Tandem Michael-addition/cyclization synthesis and EGFR kinase inhibition activity of pyrido[2,3-d]pyrimidin-7(8H)-ones

Article abstract of DOI:10.1002/jhet.5570410308

5-Methoxy and 5-anilinopyrido[2,3-d]pyrimidin-7(8H)-ones 2a-2f were obtained by a tandem Michael addition-cyclization reaction of methanol and anilines with pyrimidinylpropynoate 5. Methoxy derivative 2a was obtained in 62% yield by treatment of 5 with methanol and potassium carbonate. Anilino derivatives 2b-2f were prepared in 31-71% yields by reacting 5 with the corresponding anilines in refluxing methanol. This methodology accomplishes Michael-addition and pyridopyrimidinone ring formation in one-pot and affords the desired products in reasonable yield without chromatography. Propynoate 5 did not react with 4-cyanoaniline under these conditions. Reaction of 5 with 2-aminopyridine gave the unexpected arylpyrido[2,3-d]pyrimidinone 8 in 58% yield and reaction of 5 with imidazole afforded Michael-adduct 9 in 69% yield. Compounds 2a and 5 were submicromolar inhibitors of epidermal growth factor receptor (EGFR) tyrosine kinase.

Full text of DOI:10.1002/jhet.5570410308

May-Jun 2004
355
Tandem Michael-Addition/Cyclization Synthesis and EGFR Kinase
Inhibition Activity of Pyrido[2,3-d]pyrimidin-7(8H)-ones
Eric E. Boros†*, Edgar R. Wood§, O. Bradley McDonald§, Timothy D. Spitzer¶,
Andrea M. Sefler¶, Bryan R. Reep‡, and James B. Thompson†
GlaxoSmithKline Research & Development, Five Moore Drive, Research Triangle Park, NC 27709
†
Medicinal Chemistry
Systems Research
§
¶
Analytical Sciences
‡
Current address: Icagen, Inc., RTP, NC 27709
Received December 5, 2003
5-Methoxy and 5-anilinopyrido[2,3-d]pyrimidin-7(8H)-ones 2a-2f were obtained by a tandem Michael
addition-cyclization reaction of methanol and anilines with pyrimidinylpropynoate 5. Methoxy derivative
2a was obtained in 62% yield by treatment of 5 with methanol and potassium carbonate. Anilino derivatives
2b-2f were prepared in 31-71% yields by reacting 5 with the corresponding anilines in refluxing methanol.
This methodology accomplishes Michael-addition and pyridopyrimidinone ring formation in one-pot and
affords the desired products in reasonable yield without chromatography. Propynoate 5 did not react with
4-cyanoaniline under these conditions. Reaction of 5 with 2-aminopyridine gave the unexpected
arylpyrido[2,3-d]pyrimidinone 8 in 58% yield and reaction of 5 with imidazole afforded Michael-adduct 9 in
69% yield. Compounds 2a and 5 were submicromolar inhibitors of epidermal growth factor receptor
(EGFR) tyrosine kinase.
J. Heterocyclic Chem., 41, 355 (2004).
Introduction.
cross-coupling methyl propiolate with iodopyrimidine 4
followed by reaction of the resulting pyrimidinylpropiolate
5 with methanol or anilines [11]. Interestingly, this
methodology appears to incorporate the 5-substituent and
form the pyridopyrimidinone ring in one pot through a tan-
dem Michael-addition/cyclization mechanism. Herein are
described some scope and limitations of the methodology
and inhibitory properties of the products against ErbB-2
and EGFR tyrosine kinases.
The benzyloxyanilinoquinazoline substructure 1 is
prevalent in a number of potent inhibitors of epidermal
growth factor receptor (EGFR) tyrosine kinase and Type I
receptor tyrosine kinases (also known as the HER or ErbB
family). In addition, a number of dual EGFR/ErbB-2
kinase inhibitors show potential utility as anti-cancer
agents [1-4]. As part of a medicinal-chemistry effort tar-
geting analogs of 1, we wished to synthesize 3-(4-anilino-
pyrimidin-5-yl)prop-2-ynoates 5 and 5,8-disubstituted
pyrido[2,3-d]pyrimidin-7-ones 2 as alkynyl and conforma-
tionally constrained versions of 1, respectively.
Results and Discussion.
Syntheses of 2 a-2 f are outlined in Scheme 1.
Preparation of 4-chloro-5-iodopyrimidine (3) was accom-
plished in 2 steps and 37% overall yield employing pub-
lished procedures [12]. Reaction of 3 with 3-chloro-4-[(3-
fluorobenzyl)oxy]aniline [1] proceeded in 52% yield to
afford anilinopyrimidine 4. Coupling of 4 to methyl propi-
olate [13] provided the pyrimidinylpropynoate 5 in 67%
yield.
Reaction of 5 with methanol was investigated under
basic conditions. Stirring a methanolic solution of 5 with
potassium carbonate for 3 days at room temperature pro-
duced methoxypyridopyrimidinone 2a in 62% yield. The
formation and disappearance of a methanol-addition prod-
uct/Michael adduct (m/z = 444, MH+) during the course of
the reaction was supported by hplc and mass spectrometry.
The proton nmr spectrum of the final product 2a displayed
a methine singlet at 6.24 ppm for the C-6 hydrogen, and ir
spectroscopy revealed a carbonyl stretch at 1672 cm-1 con-
sistent with the proposed structure.
Numerous examples of pyrido[2,3-d]pyrimidin-7-ones
exist in the literature and the majority contain substitution
at the 2- and 4-positions [5-8]. Few if any 5,8-disubsti-
tuted pyrido[2,3-d]pyrimidin-7-ones (e.g., 2) are reported,
and limited examples are known with hydrogen at the 2-,
4- and/or 6-positions [9,10]. Consequently, an efficient
synthesis of analogs of 2 was needed. We subsequently
found that 5-methoxy and 5-anilino-8-arylpyrido[2,3-d]-
p y r i m i d i n - 7 ( 8H)-ones 2 a-f are conveniently prepared by
Addition of anilines to 5 was accomplished in methanol
without base. Heating a mixture of 5 and excess aniline in
methanol at reflux afforded anilinopyrido[2,3-d]pyrimidi-

356
E. E. Boros, E. R. Wood, O. B. McDonald, T. D. Spitzer,
A. M. Sefler, B. R. Reep, and J. B. Thompson
Vol. 41
none 2b in 31% yield. The HMBC spectrum of 2b showed
three-bond correlations between the anilino hydrogen (δH
= 9.20 ppm) and C-6 carbon (δC = 94.6 ppm) and also
between the C-6 hydrogen (δH = 5.77 ppm) and pyrimi-
dine carbon (δC = 109.0 ppm) attached to C-5.
Alkoxy-, alkyl-, halo- and acetamido-substituted ani-
lines reacted smoothly with 5 a ffording pyridopyrimidi-
nones 2c-2f in 44-71% yields. It is important to note that 5
did not react with 4-cyanoaniline under these conditions,
presumably because of the electron-deficient nature of this
aniline.
R = 3-chloro-4-[(3-fluorobenzyl)oxy]phenyl; i: ArNH , Cs CO , CH CN;
2
2
3
3
ii: methyl propiolate, Pd(PPh ) , CuI, K CO ; iii: CH OH; K CO , rt;
3 4
2
3
3
2
3
iv: ArNH , CH OH, reflux.
3
2
Treatment of 5 with imidazole also failed to yield the
desired pyridopyrimidinone, and instead gave Michael
adduct 9 in 69% yield. No subsequent cyclization to the
desired pyridopyrimidinone was observed. Carbon-13
nmr spectroscopy of 9 revealed a 5.4 Hz C-H coupling
between the vinylic methine hydrogen and C-5 of the
pyrimidine ring, indicating a cis-orientation of these atoms
and therefore an anti-addition of imidazole to 5 [14].
Compounds 2a-2f and 5 were evaluated for inhibition of
ErbB-2 and EGFR tyrosine kinases [15]. The results of
these studies are shown in Table 1. Relative inhibitory
activities were compared to the known dual kinase
inhibitor GW2016 under the same assay conditions [16].
5-Methoxy analog 2a and pyrimidinylpropiolate 5 showed
IC50s against EGFR in the 190-320nM range and 6-7 fold
selectivities over ErbB-2 kinase. The 5-anilino derivative
2b was less active with an IC50 versus EGFR of 1.23 µM;
interestingly, this compound showed greater selectivity
over ErbB-2 kinase (>16-fold). Substitution at the 4-posi-
tion of the anilino ring in 2b (e . g ., 2 c-2 f) produced no
improvement in the activity of this series. Compounds 8
and 9 were inactive against EGFR and ErbB-2 kinase
(IC50s > 20 µM).
In an effort to improve the solubility of 2a-2f, replace-
ment of the anilino and methoxy groups in 2a-2f with
aminopyridine and imidazole rings was attempted.
However, treatment of 5 with 2-aminopyridine afforded an
unanticipated product–namely, arylpyrido[2,3-d]pyrimidi-
none 8 in 58% yield. The C-3 hydrogen in the proton nmr
spectrum of 8 (δH = 6.53 ppm) appeared ca. 1 ppm higher
than the C-6 hydrogens of 2 b-2 f. Furthermore, HMBC
spectroscopy showed three-bond correlations between the
anilino hydrogen (δH = 8.90 ppm) and the ortho-carbons
of the chlorinated phenyl ring (δC = 123.0 and 125.1 ppm).
Similar correlations were observed between the C-5
hydrogen (δH = 7.81 ppm) and C-4 carbon (δC = 145.3
ppm) of the pyridopyrimidinone ring.
Table 1
ErbB-2 and EGFR Tyrosine Kinase Inhibition Activity of 5-Methoxy
and 5-Anilino-pyrido[2,3-d]pyrimidin-7(8H)-ones 2a-2f and
Pyrimidinylpropynoate 5 [a], [b], [c], [d]
IC (µM)
50
Compound
ErbB-2
EGFR
In summary, 5-methoxy and 5-anilinopyridopyrimidi-
nones 2a-2f proved readily accessible from propiolate 5 by
employing the tandem Michael addition-cyclization chem-
istry shown in Scheme 1. This methodology incorporates
the 5-substituent and forms the pyridopyrimidinone ring in
one step, affording reasonable yields of the desired prod-
ucts without chromatography. Propiolate 5 did not react
with 4-cyanoaniline under the reported conditions and
treatment of 5 with 2-aminopyridine or imidazole gave
pyridopyrimidinone 8 and Michael adduct 9, respectively.
2a
2b
2c
2d
2e
2f
5
2.34 (N = 2)
>20 (N = 1)
ND
>20 (N = 1)
>20 (N = 1)
4.86 (N = 3)
1.26 (N = 2)
0.32 (N = 2)
1.23 (N = 1)
1.12 (N = 1)
3.98 (N = 1)
7.76 (N = 1)
1.36 (N = 3)
0.19 (N = 2)
[a] Mean IC values (N > 1); [b] N = number of measurements; [c] ND
= not determined; [d] IC values for inhibition of ErbB-2 and EGFR by
dual kinase inhibitor GW2016 are 9.2 and 10.8 nM, respectively (see
reference 16).
50
50

May-Jun 2004
Tandem Michael-Addition/Cyclization Synthesis
357
5-Anilino-8-{3-chloro-4-[(3-fluorobenzyl)oxy]phenyl}pyrido -
[2,3-d]pyrimidin-7(8H)-one (2b).
Compounds 5 and 2a are submicromolar inhibitors of
EGFR tyrosine kinase.
A solution of 5 (50 mg, 0.121 mmole) and aniline (45 mg,
0.483 mmole) in methanol (2 mL) was heated at reflux for 10
hours. The mixture was diluted with water and the resulting pre-
cipitate was collected by filtration. Trituration of the filter cake
with methanol and drying under high vacuum afforded 2b as a
EXPERIMENTAL
General.
1
beige solid (18 mg, 31% yield): mp 232-235 ºC; H nmr
(dimethylsulfoxide-d ): δ 9.47 (s, 1H), 9.20 (s, 1H), 8.86 (s, 1H),
Analytical HPLC analyses were performed on C-18 columns
with 10-100% acetonitrile/water as eluent containing 0.1% triflu-
oroacetic acid. Elemental analyses were performed by Atlantic
Microlabs, Norcross, GA. Proton nmr spectra were recorded at
400 MHz and coupling constants are reported in Hz. Chemical
shifts are reported in ppm relative to the residual protonated sol-
vent resonance at 7.24 ppm (deuteriochloroform) or 2.49 ppm
6
7.47-7.16 (m, 12H), 5.77 (s, 1H), 5.27 (s, 2H); hplc: one major
peak (92%); hrms: m/z Calcd. for C
473.1180; Found: 473.1190.
Anal. Calcd. for C H ClFN O •H O: C, 63.61; H, 4.11; N,
H ClFN O (MH+):
26 19 4 2
26 18
4
2
2
11.41. Found: C, 63.65; H, 3.86; N, 11.14.
(dimethylsulfoxide-d ). Mass spectral data (ms) are reported in
6
the form m/z (molecular ion, relative intensity).
8-{3-Chloro-4-[(3-fluorobenzyl)oxy]phenyl}-5-[(4-methyl -
phenyl)amino]pyrido[2,3-d]pyrimidin-7(8H)-one (2c).
N-{3-Chloro-4-[(3-fluorobenzyl)oxy]phenyl}-5-iodopyrimidin-
4-amine (4).
This compound was prepared from 4-methylaniline and 5 by
the method described for synthesis of 2b (59% yield): mp 298-
1
299 ºC; H nmr (dimethylsulfoxide-d ): δ 9.49 (s, 1H), 9.16 (s,
A mixture of 3 [10] (10 g, 42 mmol) and 3-chloro-4-[(3-fluo-
robenzyl)oxy]aniline [1] (10.5 g, 42 mmol) in ethanol (500 mL)
was heated at reflux for 2.5 hours. The resulting precipitate was
collected by filtration and the solid partitioned between ethyl
acetate and sodium hydroxide solution. The organic phase was
washed with brine, dried over sodium sulfate, filtered and con-
6
1H), 8.87 (s, 1H), 7.48 (dd, 1H, J=14, 8), 7.41 (d, 1H, J=2), 7.35-
7.20 (m, 7H), 7.18 (dd, 2H, J=8, 3), 5.68 (s, 1H), 5.30 (s, 2H),
2.33 (s, 3H); hplc: one major peak (99.9%); hrms: m/z Calcd. for
C H ClFN O (MH+): 487.1337; Found: 487.1338.
27 21
4 2
Anal. Calcd. for C H ClFN O : C, 66.60; H, 4.14; N, 11.51.
27 20 4 2
Found: C, 66.74; H, 4.13; N, 11.47.
centrated to an off-white solid which was used without further
1
purification (10 g, 52% yield): H nmr (dimethylsulfoxide-d ): δ
6
8-{3-Chloro-4-[(3-fluorobenzyl)oxy]phenyl}-5-[(4-methoxy -
phenyl)amino]pyrido[2,3-d]pyrimidin-7(8H)-one (2d).
8.61 (s, 1H), 8.45 (s, 1H), 8.41 (s, 1H), 7.64 (d, 1H, J=3), 7.45-
7.39 (m, 2H), 7.28-7.24 (m, 2H), 7.17-7.11 (m, 2H), 5.20 (s, 2H);
ms: m/z 456 (MH+, 100).
This compound was prepared from 4-methoxyaniline and 5 by
the method described for synthesis of 2b (71% yield): mp 295-
Methyl 3-[4-({3-Chloro-4-[(3-fluorobenzyl)oxy]phenyl}amino)-
pyrimidin-5-yl]prop-2-ynoate (5).
1
298 ºC; H nmr (dimethylsulfoxide-d ): δ 9.48 (s, 1H), 9.12 (s,
6
1H), 8.87 (s, 1H), 7.47 (dd, 1H, J=14, 8), 7.41 (d, 1H, J=3), 7.34
(d, 1H, J=7), 7.31-7.27 (m, 4H), 7.21-7.16 (m, 2H), 7.05 (d, 2H,
J=9), 5.53 (s, 1H), 5.30 (s, 2H), 3.78 (s, 3H); hplc: one major
A mixture of 4 (100 mg, 0.219 mmole), methyl propiolate (70
µL, 0.838 mmole), potassium carbonate (61 mg, 0.441 mmole),
cuprous iodide (2 mg, 0.011 mmole) and tetrakis(triphenylphos-
phine)palladium(0) (3 mg, 0.0043 mmole) in tetrahydrofuran (2
mL) was heated at 70 °C for 4 hours. The solvent was evaporated
and the crude material then purified by silica gel chromatography
eluting with 45% ethyl acetate/hexanes. This afforded 5 as a vis-
peak (99.9%); hrms: m/z Calcd. for C H ClFN O (MH+):
27 21
4 3
503.1286; Found: 503.1297.
Anal. Calcd. for C H ClFN O : C, 64.48; H, 4.01; N, 11.14.
Found: C, 64.46; H, 4.05; N, 11.12.
27 20
4 3
8 - { 3 - C h l o r o - 4 - [ ( 3 - f l u o r o b e n z y l ) o x y ] p h e n y l } - 5 - [ ( 4 - f l u o -
rophenyl)amino]pyrido[2,3-d]pyrimidin-7(8H)-one (2e).
1
cous oil (60 mg, 67% yield): H nmr (deuteriochloroform): δ 8.67
(br s, 1H), 8.54 (br s, 1H), 7.70 (d, 1H, J=2), 7.37-7.30 (m, 2H),
7.23-7.16 (m, 3H), 6.99 (dt, 1H, J=8, 3), 6.93 (d, 1H, J=9), 5.12 (s,
2H), 3.85 (s, 3H); hplc: one major peak (99.9%); hrms: m/z Calcd.
for C H ClFN O (MH+): 412.0864; Found: 412.0863.
This compound was prepared from 4-fluoroaniline and 5 by
the method described for synthesis of 2b (44% yield): mp 268-
1
269 ºC; H nmr (dimethylsulfoxide-d ): δ 9.47 (s, 1H), 9.21 (s,
6
21 16
3 3
1H), 8.89 (s, 1H), 7.48 (dd, 1H, J=14, 8), 7.42-7.29 (m, 8H),
7.21-7.17 (m, 2H), 5.66 (s, 1H), 5.30 (s, 2H); hplc: one major
peak (100%); hrms: m/z Calcd. for C H ClF N O (MH+):
8-{3-Chloro-4-[(3-fluorobenzyl)oxy]phenyl}-5-methoxypyrido-
[2,3-d]pyrimidin-7(8H)-one (2a).
26 18
2 4 2
A mixture of 5 (50 mg, 0.121 mmole) and potassium carbonate
(17 mg, 0.121 mmole) in methanol (1 mL) was stirred for 3 days
at room temperature. Water was added to the reaction mixture
and the resulting precipitate was collected by filtration. The filter
cake was washed with methanol and ethyl acetate and dried
under high vacuum to yield 2a as an off-white solid (31 mg, 62%
491.1086; Found: 491.1071.
Anal. Calcd. for C H ClF N O •2H O: C, 59.26; H, 4.02;
N, 10.63. Found: C, 59.35; H, 3.85; N, 10.58.
26 17
2
4
2
2
N-{4-[(8-{3-Chloro-4-[(3-fluorobenzyl)oxy]phenyl}-7-oxo-7,8-
dihydropyrido[2,3-d]pyrimidin-5-yl)amino]phenyl}acetamide
(2f).
1
yield): mp 249-251 ºC; H nmr (dimethylsulfoxide-d ): δ 9.10 (s,
6
This compound was prepared from 4'-aminoacetanilide and 5
by the method described for synthesis of 2b (56% yield): mp 345-
1H), 8.91 (s, 1H), 7.50-7.45 (m, 2H), 7.36-7.32 (m, 3H), 7.23 (dd,
1H, J=9, 3), 7.19 (dt, 1H, J=9, 3), 6.24 (s, 1H), 5.31 (s, 2H), 4.01
(s, 3H); hrms: m/z Calcd. for C H ClFN O (MH+): 412.0864;
1
347 ºC; H nmr (dimethylsulfoxide-d ): δ 10.04 (s, 1H), 9.48 (s,
6
21 16
3 3
1H), 9.16 (s, 1H), 8.87 (s, 1H), 7.68 (d, 2H, J=9), 7.48 (dd, 1H,
J=14, 8), 7.41 (d, 1H, J=3), 7.35-7.27 (m, 5H), 7.21-7.17 (m, 2H),
5.66 (s, 1H), 5.30 (s, 2H), 2.04 (s, 3H); hplc: one major peak
Found: 412.0870.
Anal. Calcd. for C H ClFN O : C, 61.25; H, 3.67; N, 10.20.
Found: C, 60.84; H, 3.69; N, 10.11.
21 15
3 3

358
E. E. Boros, E. R. Wood, O. B. McDonald, T. D. Spitzer,
A. M. Sefler, B. R. Reep, and J. B. Thompson
Vol. 41
Lackey, Bioorg. Med. Chem. Lett., 13, 637 (2003).
(99.9%); hrms: m/z Calcd foπr C
530.1395; Found 530.1398.
Anal. Calcd. for C H ClFN O : C, 63.46; H, 3.99; N, 13.22.
H C l F N O ( M H + ) :
2 8 2 2 5 3
[3] M. S. McClure, F. Roschangar, S. J. Hodson, A. Millar and M.
H. Osterhout, Synthesis, 1681 (2001) and references cited therein.
[4] F. Roschangar, J. C. Brown, B. E. Cooley, Jr., M. J. Sharp and
R. T. Matsuoka, Tetrahedron, 5 8, 1657 (2002) and references cited
therein.
28 21
Found: C, 63.60; H, 3.99; N, 13.26.
5 3
4-[4-({3-Chloro-4-[(3-fluorobenzyl)oxy]phenyl}amino)pyrim-
idin-5-yl]-2H-pyrido[1,2-a]pyrimidin-2-one (8).
[5] A. Gangjee, J. Shi and S. F. Queener, J. Med. Chem., 40, 1930
(1997).
This compound was prepared from 2-aminopyridine and 5 by
the method described for synthesis of 2b (58% yield): mp 276-
[6] D. H. Boschelli, Z. Wu, S. R. Klutchko, H. D. H. Showalter, J.
M. Hamby, G. H. Lu, T. C. Major, T. K. Dahring, B. Batley, R. L. Panek,
J. Keiser, B. G. Hartl, A. J. Kraker, W. D. Klohs, B. J. Roberts, S.
Patmore, W. L. Elliott, R. Steinkampf, L. A. Bradford, H. Hallak and A.
M. Doherty, J. Med. Chem., 41, 4365 (1998).
[7] J. W. Ellingboe, M. D. Collini, D. Quagliato, J. Chen, M.
Antane, J. Schmid, D. Hartupee, V. White, C. H. Park, T. Tanikella and J.
F. Bagli, J. Med. Chem., 41, 4251 (1998).
[8] A. Vasudevan, F. Mavandadi, L. Chen and A. Gangjee, J. Org.
Chem., 64, 634 (1999).
[9] H. Bredereck, F. Eff e n b e rg e r, E. Henseleit and E. H.
Schweizer, Chem. Ber., 96, 1868 (1963).
1
278 ºC; H nmr (dimethylsulfoxide-d ): δ 8.87 (s, 1H), 8.71 (s,
6
1H), 8.41 (s, 1H), 7.79 (d, 1H, J=7), 7.67 (t, 1H, J=8), 7.62 (d,
1H, J=3), 7.43 (dd, 1H, J=14, 8), 7.32 (dd, 1H, J=9, 2), 7.28-7.22
(m, 3H), 7.16-7.12 (m, 2H), 6.80 (t, 1H, J=7), 6.50 (s, 1H), 5.19
(s, 2H); hplc: one major peak (100%); hrms: m/z Calcd for
C H ClFN O (MH+): 474.1133; Found: 474.1146.
25 18 5 2
Anal. Calcd. for C H ClFN O : C, 63.36; H, 3.62; N, 14.78.
25 17 5 2
Found: C, 63.50; H, 3.64; N, 14.74.
Methyl (2Z)-3-[4-({3-Chloro-4-[(3-fluorobenzyl)oxy]phenyl} -
amino)pyrimidin-5-yl]-3-(1H-imidazol-1-yl)prop-2-enoate (9).
[10] A. Rosowsky and N. Papathanasopoulos, J. Heterocyclic
Chem., 11, 1081 (1974).
This compound was prepared from imidazole and 5 by the
method described for synthesis of 2b. Purification by silica gel
chromatography eluting with 5% methanol/ethyl acetate fol-
lowed by recrystallization from chloroform provided 9 as a light
[11] Syntheses of pyrido[2,3-d]pyrimidin-7(8H)-ones by Heck
coupling of ethyl acrylate to 4-amino-5-iodopyrimidines followed by
base-catalyzed ring closure are known; see, T. Sakamoto, Y. Kondo and
H. Yamanaka, Chem. Pharm. Bull., 30, 2410 (1982).
[12] T. Sakamoto, Y. Kondo, R. Watanabe and H. Yamanaka,
Chem. Pharm. Bull., 34, 2719 (1986).
[13] T. Eckert and J. Ipaktschi, Synth. Commun., 28, 327 (1998).
[14] R. M. Acheson, M. W. Foxton, P. J. Abbot and K. R. Mills, J.
Chem. Soc. (C), 882 (1967).
[15] Inhibition of EGFR and ErbB-2 tyrosine kinases were evalu-
ated using an in vitro assay for enzyme inhibition. The assay measured
the ability of intracellular domains of the human receptors to phosphory-
late a synthetic peptide substrate; for experimental details, see: P. S.
Brignola, K. Lackey, S. H. Kadwell, C. Hoffman, E. Horne, H. L. Carter,
J. D. Stuart, K. Blackburn, M. B. Moyer, K. J. Alligood, W. B. Knight and
E. R. Wood, J. Biol. Chem., 277, 1576 (2002).
1
yellow solid (69% yield): mp 91-94 °C (decomp.); H nmr
(dimethylsulfoxide-d ): δ 8.61 (s, 1H), 8.59 (s, 1H), 8.19 (s, 1H),
6
7.84 (s, 1H), 7.56 (s, 1H), 7.43 (dd, 1H, J=14, 8), 7.28-7.24 (m,
3H), 7.17-7.13 (m, 3H), 6.94 (s, 1H), 6.28 (s, 1H), 5.18 (s, 2H),
3.65 (s, 3H); ms: m/z 480 (MH+, 100).
Anal. Calcd for C H ClFN O •0.25H O: C, 59.51; H, 4.06;
24 19
N, 14.46. Found: C, 59.43; H, 3.99; N, 14.26.
5
3
2
REFERENCES AND NOTES
[16] IC values for inhibition of ErbB-2 and EGFR by GW2016
[1] G. S. Cockerill, M. C. Carter, M. Clive, S. B. Guntrip and K. J.
Smith, US Patent 6,391,874 (1998); Chem. Abstr., 128, 140718 (1998).
[2] M. D. Gaul, Y. Guo, K. Affleck, G. S. Cockerill, T. M. Gilmer,
R. J. Griffin, S. Guntrip, B. R. Keith, W. B. Knight, R. J. Mullin, D. M.
Murray, D. W. Rusnak, K. Smith, S. Tadapalli, E. R. Wood and K.
50
are 9.2 and 10.8 nM, respectively, see: D. W. Rusnak, K. Lackey, K.
A ffleck, E. R. Wood, K. J. Alligood, N. Rhodes, B. R. Keith, D. M.
Murray, K. Glennon, W. B. Knight, R. J. Mullin and T. M. Gilmer, Mol.
Cancer Ther., 1, 85 (2001).