realized when ortho-Me, Cl, or F was combined
with a meta-substituent. The most interesting example is
compound 25 (ortho-Me with meta-acetamide), which
showed 13-fold selectivity for BTK over JAK2. A
similar effect was observed in other 2,3-disubstituted
phenyl compounds (entries 21 through 24). Among
these, the 2,3-difluoro analog 22 had the most potent
BTK activity (7 nM). Other difluoro analogs (2,4-, 2,5-,
and 2,6-difluoro; entries 26 – 28) were 2-3 fold less
potent. This SAR suggested that potency and selectivity
could be potentially increased by optimization of the
ortho- and meta- substituents.
Figure 3. X-ray structure of compound 13 bound to BTK. (PDB ID
20
5BQ0) Both resolved rotamersof the 2-chlorophenyl group are shown.
The x-ray structure of 13 suggested the pendant phenyl
would be tolerant to diverse substitution. To follow up
on the early SAR described above, small ortho-
substituents (F, Me) were paired with a wide variety of
meta-substituents.13 As part of this effort, a small set of
carbazoles with meta-benzamide substituents was
synthesized (Table 2). Potency was maintained or
improved, and good to excellent selectivity over JAK2
was achieved.
An x-ray crystal structure of compound 13 bound to the
active site of BTK was obtained (PDB ID 5BQ0), and
showed the carbazole amide bound to the hinge region
as expected, with the piperazine amide projecting
The simple 2-methyl-3-benzamide compound 29 was
potent (BTK IC50 7 nM) with good (28-fold) JAK2

selectivity. Para-substitution of the benzamide (entries
30 and 31) gave a 2-fold improvement in BTK potency,
but increased JAK2 selectivity dramatically (58- and
114- fold, respectively). The bulky tert-butyl group
(entry 32) maintained good potency but further
improved JAK2 selectivity to 140-fold. Similar trends
were observed in compounds 33 and 34, bearing ortho-
F in place of ortho-Me. The dimethylamino analog 34
showed not only improved BTK potency (IC50 3 nM)
but also more than 300-fold JAK2 selectivity. In
contrast, compound 35 (lacking an ortho-substituent)
suffered a 4- to 10-fold loss in potency, and 4- to 6-fold
loss in JAK2 selectivity, relative to 30 and 33.
removal of the benzamide moiety (compound 11)
causes only a 2-fold change in potency compared to 32.
Table 3. Kinase selectivity for three BTK inhibitors.a
Kinase
BTK
Compd 6
15
Compd 25
16
Compd 34
3.0
JAK2
BMX
ITK
50 (3.3)
119 (7.9)
39 (2.6)
116 (7.7)
119 (7.9)
444 (30)
610 (41)
41 (2.7)
81 (5.4)
68 (4.5)
753 (50)
212 (13)
193 (12)
55 (3.4)
1020 (339)
109 (36)
115 (38)
41 (14)
95 (32)
493 (164)
>50000
1050 (350)
569 (190)
824 (275)
14300 (4770)
TEC
162 (10)
172 (11)
>2000 (>125)
2700 (169)
471 (29)
108 (6.8)
204 (13)
>2000 (>125)
TXK
AURa
CDK2
cKIT
LCK
Table 2. Potent and selective BTK inhibitors.
LYNa
TYK2
a IC50 (nM). Numbers in parentheses are selectivities for BTK over the
indicated kinase.
Additionally, the extended conformation reported for
the imidazopyrazine, pyrazinone and pyridinone
series,21-23 where the tert-butylphenyl occupies the so-
called H3 pocket, is thought to be important for both
potency and selectivity, but this conformation is
unlikely in the carbazole series. The presence of the
tricyclic ring system would destabilize this extended
conformation through steric clash between the carbazole
core and the 4-phenyl substituent, as suggested by the
near-orthogonal arrangement observed in the X-ray
structure of 13. Further, the potency of compounds 29-
34 suggests that for these compounds, a conformation
analogous to that shown in yellow in Figure 3, with the
ortho-substituent pointing toward Cys 481, is the
rotamer responsible for BTK inhibiton. The other
rotamer (comparable to that shown in orange) would be
expected to introduce a serious steric clash between the
benzamide and the P-loop of the enzyme (shown as a
blue ribbon in Figure 3).
BTK
Compds
Y
R
JAK2/BTK14
IC50, nM13
7.2
29
30
31
32
33
34
35
Me
Me
Me
Me
F
H
F
28
58
114
141
29
3.8
3.5
12
9.4
N(Me)2
t-Butyl
F
F
H
N(Me)2
F
3.0
39
339
7
Activities for three example compounds against selected
kinases are shown in Table 3. Selectivity against other
additional kinases (20-25 enzymes examined) were
generally >100-fold, with greatly reduced potencies
(IC50 values > 1 µM) against most of them.
The reason for the enhanced selectivity of compounds
bearing a meta-carboxamide on the 4-phenyl substituent
is not obvious. Although the 4-substituents of
compounds 29-35 are similar to substituents in
previously reported BTK inhibitors,21-23 it is doubtful
that these substituents play the same role in enzyme
potency and selectivity in the carbazole series. In the
earlier-reported cases, BTK potency is exquisitely
sensitive to the presence of the tert-butylphenyl (or a
similar group): replacement by a simple unsubstituted
benzamide22 or acetamide21 leads to dramatic loss of
potency (575-fold and 1420-fold, respectively).
However, analogous changes in the carbazole series
gave compounds with potencies within 3-fold of each
other (compare compounds 32, 29 and 16), suggesting
that the innate binding affinity of the carbazole core is
greater than in the other cases. Indeed, complete
Notably, compounds of this series were less selective
against the other kinases in the TEC family (TEC,
BMX, ITK and TXK), of which BTK is a member,
where selectivities ranged from less than 3-fold to about
40-fold (Table 3). This could be due to the presence of a
cysteine residue (homologous to Cys 481 of BTK) in
the other members of the TEC family, since a
hydrophobic interaction with this residue was suggested
by the X-ray structure of 13 with BTK, particularly with
the conformation shown in yellow (Figure 3). Cysteine
in this position is rare in the kinome, found in only 10
known kinases. (In Jak2 and LCK, for example, Cys
481 is replaced by the less lipophilic serine.)
In addition to 4,7- and 4,6-disubstituted carbazole-1-
carboxamides, 3,7- and 3,6-disubstituted isomers were
also synthesized (Table 4). Surprisingly, these proved to

be very potent and selective inhibitors of JAK2.
Compounds 36-40, bearing a morpholine amide at the
6-position, were over 100 times less potent against BTK
than against JAK2. Replacement of the morpholine with
N-methylpiperazine to give 41 increased both the BTK
and JAK2 potencies but failed to alter the selectivity.
Table 4. 3,6- and 3,7-Disubstituted-carbazole-1-carbozamides.
Scheme 1. Reagents and conditions: i. NaNO2, H2O, conc. HCl, -10
oC to -5 oC, 10 min; ii. SnCl2, conc. HCl, -10 oC to rt, 1 h, 82% in two
steps; iii. ethyl 3-oxocyclohexanecarboxylate, AcOH, reflux, 4 h,
64%; iv. NH4OH, EDC, HOBT, in THF/CH2Cl2, rt, 16 h, 98%; v.
DDQ, toluene, reflux, 2.5 h, 91%; vi. LiOH in THF/EtOH/H2O,
reflux, 3 h, 90%; vii. N-methyl piperazine, EDC, HOBT, rt, 16 h,
76%; viii. boronic esters or boronic acids, PdCl2(dppf)2 and K2CO3 or
Pd(Ph3P)4 and Na2CO3, toluene/EtOH, 90 oC, 10 h, 15–80%.
Compds
X
Amide
Position, Z
6, O
BTK
IC50, nM13
360
189
327
308
461
110
404
JAK2
IC50, nM14
2.8
36
37
38
39
40
41
42
43
44
45
3-OMe
3-Cl
4-OMe
4-Cl
3,4-Cl2
4-Cl
3-OMe
4-OMe
3,4-Cl2
3-NHCOMe
6, O
6, O
6, O
6, O
6, N-Me
7, N-Me
7, N-Me
7, N-Me
7, N-Me
1.7
2.0
2.6
2.4
1.2
4.3
5.5
6.2
In conclusion, we have designed and synthesized novel
4,7- and 4,6-disubstituted carbazole-1-carboxamides as
potent and selective BTK inhibitors. The 4-position
substituents had a significant effect on potency and
selectivity for BTK relative to other kinases,
particularly JAK2. The 3,7- and 3,6-disubstituted
carbazole-1-carboxamides have also been identified as
highly potent and selective JAK2 inhibitors with
potential utility in oncology. Further exploration of the
intriguing BTK activity and SAR of the carbazole
carboxamides will be reported in due course.
436
812
379
27
Moving the amide to C-7 (42-45) showed similar
potency and selectivity except for the 4-acetanilide 45,
which was less potent and less selective for JAK2. The
selectivity of the 3-arylcarbazole-1-carboxamides for
JAK2 over BTK, and also the dramatic selectivity of
these compounds with respect to other JAK family
members (JAK1 and JAK3, data not shown) have
prompted extensive exploration of this isomeric series
for oncology indications.15,24
Acknowledgment
We would like to thank Dr. George De Lucca for
fruitful discussions and Dr. Joel Barrish for his support
and encouragement.
The synthesis of the 4,7-disubstituted carbazole-1-
carboxamides is summarized in Scheme 1.
The
commercially available 2-amino-4-bromobenzoic acid
(46) was treated with sodium nitrite in hydrochloric acid
to form the diazonium intermediate, which was then
reduced with tin (II) chloride to the hydrazine 47.25 The
tetrahydrocarbazole acid 48 was prepared in good yield
by Fischer indole synthesis26 from 47 and ethyl 3-
oxocyclohexanecarboxylate in boiling acetic acid. The
carboxylic acid of 48 was converted to the primary
amide, and the tricyclic core was aromatized by
treatment with DDQ to give the bromocarbazole-1-
carboxamide ester. Saponification provided the
carboxylic acid 49, which was coupled with N-methyl
piperazine in the presence of EDC and HOBT to
provide the corresponding amide. Suzuki coupling27,28
then gave the final products 50. The isomeric 4,6-, 3,6-
and 3,7-disubstituted compounds were prepared
analogously.
References and notes:
1. Rokosz, L. L.; Beasley, J. R.; Carroll, C. D.; Lin, T.;
Zhao, J.; Appell, K. C.; Webb, M. L. Expert Opin.
Ther. Targets 2008, 12, 883.
2. Kurosaki, T.; Hikida, M. Immunological Reviews
2009, 228, 132.
3. Lindvall, J. M.; Blomberg, K. E. M.; Väliaho, J.;
Vargar, L.; Heinonen, J. E.; Berglöf, A.; Mohamed, A.
J.; Nore, B. F.; Vihinen, M. Immunological Reviews
2005, 203, 200.
4. Kurosaki, T. Annu Rev. Immunol. 1999, 17, 555.
5. Satterthwaite, A. B.; Witte, O. N. Immunological
Reviews 2000, 175, 120.
6. Mease, P. J. J. Rheumatology 2008, 35, 1245.
7. Venetz, J.; Pascual, M. Expert Opin. Invest. Drugs
2007, 16, 625.
8. Hauser, S. L.; Waubaut, E.; Arnold, D. L.; Vollmer,

T.; Antel, J.; Fox, R. F.; Bar-Or, A.; Panzara, M.;
Sarkar, N.; Agarwal, S.; Langer-Gould, A.; Smisth, C.
H. N. Engl. J. Med. 2008, 358, 676.
Sweeney, Z. K.; Soth, M.; McIntosh, J.; Litman, R.;
Suh, J.; Kocer, B.; Davis, D.; Park, J.; Frauchiger, S.;
Dewdney, N.; Zecic, H.; Taygerly, J. P.; Sarma, K.;
Hong, J.; Hill, R. J.; Gabriel, T.; Goldstein, D. M.;
Owens, T. D. J. Med. Chem. 2015, 58, 512.
9. Tamimoto, Y.; Horiuchi, T.; Tsukamoto, H.; Otsuka,
J.; Mitoma, H., Kimoto, Y.; Nakashima, H.; Muta, K.;
Abe, Y.; Kiyohara, C.; Ueda, A.; Nagasawa, K.;
Yoshizawa, S.; Shimoda, T.; Harada, M.
Rheumatology 2008, 47, 821.
24. Zimmermann, K.; Sang, X.; Mastalerz, H. A.;
Johnson, W. L.; Zhang, G.; Liu, Q.; Batt D. G.;
Lombardo. L. J.; Vyas, D.; Trainor, G. L.; Tokarski, J.
S.; Lorenzi, M. V.; You, D.; Gottardis, M. M.; Lippy,
J.; Khan, J.; Sack, J. S.; Purandare, A. V. Bioorg.
Med. Chem. Letters 2015, 25, 2809.
25. Street, L. J.; Baker, R.; Castro, J. L.; Chambers, M. S.;
Guiblin, A. R.; Hobbs, S. C.; Matassa, V. G.; Reeve,
A. J.; Beer, M. S.; Middlemiss, D. N.; Noble, A. J.;
Stanton, J. A.; Scholey, K.; Hargreaves, R. J. J. Med.
Chem. 1993, 36, 1529.
10. De Lucca, G. V.; Shi, Q.; Liu, C.; Duan, J.; Tebben,
A. J. US Patent 8,586,751, 2013.
11. De Lucca, G. V.; Shi, Q.; Liu, C.; Tebben, A.; Strnad,
J.; Surti, N.; Muckelbauer, J. K.; McIntyre, K.; Burke,
I. R.; Leftheris, K. Abstracts of Papers, 242nd National
Meeting & Exposition of American Chemical Society,
Denver, CO, United States, Aug 28-Sept.1, 2011,
MEDI-317.
12. The crystal structure of BTK in complex with (R)-6-
(3-(4-tert-butylbenzamido)-piperidin-1-yl)-2-(4-
(morpholine-4-carbonyl)phenylamino)nicotinamide
has been deposited into RCSB (PDB ID 5BPY).
13. Liu, Q.; Batt, D. G.; De Lucca, G. V.; Shi, Q.; Tebben,
A. J. US Patent, 8,084,620, 2011.
14. IC50 values were determined in a human recombinant
BTK enzyme assay, as described in reference 13.
15. IC50 values were determined in a JAK2 enzyme assay,
as described in Purandare, A. V.; Batt, D. G.; Liu, Q.;
Johnson, W. L.; Mastalerz, H.; Zhang, G.;
26. Kamata, J.; Okada, T.; Kotake, Y.; Niijima, J.;
Nakamura, K.; Uenaka, T.; Yamaguchi, A.;
Tsukahara, K.; Nagasu, T.; Koyanagi, N.; Kitoh, K.;
Yoshimatsu, K.; Yoshino, H.; Sugumi, H. Chem.
Pharm. Bull. 2004, 52, 1071.
27. Anderson, H. S.; Olsen, O. H.; Iverson, L. F.;
Sorensen, A. L. P.; Mortensen, S. B.; Christensen, M.
S.; Branner, S.; Hansen, T. K.; Lau, J. F.; Jeppesen,
L.; Moran, E. J.; Su, J.; Bakir, F.; Judge, L.; Shahbaz,
M.; Collins, T.; Vo, T.; Newman, M. J.; Ripka, W. C.;
Moller, P. H. J. Med. Chem. 2002, 45, 4443.
Zimmermann,
K.
PCT
patent
application
28. Occhiato, E. G.; Trabocchi, A.; Guarna, A. J. Org.
WO2010/080474.
Chem. 2001, 66, 2459.
16. Uddin, S.; Hussain, A. R.; Al-Kuraya, K. S. Curr.
Enzyme Inhib. 2006, 2, 163.
17. Levine, R. L.; Pardanani, A.; Tefferi, A.; Gilliland, D.
G. Nat. Rev. Cancer, 2007, 7, 673.
18. Kumar, C. ; Purandare, A. V.; Lee, F. Y.; Lorenzi, M.
V. Oncogene 2009, 28, 2305.
19. Mesa, R. A.; Tefferi, A. Expert Opin. Emerging Drugs
2009, 14, 1.
20. The crystal structure of BTK in complex with
Compound 13 was determined by Proteros. The
structure has been deposited into RCSB (PDB ID
5BQ0).
21. Di Paolo, J. A.; Huang, T.; Balazs, M.; Barbosa, J.;
Barck, K. H.; Bravo, B. J.; Carano, R. A. D.; Darrow,
J.; Davies, D. R.; DeForge, L. E.; Diehl, L.; Ferrando,
R.; Gallion, S. L.; Giannetti, A. M.; Gribling, P.;
Hurez, V.; Hymowitz, S. G.; Jones, R.; Kropf, J. E.;
Lee, W. P.; Maciejewski, P. M.; Mitchell, S. A.; Rong,
H.; Staker, B. L.; Whitney, J. A.; Yeh, S.; Young, W.
B.; Yu, C.; Zhang, J.; Reif, K.; Currie, K. S. Nature
Chem. Biol. 2011, 7, 41.
22. Young, W. B.; Barbosa, J.; Blomgren, P.; Bremer, M.
C.; Crawford, J. J.; Dambach, D.; Gallion, S.;
Hymowitz, S. G.; Kropf, J. E.; Lee, S. H.; Liu, L.;
Lubach, J. W.; Macaluso, J.; Maciejewski, P.; Maurer,
B.; Mitchell, S. A.; Ortwine, D. F.; Di Paolo, J.; Reif,
K.; Scheerens, H.; Schmitt, A.; Sowell, C. G.; Wang,
X.; Wong, H.; Xiong, J.; Xu, J.; Zhao, Z.; Currie, K.
S. Bioorg. Med. Chem. Letters 2015, 25, 1333.
23. Lou, Y.; Han, X.; Kuglstatter, A.; Kondru, R. K.;

Graphical abstract