Design, synthesis, and anti-inflammatory properties of orally active 4-(phenylamino)-pyrrolo[2,1-f][1,2,4]triazine p38α mitogen-activated protein kinase inhibitors

Article abstract of DOI:10.1021/jm7009414

A novel structural class of p38 mitogen-activated protein (MAP) kinase inhibitors consisting of substituted 4-(phenylamino)-pyrrolo[2,1-f][1,2,4] triazines has been discovered. An initial subdeck screen revealed that the oxindole-pyrrolo[2,1-f][1,2,4]tria

Full text of DOI:10.1021/jm7009414

4
J. Med. Chem. 2008, 51, 4–16
Articles
Design, Synthesis, and Anti-inflammatory Properties of Orally Active
4-(Phenylamino)-pyrrolo[2,1-f][1,2,4]triazine p38r Mitogen-Activated Protein Kinase Inhibitors
John Hynes, Jr.,*,† Alaric J. Dyckman,† Shuqun Lin,† Stephen T. Wrobleski,† Hong Wu,† Kathleen M. Gillooly,‡
Steven B. Kanner,‡ Herinder Lonial,‡ Derek Loo,‡ Kim W. McIntyre,‡ Sidney Pitt,‡ Ding Ren Shen,‡ David J. Shuster,‡
XiaoXia Yang,‡ Rosemary Zhang,‡ Kamelia Behnia,§ Hongjian Zhang,§ Punit H. Marathe,§ Arthur M. Doweyko,
John S. Tokarski, John S. Sack, Matthew Pokross, Susan E. Kiefer, John A. Newitt, Joel C. Barrish,† John Dodd,†
Gary L. Schieven,‡ and Katerina Leftheris†
Departments of Immunology Chemistry, Immunology Biology, Metabolism and Pharmacokinetics, and Molecular Biosciences, Bristol-Myers
Squibb Pharmaceutical Research Institute, P.O. Box 4000, Princeton, New Jersey 08543-4000
ReceiVed July 31, 2007
A novel structural class of p38 mitogen-activated protein (MAP) kinase inhibitors consisting of substituted
4-(phenylamino)-pyrrolo[2,1-f][1,2,4]triazines has been discovered. An initial subdeck screen revealed that
the oxindole-pyrrolo[2,1-f][1,2,4]triazine lead 2a displayed potent enzyme inhibition (IC50 60 nM) and was
active in a cell-based TNFR biosynthesis inhibition assay (IC50 210 nM). Replacement of the C4 oxindole
with 2-methyl-5-N-methoxybenzamide aniline 9 gave a compound with superior p38 kinase inhibition (IC50
10 nM) and moderately improved functional inhibition in THP-1 cells. Further replacement of the C6 ester
of the pyrrolo[2,1-f][1,2,4]triazine with amides afforded compounds with increased potency, excellent oral
bioavailability, and robust efficacy in a murine model of acute inflammation (murine LPS-TNFR). In rodent
disease models of chronic inflammation, multiple compounds demonstrated significant inhibition of disease
progression leading to the advancement of 2 compounds 11b and 11j into further preclinical and toxicological
studies.
Introduction
The cytokines TNFR and IL-1ꢀ are two of the predominant
pro-inflammatory mediators associated with systemic inflam-
matory diseases such as rheumatoid arthritis (RA).1 The use of
protein therapeutics which target these cytokines is now the
standard of care for the treatment of RA.2 Extension of these
therapies into additional indications, such as psoriasis and
Crohn’s disease, has increased the utility of the biologic
approach to inflammatory disease management. However, the
limitations of protein based therapies has stimulated significant
research aimed at providing small molecule, orally bioavailable,
anti-TNFR and anti-IL-1ꢀ agents.
p38 Mitogen-activated protein kinase (MAPK) has emerged
as an attractive target for chemotherapeutic intervention for the
treatment of RA and other inflammatory disorders.3 Activation
Figure 1. Examples of p38 MAPK inhibitors that have reached in-
of p38, a serine threonine kinase consisting of 4 isoforms (R,ꢀ,γ,
and δ), leads to the up-regulation of both TNFR and IL-1ꢀ.4
Additionally, small molecule p38 blockade in humans dose-
dependently inhibited exogenously induced TNFR production,
providing validation of the pathway in humans.5 Expression of
the p38 MAPK isoforms varies across cell types of the immune
system, and it is believed that the predominant isoform involved
in inflammation is p38R.6 Currently, there are several p38R
inhibitors undergoing clinical trials for the treatment of RA
(Figure 1).7
human studies.
We previously reported the in vitro and in vivo evaluation
of 1,3,5-triaminotriazines (1, Figure 2) as p38R inhibitors.8
Further screening of a focused deck of internal compounds
revealed the pyrrolo[2,1-f][1,2,4]triazine oxindoles 2a and 2b
as potent inhibitors of p38R with enzyme–inhibitory concentra-
tions (IC50 values) of 60 and 80 nM, respectively. In a whole
cell-based functional assay of lipopolysachharide (LPS) induced
TNFR production, both compounds inhibited TNFR biosynthesis
(2a, IC50 210 nM; 2b, IC50 570 nM).
Substituted phenylaminopyrrolo[2,1-f][1,2,4]triazines have
previously been used as a template for kinase inhibitor design,9
and it was envisioned that analogs containing the 3-methyl-5-
benzamido aniline of 1 coupled to a pyrrolo[2,1-f][1,2,4]triazine
at C4 would provide an alternative class of p38 inhibitors. It is
* To whom correspondence should be addressed. Phone: (609) 252-4431.
Fax: (609) 252-3993. E-mail: john.hynes@bms.com.
†
Department of Immunology Chemistry.
Department of Immunology and Inflammation Biology.
Department of Metabolism and Pharmacokinetics.
‡
§
Department of Molecular Biosciences.
10.1021/jm7009414 CCC: $40.75
2008 American Chemical Society
Published on Web 12/12/2007

Properties of MAP Kinase Inhibitors
Journal of Medicinal Chemistry, 2008, Vol. 51, No. 1 5
Figure 2. Discovery of the pyrrolo[2,1-f][1,2,4]triazine p38 inhibitors.
Figure 3. Proposed binding modes of 3b.
noteworthy that the binding mode of the 1,3,5-triaminotriazine
p38R inhibitors has been established via X-ray crystallography
(Figure 2, compound 1 detail), revealing a hydrogen bond
between Glu71 and the N-alkoxyamide NH (2.4 Å), in addition
to a hydrogen bond between the backbone NH of Asp168 and
the N-methoxyamide carbonyl (2.2 Å). A similar binding mode
for the proposed pyrrolo[2,1-f][1,2,4]triazine p38R inhibitors (3a,
b) can be envisioned; however, the critical Met109 interaction
found in most p38R MAP kinase inhibitors is not obvious.
Assuming that the aniline of 3b binds in an identical pocket as
1, two potential Met109 backbone hydrogen bond acceptors can
be proposed: the C6 pendant carbonyl oxygen (A, Figure 3) or
the pyrrolo[2,1-f][1,2,4]triazine core N1 (B, Figure 3). Molecular
modeling suggested that both potential binding modes could
be accessed with this class of inhibitors.
6 in refluxing formamide afforded the 3,4-dihydropyrrolo[2,1-
f][1,2,4]triazine-4-one 7, which was reacted with POCl3 to give
4-chloropyrrolo[2,1-f][1,2,4]triazine 8. Coupling with aniline 9
furnished 3g, which was hydrolyzed to the corresponding acid
10 and converted to the amide analogs 11a–l via standard amide
bond forming conditions.
A small library of C6-aminopyrrolo[2,1-f][1,2,4]triazines was
also prepared from acid 10 as outlined in Scheme 2. Reaction
of 10 with diphenyl phosphoryl azide (DPPA) furnished the
intermediate acyl azide, which was subjected to direct Curtius
rearrangement in the presence of various alcohols to furnish
the carbamate analogs 17a–d. The para-methoxybenzyl car-
bamate 17d was reacted with TFA to furnish the C6 amino
analog 14. Further reaction with acid anhydrides or ethyl
isocyanate gave the reversed amides 15a–c and urea 16.
Compounds 3a and 3b were synthesized to test our initial
hypothesis and were shown to inhibit p38R kinase with IC50
values of 220 and 1.1 nM, respectively. The more potent 3b
blocked LPS induced TNFR production with an IC50 of 160
nM, similar to the potency observed with the oxindole 2a. When
dosed orally in BALB/c mice at 30 mg/kg, 3b failed to inhibit
serum TNFR production following i.p. LPS administration (data
not shown). The C6 ester was presumed to be a liability for in
vivo efficacy, as predicted by the high rate of in vitro
metabolism,10 and efforts to stabilize this region of the molecule
along with structure-activity relationship (SAR) studies aimed
at increasing functional activity and oral efficacy were initiated.
The synthesis of a related series, in which the C5′ carboxa-
mide is converted to a carbamate, is outlined in Scheme 3.
Reaction of chloride 8 with 3-nitro-6-methyl aniline gave 18,
which was hydrolyzed and coupled with n-propylamine to
furnish 19. Compound 19 was reduced to the C5′ amine 20
and reacted with chloroformates or acid chlorides to give
compounds 21a–f. Alternatively, reaction of 4-chloropyrrolot-
riazine 12 and ethyl 3-amino-4-methylphenylcarbamate 22
furnished the methyl ester 23. Subsequent hydrolysis afforded
24, which was reacted with various amines to provide the
analogs 22g–i.
In Vitro Pharmacology and SAR. Subsequent to the
discovery of 3b, the synthesized pyrrolo[2,1-f][1,2,4]triazine
analogs were screened and optimized for inhibition of human
p38R MAP kinase. Compounds with significant enzyme inhibi-
tion (IC50 < 50 nM) were then evaluated in a cell-based
functional assay, where the inhibition of LPS induced TNFR
biosynthesis in human peripheral blood mononuclear cells
(PBMCs) was determined.
The original C4 phenylaminopyrrolo[2,1-f][1,2,4]triazine
analogs, 3a and 3b, provided the framework for establishing a
more potent and orally efficacious series. Table 1 summarizes
the C5′ SAR at the outset of our effort. Generation of the
primary amide 3c resulted in an 80-fold decrease in p38R
Results and Discussion
Chemistry. Pyrrolo[2,1-f][1,2,4]triazine derivatives 3a–f, h,
and i were prepared using methods and materials previously
described, as shown in Scheme 1.11 Briefly, the 4-chloro-
pyrrolo[2,1-f][1,2,4]triazines 4, 12, 13a, and 13b were reacted
with various anilines to afford the C4 phenylaminopyrrolo[2,1-
f][1,2,4]triazines (eq a and b). Additional analogs addressing
the SAR at C6 were synthesized as outlined in Scheme 1.
Amino-pyrrole 6 was synthesized via the electrophilic N-
amination of pyrrole 5 with either O-(2,4-dinitrophenyl)hy-
droxylamine (DnpONH2) or monochloramine.12 Cyclization of

6
Journal of Medicinal Chemistry, 2008, Vol. 51, No. 1
Hynes et al.
Scheme 1a
a Reagents and conditions: (a) DnpONH2 or NH2Cl, NaH, DMF, 85%; (b) formamide, 165 °C, 89%; (c) POCl3, 110 °C, 3 h, 94%; (d) DMF, DIPEA,
55 °C, 12-18 h; (e) 1 N NaOH, THF, 55 °C; (f) R-NH2 or R-NH3Cl, EDC, HOBt, DMF, DIPEA, rt.
Scheme 2a
a Reagents and conditions: (a) (i) DPPA, TEA, dioxane, 60 °C (ii) ROH, 80 °C; (b) TFA, CH2Cl2, 93%; (c) (RCO)2O, CH2Cl2, TEA; (d) RsNdCdO,
CH2Cl2, TEA.
inhibition relative to 3b and only a slight increase relative to
methyl amide 3a. The C5′ ethyl amide 3d had minimal p38R
inhibition whereas the N-ethoxyamide 3e was slightly less potent
than 3b in both enzyme and cell-based assays.
While fixing the C5′ substituent as the N-methoxy amide,
SAR studies were initiated at C5 and C6 of the pyrrolo[2,1-
f][1,2,4]triazine core. As shown in Table 2, removal of the C5
methyl group (3f) resulted in a 40-fold decrease in enzyme
inhibition with a corresponding loss of functional activity
relative to 3b. Interestingly, the C6 ethyl ester 3g was equipotent
to 3b in the enzyme inhibition assay and ∼4.5-fold more potent
in the LPS-TNFR cell-based assay. This moderate increase in
cellular potency suggested that larger alkyl groups or more
lipophilic substitution at C6 leads to compounds with improved

Properties of MAP Kinase Inhibitors
Journal of Medicinal Chemistry, 2008, Vol. 51, No. 1 7
Scheme 3a
a Reagents and conditions: (a) 3-nitro-6-methyl aniline, DIPEA, DMF, 55 °C, 86%; (b) (i) 1 N NaOH, THF, MeOH (ii) propyl amine, DMF, EDC, HOBt,
93%; (c) H2, 10% Pd/C, MeOH, 95%; (d) ROC(O)Cl, CH2Cl2, DIPEA; (e) DMF, DIPEA, 55 °C, 81%; (f) 1 N NaOH, THF, MeOH, 65 °C; (g) RNH2 or
RNH3Cl, EDC, HOBt, DMF DIPEA, rt.
Table 1. Effect of the C5′-Substituent on Enzymatic and Cellular
Activity
Table 3. Effect of the C6-Substituent on Enzymatic and Cellular
Activity
IC50 (nM)
IC50 (nM)
cmpd
R
p38Ra
TNFRb
cmpd
R1
p38Ra
TNFRb
3a
3b
3c
3d
3e
Me
-OMe
H
Et
-OEt
220
1.1
>5000
160
>2000
11a
11b
11c
11d
11e
11f
11g
11h
11i
Me
Et
n-Pr
i-Pr
(S)-sec-Bu
-(CH2)2-OMe
cyc-pentyl
23
3.1c
0.9
10
3.0
2.2
8.0
0.4
1.2
2.2
180
8.0
580
61d
30
78
24%c
4.0
41
380
<2.0
140
43.0
9.6
2.4
10
a Compounds were assayed in triplicate unless otherwise noted. Vari-
ability around the mean value was <50%. b n ) 1 determination. c Percent
inhibition at 1 µM (n ) 1).
-CH2-Ph
-CH2-(2-pyr)
(S)-R-Me-benzyl
(R)-R-Me-benzyl
morpholino-ethyl
11j
11k
11l
Table 2. Effect of the C5 and C6 Substituent on Enzymatic and
Cellular Activity
>1000
72
a Compounds were assayed in triplicate unless otherwise noted. Vari-
ability around the mean value was <50%. b Compounds were typically
assayed in duplicate. Assay variability was measured using a standard
control, <60%. c n ) 5 determinations. d n ) 6 determinations.
As stated previously, the lack of in vivo efficacy of 3b was
presumed to be due to the presence of the potentially labile C6
methyl ester and it was anticipated that the ethyl ester 3g would
encounter a similar fate upon oral dosing. Therefore, a series
of C6 amides were prepared. As shown in Table 3, the C6
methyl amide 11a was 20-fold less potent in the p38R enzyme
inhibition assay relative to 3b, whereas the ethyl amide 11b
(IC50 3.1 nM) had increased p38R inhibition.13 Additionally,
11b was a potent inhibitor of LPS-induced TNFR release in
cells (IC50 61 nM). These results parallel the previous observa-
tion that increased lipophilicity at C6 increases cellular potency
(e.g., 3b to 3g). For example, the propyl and (S)-sec-butyl
amides (11c–e) displayed significant p38R enzyme inhibition
(IC50 e 10 nM) and in the LPS-TNFR assay, and 11c and
IC50 (nM)
cmpd
R
R1
p38Ra
TNFRb
3b
3f
3g
3h
3i
Me
H
Me
Et
-OMe
-OMe
-OEt
-OEt
-OEt
1.1
42
160
>2000
37
0.9
61%c
63%c
i-Pr
a Compounds were assayed in triplicate unless otherwise noted. Vari-
ability around the mean value was <50%. b n ) 1 determination. c Percent
inhibition at 1 µM (n ) 1).
cellular potency. Increasing the size of the C5 substituent (3h,
i) resulted in significantly decreased enzyme inhibition.

8
Journal of Medicinal Chemistry, 2008, Vol. 51, No. 1
Hynes et al.
Table 5. Effect of the C5′-Amino Substituent on Enzymatic and
Table 4. Effect of the C6-Amino Substituent on Enzymatic and
Cellular Activity
Cellular Activity
IC50 (nM)
IC50 (nM)
cmpd
R
R1
p38Ra
TNFRb
cmpd
X
p38Ra
TNFRb
21a
21b
21c
21d
21e
21f
21g
21h
21i
n-Pr
-OMe
-OEt
-O-i-Pr
-OPh
15
150
69
15a
15b
15c
16
17a
17b
17c
Me
Et
i-Pr
3.6
13
13
190
530
n-Pr
n-Pr
n-Pr
n-Pr
n-Pr
Et
5.5
680
32%c
20
120
-NH-i-Pr
12
>2000c
100
-CH2OMe
-Me
43
-OMe
3.3
1.5
1.2
230
4.7
7.7
5.6
-OEt
26
110
-OEt
72
110
47
-O-i-Pr
i-Pr
-OEt
a Compounds were assayed in triplicate unless otherwise noted. Vari-
ability around the mean value was <50%. b Compounds were typically
assayed in duplicate. Assay variability was measured using a standard
(S)-sec-Bu
-OEt
a Compounds were assayed in triplicate unless otherwise noted. Vari-
ability around the mean value was <50%. b Compounds were typically
assayed in duplicate. Assay variability was measured using a standard
control, <60%. c Percent inhibition at 1 µM (n ) 1).
control, <60%.
c n ) 1.
11d were nearly equipotent and comparable in activity to 11b.
In the PBMC TNFR assay, 11e was highly potent, (IC50 < 2
nM) and represented the most active compound prepared in this
series. Incorporation of an ether linkage in the C6 amide chain
(11f) was less tolerated in the functional assay, whereas large
alkyl groups (11g), benzyl amides (11h, j, k), and pyridyl amides
(11i) were tolerated in both the biochemical and cellular assays.
Interestingly, the (R)-R-methylbenzamide, 11k, was shown to
be 60-fold less potent in the enzyme inhibition assay and over
200-fold less active in the functional assay relative to the
enantiomeric 11j. The ability of p38R kinase to discriminate
between enantiomeric pairs of small molecule inhibitors has
been well established.14 More importantly, the chiral discrimina-
tion has been associated with the orientation of the chiral group
proximal to the Met109 binding site. It was therefore proposed
that the C4-phenylaminopyrrolo[2,1-f][1,2,4]triazine based p38R
MAP kinase inhibitors were binding to p38R via a hydrogen
bond between the C6 amide carbonyl and the backbone NH of
Met109 (Figure 3, binding mode A). This binding mode would
allow for the positioning of the C6 substituent out to the enzyme
protein surface exposed to the solvent (water) interface. As a
further test of this binding model, C6 substituents containing a
basic, solubilizing group were prepared. As seen with the
morpholino ethyl amide 11l, this substitution allows for
significant p38R enzyme inhibition (IC50 8 nM) and reasonable
functional inhibition in cells (IC50 72 nM).
It was anticipated that reversing the C6 carboxamide to the
C6 aminopyrrolo[2,1-f][1,2,4]triazines would provide additional
analogs containing a Met109 hydrogen bond acceptor. As shown
in Table 4, the C6 reversed amide analogs (15a–c), the urea
(16), and the carbamates (17a–c) provided an additional series
with p38R enzyme inhibition SAR trends similar to those
observed in Table 3. Evaluation of compounds 15a–c in the
LPS-TNFR PBMC assay revealed that cellular potency was
significantly less than the p38R enzyme inhibition. A more
pronounced disconnect between enzyme and functional inhibi-
tion was observed for 16, presumably an indication of poor
cellular permeability. Analogous to the corresponding amide
SAR, the ethyl and isopropyl carbamates 17b and 17c had
excellent enzyme inhibition and acceptable functional activity.
Having identified the C6 amide as an optimal substituent,
C5′ reversed amide anilines were investigated. As shown in
Table 5, small alkoxy groups (R′ ) OMe, OEt) inhibited p38R
kinase with moderate inhibition of LPS induced TNFR in
PBMCs. Larger C5′ substitutions reduced enzyme inhibition
(21c, d). Interestingly, the methoxyacetyl analog 21e had
moderate activity in both the enzyme and PBMC assays,
whereas removal of the chain oxygen (21f) significantly
decreased enzyme inhibition. The smaller C5′ ethyl carbamate
present in 21b was then used to find matched substitutions at
C6. As shown in examples 21g–i, significant potency enhance-
ments relative to 21b were not observed.
Subsequent to the recognition of the C6 amide carbonyl as
the potential Met109 hydrogen bond acceptor, X-ray structures
of 11b and 11j bound to unphosphorylated p38R were obtained
confirming the proposed binding mode in addition to revealing
several key binding interactions (Figure 4). As previously
hypothesized, Glu71 and Asp168 form hydrogen bonds with
the C5′ hydroxamate NH (1.61 Å) and carbonyl (1.77 Å),
respectively, with 11j. Additionally, the Asp168 carboxyl group
forms a bridging hydrogen bond via water with N3 of the
pyrrolo[2,1-f][1,2,4]triazine core and Lys53. As suggested by
the observed SAR, Met109 forms a hydrogen bond (1.6–1.7
Å) with the pendant C6 amide carbonyl oxygen for both 11b
and 11j. Two hydrophobic interactions are also evident from
these structures. The C4 aniline occupies the typical hydrophobic
pocket accessed by most reported p38R kinase inhibitors and
the C6 substituent orients along a hydrophobic surface near the
hinge region of the enzyme. Much of the experimentally
observed SAR can be rationalized from these structures. Larger
C5 substitutions (ethyl, iso-propyl, Table 2, 3g and h) are not
allowed due to disfavored steric interactions along the
His107-Thr106 region surface. Additionally, the broader array
of allowed substitution at C6 is due to the orientation of these
substituents relative to the solvent exposed protein surface.
Kinase Selectivity Profile for Select Analogs. Advanced
compounds (11b–e, j, 21b) were screened against a panel of
kinases (e.g., EMT, LCK, Zap70, IKK-ꢀ2, HER-1/2, PKA/C,
KDR) for potential off target liabilities. The compounds tested
exhibited >2000-fold selectivity for p38R against the various
kinases tested, whereas these compounds were less selective
against p38ꢀ (e.g., 11b p38ꢀ IC50 15 nM). In a broader
selectivity screen encompassing G-protein coupled receptors,
ion channels and various transporters, these compounds did not
demonstrate any off-target interactions when tested at 10 µM
concentrations.

Properties of MAP Kinase Inhibitors
Journal of Medicinal Chemistry, 2008, Vol. 51, No. 1 9
Figure 4. X-ray cocrystal structure of 11b and 11j with p38R.
Table 6. Inhibition of Circulating TNFr in LPS Challenged Mice
entry cmpd dosea (mg/kg) dosing interval (min) percent inhibb
Table 7. Rat Exposure Data Following Oral Administration (10
mg/kg) of Select Compoundsa
plasma level
AUCc
(µM·h)
1
2
3
4
5
6
7
8
9
11b
11j
11b
11c
11d
11e
11i
10
10
2
2
2
2
2
2
2
-30
-30
80 ( 10c
95 ( 6
61 ( 13d
60 ( 23
65 ( 11
50 ( 30
62 ( 23
nae
cmpd
(0.5 h, µM)b
RLMd
HLMe
11b
11c
11d
11e
11i
11j
21b
0.8
6.6
3.8
4.3
3.4
2.1
0.4
0.7
2.1
3.7
9.2
2.8
2.1
0.7
100
82
69
83
-120
-120
-120
-120
-120
-120
-120
96
90
62
72
17b
21b
66 ( 21
a Vehicle: 9/0.5/0.5 water/EtOH/Tween 80. b Average of 2 rats. c AUC0-4h
,
a Using PEG 300 as the vehicle, 6–8 mice per group. b Maximum percent
inhibition relative to vehicle group; >50% inhibition is considered active
in this study. Variability is expressed as ( standard error of the mean (SEM)
for the individual animals in each study unless otherwise noted. c Average
of 8 separate studies. d Average of 10 separate studies. e na ) not active.
average of 2 rats. d Rat liver microsome incubation, percent remaining of
parent drug at 10 min, (n ) 1). e Human liver microsome incubation, percent
remaining of parent drug at 10 min, (n ) 1).
In Vivo Anti-inflammatory Efficacy and Pharma-
cokinetics. A murine model of acute inflammation (LPS induced
serum TNFR production) was used as a primary screen of oral
efficacy for advanced compounds with favorable in vitro
pharmacological profiles (Table 6). A single 10 mg/kg dose of
11b provided an 80% reduction in circulating TNFR (entry 1).
Similarly, 11j provided >90% reduction of TNFR production
(entry 2). In a dose response study, 11b demonstrated an ED50
of 0.3–1 mg/kg when dosed 30 min prior to LPS challenge.
Extending the dosing interval prior to LPS challenge (2 vs 0.5 h),
in addition to reducing the compound dose (2 vs 10 mg/kg)
provided a reasonable (61%, entry 3) reduction in serum TNFR
levels using 11b. Other analogs were then screened under these
conditions. As shown in Table 6, additional C6 amides (entries
4–7) exhibited similar efficacy to 11b. The C6 ethyl carbamate
17b (entry 8) was not efficacious in this model, whereas the
C5′ ethyl carbamate 21b (entry 9) was highly efficacious.
Prior to evaluation in a chronic RA disease model, several
C6 amido pyrrolo[2,1-f][1,2,4]triazine p38R inhibitors were
evaluated in 4 h of oral exposure studies in rats. As shown in
Table 7, moderate to high levels of systemic drug exposure was
observed for compounds of similar (11b, c) and varying
(11d–11j) C6 substitution. A partial explanation for the reduced
exposure at 0.5 h of 11b is the lower intrinsic permeability of
11b relative to other compounds as measured in a Caco-2
permeability assay (20 nm/s for 11b vs 58 nm/s for 11c and
131 nm/s for 11j). The C5′ carbamate 21b had reduced drug
exposure relative to the C6 amide analogs and was not evaluated
further. Incubation of several analogs in rat and human liver
microsomes indicated that low (rat) to moderate (human) levels
of parent drug would be metabolized in the liver.
Figure 5. Efficacy in the rat adjuvant arthritis model (6–8 mice per
group). Terminal paw measurements (mean ( SEM) were as follows:
11b, 0.78 ( 0.15 mL; 11c, 0.85 ( 0.0.15 mL; 11d, 0.83 ( 0.20 mL;
11j, 0.86 ( 0.16 mL; vehicle, 1.5 ( 0.17 mL.
11b, c, d, and j inhibited disease progression equally in this
model and the statistical significance between compounds was
not observed. Compounds 11e and 11i were not efficacious in
this model.
Subsequently, a discrete pharmacokinetic analysis in mice
of 11b, 11c, and 11j was performed in an effort to further
differentiate these advanced compounds and as a precursor to
chronic studies in mice (Table 8). All compounds had good to
excellent oral bioavailability and drug exposure over the time
course of the study. Moderate to high clearance was observed
for all compounds tested.
C6 amido pyrrolo[2,1-f][1,2,4]triazine analogs 11b, 11c, and
11j were then evaluated in the mouse collagen induced arthritis
(mCIA) disease model. As can be seen in Figure 6, 11b provided
significant reduction in the measured outcome of disease
progression relative to the vehicle group when dosed orally at
3 mg/kg, bid (49% reduction). Compound 11c demonstrated
reduced efficacy relative to 11b in the mouse CIA model at an
The rat adjuvant induced arthritis (RAA) disease model was
then incorporated into the compound efficacy evaluation para-
digm. Accordingly, compounds were evaluated at 10 mg/kg,
bid, in this disease model (Figure 5). Interestingly, compounds

10 Journal of Medicinal Chemistry, 2008, Vol. 51, No. 1
Hynes et al.
Table 8. Discrete Pharmacokinetic Properties of Compounds 11b,
11c, and 11j in Micea
F254 (0.25 mm). Compounds were visualized by UV light and/or
stained with either p-anisaldehyde, potassium permanganate, or
cerium molybdate solutions followed by heating. Flash column
chromatography was performed on EM Science silica gel 60
(particle size of 40-63 µm). Analytical high pressure liquid
chromatography (HPLC) and LC-MS analyses were conducted
using Shimadzu LC-10AS pumps and a SPD-10AV UV–vis
detector set at 220 nm with the MS detection performed with a
Micromass Platform LC spectrometer. Analytical HPLC analyses
were performed using one of the following conditions: (column
A) YMC S5 ODS, 4.6 × 50 mm, 4 min gradient, 10% MeOH/
water/0.2% H3PO4 to 90% MeOH/water/0.2% H3PO4, 4 mL/min
flow rate; (column B) Chromalith Speedrod, 4.6 × 50 mm, 4 min
gradient, 10% MeOH/water/0.2% H3PO4 to 90% MeOH/water/0.2%
H3PO4, 4 mL/min flow rate; (column C) YMC S5 ODS, 4.6 × 50
mm, 4 min gradient, 10% MeOH/water/0.1% TFA to 90% MeOH/
water/0.1% TFA, 4 mL/min flow rate; or (column D) Phenomenex
Phenom-Prime, 4.6 × 30 mm, 2 min gradient, 10% MeOH/water/
0.1% TFA to 90% MeOH/water/0.1% TFA, 4 mL/min flow rate.
Preparative reverse phase (RP) HPLC was performed using two
Shimadzu LC-8A pumps, a SPD-10AV UV–vis detector set at 220
nm, and a YMC C18 ODS-A 5 µm, 20 × 100 mm column (eluting
at 20 mL/min with a 12 min gradient of 0–100% B where solvent
A ) 10% MeOH/90% H2O/0.1% TFA and solvent B ) 90%
MeOH/10% H2O/0.1% TFA).
PK parameter
11b
11c
11j
% Fpo
79
3.1 (0.6
0.25
97
34
3.7(1.8
0.5
Cmax (µM)b
Tmax (h)
18 (1.9
0.25
2.5
t1/2 (h)
2.2
1.2
MRT (h)
1.4
1.0
0.8
CL (mL/min/kg)
VSS (L/kg)
AUC0–8h (µM·h)
93
7.6
3.6
28
1.6
13
31
1.5
3.8
a Vehicle: 9/0.5/0.5 water/EtOH/Tween 80; dose 5 mg/kg i.v., 10 mg/
kg p.o.; 3 mice per group. b Average ( SEM.
NMR (1H and 13C) spectra were recorded on one of the following
instruments: JEOL GSX-500 MHz, or Bruker ARX-400 MHz
spectrometers and calibrated using an internal reference. High-
resolution mass spectra (HMRS) were recorded on a JEOL SX102
mass spectrometer. Elemental analyses were performed by Rob-
ertson Microlit Laboratories, and the results obtained are within
(0.4% of the theoretical values.
Figure 6. Efficacy in mouse collagen induced arthritis (6–8 mice per
group). Compounds 11b and 11j achieved statistically significant
reduction in clinical score (p < 0.05, Kruskall-Wallis test) vs vehicle
(PEG300 or Tween80/EtOH/water 90/5/5). Compound 11b was dosed
as the monomethanesulfonic acid salt; 11c was dosed as the mono-
bisulfate salt; 11j was dosed as the monohydrochloride salt. All doses
were adjusted to the free base equivalent. The study is inclusive of
two separate experiments in which the vehicle and dexamethazone
controls were nearly identical.
Methyl 4-(2-methyl-5-(methylcarbamoyl)phenylamino)-5-meth-
ylpyrrolo[2,1-f][1,2,4]triazine-6-carboxylate (3a). Representa-
tive Procedure for the Preparation of an m-Amino-N-substi-
tuted Benzamide Intermediate and Subsequent Coupling To
Methyl 4-Chloro-5-methylpyrrolo[2,1-f][1,2,4]triazine-6-car-
boxylate. To a solution of 3-nitro-4-methyl benzoyl chloride (19.9
g, 100 mmol) in CH2Cl2 (115 mL) at 0 °C was added methylamine
(100 mmol, 100 mL, 2 M in THF), and the reaction mixture was
allowed to warm to room temperature. Stirring was continued for
1 h, and then, a second aliquot of methylamine was added (20 mL,
20 mmol) and the reaction mixture was allowed to stir overnight.
The volatile solvents were removed on a rotovap, and the residue
was suspended in ethanol (100 mL) and treated with NaOH (0.1
N, 200 mL) to quench the remaining acid halide. The reaction
mixture was neutralized with 1 N HCl, and the volatile solvents
were removed on a rotovap. Additional water (200 mL) was added,
and the resulting solids were stirred rapidly for 2 h and then filtered
and rinsed with water to give methyl 3-nitro-4-methyl benzamide
(17.2 g, 89% yield).
equivalent dose (3 mg/kg, 29% reduction) which was not
statistically significant relative to the vehicle control. Compound
11j provided 54% reduction in the measured clinical score albeit
at 30 mg/kg, bid.
Conclusions
A focused screening effort identified the oxindole-pyrrolo[2,1-
f][1,2,4]triazines (2a, b) as novel p38 MAPK inhibitors.
Replacement of the C4 oxindole with a substituted aniline
yielded potent p38R inhibitors. The C5′ alkoxy amide substitu-
tion was found to be important for achieving significant enzyme
inhibition and whole cell functional activity. SAR studies at
C6swhich included a survey of amide-, reversed amide-, urea-,
and carbamate-linked pyrrolo[2,1-f][1,2,4]triazinessled to com-
pounds with oral efficacy in multiple rodent models of inflam-
mation. The combined in vitro pharmacology, in vivo efficacy,
and suitable pharmacokinetics of 11b and 11j resulted in the
selection of both compounds for advanced preclinical studies
in higher species. As will be described separately,15 the results
of these studies prompted the nomination of amide 11b as a
candidate for clinical development.
To a solution of methyl 3-nitro-4-methyl benzamide (6.0 g, 30.9
mmol) in EtOH (150 mL) was added 10% Pd-C (380 mg, wet),
and the reaction placed under a H2 atmosphere (43 psi) on a Parr
shaker for 3 h. The reaction solution was filtered through celite.
This step was repeated on an additional 6 g, and the filtrates were
combined and concentrated in vacuo. EtOH (150 mL) was added
to slurry the solids, and concentrated HCl (5.4 mL, 65 mmol) was
added dropwise; the slurry was then stirred overnight. The slurry
was then cooled to ∼5 °C, and the solids were collected by filtration
to give methyl 3-amino-4-methyl benzamide hydrochloride (9.52
1
g, 77% yield). H NMR (400 MHz, DMSO-d6) δ 9.89 (br s, 2H),
8.40 (s, 1H), 7.68 (s, 1H), 7.55 (d, J ) 7.7 Hz, 1H), 7.23 (d, J )
7.8 Hz, 1H), 2.64 (d, J) 4.4 Hz, 3H), 2.25 (s, 3H); Anal. RP-
HPLC tR ) 0.23 min (column A, purity 99.5%); MS (ESI) m/z
165.10 (M + H)+.
Experimental Section
Chemistry. All nonaqueous reactions were carried out under an
argon or nitrogen atmosphere at room temperature, unless otherwise
noted. All commercial reagents and anhydrous solvents were
purchased from Aldrich and were used without further purification
or distillation, unless otherwise stated. Analytical thin layer
chromatography (tlc) was performed on EM Science silica gel 60
To a solution of methyl 4-chloro-5-methylpyrrolo[2,1-f][1,2,4]
triazine-6-carboxylate 12 (13.4 mg, 0.059 mmol) in DMF (0.25
mL) was added methyl 3-amino-4-methyl benzamide (9.8 mg, 0.59
mmol), and the reaction mixture stirred at room temperature for
18 h. The solution was filtered, and the filtrate was dissolved in

Properties of MAP Kinase Inhibitors
Journal of Medicinal Chemistry, 2008, Vol. 51, No. 1 11
MeOH and purified by preparative HPLC to afford 3a (10.3 mg,
37% yield, TFA salt) as a white solid. 1H NMR (400 MHz, CD3OD)
δ 8.05 (s, 1H), 7.95 (s, 1H), 7.72 (s, 2H), 7.45 (m, 1H), 3.89 (s,
3H), 2.92 (s, 6H), 2.36 (s, 3H); Anal. RP-HPLC tR ) 3.17 min
(column A, purity 99.4%); HRMS for C18H19N5O3, (M + H)+ calcd
354.1566, found 354.1572.
N-Methoxy-3-amino-4-methyl benzamide hydrochloride (9). A
mixture of commercially available 3-amino-4-methylbenzoic acid
(100 g, 0.66 mol) and N-(tert-butoxycarbonyl)anhydride (150 g,
0.68 mol) in THF (1000 mL) was slowly heated to 50 °C overnight.
The resulting mixture was cooled to rt, and the solvent was removed
on a rotary evaporator. The resulting solids were triturated with
hexanes and dried in vacuo to afford 151 g (91%) of the crude
BOC-protected aniline as a light pink solid.
To the above solid was added EDC (127 g, 0.66 mol), HOBt
(90 g, 0.66 mol), and DMF (1000 mL), and the resulting mixture
was stirred at rt for 30 min followed by addition of methoxyamine
hydrochloride (55 g, 0.66 mol). After stirring for 10 min, the mixture
was cooled using an ice bath. DIPEA (250 mL, 1.4 mol) was added
at such a rate so as to maintain the internal reaction temperature
below 25 °C. After the addition was complete, the ice bath was
removed and the reaction was stirred overnight at rt. The reaction
mixture was partitioned between 0.5 L of water and 1.5 L of EtOAc,
and the resulting layers were separated. The aqueous portion was
extracted with additional EtOAc (3 × 400 mL), and the combined
organic extracts were washed with water (3 × 300 mL), cold 0.5
N aqueous HCl (2 × 400 mL), and water (500 mL). The product
was then extracted with cold 0.5 N aqueous NaOH (3 × 300 mL),
and the combined basic aqueous extracts were neutralized to pH
) 8 by a slow addition of cold 0.5 N aqueous HCl. The resulting
solid which precipitated was collected by filtration and washed with
cold water. The wet solid was decolorized in hot EtOH with
activated charcoal to give 106 g of white solid as the BOC-protected
N-methoxyamide intermediate.
To a slurry of the above solid (91 g, 0.32 mol) in 1,4-dioxane
(400 mL) at rt was added a 4 M solution of HCl in dioxane (400
mL), and the resulting mixture was stirred at rt overnight. Diethyl
ether (1000 mL) was added, and the precipitated solid was collected
by filtration and triturated with a hot EtOH/H2O mixture (4:1 v/v).
Drying the resulting solid in vacuo afforded N-methoxy-3-amino-
4-methyl benzamide hydrochloride 9 (53 g, 76% yield) as a white
solid. 1H NMR (400 MHz, DMSO-d6) δ 11.77 (br s, 1H), 9.00 (br
s, 2H), 7.59 (s, 1H), 7.41 (br d, 1H), 7.30 (br d, 1H), 3.70 (s, 3H),
2.31 (s, 3H); Anal. RP-HPLC tR ) 0.36 min (column A, purity
99.5%).
Methyl4-(2-methyl-5-(ethoxycarbamoyl)phenylamino)-5-meth-
ylpyrrolo[2,1-f][1,2,4]triazine-6-carboxylate (3e). This compound
was prepared according to the procedure outlined as in 3a from
N-ethoxy-3-amino-4-methylbenzamide. 1H NMR (400 MHz,
CD3OD) δ 7.92 (s, 1H), 7.80 (s, 1H), 7.62 (s, 1H), 7.55 (d, J )
7.6 Hz, 1H), 7.35 (d, J ) 8.0 Hz, 1H), 3.91 (t, J ) 7.1 Hz, 2H),
3.76 (s, 3H), 2.80 (s, 3H), 2.24 (s, 3H), 1.21 (t, J ) 7.0 Hz, 3H);
Anal. RP-HPLC tR ) 3.30 min (column A, purity 97.2%, 254 nm);
HRMS for C19H21N5O4, (M + H)+ calcd 384.1672, found 384.1675.
Methyl 4-(2-methyl-5-(methoxycarbamoyl)phenylamino)pyr-
rolo[2,1-f][1,2,4]triazine-6-carboxylate (3f). This compound was
prepared using the general coupling procedure using 9 and methyl
4-chloro-pyrrolo[2,1-f][1,2,4]triazine-6-carboxylate 4.17 1H NMR
(400 MHz, CD3OD) δ 7.98 (d, J ) 1.4 Hz, 1H), 7.73 (s, 1H), 7.68
(s, 1H), 7.57 (d, J ) 8.0 Hz, 1H), 7.35 (d, J ) 8.0 Hz, 1H), 7.28
(m, 1H), 3.79 (s, 3H), 3.70 (s, 3H), 2.23 (s, 3H); Anal. RP-HPLC
tR ) 2.97 min (column A, purity 95.0%); HRMS for C17H17N5O4,
(M + H)+ calcd 356.1359, found 356.1375.
Ethyl 4-oxo-5-methyl-1,4-dihydropyrrolo[2,1-f][1,2,4]triazine-
6-carboxylate (7). A solution of the amino pyrrole 6 (51.0 g, 212
mmol) in formamide (400 mL) was heated at 120 °C for 20 h. The
reaction mixture was cooled and then poured into a rapidly stirring
solution of ice-water (2 L) to precipitate the product. The solids
were collected by filtration and washed with water (2 × 50 mL)
and ether (150 mL) to furnish 7 (41.6 g, 89% yield) as a tan solid.
1H NMR (400 MHz, DMSO-d6) δ 11.64 (s, 1H), 7.89 (s, 1H), 7.85
(s, 1H), 4.24 (q, J ) 7.1 Hz, 2H), 2.61 (s, 3H), 1.30 (t, J ) 7.1 Hz,
3H); 13C NMR (100 MHz) δ 163.8, 155.5, 140.4, 123.7, 123.2,
118.1, 114.4, 60.0, 14.6, 11.4; Anal. RP-HPLC tR ) 3.19 min
(column A, purity 99%); HRMS for C10H11N3O3, (M + H)+ calcd
222.0879, found 222.0876.
Ethyl 4-chloro-5-methylpyrrolo[2,1-f][1,2,4]triazine-6-car-
boxylate (8). A solution of 7 (41.8 g, 189 mmol) in POCl3 (400
mL) was heated at 100 °C for 20 h. The reaction mixture was
cooled, diluted with dichloromethane (200 mL), poured into ice-
cold sat. aqueous NaHCO3-dichloromethane (1500-500 mL), and
stirred rapidly to ensure quenching of the excess POCl3. The
solution was filtered through celite, the layers were separated, and
the aqueous layer was extracted with dichloromethane (500 mL).
The organic extracts were combined, washed with brine, dried over
Na2SO4, filtered, and concentrated in vacuo to afford 8 (42.4 g,
94% yield) as a tan yellow solid which was used without further
purification.
Ethyl 4-(2-methyl-5-(methoxycarbamoyl)phenylamino)-5-
methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxylate (3g). To a solu-
tion of 9 (41.2 g, 190 mmol) in DMF (230 mL) was added DIPEA
(33.1 mL, 180.7 mmol, 0.95 equiv), and the reaction vessel was
heated to 55 °C. Solid ethyl 4-chloro-5-methylpyrrolo[2,1-
f][1,2,4]triazine-6-carboxylate (8) (45.6 g, 190 mmol) was added
in several portions over 10 min, and the flask was rinsed with DMF
(150 mL) and added to the reaction. The reaction was heated for
10 h at 55 °C and cooled to rt. The mixture was then poured into
1.5 L water diluted to 2.2 L with ice slowly over 10 min. The pH
was adjusted to 6, and the solids were stirred for 1 h. The solids
were filtered, washed with water (2 × 200 mL), and dried on the
filter to give 71.9 g of the crude ester. The solid was then suspended
in MeCN (450 mL) and heated with stirring (rotovap) at 50 °C for
1 h. The mixture was cooled and filtered to give 64.2 g product
(>99% purity). These solids were then dissolved in hot ethanol
(2.8 L), and decolorizing carbon was added (6.4 g) and heated at
reflux for 15 min. The mixture was then filtered through a pad of
celite, and the reaction flask was rinsed with hot ethanol (1 L).
The solution was then concentrated to ∼1 L of ethanol by
distillation upon which the product started to crystallize out of
solution at a volume of 2.5 L. The solution was cooled and placed
in a cold room with stirring for 40 h. The solids were filtered and
rinsed with 1/1 EtOH/Et2O (500 mL) to give 3g (58.5 g, 80% yield)
Methyl 4-(2-methyl-5-(methoxycarbamoyl)phenylamino)-5-
methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxylate (3b). This com-
pound was prepared according to the procedure outlined as in 3a
from N-methoxy-3-amino-4-methyl benzamide hydrochloride 9. 1H
NMR (400 MHz, CD3OD) δ 8.06 (s, 1H), 7.82 (s, 1H), 7.68 (m,
2H), 7.45 (m, 1H), 3.89 (s, 3H), 3.83 (s, 3H), 2.91 (s, 6H), 2.35 (s,
3H); Anal. RP-HPLC tR ) 3.20 min (column A, purity 98.7%);
HRMS for C18H19N5O4, (M + H)+ calcd 370.1515, found 370.1510.
Methyl 4-(2-methyl-5-carbamoyl-phenylamino)-5-methylpyr-
rolo[2,1-f][1,2,4]triazine-6-carboxylate (3c). This compound was
prepared according to the procedure outlined as in 3a from
commercially available 3-amino-4-methylbenzamide. 1H NMR (500
MHz, CD3OD) δ 7.90 (br s, 1H), 7.71 (m, 2H), 7.42 (m, 2H), 3.86
(s, 3H), 2.87 (s, 3H), 2.31 (s, 3H); Anal. RP-HPLC tR ) 3.06 min
(column A, purity 97.4%); HRMS for C17H17N5O3, (M + H)+ calcd
340.1410, found 340.1405.
Methyl 4-(2-methyl-5-(ethylcarbamoyl)phenylamino)-5-meth-
ylpyrrolo[2,1-f][1,2,4]triazine-6-carboxylate (3d). This compound
was prepared according to the procedure outlined as in 3a starting
with ethyl 3-amino-4-methylbenzamide.16 1H NMR (500 MHz,
CDCl3) δ 8.16 (br s, 1H), 7.92 (s, 1H), 7.83 (br s, 1H), 7.47 (d, J
) 7.5 Hz, 1H), 7.23 (d, J ) 7.7 Hz, 1H), 3.81 (s, 3H), 3.40 (dq, J
) 7.1 Hz, 2H), 2.87 (s, 3H), 2.30 (s, 3H), 1.18 (m, 3H); Anal.
RP-HPLC tR ) 3.31 min (column A, purity 98.1%); HRMS for
C19H21N5O3, (M + H)+ calcd 368.1723, found 368.1725.
1
as a white solid. H NMR (400 MHz, CDCl3, rotameric) δ 9.55
(br s, 1H), 8.09 (br s, 1H), 7.93 (s, 2H), 7.82 (s, 1H), 7.44 (m,
1H), 7.22 (m, 1H), 4.28 (q, J ) 7.1 Hz, 2H), 3.79 (s, 3H), 2.88 (s,
3H), 2.29 (s, 3H), 1.33 (t, J ) 7.1 Hz, 3H); Anal. RP-HPLC tR )

12 Journal of Medicinal Chemistry, 2008, Vol. 51, No. 1
Hynes et al.
3.51 min (column A, purity 96.1%); HRMS for C19H21N5O4, (M
+ H)+ calcd 384.1671, found 384.1672; Anal. calcd C, 59.52; H,
5.52; N, 18.26; found C, 59.44; H, 5.61; N, 18.19.
) 6.9 Hz, 1H), 7.45 (d, J ) 7.5 Hz, 1H), 3.83 (s, 3H), 3.41 (q, J
) 7.2 Hz, 2H), 2.86 (s, 3H), 2.36 (s, 3H), 1.25 (t, J ) 7.2 Hz, 3H);
Anal. RP-HPLC tR ) 2.57 min (column A, purity 99.2%); HRMS
for C19H22N3O6, (M + H)+ calcd 383.1832, found 383.1829; Anal.
Calcd C, 59.67; H, 5.79; N, 21.97; found: C, 59.42; H, 5.83; N,
22.00.
N-n-Propyl-4-(2-methyl-5-(methoxycarbamoyl)phenylamino)-
5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxamide (11c). 1H
NMR (400 MHz, CD3OD) δ 8.18 (s, 1H), 7.78 (m, 3H), 7.54 (d,
J ) 6.6 Hz, 1H), 3.72 (s, 3H), 3.24 (m, 2H), 2.82 (s, 3H), 2.33 (s,
3H), 1.57 (m, 2H), 0.90 (t, J ) 7.3 Hz, 3H); Anal. RP-HPLC tR )
2.88 min (column A, purity 95.2%); HRMS for C20H24N6O3, (M
+ H)+ calcd 397.1988, found 397.1995.
Ethyl 4-(2-methyl-5-(methoxycarbamoyl)phenylamino)-5-eth-
ylpyrrolo[2,1-f][1,2,4]triazine-6-carboxylate (3h). This compound
was prepared using the general coupling procedure from 9 and ethyl
4-chloro-5-ethylpyrrolo[2,1-f][1,2,4]triazine-6-carboxylate 13a.17 1
H
NMR (400 MHz, CDCl3) δ 9.20 (s, 1H), 8.34 (s, 1H), 8.03 (s,
1H), 7.93 (s, 1H), 7.54 (d, J ) 7.1 Hz, 1H), 7.33 (d, J ) 7.8 Hz,
1H), 7.20 (s, 1H), 4.36 (q, J ) 7.1 Hz, 2H), 3.89 (s, 3H), 3.32 (q,
J ) 7.7 Hz, 2H), 2.93 (s, 3H), 1.40 (m, 6H); Anal. RP-HPLC tR )
3.72 min (column A, purity 96.6%); HRMS for C20H23N5O4, (M
+ H)+ calcd 398.1824, found 398.1822.
N-iso-Propyl-4-(2-methyl-5-(methoxycarbamoyl)phenylamino)-
5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxamide (11d). 1H
NMR (400 MHz, CD3OD) δ 7.98 (s, 1H), 7.77 (s, 1H), 7.62 (m,
2H), 7.41 (d, J ) 8.0 Hz, 1H), 4.10 (m, 1H), 3.71 (s, 3H), 2.76 (s,
3H), 2.27 (s, 3H), 1.16 (d, J ) 6.6 Hz, 6H); Anal. RP-HPLC tR )
2.77 min (column A, purity 97.5%); HRMS for C20H24N6O3, (M
+ H)+ calcd 397.1988, found 397.1987.
Ethyl 4-(2-methyl-5-(methoxycarbamoyl)phenylamino)-5-iso-
propylpyrrolo[2,1-f][1,2,4]triazine-6-carboxylate (3i). This com-
pound was prepared using the general coupling procedure from 9
and ethyl 4-chloro-5-iso-propylpyrrolo[2,1-f][1,2,4]triazine-6-car-
boxylate 13b.18 1H NMR (500 MHz, CDCl3) δ 7.99 (br s, 2H),
7.82 (s, 1H), 7.45 (br s, 2H), 7.27 (m, 2H), 4.28 (q, J ) 7.2 Hz,
2H), 3.81 (s, 3H), 1.97 (s, 3H), 1.50 (d, J ) 6.6 Hz, 6H), 1.33 (t,
J ) 7.2 Hz, 3H); Anal. RP-HPLC tR ) 3.96 min (column A, purity
91.3%); HRMS for C21H25N5O4, (M + H)+ calcd 412.1985, found
412.1995.
N-(S)-sec-Butyl-4-(2-methyl-5-(methoxycarbamoyl)phen-
ylamino)-5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxamide
1
(11e). H NMR (400 MHz, CD3OD, rotameric) δ 8.08 (m, 1H),
7.88 (m, 1H), 7.73 (m, 2H), 7.53 (m, 1H), 4.05 (m, 1H), 3.83 (s,
3H), 2.88 (s, 3H), 2.35 (s, 3H), 1.61 (m, 2H), 1.25 (m, 3H), 1.01
(m, 3H); Anal. RP-HPLC tR ) 3.05 min (column A, purity 99.4%);
HRMS for C21H26N6O3, (M + H)+ calcd 411.2145, found 411.2161.
N-(2-Methoxyethyl)-4-(2-methyl-5-(methoxycarbamoyl)phe-
nylamino)-5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxam-
ide (11f). 1H NMR (500 MHz, CD3OD, TFA salt) δ 7.93 (s, 1H),
7.82 (br s, 1H), 7.62 (m, 2H), 7.42 (d, J ) 7.7 Hz, 1H), 3.80 (s,
3H), 3.56 (app dd, J ) 14.3, 2.7 Hz, 4H), 3.39 (s, 3H), 2.83 (s,
3H), 2.32 (s, 3H); Anal. RP-HPLC tR ) 2.09 min (column A, purity
96.4%); HRMS for C20H24N6O4, (M + H)+ calcd 413.1937, found
413.1926.
N-Cyclopentyl-4-(2-methyl-5-(methoxycarbamoyl)phenylami-
no)-5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxamide (11g).
1H NMR (400 MHz, CDCl3) δ 9.32 (s, 1H), 8.37 (s, 1H), 7.88 (s,
3H), 7.69 (s, 1H), 7.52 (m, 1H), 7.30 (m, 1H), 7.22 (s, 1H), 5.92
(d, J ) 7.1 Hz, 1H), 4.39 (q, J ) 7.0 Hz, 1H), 3.90 (s, 3H), 2.86
(s, 3H), 2.37 (s, 3H), 2.10 (m, 2H), 1.74 (m, 2H), 1.51 (m, 2H);
Anal. RP-HPLC tR ) 3.15 min (column A, purity 98%); HRMS
for C22H26N6O3, (M + H)+ calcd 423.2145, found 423.2154.
N-Benzyl-4-(2-methyl-5-(methoxycarbamoyl)phenylamino)-
5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxamide (11h). 1H
NMR (500 MHz, CD3OD, TFA salt) δ 7.99 (m, 1H), 7.91 (m, 1H),
7.36 (m, 7H), 7.23 (m, 1H), 4.55 (s, 2H), 3.80 (s, 3H), 2.85 (s,
3H), 2.33 (s, 3H); Anal. RP-HPLC tR ) 2.85 min (column A, purity
98.6%); HRMS for C24H24N6O3, (M + H)+ calcd 445.1988, found
445.1981.
4-(2-Methyl-5-(methoxycarbamoyl)phenylamino)-5-methylpyr-
rolo[2,1-f][1,2,4]triazine-6-carboxylic acid (10). To a suspension
of 3g (10.5 g, 27.8 mmol) in THF (110 mL) was added 1N NaOH
(110 mL, 110 mmol), and the reaction vessel was heated at 55 °C
for 16 h. The reaction mixture was cooled, filtered through a
medium porosity fritted funnel, and concentrated to remove the
THF. 1 N HCl was added to adjust the pH to ∼5–6, and the crude
acid was stirred for several hours and then filtered. The solids were
washed with water (2 × 200 mL) and then IPA/Et2O (1/1, 200
mL) and dried to give the crude acid which was used without further
purification. 1H NMR (400 MHz, DMSO-d6, rotameric) δ 12.5 (br
s, 1H), 11.68 (m, 1H), 8.79 (s, 1H), 7.20–8.05 (m, 5H), 3.69 (s,
3H), 2.84 (s, 3H), 2.25 (s, 3H); Anal. RP-HPLC tR ) 2.72 min
(column A, purity 98.2%); HRMS for C17H17N5O4, (M + H)+ calcd
356.1359, found 356.1349.
N-Methyl-4-(2-methyl-5-(methoxycarbamoyl)phenylamino)-
5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxamide (11a). To a
solution of 10 (40 mg, 0.11 mmol), HOBt (19 mg, 0.12 mmol),
EDC (24 mg, 0.12 mmol), and methylamine hydrochloride (15 mg,
0.22 mmol) in DMF was added DIPEA (0.069 mL, 0.39 mmol),
and the solution was stirred for 2 h. The reaction was concentrated
and purified via preparative HPLC to furnish 11a (40 mg, 74%
yield, TFA salt) as a white solid. 1H NMR (400 MHz, DMSO-d6)
δ 11.85 (br s, 1H), 8.75 (br s, 1H), 7.38–8.05 (m, 6H), 3.70 (s,
3H), 2.79 (s, 3H), 2.75 (s, 3H), 2.22 (s, 3H); Anal. RP-HPLC tR )
2.31 min (column A, purity 92.1%); HRMS for C18H20N6O3, (M
+ H)+ calcd 369.1675, found 369.1682.
N-(Pyridin-2-ylmethyl)-4-(2-methyl-5-(methoxycarbamoyl)phe-
N-Ethyl-4-(2-methyl-5-(methoxycarbamoyl)phenylamino)-5-
methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxamide (11b). Rep-
resentative Procedure for the Preparation of the C6 Amides
11b–11l. A solution of 10 (49 g, 139 mmol), HOBt (20.5 g, 152
mmol), EDC (29.2 g, 152 mmol), and ethylamine hydrochloride
(22.6 g, 277 mmol) in DMF (225 mL) was stirred for 30 min.
DIPEA (48.2 mL, 277 mmol) was added, and the mixture was
stirred for 8 h. Water was added (1.35 L), and the mixture was
stirred overnight to precipitate the product. The solids were filtered,
washed with water (2 × 200 mL), and dried on a filter to give a
tan solid which was slurried in hot EtOH (200 mL), cooled, and
filtered to give the crude amide. A total of 63.3 g of the above
crude solids were dissolved in hot ethanol/water (7/1, 1.7 L),
decolorizing carbon was added, and the mixture was heated at reflux
for 15 min. The mixture was then filtered through a pad of celite,
and the reaction flask was rinsed with hot ethanol (2 × 200 mL).
The solution was cooled slowly and allowed to stir overnight. The
vessel was then cooled in an ice bath for 3 h, and the solids were
filtered and rinsed with ice cold ethanol (100 mL) and water (200
mL) to give 47.5g of 11b (77% recovery) as a white solid. 1H NMR
(400 MHz, CD3OD) δ 7.94 (m, 2H), 7.72 (s, 1H), 7.65 (app d, J
nylamino)-5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxam-
ide (11i). H NMR (500 MHz, CD3OD) δ 8.49 (d, J ) 4.4 Hz,
1H), 8.06 (s, 1H), 7.91 (s, 1H), 7.83 (m, 1H), 7.72 (s, 1H), 7.65
(m, 1H), 7.47 (m, 2H), 7.33 (m, 1H), 4.67 (s, 2H), 3.80 (s, 3H),
2.86 (s, 3H), 2.34 (s, 3H); Anal. RP-HPLC tR ) 1.58 min (column
A, purity 92.4%); HRMS for C23H23N7O3, (M + H)+ calcd
446.1941, found 446.1933.
1
N-((S)-1-Phenylethyl)-4-(2-methyl-5-(methoxycarbamoyl)phe-
nylamino)-5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxam-
ide (11j). 1H NMR (500 MHz, CD3OD) δ 8.02 (br s, 1H), 7.41 (s,
1H), 7.70 (s, 1H), 7.62 (m, 1H), 7.40 (m, 2H), 7.33 (t, J ) 7.7 Hz,
2H), 7.22 (t, J ) 7.2 Hz, 1H), 5.21 (q, J ) 7.6 Hz, 1H), 3.79 (s,
3H), 2.80 (s, 3H), 2.32 (s, 3H), 1.55 (d, J ) 7.2 Hz, 3H); Anal.
RP-HPLC tR ) 2.95 min (column A, purity 99.8%); HRMS for
C25H26N6O3, (M + H)+ calcd 459.2145, found 459.2139.
N-((R)-1-Phenylethyl)-4-(2-methyl-5-(methoxycarbamoyl)phe-
nylamino)-5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxam-
1
ide (11k). H NMR (500 MHz, CD3OD, TFA salt) δ 8.06 (br s,
1H), 7.84 (s, 1H), 7.65 (m, 2H), 7.44 (d, J ) 7.7 Hz, 1H), 7.41 (m,
2H), 7.34 (t, J ) 7.2 Hz, 2H), 7.23 (t, J ) 7.2 Hz, 1H), 5.22, (q,

Properties of MAP Kinase Inhibitors
Journal of Medicinal Chemistry, 2008, Vol. 51, No. 1 13
J ) 7.2 Hz, 1H), 3.79 (s, 3H), 2.81 (s, 3H), 2.35 (s, 3H), 1.55 (d,
J ) 7.2 Hz, 3H); Anal. RP-HPLC tR ) 2.81 min (column A, purity
97%); HRMS for C25H26N6O3, (M + H)+ calcd 459.2145, found
459.2135.
min (column A, purity 97.5%); HRMS for C20H25N7O3, (M + H)+
calcd 412.2097, found 412.2089.
Methyl 4-(2-Methyl-5-(methoxycarbamoyl)phenylamino)-5-
methylpyrrolo[2,1-f][1,2,4]triazin-6-ylcarbamate (17a). 1H NMR
(400 MHz, CD3OD) δ 7.90 (s, 1H), 7.66 (m, 1H), 7.43 (m, 1H),
7.23 (m, 2H), 3.80 (s, 3H), 3.77 (s, 3H), 2.53, (s, 3H), 2.33 (s,
3H); Anal. RP-HPLC tR ) 2.38 min (column A, purity 98%);
HRMS for C18H20N6O4, (M + H)+ calcd 385.1624, found 385.1614.
Ethy4l-(2-Methyl-5-(methoxycarbamoyl)phenylamino)-5-meth-
ylpyrrolo[2,1-f][1,2,4]triazin-6-ylcarbamate (17b). 1H NMR (400
MHz, CD3OD) δ 7.90 (br s, 1H), 7.81 (br s, 1H), 7.53 (m, 2H),
7.32 (br d, 1H), 4.20 (q, J ) 7.0 Hz, 2H), 3.79 (s, 3H), 2.53 (s,
3H), 2.33 (s, 3H), 1.32 (t, J ) 6.9 Hz, 3H); Anal. RP-HPLC tR )
2.66 min (column A, purity 99%); HRMS for C19H22N6O4, (M +
H)+ calcd 399.1781, found 399.1771.
N-(2-Morpholinoethyl)-4-(2-methyl-5-(methoxycarbamoyl)phe-
nylamino)-5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxam-
1
ide (11l). H NMR (500 MHz, CD3OD, TFA salt) δ 7.95 (br s,
1H), 7.76 (s, 1H), 7.61 (m, 2H), 7.42 (d, J ) 7.7 Hz, 1H), 4.10 (br
m, 4 H), 3.80 (s, 3H), 3.75 (t, J ) 6.0 Hz, 2H), 3.40 (t, J ) 6.1 Hz,
2H), 3.29 (br m, 4H), 2.87 (s, 3H), 2.31 (s, 3H); Anal. RP-HPLC
tR ) 1.39 min (column A, purity 96.9%); HRMS for C23H29N7O4,
(M + H)+ calcd 468.2359, found 468.2351.
4-Methoxybenzyl 4-(2-methyl-5-(methoxycarbamoyl)phenyl-
amino)-5-methylpyrrolo[2,1-f][1,2,4]triazin-6-ylcarbamate (17d).
Representative Procedure for the Preparation of 4-Alkyl 4-(2-
methyl-5-(methoxycarbamoyl)phenylamino)-5-methylpyrrolo[2,1-
f][1,2,4]triazin-6-ylcarbamates (17a–d). To a suspension of 10
(330 mg, 0.93 mmol) and 4 Å molecular sieves in dioxane (15
mL) at 50 °C was added TEA (323 µL, 2.3 mmol) and diphenyl
phosphoryl azide (503 µL, 2.3 mmol). The reaction mixture was
stirred for 1.5 h at which point p-methoxy benzyl alcohol (1.16
mL, 9.3 mmol) was added, and the reaction temperature was
increased to 80 °C for 2 h. The reaction was cooled, diluted with
EtOAc, and filtered. After concentrating, the residue was purified
via flash chromatography (75% EtOAc/hexane) to afford 4-meth-
oxybenzyl4-(2-methyl-5-(methoxycarbamoyl)phenylamino)-5-meth-
ylpyrrolo[2,1-f][1,2,4]triazin-6-ylcarbamate 17d (150 mg, 33%
Isopropyl 4-(2-Methyl-5-(methoxycarbamoyl)phenylamino)-
5-methylpyrrolo[2,1-f][1,2,4]triazin-6-ylcarbamate (17c). 1H NMR
(400 MHz, CD3OD) δ 7.81 (s, 1H), 7.72 (br s, 1H), 7.53 (m, 2H),
7.32 (d, J ) 7.9 Hz, 1H), 4.88 (q, J ) 6.6 Hz, 2H), 3.71 (s, 3H),
2.43 (s, 3H), 2.33 (s, 3H), 1.23 (s, 3H), 1.22 (s, 3H); Anal. RP-
HPLC tR ) 2.87 min (column A, purity 98.5%); HRMS for
C20H24N6O4, (M + H)+ calcd 413.1937, found 413.1930.
Ethyl 4-[(2-Methyl-5-nitro)phenylamino]-5-methylpyrrolo[2,1-
f][1,2,4]triazine-6-carboxylate (18). To a solution of chloride 8
(4.0 g, 16.7 mmol) in DMF (50 mL) was added 2-methyl-5-nitro
aniline (2.8 g, 18.4 mmol), and the reaction mixture was stirred
for 48 h. Water (200 mL) was added slowly via addition funnel,
and the resulting suspension was adjusted to pH 7 with NaHCO3
(sat. aq.). The resulting precipitate was stirred for 2 h, filtered, and
washed with water (2 × 25 mL) to afford 18 (5.09 g, 86% yield)
as a pale tan solid. 1H NMR (400 MHz, CD3OD, rotameric) δ 8.57
(s, 1H), 8.17 (m, 1H), 8.07 (s, 1H), 7.81 (m, 2H), 4.37 (m, 2H),
2.95 (s, 3H), 2.44 (s, 3H), 1.41 (m, 3H); Anal. RP-HPLC tR ) 4.04
min (column A, purity 96.6%); MS (ESI) m/z 356.19 (M + H).
N-n-Propyl-4-[(2-methyl-5-nitro)phenylamino]-5-methylpyr-
rolo[2,1-f][1,2,4]triazine-6-carboxamide (19). To a solution of 18
(825 mg, 2.32 mmol) in THF (2 mL) and MeOH (1 mL) was added
1 N NaOH (6 mL), and the reaction mixture was heated at 60 °C
for 24 h. The reaction mixture was then cooled and concentrated
to remove the organic solvents. The pH of the solution was adjusted
to ∼6 with 1 N HCl, and the resulting solids were filtered, washed
successively with water, and dried to afford the crude acid which
1
yield) as a pale yellow solid. H NMR (500 MHz, CDCl3) δ 8.90
(s, 1H), 8.39 (m, 1H), 7.91 (s, 2H), 7.53 (d, J ) 8.8 Hz, 1H), 7.35
(m, 3H), 6.92 (m, 2H), 6.42 (s, 1H), 5.17 (s, 2H), 3.90 (s, 3H),
3.83 (s, 3H), 2.49 (s, 3H), 2.38 (s, 3H); Anal. RP-HPLC tR ) 2.86
min (column A, purity 98%); MS (ESI) m/z 491.30 (M + H)+.
4-(2-Methyl-5-(methoxycarbamoyl)phenylamino)-5-methylpyr-
rolo[2,1-f][1,2,4]triazin-6-amine (14). Carbamate 17d (150 mg)
was dissolved in dichloromethane (10 mL), and TFA was added
(0.5 mL) The mixture was stirred at rt for 30 min and concentrated
to give the crude amine 14 (126 mg, 93% yield) as a brown oil
which was used without further purification.
4-(2-Methyl-5-(methoxycarbamoyl)phenylamino)-5-methylpyr-
rolo[2,1-f][1,2,4]triazin-6-acetamide (15a). Representative Pro-
cedure for the Conversion of 14 To the Amides 15a–c and
Urea 16. To a suspension of 14 (20 mg, 0.06 mmol) in dichlo-
romethane (3 mL) was added TEA (26 µL, 0.18 mmol) followed
by acetic anhydride (10 mg, 0.1 mmol) and the reaction mixture
was stirred for 3 h. Water (2 mL) was added, and the product was
extracted with dichloromethane (3 × 10 mL). The organic layer
was dried over Na2SO4, filtered, and concentrated to an oil which
was purified via flash chromatography (33% EtOAc/hexane) to give
1
was used without further purification. H NMR (DMSO-d6, 400
MHz) δ 12.4 (br s, 1H), 7.55–7.86 (m, 5H), 2.79 (s, 3H), 2.28 (s,
3H); Anal. RP-HPLC tR ) 3.40 min (column A, purity 98%); MS
(ESI) m/z 328.1 (M + H)+.
To a solution of the above acid (2.32 mmol) in DMF (6 mL)
was added HOBt (345 mg, 2.6 mmol) and EDC (489 mg, 2.6
mmol), and the resulting mixture was stirred at rt for 1 h.
n-Propylamine (0.38 mL, 6.4 mmol) was added, and the reaction
was stirred for an additional 4 h. Water was added (25 mL) to
precipitate the product, and the solids were stirred rapidly for 10
min, filtered, and washed with additional water (2 × 10 mL). The
collected solids were purified via column chromatography (33%
EtOAc/hexanes) to give 19 (0.79 g, 93% yield, 2 steps) as a white
1
15a (5 mg, 23% yield). H NMR (400 MHz, CD3OD) δ 7.95 (m,
2H), 7.67 (m, 2H), 7.41 (m, 1H), 3.81 (s, 3H), 2.58 (s, 3H), 2.34
(s, 3H), 2.20 (s, 3H); Anal. RP-HPLC tR ) 1.60 min (column A,
purity 94%); MS (ESI) m/z 369.23 (M + H)+.
4-(2-Methyl-5-(methoxycarbamoyl)phenylamino)-5-methylpyr-
rolo[2,1-f][1,2,4]triazin-6-propylamide (15b). 1H NMR (400
MHz, CD3OD) δ 8.22 (s, 1H), 7.88 (s, 1H), 7.78 (d, J ) 8.3 Hz,
1H), 7.72 (s, 1H), 7.75 (d, J ) 7.9 Hz, 1H), 3.81 (s, 3H), 2.62 (s,
3H), 2.49 (q, J ) 7.5 Hz, 2H), 2.38 (s, 3H), 1.33 (t, J ) 7.4 Hz,
3H); Anal. RP-HPLC tR ) 2.33 min (column A, purity 96%);
HRMS for C19H22N6O3, (M + H)+ calcd 383.1826, found 383.1816.
4-(2-Methyl-5-(methoxycarbamoyl)phenylamino)-5-methylpyr-
rolo[2,1-f][1,2,4]triazin-6-iso-butyramide (15c). 1H NMR (400
MHz, CDCl3) δ 8.47 (s, 1H), 7.72 (s, 1H), 7.48 (m, 2H), 7.36 (d,
J ) 7.9 Hz, 1H), 7.24 (m, 1H), 5.50 (br s, 1H), 3.74 (s, 3H), 2.71
(m, 1H), 2.56 (s, 3H), 2.33 (s, 3H), 1.33 (s, 3H), 1.31 (s, 3H);
Anal. RP-HPLC tR ) 2.50 min (column A, purity 96.4%); HRMS
for C20H24N6O3, (M + H)+ calcd 397.1988, found 397.1977.
4-(2-Methyl-5-(methoxycarbamoyl)phenylamino)-5-methylpyr-
rolo[2,1-f][1,2,4]triazin-6-iso-propylurea (16). 1H NMR (500
MHz, CD3OD) δ 7.81 (br s, 1H), 7.74 (br s, 1H), 7.50 (m, 2H),
7.31 (d, J ) 8.2 Hz, 1H), 3.80 (m, 1H), 3.71 (s, 3H), 2.42 (s, 3H),
2.23 (s, 3H), 1.10 (s, 3H), 1.08 (s, 3H); Anal. RP-HPLC tR ) 2.58
1
solid. H NMR (400 MHz, CDCl3) δ 9.11 (s, 1H), 7.92 (m, 2H),
7.71 (s, 1H), 7.36 (d, J ) 8.4 Hz, 1H), 7.25 (m, 1H), 5.82 (br m,
1H), 3.34 (q, J ) 6.7 Hz, 2H), 2.86 (s, 3H), 2.41 (s, 3H), 1.58 (m,
2H), 1.16 (t, J ) 7.5 Hz, 3H); MS (ESI) m/z 369.3 (M + H)+.
N-n-Propyl-4-[(2-methyl-5-amino)aminophenyl]-5-methylpyr-
rolo[2,1-f][1,2,4]triazine-6-carboxamide (20). A solution of 19
(794 mg, 2.16 mmol) and 10% Pd/C (250 mg, wet) in MeOH (20
mL) wad degassed and backfilled with hydrogen gas. The reaction
was maintained under a hydrogen atmosphere for 2 h with stirring
at which time the reaction solution was filtered and concentrated
1
to give 20 (691 mg, 95% yield). H NMR (400 MHz, CDCl3) δ
7.94 (m, 1H), 7.73 (s, 1H), 7.53 (s, 1H), 7.23 (s, 1H), 7.06 (d, J )
8.1 Hz, 1H), 6.53 (dd, J ) 8.1, 2.2 Hz, 1H), 5.86 (br m, 1H), 3.43
(q, J ) 6.6 Hz, 2H), 2.91 (s, 3H), 2.27 (s, 3H), 1.68 (m, 2H), 1.02
(t, J ) 7.3 Hz, 3H); Anal. RP-HPLC tR ) 2.39 min (column A,
purity 98%); MS (ESI) m/z 339.2 (M + H)+.

14 Journal of Medicinal Chemistry, 2008, Vol. 51, No. 1
Hynes et al.
1
N-n-Propyl-4-[(2-methyl-5-methylcarbamoyl)aminophenyl]-
5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxamide (21a). Rep-
resentative Procedure for the Conversion of 20 to the Carbam-
ates (21a–d). To a solution of 20 (25.2 mg, 0.075 mmol) in
dichloromethane (250 µL) was added DIPEA (14.3 µL, 0.082
mmol) followed by methyl chloroformate (6.4 µL, 0.082 mmol).
The reaction was stirred for 1 h, and then, IPA was added (1 mL).
The resulting solids were collected on a filter and washed with cold
IPA (1 mL) to afford, after drying, 21a (20.1 mg, 68% yield) as a
white solid. 1H NMR (400 MHz, DMSO-d6, rotameric) δ 9.64 (s,
1H), 8.56 (s, 1H), 8.09 (m, 2H), 7.78 (s, 1H), 7.52 (m, 1H), 7.31
(m, 1H), 7.18 (d, J ) 8.4 Hz, 1H), 3.65 (s, 3H), 3.18 (m, 2H), 2.79
(s, 3H), 2.12 (s, 3H), 1.51 (m, 2H), 0.90 (t, J ) 7.4 Hz, 3H); Anal.
RP-HPLC tR ) 2.94 min (column A, purity 96.6%); HRMS for
C20H24N6O3, (M + H)+ calcd 397.1988, found 397.1955.
to provide 23 (339 mg, 81% yield). H NMR (500 MHz, DMSO-
d6, rotameric) δ 9.62 (s, 1H), 8.73 (s, 1H), 8.09 (s, 1H), 7.81 (m,
1H), 7.55 (m, 1H), 7.31 (m, 1H), 7.17 (m, 1H), 4.11 (q, J ) 7.1
Hz, 2H), 3.80 (s, 3H), 3.33 (s, 3H), 2.82 (s, 3H), 2.11 (s, 3H), 1.24
(m, 3H); Anal. RP-HPLC tR ) 3.51 min (column A, purity 98%);
MS (ESI) m/z 384.23 (M + H)+.
4-(2-Methyl-5-(ethoxycarbonylamino)phenylamino)-5-meth-
ylpyrrolo[2,1-f][1,2,4]triazine-6-carboxylic acid (24). To a solu-
tion of 23 (290 mg, 0.59 mmol) in THF (2 mL) and MeOH (2 mL)
was added 1 N NaOH (1.77 mL, 1.77 mmol), and the reaction
mixture was heated at 55 °C for 24 h. The reaction mixture was
then cooled and concentrated to remove the organic solvents. The
pH of the solution was adjusted to ∼6 with 1 N HCl, and the
resulting solids were filtered, washed successively with water, and
1
dried to afford the crude acid 24 as a white solid. H NMR (400
N-n-Propyl-4-[(2-methyl-5-ethylcarbamoyl)aminophenyl]-5-
methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxamide (21b). 1H NMR
(400 MHz, DMSO-d6, rotameric) δ 9.62 (br s, 1H), 8.57 (br s, 1H),
8.08 (m, 2H), 7.78 (s, 1H), 7.59 (m, 1H), 6.89–7.32 (m, 2H), 4.11
(app q, J ) 7.1 Hz, 2H), 3.18 (app q, J ) 6.5 Hz, 2H), 2.80 (s,
3H), 2.12 (s, 3H), 1.52 (m, 2H), 1.24 (t, J ) 7.0 Hz, 3H), 0.95 (t,
J ) 7.4 Hz, 3H); Anal. RP-HPLC tR ) 3.16 min (column A, purity
99.5%); HRMS for C21H26N6O3, (M-H)+ calcd 409.1988, found
409.2006; Anal. calcd C, 61.45; H, 6.38; N, 20.47; found C, 61.39;
H, 6.46; N, 20.49.
N-n-Propyl-4-[(2-methyl-5-iso-propylcarbamoyl)aminophenyl]-
5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxamide (21c). 1H
NMR (500 MHz, DMSO-d6, rotameric) δ 9.52 (br s, 1H), 8.56 (br
s, 1H), 8.07 (m, 2H), 7.77 (s, 1H), 7.60 (m, 1H), 7.16–7.31 (m,
2H), 4.86 (m, 1H), 3.17 (m, 2H), 2.79 (s, 3H), 2.11 (s, 3H), 1.51
(m, 2H), 1.25 (s, 3H), 1.24 (s, 3H), 0.90 (t, J ) 7.2 Hz, 3H); Anal.
RP-HPLC tR ) 3.38 min (column A, purity 94.9%); HRMS for
C22H28N6O3, (M + H)+ calcd 425.2301, found 425.2307.
MHz, DMSO-d6, rotameric) δ 9.60 (s, 1H), 8.23 (s, 1H), 7.66 (m,
2H), 7.20 (m, 2H), 4.10 (m, 2H), 2.88 (s, 3H), 2.14 (s, 3H), 1.24
(br m, 3H); Anal. RP-HPLC tR ) 3.07 min (column A, purity
98.5%); MS (ESI) m/z 370.28 (M + H)+.
N-Ethyl-4-[(2-methyl-5-ethylcarbamoyl)aminophenyl]-5-meth-
ylpyrrolo[2,1-f][1,2,4]triazine-6-carboxamide (21g). Representa-
tive Procedure for the Coupling of 24 with an Amine for the
Preparation of 21g–i. To a solution of acid 24 (25 mg, 0.07 mmol)
in DMF was added HOBt (10.1 mg, 0.075 mmol) and EDC (14.3
mg, 0.075 mmol), and the mixture was stirred for 30 min. Ethyl
amine hydrochloride (11.4 mg, 0.14 mmol) was added followed
by DIPEA (24.4 µL, 0.14 mmol), and the reaction mixture was
stirred for 2 h. Water (1 mL) was added to precipitate the product,
and the solids were stirred for 2 h, filtered, and dried under high
1
vacuum to afford 21 g (18.0 mg, 66% yield) as a white solid. H
NMR (400 MHz, CD3OD) δ 7.88 (br s, 1H), 7.65 (br m, 2H), 7.28
(m, 1H), 7.21 (m, 1H), 4.16 (app q, J ) 7.0, 2H), 3.37 (app q, J )
7.5 Hz, 2H), 2.81 (s, 3H), 2.20 (s, 3H), 1.28 (t, J ) 7.0 Hz, 3H),
1.22 (t, J ) 7.6 Hz, 3H); Anal. RP-HPLC tR ) 2.89 min (column
A, purity 96%); HRMS for C20H24N6O3, (M + H)+ calcd 397.1988,
found 397.1992.
N-iso-Propyl-4-[(2-methyl-5-ethylcarbamoyl)aminophenyl]-5-
methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxamide (21h). 1H NMR
(400 MHz, CD3OD) δ 7.92 (br s, 1H), 7.68 (m, 2H), 7.31 (m, 1H),
7.23 (m, 1H), 4.16 (m, 2H), 2.81 (s, 3H), 2.22 (s, 3H), 1.28 (t, J )
7.0 Hz, 3H), 1.25 (s, 3H), 1.24 (s, 3H); Anal. RP-HPLC tR ) 3.06
min (column A, purity 97.4%); HRMS for C21H26N6O3, (M + H)+
calcd 411.2145, found 411.2146.
N-n-Propyl-4-[(2-methyl-5-phenylcarbamoyl)aminophenyl]-
5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxamide (21d). 1H
NMR (500 MHz, DMSO-d6, rotameric) δ 10.23 (br s, 1H), 8.57
(s, 1H), 8.10 (s, 1H), 8.07 (t, J ) 5.5 Hz, 1H), 7.79 (s, 1H), 7.44
(s, 1H), 7.43 (t, J ) 6.3 Hz, 2H), 7.35 (m, 1H), 7.23 (m, 3H), 3.18
(m, 2H), 2.80 (s, 3H), 2.15 (s, 3H), 1.51 (m, 2H), 0.90 (t, J ) 7.2
Hz, 3H); Anal. RP-HPLC tR ) 3.46 min (column A, purity 91.5%);
HRMS for C25H26N6O3, (M + H)+ calcd 459.2145, found 459.2136.
Ethyl 3-Amino-4-methylphenylcarbamate (22). To a solution
of 3-nitro-4-methyl aniline (2.0 g, 13.1 mmol) in dichloroethane
(40 mL) wad added ethyl chloroformate (1.38 mL, 14.4 mmol)
followed by DIPEA (2.3 mL, 14.4 mmol). The reaction was stirred
for 12 h and then poured into a separatory funnel containing water
(75 mL) and dichloromethane (50 mL). The layers were separated,
and the organic layer was washed with aqueous NaHCO3, dried
over Na2SO4, filtered, and concentrated to an oil. The product was
purified via column chromatography (20% EtOAc/hexanes) to
furnish ethyl-3-nitro-4-methyl phenyl carbamate (2.39 g, 82% yield)
N-(S)-sec-Buytl-4-[(2-methyl-5-ethylcarbamoyl)aminophenyl]-
5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxamide (21i). 1H
NMR (400 MHz, CD3OD) δ 7.92 (br s, 1H), 7.65 (m, 2H), 7.30
(m, 1H), 7.25 (m, 1H), 4.16 (q, J ) 7.4 Hz, 2H), 4.00 (m, 1H),
2.98 (m, 2H), 2.81 (s, 3H), 2.22 (s, 3H), 1.58 (m, 2H), 1.29 (t, J )
7.0 Hz, 3H), 1.22 (d, J ) 6.6 Hz, 3H), 0.97 (t, J ) 7.5 Hz, 3H);
Anal. RP-HPLC tR ) 3.25 min (column A, purity 94.1%); HRMS
for C22H28N6O3, (M + H)+ calcd 425.2301, found 425.2305.
N-n-Propyl 4-(2-methyl-5-(methoxyacetamido)phenylamino)-
5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxamide (21e). This
compound was prepared via the acylation of 20 with 2-methoxy-
1
as a white solid. H NMR (400 MHz, CDCl3) δ 8.08 (d, J ) 2.3
Hz, 1H), 7.61 (d, J ) 7.4 Hz, 1H), 7.32 (s, 1H), 6.74 (s, 1H), 4.30
(q, J ) 7.1 Hz, 2H), 2.59 (s, 3H), 1.38 (t, J ) 7.1 Hz, 3H); Anal.
RP-HPLC tR ) 3.37 min (column A, purity 97.8%); MS (ESI) m/z
225.13 (M + H)+.
1
acetyl chloride using the general procedure outlined for 21a. H
NMR (400 MHz, DMSO-d6): δ 9.60 (s, 1H), 8.39 (s, 1H), 7.91
(m, 2H), 7.63 (m, 2H), 7.29 (m, 1H), 7.03 (m, 1H), 3.80 (s, 2H),
3.19 (s, 3H), 2.62 (s, 3H), 1.97 (s, 3H), 1.36 (m, 2H), 0.73 (m,
3H); Anal. RP-HPLC tR ) 2.84 min (column A, purity 95.9%);
HRMS for C21H26N6O3, (M + H)+ calcd 411.2145, found 411.2145.
N-n-Propyl 4-(2-methyl-5-(acetamido)phenylamino)-5-meth-
ylpyrrolo[2,1-f][1,2,4]triazine-6-carboxamide (21f). This com-
pound was prepared via the acylation of 20 with acetylchloride
using the general procedure outlined for 21a. 1H NMR (400 MHz,
DMSO-d6): δ 9.94 (s, 1H), 8.54 (s, 1H), 8.07 (m, 2H), 7.75 (m,
2H), 7.40 (m, 1H), 7.19 (m, 1H), 3.18 (m, 2H), 2.80 (s, 3H), 2.14
(s, 3H), 2.03 (s, 3H), 1.51 (m, 2H), 0.90 (t, J ) 7.5 Hz, 3H); Anal.
RP-HPLC tR ) 2.74 min (column A, purity 95%); LRMS for
C2oH24N6O2, (M + H)+ calcd 381.45, found 381.23.
To a solution of ethyl-3-nitro-4-methyl phenyl carbamate (1.33
g, 5.9 mmol) in MeOH (30 mL) was added 5% Pd/C (480 mg,
wet), and the reaction vessel was evacuated and backfilled with
hydrogen gas. The reaction was maintained under a hydrogen
atmosphere for 2 h with stirring at which time the reaction solution
1
was filtered and concentrated to give 22 (1.15 g, 99% yield). H
NMR (400 MHz, CDCl3) δ 6.86 (m, 2H), 6.46 (dd, J ) 8.0, 2.1
Hz, 1H), 6.36 (s, 1H), 4.13 (q, J ) 7.1 Hz, 2H), 3.42 (br s, 2H),
2.04 (s, 3H), 1.22 (t, J ) 7.1 Hz, 3H); Anal. RP-HPLC tR ) 1.43
min (column A, purity 98.7%).
Methyl 4-(2-Methyl-5-(ethoxycarbonylamino)phenylamino)-
5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxylate (23). This
compound was prepared according to the procedure outlined for
compound 18 starting from chloride 12 (248 mg, 1.1 mmol) and
ethyl 3-amino-4-methylphenylcarbamate 22 (235 mg, 1.2 mmol)
p38 Kinase Assay. The assays were performed in V-bottomed
96-well plates. For both assays, the final assay volume was 60 µL

Properties of MAP Kinase Inhibitors
Journal of Medicinal Chemistry, 2008, Vol. 51, No. 1 15
which was from three 20-µL additions of enzyme, substrates (myelin
basic protein (MBP) and ATP), and test compounds in assay buffer
(50 mM Tris pH 7.5, 10 mM MgCl2, 50 mM NaCl, and 1 mM
DTT). Bacterially expressed, activated p38R was preincubated with
test compounds for 10 min prior to the initiation of reaction by
adding substrates. The plates were incubated at room temperature
for 45 min. The reaction was terminated by adding 5 µL of 0.5 M
EDTA to each well. The reaction mixture was aspirated onto a
prewetted filtermat using a Skatron Micro96 cell harvester (Skatron)
and then washed with PBS. The filtermat was dried in a microwave
oven for 1 min, coated with a layer of MeltilLex A scintillation
wax (PerkinElmer), and counted on a Microbeta scintillation counter
(Model 1450, PerkinElmer). The data were analyzed using Prizm
nonlinear least-squares regression (GraphPad Software). The final
concentrations of reagents in the assays were [ATP], 1 µM;
[[γ-33P]ATP]], 3 nM; [MBP] (Sigma, M1891), 2 µg/well; [p38],
15 ng/well; [DMSO], 0.3%.
LPS-Induced TNFr Production in THP-1 Cells. Human
monocytic THP-1 cells, obtained from ATCC, were maintained in
RPMI 1640 medium supplemented with 10% fetal bovine serum.
Cells (40 000 cells in 80 µL) were added to wells of 96-well flat-
bottomed plates. Tested compounds (10 µL) or vehicle (1% DMSO
final) was added to cells. Subsequently, LPS (Sigma, No. L7261;
10 µL /well) was added to the cells for a final concentration of 1
µg/mL. Plates were incubated overnight at 37 °C and 5% CO2.
Supernatant (50 µL/well) was harvested for an ELISA assay. TNFR
was captured by an antihuman TNFR antibody (R&D, No.
MAB610) which was preabsorbed in high binding EIA plates
(Costar, No. 3590). Captured TNF was recognized by a biotinylated
antihuman TNF polyclonal antibody (R&D, No. BAF210). Strepta-
vidin conjugated with peroxidase was added to each well, and the
activity of peroxidase was quantitated by a peroxide substrate kit
(Pierce, Nos. 34062 and 34006).
lowing conditions: compound, 3 µM final concentration; final
microsomal protein concentration approximately 1 mg/mL; NADPH
1 mM; pH 7.4 potassium phosphate buffer, 56 mM. Incubations
were performed at 37 °C and were initiated by the addition of the
substrate. Aliquots (100 µL) of the incubation were quenched at 0,
10, 20, 30, and 40 min by the addition of 1 volume of acetonitrile.
Results from 10-min incubations were used for the rate calculations.
Samples were analyzed by the LC/MS/MS assay for the amount
of the drug remaining at any time point. The percent metabolized
was calculated based on the disappearance of the parent compound.
Rat Adjuvant Arthritis. Male Lewis rats (Harlan, 175–200 g)
were immunized sc at the base of the tail with 0.1 mL complete
Freund’s adjuvant containing 10 mg/mL Mycobacterium butyricum.
Seven days later, baseline (predisease) measurements of hind paw
volume were determined by volume displacement plethysmometry
(Ugo Basile, Italy). Compound was administered orally in 1 mL
PEG 300 bid beginning on day 11. Paw volume measurements were
repeated 3 times/week for the remainder of the study. Data are
presented as the summed increase in volume (expressed in mL)
above baseline for each rat’s two hind paws. Dexamethasone (1
mg/kg) was used as a positive control.
Mouse Collagen Induced Arthritis. DBA/1LacJ male mice 6–8
weeks (The Jackson Laboratory, Bar Harbor, ME) were immunized
subcutaneously on day 0 and day 21 with 200 µg bovine type II
collagen in a 0.1 mL RIBI adjuvant system (RAS) with mono-
phosphoryl lipid A (RIBI ImmunoChem Research, Hamilton,
Montana). Following the day 21 booster, mice were monitored daily
for the development paw inflammation. On day 26, the animals
were randomly assigned to a treatment group and treatment (po,
bid) was initiated immediately. Clinical paw scores for all four paws
were summed for each mouse and mean ( SD was calculated for
each treatment group. Dexamethasone (5 mg/kg) was used as a
positive control.
LPS-Induced TNFr Production in Human PBMC. Human
PBMCs were isolated from whole blood collected from healthy
donors. Blood was diluted into RPMI 1640 (Life Technologies)
containing 2.5 mM EDTA (Life Technologies) and 10 µg/mL
polymyxin (Sigma) and, then, underlaid with ficoll (Accurate
Scientific Co.) and centrifuged at 600g for 25 min. The interface
was collected, and cells were washed twice and resuspended in
RPMI, 10% FBS. Cells were then distributed (200 µL/well) into
96-well tissue culture treated plates (Falcon) at 1 × 106 cells/mL
in RPMI, 10% FBS. Test compounds were added to appropriate
wells and incubated with cells for 30 min. Cells were then
stimulated by the addition of lipopolysaccharide (LPS, BioWhit-
taker), with a final concentration of 25 ng/mL, and incubated for
6 h at 37 °C, 5% CO2. The cell supernatants were removed and
assayed for TNFR by ELISA (R&D Systems).
Inhibition of TNFr Release in Mice. BALB\c female mice,
6–8 weeks of age, were obtained from Harlan Laboratories and
maintained ad libitum on water and standard rodent chow (Harlan
Teklad). Mice were acclimated to ambient conditions for at least 1
week prior to use. For oral dosing, the compounds were prepared
in a solution of 100% polyethylene glycol (MW 300), and a dosing
volume of 0.2 mL per mouse was administered by gavage 30 or
120 min prior to LPS injection (0.1 mL of LPS suspended at 10
µg/mL in PBS, administered ip). Blood samples were obtained 90
min after LPS injection. Serum was separated from clotted blood
samples by centrifugation (5 min, 5000g, room temperature) and
analyzed for levels of TNFR by ELISA assay (R&D Systems)
according to the manufacturer’s directions. Results are shown as
mean percent inhibition of n ) 6–8 mice per treatment group. All
studies were performed using 11b as a positive control and as a
measure of model variability. All procedures involving animals were
reviewed and approved by the Institutional Animal Care and Use
Committee.
Clinical Scoring. Each paw was visually scored by the following
criteria: 0 ) normal; 1 ) one (or more) joints inflamed on digits;
2 ) inflammation of plantar surface of paw and paw thickness
increased; 3 ) ankylosis of ankle joint (significantly reduced hock
joint motion on flexion/extension).
Crystal Structure of p38 MAP Kinase. Recombinant p38R
MAP Kinase with an N-terminal (His)5-affinity tag was expressed
in E. coli and purified by sequential Q-Sepharose FF, His-Trap HP
Ni2+-affinity, and Superdex 200 size exclusion chromatography.
Purified (His)5-p38R, at 2 mg/mL in 25 mM Tris (pH 7.5), 50 mM
NaCl, 5% glycerol, 0.5 mM EDTA, 2 mM DTT, was combined
with a 5-fold molar excess of inhibitor from a 50 mM stock in
DMSO, incubated at 20 °C for 1 h, and ultrafiltered (10 kDa cutoff)
to a retentate protein concentration of 10 mg/mL. Cocrystals of
(His)5-p38R 11j inhibitor complexes grew spontaneously in hanging
drop vapor-diffusion trials conducted at 4 °C with drops containing
1 µL of concentrated protein-inhibitor complex mixed with an
equal volume of reservoir solution (50 mM Mes pH 6.0, 4% PEG
3350, 5 mM MgSO4). More perfect crystals of 11j and 11b were
obtained using a cat whisker to streak clear drops with microseeds
from crushed cocrystals of (His)5-p38R and 11j. Prior to data
collection, the crystals were slowly transferred to a stabilization
solution (5% glycerol, 30% PEG 3350, 50 mM Mes pH 6.0, 50
mM NaCl) and then flash frozen in liquid nitrogen. Data were
collected at the IMCA-CAT beamline ID-17 at the Advanced
Photon Source, Argonne, IL, reduced with the programs DENZO
and SCALEPACK,19 and refined by with the program autoBuster
(Global Phasing, Ltd., Cambridge, U.K.). The final crystallographic
refinement statistics are summarized in the Supporting Information.
Details of the data collection, reduction, and refinement will be
presented elsewhere.20
Acknowledgment. The authors would like to thank Robert
Borzilleri and Brian Fink for helpful discussions and useful
intermediates at the outset of this effort, the Discovery Analytical
Sciences Department for obtaining high-resolution MS analysis,
and the staff of the IMCA-CAT beamline 17- ID at the
Rat and Human Liver Microsome Stability. Rat microsomes
were purchased from XenoTech (Kansas City, KS). The human
microsomes were purchased from In Vitro Technology (Baltimore,
MD) and were pooled from 10 individual donors. The rates of
oxidative metabolism were measured in triplicate under the fol-

16 Journal of Medicinal Chemistry, 2008, Vol. 51, No. 1
Hynes et al.
the American Chemical Society, San Diego, CA, 2004; MEDI 296.
(e) Miwatashi, S.; Arikawa, Y.; Kotani, E.; Miyamoto, M.; Naruo,
K.; Kimura, H.; Tanaka, T.; Asahi, S.; Ohkawa, S. Novel Inhibitor of
p38 MAP Kinase as an Anti-TNFR Drug: Discovery of N-[4-[2-ethyl-
4-(3-methylphenyl)-1,3-thiazol-5-yl]-2-pyridyl]benzamide (TAK-715)
as a Potent and Orally Active Anti-rheumatoid Arthritis Agent. J. Med.
Chem. 2005, 48, 5966–5979. (f) Dugar, S. Discovery of p38-alpha
MAP Kinase Inhibitor SCIO-469. Inflammation Res. 2005, 54 (Suppl
2), Abs 1027.
Advanced Photon Source, Argonne, IL. The use of the beamline
was supported by the companies of the Industrial Macromo-
lecular Crystallography Association through a contract with the
Center for Advanced Radiation Sources at the University of
Chicago.
Supporting Information Available: Table of HPLC purity
analysis or combustion analysis of key compounds and final X-ray
crystallographic refinement statistics. This material is available free
of charge via the Internet at http://pubs.acs.org.
(8) Leftheris, K.; Ahmed, G.; Chan, R.; Dyckman, A. J.; Hussain, Z.;
Ho, K.; Hynes, J., Jr.; Letourneau, J.; Li, W.; Lin, S.; Metzger, A.;
Moriarty, K. J.; Riviello, C.; Shimshock, Y.; Wen, J.; Wityak, J.;
Wrobleski, S. T.; Wu, H.; Wu, J.; Desai, M.; Gillooly, K. M.; Lin,
T. H.; Loo, D.; McIntyre, K. W.; Pitt, S.; Shen, D. R.; Shuster, D. J.;
Zhang, R.; Diller, D.; Doweyko, A.; Sack, J.; Baldwin, J.; Barrish, J.;
Dodd, J.; Henderson, I.; Kanner, S.; Schieven, G. L.; Webb, M. The
Discovery of Orally Active Triaminotriazine Aniline Amides as
Inhibitors of p38 MAP Kinase. J. Med. Chem. 2004, 47, 6283–6291.
(9) Hunt, J. T.; Mitt, T.; Borzilleri, R.; Gullo-Brown, J.; Fargnoli, J.; Fink,
B.; Han, W.-C.; Mortillo, S.; Vite, G.; Wautlet, B.; Wong, T.; Yu, C.;
Zheng, Z.; Bhide, R. Discovery of the Pyrrolo[2,1-f][1,2,4]triazine
Nucleus as a New Kinase Inhibitor Template. J. Med. Chem. 2004,
47, 4054–4059.
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JM7009414