Novel oxazolo[4,5-g]quinazolin-2(1H)-ones: Dual inhibitors of EGFR and Src protein tyrosine kinases

Article abstract of DOI:10.1016/j.ejmech.2012.06.055

Quinazoline-containing derivatives are an important class of synthetic products and represent an attractive scaffold for EGFR inhibitors. A series of oxazolo[4,5-g]quinazolin-2(1H)-one derivatives were synthesized and the EGFR and Src inhibition activities were evaluated using Gefitinib as lead compound. The three most potent compounds 5y, 5l and 5a each inhibited EGFR at the IC ₅₀ value of 61 nM, 67 nM and 78 nM. Among them, 5c also demonstrated excellent inhibition activity against Src with the IC₅₀ value of 3.1 μM. Several of these derivatives also showed good anti-proliferation effects against KB and A498 cells.

Full text of DOI:10.1016/j.ejmech.2012.06.055

European Journal of Medicinal Chemistry 55 (2012) 39e48
Contents lists available at SciVerse ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
Novel oxazolo[4,5-g]quinazolin-2(1H)-ones: Dual inhibitors of EGFR and Src
protein tyrosine kinases
*
Jinsheng Lin, Wei Shen, Jingwei Xue, Juan Sun, Xue Zhang, Can Zhang
Center of Drug Discovery, State Key Laboratory of Natural Medicines, China Pharmaceutical University, No. 24 Tongjia Xiang, Gulou District, Nanjing 210009, PR China
a r t i c l e i n f o
a b s t r a c t
Article history:
Quinazoline-containing derivatives are an important class of synthetic products and represent an
attractive scaffold for EGFR inhibitors. A series of oxazolo[4,5-g]quinazolin-2(1H)-one derivatives were
synthesized and the EGFR and Src inhibition activities were evaluated using Gefitinib as lead compound.
The three most potent compounds 5y, 5l and 5a each inhibited EGFR at the IC50 value of 61 nM, 67 nM
and 78 nM. Among them, 5c also demonstrated excellent inhibition activity against Src with the IC50
Received 8 May 2012
Received in revised form
25 June 2012
Accepted 27 June 2012
Available online 7 July 2012
value of 3.1
A498 cells.
m
M. Several of these derivatives also showed good anti-proliferation effects against KB and
Keywords:
Ó 2012 Elsevier Masson SAS. All rights reserved.
Protein tyrosine kinases (PTK)
Anti-tumor agents
EGFR inhibitor
Src inhibitor
Oxazolo[4,5-g]quinazolin-2(1H)-one
scaffold
1. Introduction
Gefitinib (Iressa, AstraZeneca, 1), Erlotinib (Tarceva, OSI Pharma-
ceuticals, 2) and Lapatinib (Tykerb, Glaxo-SmithKline, 3) etc. (Fig. 1)
Human tumors overexpress growth factor receptor tyrosine
kinase enzymes of the erbB family, and this overexpression is
associated with poor prognosis of the disease [1e3]. Inhibitors of
growth factor signaling through these pathways, especially via
erbB-1 (EGFR, HER-1) and erbB-2 (HER-2, neu), have thus been
thought as potential anticancer drugs [4]. Overexpression of
epidermal growth factor receptor (EGFR) plays a crucial role in
mediating tumor cell growth of NSCLC and is observed as well as
many other types of cancer, such as ovarian cancer, breast cancer,
etc. [5e9].
There are two classes of inhibitors of EGFR: (i) monoclonal
antibodies such as Cetuximab (IMC-C225) and Panitumumab (INN)
which block binding of native EGF ligand to the receptor for
treatment of metastatic colorectal cancer and head and neck
cancer, (ii) small molecules that compete with ATP in the intra-
cellular tyrosine kinase domain (TKD) and block activity which
don’t need to consider about endogenous ligand binding [10]. In
recent years, the development of EGFR inhibitors focuses on ATP
competitive inhibitors, and many small molecules including
were approved [11e15]. These quinazoline-containing derivatives
form an important class of synthetic products and represent an
attractive scaffold for EGFR inhibitors. However, due to the recent
findings of EGFR mutations which render the kinase resistant to
Gefitinib and Erlotinib, there is an urgent need for new scaffolds to
solve this tough problem [16]. A surprising dearth of chemically
distinct small inhibitors is still existing despite years of intensive
researches on EGFR inhibitors. Many studies have been targeted to
find new structures containing 4-anilinoquinazolines as basic core
which can overcome EGFR drug resistance mutations [17e19].
In order to search new promising anti-tumor agents which act
similar to quinazoline-containing EGFR inhibitors, a series of
1-akyl-oxazolo[4,5-g]quinazolin-2(1H)-one
derivatives
were
synthesized and evaluated for the EGFR inhibition activity applying
Gefitinib as parent compounds. With the purpose of developing
new scaffold, the 6 and 7-positon heteroatoms of quinazoline ring
was condensed with carbonyl reagent to give tricyclic oxazolo[4,5-
g]quinazolin-2(1H)-one on the basis of retaining the hydrophilic
alkyl groups of the structure of Gefitinib. And then several different
phenyl amines substituted the 8-substituted aromatic head frag-
ment to further investigate the structureeactivity relationship
(SAR). Among these designed compounds, it is remarkably
inspiring that the compound 5y with new structure showed better
* Corresponding author. Tel./fax: þ86 25 83271171.
E-mail
addresses:
zhangcan@cpu.edu.cn,
zhangcancpu@yahoo.com.cn
(C. Zhang).
0223-5234/$ e see front matter Ó 2012 Elsevier Masson SAS. All rights reserved.
http://dx.doi.org/10.1016/j.ejmech.2012.06.055

40
J. Lin et al. / European Journal of Medicinal Chemistry 55 (2012) 39e48
Fig. 1. The structures of Gefitinib, Erlotinib, Lapatinib and SU6656.
inhibition against EGFR compared with the parent compound
(Fig. 2).
chloropropyl)morpholine in the presence of K2CO3 in refluxing of
acetonitrile to give compound 11. Then the intramolecular
condensation of compound 11 with formamidine acetate in EtOH
at reflux produced oxazolo[4,5-g]quinazoline-2,8(1H,7H)-dione 12.
Treatment of compound 12 with thionyl chloride using DMF as the
catalyst at reflux yielded compound 13 and the final nucleophilic
substitution with aniline furnish the target molecules.
The Src inhibition activity of the designed compounds was also
evaluated using SU6656 (4) as positive control. Several of them
demonstrated moderate inhibition against Src, and among these
compounds 5c was the most potent compound for the inhibition of
this kinase enzyme.
2. Results and discussion
2.2. Biological activities
2.1. Chemistry
2.2.1. In vitro inhibition activities studies of kinases
All the designed compounds were tested for effect on EGFR
tyrosine kinase inhibition, as showed in Table 1. Many compounds
bearing aromatic group at 8-position displayed potent inhibition
activity against EGFR. Among them compounds 5a, 5l and 5y
The synthetic procedures were showed in Scheme 1 and
Scheme 2. Nitration of compound 7 with concentrated HNO3
gave the mixture of nitrobenzene 9 and its isomer compound 8,
which were purified through column chromatography to obtain
compound 9. Reduction of compound 9 with iron power in the
mixture of MeOH and glacial acetic acid afforded amino benzene
10, which was further nucleophilically substituted with 1-(3-
inhibited EGFR at the IC50 values of 0.078, 0.067 and 0.061
mM
respectively (summarized in Table 2). Many compounds without
8-subistituted phenyl groups showed poor EGFR inhibitory activity
which further demonstrated that phenyl moiety was essential for
Fig. 2. The designed inhibitors of EGFR.

J. Lin et al. / European Journal of Medicinal Chemistry 55 (2012) 39e48
41
Scheme 1. Reagents and reaction conditions: (a) conc. HNO3, 60 ꢀC, 8 h; (b) reduced iron powder, acetic acid, MeOH, 65 ꢀC, overnight; (c) 1-(3-chloropropyl)morpholine,
acetonitrile, K2CO3, KI, reflux, 3 h; (d) formamidine acetate, ethanol, reflux, 24 h; (e) SOCl2, DMF (cat.), reflux, 16 h; (f) aniline, i-PrOH, 60 ꢀC to reflux, 6e24 h.
this kind of EGFR inhibitors. In comparing with other benzyl amino
groups, aniline moieties directly conjugating to the 8-position
increased EGFR inhibition activities, as illustrated by the more
potent activities of compounds 5y, 5l than 6b, 6c and 6d. Further-
more, although most of the designed compounds exhibited poor
activities to Src, it is quite interesting to note that 5c exhibited
cells by MTT assay using Gefitinib as a positive control. As shown in
Table 4, some compounds exhibited good anti-proliferative activi-
ties with low
mM IC50 values, among which compounds 5y showed
the best activities with IC50 values at 0.82 and 3.0
mM against KB
and A498 cells, respectively. It is worthy to note that compounds 5c
only showed both moderate activities against EGFR and Src, but it
exhibited promising anti-proliferative effects against KB and A498
cells.
moderate activity to Src (IC50 ¼ 3.1
mM) while the reference
compound Gefitinib showed no activity (Table 3).
Among the compounds synthesized, we found that replacement
of the aromatic ring with other no-aromatic group at 8-position (6e
and 6f) resulted in significantly reduced biochemical potency
against EGFR, Src, KB and A498 cells. Phenyl amines directly
2.2.2. In vitro cell cytotoxicity assay
In vitro cell cytotoxicity of the 33 oxazolo[4,5-g]quinazolin-
2(1H)-one derivatives was initially evaluated against KB and A498
Scheme 2. Reagents and reaction conditions: (a) aniline, i-PrOH, 60 ꢀC to reflux, 10e18 h; (b) trans-4-aminocyclohexanol, i-PrOH, TEA, 50 ꢀC, 24 h; (c) 1-methylpiperazine, i-PrOH,
TEA, reflux, 12 h; (d) 1H-indazol-5-amine, i-PrOH, reflux, 13 h.

42
J. Lin et al. / European Journal of Medicinal Chemistry 55 (2012) 39e48
Table 1
Table 3
Structures and in vitro EGFR inhibited activities of compounds with 8-subistituted
phenyl groups.
In vitro Src inhibited activities of compounds with 8-subistituted phenyl groups.
Compd
Srca IC50
(
m
M)
Compd
Srca IC50
66
(mM)
Compd
R
EGFRa IC50
(mM)
5c
3.1
5j
5a
5b
5c
5d
5e
5f
5g
5h
5i
5j
5k
5l
5m
5n
5o
5p
5q
5r
3-Cl-4-F
3-Ethynyl
4-Ethoxycarbonyl
4-(SO2NH2)
4-OCH3
3,4-Di-OCH3
4-(4-Cl-BnOCO)
3,5-Di-CH3
3-Ethoxycarbonyl-6-OH
4-OH
4-OC2H5
4-CH3
4-(4-Cl-BnO)
4-Cl
4-BnO
2-CH3
2-OH
3,4-Di-F
3-Isopropoxyl
3-Acetyl
0.078
0.38
5l
7.5
Gefitinib
Inactiveb
SU6656
0.073
5.8
a
Data shown are from triplicate experiments.
Inactive at >100 mM.
Inactiveb
0.38
b
Inactiveb
Inactiveb
75
Table 4
Cellular anti-proliferative data for the selected compounds.
0.23
Inactiveb
1.4
a
a
Compd
Cell inhibition IC50
(
m
M)
Compd Cell inhibition IC50
(
mM)
KBb
A498c
KBb
A498c
0.067
0.99
5a
5i
5o
5y
6.5
8.1
37.6
0.82
2.8
32
5c
6.0
37.1
16.0
18.5
8.8
7.4
35.3
18.7
Inactiveb
0.14
15.7
14.8
3.0
5m
5w
6g
Inactiveb
30
Gefitinib
8.6
0.57
3.0
6.8
7.8
a
IC50 values are reported as means of at least three determinations.
KB cells is a cell line derived from a human carcinoma of the nasopharynx that
5s
5t
b
overexpresses both EGFR and Src.
5u
5v
5w
5x
5y
4-[(3-CH3-4-OCH2CF3)ePyr.-2-CH2O]
4-CH3CONH
3-[(3-CH3-4-OCH2CF3)ePyr.-2-CH2O]
4-(2-Pyr.CH2O)
3-Cl-4-(4-Cl-BnO)
4-Tert-butyl
c
Inactiveb
0.099
1.7
A498 cells is a renal cell carcinoma (RCC) cell line that overexpresses both EGFR
and Src.
0.061
79
0.072
5z
Gefitinib
structures of the enzyme with Lapatinib (ID: 1XKK) and Gefitinib
(ID: 1M17) were obtained from protein data bank PDB.
a
Data shown are from triplicate experiments.
Inactive at >100 mM.
Since it is found that Gefitinib mimic ATP and the ATP binding
site is sandwiched between the lobes where ATP forms critical
hydrogen bonding interactions to the hinge region, the binding of
ATP itself involves two important hydrogen bonding interactions
between the purine base of ATP and the kinase backbone between
amino acids Gln767 and Met769 and the quinazoline ring of Gefi-
tinib have two nitrogen atoms that act as hydrogen bond acceptors
[20]. The kinase or catalytic domain consists of an N-terminal lobe,
b
conjugating to the 8-position in comparing with other benzyl
amines contributed more to the cytotoxicity and inhibition against
kinases, as it was suggested by the results of compounds 5l, 5y and
6b, 6c, 6d; whereas some compounds bearing other aromatic ring
such as benzoheterocycle at the 8-position also showed obvious
EGFR inhibition and cytotoxicity to KB and A498 cells, for example,
which consists mainly of
b
-strands but contains one
a-helix and C
compound 6g was found to be active at 18.5 and 18.7
mM; and 6g
helix. The C-terminal lobe is mainly
a
-helical, and a short strand
also showed high inhibition to EGFR with the IC50 value of 0.12
mM;
termed the hinge region connects the two lobes.
introducing methyl group, halogen or alkoxyl group into the m- or
p-position on the 8-postion aniline ring contributed to the increase
of biochemical activity, while o-substitution resulted in a signifi-
cant loss of potency (such as 5p and 5q). This probably arises from
the augmentation of steric interactions between the o-substituent
groups and the oxazolo[4,5-g]quinazolin-2(1H)-ones core which
force the aniline ring to adopt a less optimal geometry in the
binding pocket. The kinase inhibition activities and cytotoxicities
would reduced or even disappear after adopting highly hydrophilic
moiety such as sulphonylamino, acetyl and acetylamino group to 8-
postion phenyl ring as the illustration of 5d, 5t and 5v.
Compound 5a was initially docked to the EGFR active site cavity
based on the structure of the Gefitinib DEP-in enzyme complex
(EGFR; PDB ID: 1M17) and the resulting structure of the active site
2.3. Molecular docking study
Docking study was carried out for the target compounds into
EGFR using Discovery Studio version 2.5.5 and Glide version 7.3,
Tripos Inc and Molegro virtual docker version 2007. The crystal
Table 2
In vitro EGFR inhibited activities of compounds with non-phenyl 8-subistituted
amine groups.
Compd
EGFRa IC50
(
m
M)
Compd
EGFRa IC50
(mM)
6a
6c
6e
6g
7.2
4.5
6b
6d
6f
3.7
65
Inactiveb
0.12
Inactiveb
0.072
Fig. 3. Docking model of compounds’ enzyme complex. Gefitinib (purple), 5a (yellow)
docked into the catalytic gorge of EGFR (PDB ID: 1M17). (For interpretation of the
references to color in this figure legend, the reader is referred to the web version of this
article.)
Gefitinib
a
Data shown are from triplicate experiments.
b
Inactive at >100 mM.

J. Lin et al. / European Journal of Medicinal Chemistry 55 (2012) 39e48
43
was shown in Fig. 3. The most likely conformations of the ligand
were selected based on the calculated docking score for the
bonding strength.
It was found that 5a forms hydrogen binding interactions in the
hinge region between the N5 nitrogen and the backbone NH of
Met769, N7 nitrogen and the side-chain OH of Thr 830 via
a bridging water molecule which is similar to Gefitinib. But it was
disappointed to find that 5y was poorly docked into EGFR active
conformation. As 5y showed promising activity against EGFR, we
hypothesized there may be exist another mechanism. So we docked
5y into the inactive conformation of EGFR with the ligand of
Lapatinib (PDB ID: 1XKK), and it was excited to see that 5y fit well in
the DEP-out form of the enzyme (Fig. 4).
These docking studies had revealed that the oxazolo[4,5-g]
quinazolin-2(1H)-one ring binds to a narrow hydrophobic pocket in
the N-terminal domain of EGFR where N5 of the quinazoline ring
interacts with the backbone NH of Met 793 via a hydrogen bond,
and similarly, a water molecule-mediated hydrogen bonding
interaction was observed between the N7 of the quinazoline ring
and the Thr 854 side chain, and it was glad to see that a water
molecule-mediated hydrogen bonding interaction also was
observed between carbonyl oxygen atom at C2 of the oxazolo[4,5-
g]quinazolin-2(1H)-one core and the backbone NH of Cys 797. The
aniline moiety lies in a deep hydrophobic pocket, which located at
the same position of the 30-chloro-40-(3-fluorobenzyl)oxy moiety of
Lapatinib. All of these demonstrated that compound 5y worked
similarly as Lapatinib (Fig. 5).
Fig. 5. Binding model of 5y to ATP binding site of EGFR DEP-out conformation (PDB ID:
1XKK).
indicated that most of these derivatives were good inhibitors with
a range of 2.2e6.4 mM, which inhibited EGF mediated phosphory-
lation of EGFR. Src inhibition activity of these compounds was also
evaluated, but only two compounds showed moderate inhibition
activityagainst it. These derivatives exhibited high potencies of anti-
proliferation activities against KB and A498 cells, among them four
tested compounds exhibited more potent inhibitive activities than
the reference compounds Gefitinib. It is worthy to note that
compound 5y showed high inhibitory activities against EGFR with
an IC50 value of 0.061 mM. These findings presented herein showed
3. Conclusions
the potential of building oxazolo[4,5-g]quinazolin-2(1H)-one scaf-
fold and adopting the hydrophilic side-chain 3-morpholinopropoxyl
group at its 1-position for EGFR small molecule inhibitors.
In summary, a series of newoxazolo[4,5-g]quinazolin-2(1H)-one
derivatives were synthesized and subjected to pharmacological
evaluation. The results showed that most of oxazolo[4,5-g]quina-
zolin-2(1H)-one derivatives possessed moderate to high EGFR
inhibition activities. Protein tyrosine kinase inhibitions assay
4. Experimental sections
4.1. Chemistry: general procedures
All commercially available starting materials, reagents and
solvents were used without further purification unless otherwise
stated. Melting points were determined with an Electro thermal
melting point apparatus, and are uncorrected. High-resolution
mass spectra (HRMS) were recorded on QSTAR XL Hybrid MS/MS
mass spectrometer. Infrared (IR) spectra were recorded on Thermo
FTIR spectrometer (KBr disks). 1H NMR and 13C NMR spectra on
a Bruker AV 300 or 500 MHz spectrometer were recorded in DMSO-
d6 or CDCl3. Chemical shifts are reported in d (ppm) units relative to
the internal standard tetramethylsilane (TMS). The reaction
conditions were not optimized for reaction yields. All oxygen-
sensitive or moisture-sensitive reactions were run under nitrogen
atmosphere. All the reactions were monitored by thin layer chro-
matography (TLC) on pre-coated silica gel G plates at 254 nm under
a UV lamp using ethyl hexane/acetate or DCM/MeOH as eluent.
Column chromatography separations were obtained on silica gel
(200e300 mesh).
4.1.1. Ethyl 6-nitro-2-oxo-2,3-dihydrobenzo[d]oxazole-5-
carboxylate (9)
Compound 7 (103.5 g, 0.500 mol) was added portionwise to
500 ml conc. HNO3 at the temperature of 0e5 ꢀC. The mixture was
heated to 60 ꢀC and stirred for 8 h at this temperature, after the
starting material was completely consumed. Then the solution was
poured to 2.5 l cold water. The resulting precipitate was filtered and
washed with chill water, dried, and the crude product was purified
by silica gel column chromatography with petroleum ether/acetate
Fig. 4. Ribbon model of the X-ray of crystal structure of 5y bond to the ATP binding
domain of EGFR DEP-out conformation (PDB ID: 1XKK).

44
J. Lin et al. / European Journal of Medicinal Chemistry 55 (2012) 39e48
(4/1, v/v) as mobile phase to give compound 9 (88.3 g, yield, 70%)
and the by-product compound 8 (34.0 g, yield, 27%) as a pale yellow
solid. Compound 9: Mp: 162e164 ꢀC, 1H NMR (300 MHz, DMSO-d6)
added dropwise and the reaction flask was heated to reflux for 16 h.
Most of the excess of thionyl chloride and DMF was then removed
under reduced pressure and the yellow residue was purified by
silica gel column chromatography with DCM/MeOH (60/1, v/v) as
mobile phase to give compound 13 (20.0 g, yield, 82%); Mp:
d
: 12.60 (1H, bs), 8.16 (1H, s), 4.30 (2H, q, J ¼ 6.9 Hz), 1.29 (3H, t,
J ¼ 6.9 Hz); IR (film, cmꢁ1): 3289, 3062, 2990, 1788, 1712, 1626,
1540, 1477, 1372, 1292, 1247, 1104, 929, 893, 651.
150e152 ꢀC; 1H NMR (500 MHz, DMSO-d6)
d: 8.98 (1H, s), 7.98 (1H,
Compound 8: Mp: 173e175 ꢀC, 1H NMR (300 MHz, DMSO-d6)
d:
s), 7.90 (1H, s), 4.07 (2H, t, J ¼ 6.4 Hz), 3.46 (4H, t, J ¼ 4.1 Hz), 2.37
(2H, t, J ¼ 6.4 Hz), 2.25 (4H, m), 1.93 (2H, p, J ¼ 7.1 Hz); IR (film,
cmꢁ1): 3075, 2947, 1799, 1604, 1567, 1481, 1443, 1350, 1258, 1109,
1071, 1021, 956, 809, 746, 682.
12.78 (1H, bs), 7.70 (1H, d, J ¼ 8.7 Hz), 7.42 (1H, d, J ¼ 8.7 Hz), 4.31
(2H, q, J ¼ 7.1 Hz), 1.27 (3H, t, J ¼ 7.1 Hz); IR (cmꢁ1): 3196, 2995,
2360, 1786, 1728, 1641, 1540, 1477, 1356, 1314, 1266, 1190, 1021, 945,
833, 740.
4.2. General procedure for the synthesis of oxazolo[4,5-g]
4.1.2. Ethyl 6-amino-2-oxo-2,3-dihydrobenzo[d]oxazole-5-
carboxylate (10)
quinazolin-2(1H)-one derivatives (5ae5z, 6ae6g)
A mixture of compound 9 (88.3 g, 0.35 mol), reduced iron power
(60.8 g, 1.08 mol), acetic acid (600 ml) in 2 l CH3OH was mechan-
ically stirred at reflux for 3 h. After cooled to room temperature, this
mixture was added aqueous ammonia until the PH was adjusted to
10. The mixture was filtered and the solid was washed with hot
CH3OH (500 ml). The solvent was removed from filtrate and the
resulting solid was extracted with boiling acetone (600 ml) and
filtered. The acetone extracts were concentrated in vacuo. The
residue was recrystallized from EtOAc (300 ml) to 71.5 g (yield, 92%)
of compound 10 as light brown solid. The compound was used
without further purification: Mp: 173e175 ꢀC; 1H NMR (300 MHz,
4.2.1. 8-(3-Chloro-4-fluorophenylamino)-1-(3-morpholinopropyl)
oxazolo[4,5-g]quinazolin-2(1H)-one (5a)
3-Chloro-4-fluoroaniline (172 mg, 1.18 mmol) was added to
a solution of compound 13 (373 mg, 1.07 mmol) in isopropanol
(10 ml) and stirred at reflux for 8 h. The mixture was cooled to room
temperature and filtered, then the solid was washed with chill
isopropanol (5 ml), treated with aqueous NaHCO3 (10 ml) and
extracted with EtOAc/MeOH (20:1, 30 ml). The organic layer was
washed with brine, dried over MgSO4, and concentrated. Chroma-
tography of the residue on silica gel with DCMeMeOH (50/1, v/v)
gave 416 mg (yield, 85%) of the title compound as white solid: Mp:
248e250 ꢀC; HRMS, ESIþ, m/z: Calcd for C22H22ClFN5O3 (M þ H)þ,
DMSO-d6) d: 8.63 (1H, bs), 7.57 (1H, s), 6.53 (1H, s), 4.35(2H, q,
J ¼ 7.0 Hz), 1.39 (3H, t, J ¼ 7.0 Hz); IR (film, cmꢁ1): 3459, 3351, 3255,
458.1390; found, 458.1388; 1H NMR (500 MHz, CDCl3)
d: 8.73 (1H,
2991, 1775, 1665, 1583, 1426, 1279, 1229, 1126, 1077, 929, 866, 706.
s), 7.95 (1H, dd, J ¼ 2.6 Hz, 6.4 Hz), 7.54 (1H, m), 7.31 (1H, s), 7.22
(1H, d, J ¼ 4.2 Hz), 7.19 (1H, m), 4.05 (2H, t, J ¼ 6.7 Hz), 3.64 (4H, t,
J ¼ 4.4 Hz), 2.47 (2H, t, J ¼ 6.6 Hz), 2.41 (4H, m), 2.05 (2H, p,
4.1.3. Ethyl 6-amino-3-(3-morpholinopropyl)-2-oxo-2,3-
dihydrobenzo[d]oxazole-5-carboxylate (11)
J ¼ 6.7 Hz); 13C NMR (125 MHz, DMSO-d6)
d:156.82, 154.27, 152.75,
152.33, 147.08, 146.43,136.38, 131.21, 123.61, 122.45, 122.40, 116.58,
116.43, 111.51, 106.48, 100.12, 65.90, 55.49, 53.24, 40.91, 22.82.
K2CO3 (24.8 g, 180 mmol), KI (0.75 g, 4.5 mmol) and 4-(3-
chloropropyl) morpholine (16.2 g, 99 mmol) were added succes-
sively to a solution of the compound 10 (20 g, 90.0 mmol) in
acetonitrile (250 ml) and the mixture was stirred at 70 ꢀC for 3 h.
The mixture was poured to water (500 ml) and the aqueous phase
was extracted with EtOAc (3 ꢂ 400 ml). The organic solution was
washed with water follow by saturated aqueous NaCl solution,
dried over anhydrous MgSO4, and the solvent was evaporated to
afford the compound 11 (30.5 g, yield, 97%), which was used to the
next reaction without further purification. Mp: 126e128 ꢀC; 1H
4.2.2. 8-(3-Ethynylphenylamino)-1-(3-morpholinopropyl)oxazolo
[4,5-g]quinazolin-2(1H)-one (5b)
White solid, 372 mg, yield, 81%; Mp: 240e243 ꢀC; HRMS, ESIþ,
m/z: Calcd for C24H23N5O3 (M þ H)þ, 430.1874; found, 430.1871; 1H
NMR (500 MHz, DMSO-d6) d: 9.66 (1H, bs), 8.57 (1H, s), 8.26 (1H, s),
8.01 (1H, s), 7.91 (1H, d, J ¼ 8.2 Hz), 7.68 (1H, s), 7.43 (1H, t,
J ¼ 7.8 Hz), 7.25 (1H, t, J ¼ 7.6 Hz), 4.20 (2H, s), 4.00 (2H, t,
J ¼ 6.4 Hz), 3.40 (4H, m), 2.39 (2H, m), 2.44 (4H, m), 2.05 (2H, m);
NMR (500 MHz, DMSO-d6) d: 7.45 (1H, s), 6.71 (1H, s), 4.28 (2H, q,
J ¼ 7.1 Hz), 3.79 (2H, t, J ¼ 3.8 Hz), 3.53 (4H, t, J ¼ 4.3 Hz), 2.28 (6H,
m), 1.81 (2H, p, J ¼ 7.3 Hz), 1.32 (3H, t, J ¼ 7.1 Hz); IR (film, cmꢁ1):
3498, 3379, 3052, 2945, 2856, 2815, 1777, 1688, 1580, 1491, 1431,
1369, 1269, 1233,1117, 1064, 955, 871, 734.
13C NMR (75 MHz, DMSO-d6)
d:156.94, 153.57, 152.86, 147.13,
146.43, 139.42,131.21, 128.88, 126.66, 124.90, 122.68, 121.76, 111.65,
106.47, 100.26, 83.32, 80.54, 65.92, 55.50, 53.25, 40.92, 22.84.
4.2.3. Ethyl 4-(1-(3-morpholinopropyl)-2-oxo-1,2-dihydrooxazolo
[4,5-g]quinazolin-8-ylamino)benzoate (5c)
4.1.4. 1-(3-Morpholinopropyl)oxazolo[4,5-g]quinazoline-
2,8(1H,7H)-dione (12)
White solid, 313 mg, yield, 75%; Mp: 234e237 ꢀC; HRMS, ESIþ,
m/z: Calcd for C25H28N5O5 (M þ H)þ, 478.2085; found, 478.2094; 1H
A solution of compound 11 (30.5 g, 87.3 mmol) and formamidine
acetate (10.9 g, 104.8 mmol) in ethanol (120 ml) was heated at
reflux for 24 h under the protection of N2. The mixture was cooled
to room temperature and filtered, then the solid was washed with
EtOH (50 ml) and water (40 ml), and dried to give compound 12 as
white power (23.1 g, yield, 80%); Mp: 218e219 ꢀC; 1H NMR
NMR (500 MHz, DMSO-d6) d: 9.86 (1H, bs), 8.63 (1H, s), 8.29 (1H, s),
8.06 (2H, d, J ¼ 8.8 Hz), 8.00 (2H, d, J ¼ 8.8 Hz), 7.71 (1H, s), 4.32 (2H,
q, J ¼ 7.0 Hz), 4.01 (2H, t, J ¼ 6.4 Hz), 3.40 (4H, t, J ¼ 4.4 Hz), 2.38 (2H,
t, J ¼ 6.6 Hz), 2.23 (4H, m), 2.01 (2H, p, J ¼ 6.5 Hz), 1.34 (3H, t,
J ¼ 7.0 Hz); 13C NMR (75 MHz, DMSO-d6)
d: 165.33, 156.68, 153.56,
152.67, 147.32, 146.54, 143.81,131.36, 129.77, 124.02, 120.78, 111.89,
106.51, 100.26, 65.93, 60.34, 55.50, 53.27, 40.92, 22.84, 14.17.
(500 MHz, DMSO-d6)
d
: 12.25 (1H, bs), 8.05 (1H, s), 7.94 (1H, s), 7.59
(1H, s), 3.98 (2H, t, J ¼ 6.4 Hz), 3.49 (4H, t, J ¼ 4.4 Hz), 2.31 (2H, t,
J ¼ 3.5 Hz), 2.23 (4H, m), 1.88 (2H, p, J ¼ 6.9 Hz); IR (film, cmꢁ1):
3496, 3159, 3011, 2871, 2810, 1780, 1658, 1589, 1487, 1368, 1270,
1116, 1067, 967, 912, 877, 788, 745.
4.2.4. 4-(1-(3-Morpholinopropyl)-2-oxo-1,2-dihydrooxazolo[4,5-g]
quinazolin-8-ylamino)benzenesulfonamide (5d)
White solid, 404 mg, yield, 78%; Mp: 273e275 ꢀC; HRMS, ESIþ,
m/z: Calcd for C22H25N6O5S (M þ H)þ, 485.1602; found, 485.1609;
4.1.5. 8-Chloro-1-(3-morpholinopropyl)oxazolo[4,5-g]quinazolin-
2(1H)-one (13)
1H NMR (500 MHz, DMSO-d6)
d: 9.88 (1H, bs), 8.62 (1H, s), 8.29 (1H,
Compound 12 (23.1 g, 69.8 mmol) was added to thionyl chloride
(180 ml) with magnetic stirring, then DMF (1.0 ml) was slowly
s), 8.05 (2H, d, J ¼ 8.6 Hz), 7.86 (2H, d, J ¼ 8.6 Hz), 7.72 (1H, s), 4.01
(2H, t, J ¼ 6.2 Hz), 3.40 (4H, m), 2.39 (2H, m), 2.24 (4H, m), 2.01 (2H,

J. Lin et al. / European Journal of Medicinal Chemistry 55 (2012) 39e48
45
p, J ¼ 7.0 Hz); 13C NMR (75 MHz, DMSO-d6)
d
:156.89, 153.62, 152.76,
4.2.10. 8-(4-Hydroxyphenylamino)-1-(3-morpholinopropyl)
147.33, 146.61, 142.34, 138.35, 131.42, 126.34, 121.41, 111.84, 106.52,
106.35, 65.91, 55.48, 53.27, 40.95, 22.83.
oxazolo[4,5-g]quinazolin-2(1H)-one (5j)
White solid, 392 mg, yield, 87%; Mp: 260e263 ꢀC; HRMS, ESIþ,
m/z: Calcd for C22H24N5O4 (M þ H)þ, 422.1823; found, 422.1830; 1H
4.2.5. 8-(4-Methoxyphenylamino)-1-(3-morpholinopropyl)oxazolo
[4,5-g]quinazolin-2(1H)-one (5e)
NMR (500 MHz, DMSO-d6) d:9.47 (1H, bs), 9.33 (1H, bs), 8.42 (1H,
s), 8.22 (1H, s), 7.60 (1H, s), 7.48 (2H, d, J ¼ 8.4 Hz), 6.81 (2H, d,
J ¼ 8.4 Hz), 3.97 (2H, t, J ¼ 6.4 Hz), 3.41 (4H, m), 2.38 (2H, t,
J ¼ 6.5 Hz), 2.24 (4H, m), 1.99 (2H, p, J ¼ 6.4 Hz); 13C NMR (75 MHz,
White solid, 423 mg, yield, 87%; Mp: 222e225 ꢀC; HRMS, ESIþ,
m/z: Calcd for C23H26N5O4 (M þ H)þ, 436.1979; found, 436.1987; 1H
NMR (500 MHz, DMSO-d6)
d
: 9.54 (1H, bs), 8.44 (1H, s), 8.22 (1H, s),
DMSO-d6) d:157.51, 154.20, 153.65, 153.35, 146.89, 146.17, 130.83,
7.65 (2H, d, J ¼ 8.6 Hz), 7.62 (1H, s), 7.00 (2H, d, J ¼ 8.6 Hz), 3.97 (2H,
t, J ¼ 6.6 Hz), 3.78 (3H, s), 3.40 (4H, t, J ¼ 4.5 Hz), 2.38 (2H, t,
J ¼ 6.6 Hz), 2.23 (4H, m), 2.01 (2H, p, J ¼ 6.6 Hz); 13C NMR (75 MHz,
130.16, 124.95, 114.99, 111.52, 106.33, 100.41, 65.96, 55.55, 53.29,
40.91, 22.90.
DMSO-d6)
d
:157.37, 155.92, 153.62, 153.23, 146.93, 146.20, 131.80,
4.2.11. 8-(4-Ethoxyphenylamino)-1-(3-morpholinopropyl)oxazolo
[4,5-g]quinazolin-2(1H)-one (5k)
130.87, 124.44, 113.68, 111.53, 106.34, 100.33, 65.96, 55.54, 55.19,
53.28, 40.89, 22.91.
White solid, 437 mg, yield, 91%; Mp: 254e257 ꢀC; HRMS, ESIþ,
m/z: Calcd for C24H28N5O4 (M þ H)þ, 450.2136; found, 422.2143; 1H
4.2.6. 8-(3,4-Dimethoxyphenylamino)-1-(3-morpholinopropyl)
oxazolo[4,5-g]quinazolin-2(1H)-one (5f)
NMR (500 MHz, DMSO-d6) d: 9.53 (1H, bs), 8.45 (1H, s), 8.22 (1H, s),
7.63 (2H, d, J ¼ 8.8 Hz), 7.62 (1H, s), 6.98 (2H, d, J ¼ 8.8 Hz), 4.05 (2H,
q, J ¼ 6.9 Hz), 3.97 (2H, t, J ¼ 6.4 Hz), 3.41 (4H, m), 2.38 (2H, t,
J ¼ 6.4 Hz), 2.24 (4H, m), 2.00 (2H, p, J ¼ 6.4 Hz), 1.35 (3H, t,
White solid, 448 mg, yield, 90%; Mp: 245e247 ꢀC; HRMS, ESIþ,
m/z: Calcd for C24H28N5O5 (M þ H)þ, 466.2085; found, 466.2090; 1H
NMR (500 MHz, DMSO-d6)
d: 9.53 (1H, bs), 8.47 (1H, s), 8.24 (1H, s),
J ¼ 6.9 Hz); 13C NMR (75 MHz, DMSO-d6)
d:157.37, 155.17, 153.64,
153.25, 146.95, 146.23, 131.67, 130.92, 124.54, 124.43, 114.20, 111.54,
106.38, 100.37, 65.95, 55.53, 53.28, 40.90, 22.88, 14.66.
7.63 (1H, s), 7.39 (1H, d, J ¼ 2.3 Hz), 7.31 (1H, dd, J ¼ 2.3 Hz, 8.7 Hz),
7.00 (1H, d, J ¼ 8.7 Hz), 3.98 (2H, t, J ¼ 6.4 Hz), 3.79 (3H, s), 3.78 (3H,
s), 3.41 (4H, t, J ¼ 4.2 Hz), 2.38 (2H, t, J ¼ 6.6 Hz), 2.23 (4H, m), 2.01
(2H, p, J ¼ 6.4 Hz); 13C NMR (75 MHz, DMSO-d6)
d
:157.36, 153.54,
4.2.12. 8-(p-Toluidino)-1-(3-morpholinopropyl)oxazolo[4,5-g]
quinazolin-2(1H)-one (5l)
153.22, 148.47, 146.96, 146.24, 145.60, 132.24, 130.94, 115.22, 111.82,
111.59, 108.17, 106.39, 100.36, 65.95, 55.74, 55.60, 55.51, 53.28,
40.90, 22.88.
White solid, 381 mg, yield, 85%; Mp: 212e216 ꢀC; HRMS, ESIþ,
m/z: Calcd for C22H24N5O4 (M þ H)þ, 420.2030; found, 420.2030; 1H
NMR (500 MHz, DMSO-d6) d: 9.53 (1H, bs), 8.46 (1H, s), 8.23 (1H, s),
4.2.7. 4-Chlorobenzyl 4-(1-(3-morpholinopropyl)-2-oxo-1,2-
dihydrooxazolo[4,5-g]quinazolin-8-ylamino)benzoate (5g)
White solid, 497 mg, yield, 81%; Mp: 309e310 ꢀC; HRMS, ESIþ,
m/z: Calcd for C30H29ClN5O5 (M þ H)þ, 574.1852; found, 574.1857;
7.64 (1H, s), 7.63 (2H, d, J ¼ 7.7 Hz), 7.20 (2H, d, J ¼ 7.7 Hz), 3.96 (2H,
t, J ¼ 5.8 Hz), 3.38 (4H, m), 2.36 (2H, t, J ¼ 6.1 Hz), 2.30 (3H, s), 2.21
(4H, m), 1.98 (2H, p, J ¼ 6.1 Hz); 13C NMR (125 MHz, DMSO-d6)
d
:157.24, 153.62, 153.13, 147.02, 146.28, 136.43, 132.84, 131.00,
1H NMR (500 MHz, DMSO-d6)
d
: 9.91 (1H, bs), 8.63 (1H, s), 8.30 (1H,
128.87, 122.66, 111.63, 106.40, 100.39, 65.94, 55.52, 53.27, 40.90,
22.88, 20.47.
s), 8.08 (2H, d, J ¼ 8.5 Hz), 7.31 (2H, d, J ¼ 8.5 Hz), 7.71 (1H, s), 7.52
(2H, d, J ¼ 8.2 Hz), 7.48 (2H, d, J ¼ 8.2 Hz), 5.35 (2H, s), 4.00 (2H, t,
J ¼ 6.6 Hz), 3.39 (4H, m), 2.38 (2H, t, J ¼ 6.6 Hz), 2.22 (4H, m), 2.00
4.2.13. 8-(4-(4-Chlorobenzyloxy)phenylamino)-1-(3-
(2H, m); 13C NMR (75 MHz, DMSO-d6)
d:165.75, 156.73, 153.60,
morpholinopropyl)oxazolo[4,5-g]quinazolin-2(1H)-one (5m)
White solid, 502 mg, yield, 86%; Mp: 335e338 ꢀC; HRMS, ESIþ,
m/z: Calcd for C29H29ClN5O4 (M þ H)þ, 546.1903; found, 546.1903;
152.69, 147.34, 146.54, 146.24, 144.36, 135.33, 132.65, 131.37, 130.00,
129.78, 128.47, 123.40, 120.89, 112.06, 106.51, 100.42, 65.94, 65.06,
55.50, 53.28, 40.93, 22.86.
1H NMR (500 MHz, DMSO-d6)
d: 9.53 (1H, bs), 8.46 (1H, s), 8.23 (1H,
s), 7.66 (1H, s), 7.64 (2H, d, J ¼ 8.8 Hz), 7.51 (2H, d, J ¼ 8.4 Hz), 7.47
(2H, d, J ¼ 8.4 Hz), 7.08 (2H, d, J ¼ 8.8 Hz), 5.14 (2H, s), 3.99 (2H, t,
J ¼ 6.4 Hz), 3.42 (4H, m), 2.39 (2H, t, J ¼ 6.3 Hz), 2.25 (4H, m), 2.01
4.2.8. 8-(3,5-Dimethylphenylamino)-1-(3-morpholinopropyl)
oxazolo[4,5-g]quinazolin-2(1H)-one (5h)
White solid, 389 mg, yield, 84%; Mp: 232e234 ꢀC; HRMS, ESIþ,
m/z: Calcd for C24H28N5O3 (M þ H)þ, 434.2187; found, 434.2194; 1H
(2H, p, J ¼ 6.4 Hz); 13C NMR (75 MHz, DMSO-d6)
d:157.33, 154.70,
153.61, 153.20, 146.95, 146.23, 136.19, 132.29, 132.51, 130.92, 129.38,
128.35, 124.46, 114.70, 111.52, 106.37, 100.36, 68.53, 65.92, 55.50,
53.26, 40.89, 22.87.
NMR (500 MHz, DMSO-d6) d: 9.46 (1H, bs), 8.52 (1H, s), 8.26 (1H, s),
7.64 (1H, s), 7.44 (2H, s), 6.80 (1H, s), 3.99 (2H, t, J ¼ 6.5 Hz), 3.40
(4H,m), 2.31 (6H, s), 2.24 (4H, m), 2.00 (2H, p, J ¼ 6.5 Hz); 13C NMR
(75 MHz, DMSO-d6)
d:157.17, 153.64, 153.14, 147.04, 146.31, 138.88,
4.2.14. 8-(4-Chlorophenylamino)-1-(3-morpholinopropyl)oxazolo
[4,5-g]quinazolin-2(1H)-one (5n)
137.42, 131.06, 125.38, 125.31, 120.16, 111.66, 106.42, 100.35, 65.93,
55.56, 53.27, 40.94, 22.84, 21.03.
White solid, 390 mg, yield, 83%; Mp: 221e223 ꢀC; HRMS, ESIþ,
m/z: Calcd for C22H23ClN5O3 (M þ H)þ, 440.1484; found, 440.1477;
4.2.9. Ethyl 4-hydroxy-3-(1-(3-morpholinopropyl)-2-oxo-1,2-
dihydrooxazolo[4,5-g]quinazolin-8-ylamino)benzoate (5i)
1H NMR (500 MHz, DMSO-d6)
d:9.69 (1H, bs), 8.53 (1H, s), 8.23 (1H,
s), 7.86 (2H, d, J ¼ 8.8 Hz), 7.65 (1H, s), 7.45 (2H, d, J ¼ 8.8 Hz), 3.98
(2H, t, J ¼ 6.5 Hz), 3.40 (4H, t, J ¼ 4.2 Hz), 2.37 (2H, t, J ¼ 6.5 Hz), 2.22
(4H, m), 1.99 (2H, p, J ¼ 6.5 Hz); 13C NMR (75 MHz, DMSO-d6)
White solid, 470 mg, yield, 89%; Mp: 323e325 ꢀC; HRMS, ESIþ,
m/z: Calcd for C25H28N5O6 (M þ H)þ, 494.2034; found, 494.2038;
1H NMR (500 MHz, DMSO-d6)
d: 10.70 (1H, bs), 9.53 (1H, bs), 8.37
d:156.96, 153.61, 152.89, 147.13, 146.42, 138.32, 131.18, 128.31, 127.14,
(1H, bs), 8.42 (1H, s), 8.25 (1H, s), 8.08 (1H, d, J ¼ 1.9 Hz), 7.76 (1H,
dd, J ¼ 1.9 Hz, 8.5 Hz), 7.66 (1H, s), 7.06 (1H, d, J ¼ 8.5 Hz), 4.28 (2H,
q, J ¼ 7.1 Hz), 3.98 (2H, t, J ¼ 6.4 Hz), 3.42 (4H, m), 2.39 (2H, t,
J ¼ 6.5 Hz), 2.26 (4H, m), 2.00 (2H, p, J ¼ 6.5 Hz); 13C NMR (75 MHz,
123.79, 111.79, 106.46, 100.38, 65.93, 55.50, 53.27, 40.92, 22.86.
4.2.15. 8-(4-(Benzyloxy)phenylamino)-1-(3-morpholinopropyl)
oxazolo[4,5-g]quinazolin-2(1H)-one (5o)
DMSO-d6)
d
:165.38, 158.15, 156.36, 153.66, 153.09, 146.90, 146.41,
White solid, 477 mg, yield, 87%; Mp: 279e282 ꢀC; HRMS, ESIþ,
m/z: Calcd for C29H30N5O4 (M þ H)þ, 512.2292; found, 513.2283; 1H
131.05, 128.65, 128.65, 128.21, 126.64, 120.59, 116.30, 106.35, 100.72,
65.98, 60.25, 55.54, 53.29, 40.93, 22.95, 14.23.
NMR (300 MHz, DMSO-d6) d:9.57 (1H, bs), 8.45 (1H, s), 8.23 (1H, s),

46
J. Lin et al. / European Journal of Medicinal Chemistry 55 (2012) 39e48
7.63 (1H, s), 7.33e7.49 (5H, m), 7.07 (2H, d, J ¼ 8.8 Hz), 5.13 (2H, s),
3.98 (2H, t, J ¼ 6.4 Hz), 3.40 (4H, t, J ¼ 4.3 Hz), 2.38 (2H, t, J ¼ 6.5 Hz),
2.23 (4H, m), 2.00 (2H, p, J ¼ 6.4 Hz); 13C NMR (75 MHz, DMSO-d6)
4.2.21. 8-(4-((3-Methyl-4-(2,2,2-trifluoroethoxy)pyridin-2-yl)
methoxy)phenylamino)-1-(3-morpholinopropyl)oxazolo[4,5-g]
quinazolin-2(1H)-one (5u)
d
:157.37, 154.96, 153.64, 153.24, 146.96, 146.25, 137.14, 132.01,
White solid, 567 mg, yield, 85%; Mp: 357e360 ꢀC; HRMS, ESIþ,
m/z: Calcd for C31H32F3N6O5 (M þ H)þ, 625.2381; found, 625.2370;
130.95, 128.37, 127.74, 127.61, 124.52, 114.69,111.54,106.39, 100.37,
69.39, 65.94, 55.53, 53.28, 40.91, 22.88.
1H NMR (500 MHz, DMSO-d6)
d:9.55 (1H, bs), 8.44 (1H, s), 8.23 (1H,
s), 7.63 (1H, s), 7.62 (2H, d, J ¼ 8.3 Hz), 7.16 (1H, d, J ¼ 5.6 Hz), 7.09
(2H, d, J ¼ 8.7 Hz), 5.21 (2H, s), 4.92 (2H, q, J ¼ 8.7 Hz), 3.98 (2H, t,
J ¼ 6.0 Hz), 3.41 (4H, m), 2.38 (2H, t, J ¼ 6.1 Hz), 2.25 (7H, m), 2.00
4.2.16. 8-(o-Toluidino)-1-(3-morpholinopropyl)oxazolo[4,5-g]
quinazolin-2(1H)-one (5p)
White solid, 363 mg, yield, 81%; Mp: 230e232 ꢀC; HRMS, ESIþ,
m/z: Calcd for C23H26N5O3 (M þ H)þ, 420.2030; found, 420.2030; 1H
(2H, p, J ¼ 6.4 Hz); 13C NMR (125 MHz, DMSO-d6)
d: 161.35, 157.39,
155.38, 154.99, 153.62, 153.21, 147.60, 146.94, 146.25, 132.09, 130.94,
124.52, 122.64, 114.62, 111.53, 107.56, 106.38, 100.37, 70.44, 65.92,
64.60, 55.49, 53.25, 40.89, 22.87, 9.98.
NMR (500 MHz, DMSO-d6) d:9.55 (1H, bs), 8.34 (1H, s), 8.22 (1H, s),
7.63 (1H, s), 7.33 (2H, m), 7.25 (2H, m), 3.96 (2H, t, J ¼ 6.6 Hz), 3.41
(4H, m), 2.39 (2H, p, J ¼ 5.8 Hz), 2.26 (4H, m), 2.18 (3H, s), 2.00 (2H,
t, J ¼ 7.0 Hz); 13C NMR (75 MHz, DMSO-d6)
d
:158.36, 153.64, 153.52,
4.2.22. N-(4-(1-(3-morpholinopropyl)-2-oxo-1,2-dihydrooxazolo
[4,5-g]quinazolin-8-ylamino)phenyl)acetamide (5v)
146.90, 146.30, 137.07, 134.96, 131.00, 130.45, 127.62, 126.38, 126.25,
111.30, 106.33, 100.57, 65.93, 55.49, 53.24, 40.91, 22.89, 17.93.
White solid, 430 mg, yield, 87%; Mp: 308e310 ꢀC; HRMS, ESIþ,
m/z: Calcd for C24H27N6O4 (M þ H)þ, 463.2088; found, 463.2084; 1H
4.2.17. 8-(2-Hydroxyphenylamino)-1-(3-morpholinopropyl)
oxazolo[4,5-g]quinazolin-2(1H)-one (5q)
NMR (500 MHz, DMSO-d6) d:9.94 (1H, bs), 9.58 (1H, bs), 8.48 (1H,
s), 8.24 (1H, s), 7.70 (2H, d, J ¼ 8.7 Hz), 7.63 (1H, s), 7.62 (2H, d,
J ¼ 8.7 Hz), 5.21 (2H, s), 3.98 (2H, t, J ¼ 6.0 Hz), 3.41 (4H, m), 2.38
(2H, t, J ¼ 6.1 Hz), 2.24 (4H, m), 2.06 (3H, s), 2.00 (2H, p, J ¼ 6.4 Hz);
White solid, 383 mg, yield, 85%; Mp: 255e257 ꢀC; HRMS, ESIþ,
m/z: Calcd for C22H24N5O4 (M þ H)þ, 422.1823; found, 422.1820; 1H
NMR (500 MHz, DMSO-d6)
d
:9.70 (1H, bs), 9.38 (1H, bs), 8.40 (1H,
13C NMR (125 MHz, DMSO-d6)
d:167.96, 157.19, 153.62, 153.14,
s), 7.64 (1H, s), 7.49 (1H, d, J ¼ 7.7 Hz), 7.11 (1H, t, J ¼ 8.1 Hz), 6.98
(1H, d, J ¼ 8.1 Hz), 6.87 (1H, t, J ¼ 7.7 Hz), 3.99 (2H, t, J ¼ 6.5 Hz), 3.41
(4H, m), 2.39 (2H, p, J ¼ 5.8 Hz), 2.26 (4H, m), 2.00 (2H, t, J ¼ 7.0 Hz);
147.01, 146.27, 135.44, 134.01, 130.98, 123.11, 119.07, 111.59, 106.38,
100.37, 65.93, 55.52, 53.26, 40.91, 23.85, 22.87.
13C NMR (75 MHz, DMSO-d6)
d
:158.15, 153.64, 153.18, 151.53,
4.2.23. 8-(3-((3-Methyl-4-(2,2,2-trifluoroethoxy)pyridin-2-yl)
methoxy)phenylamino)-1-(3-morpholinopropyl)oxazolo[4,5-g]
quinazolin-2(1H)-one (5w)
146.86, 130.96, 127.26, 126.52, 125.96, 118.92, 111.65, 106.32, 100.76,
65.91, 55.54, 53.28, 40.92, 22.97.
White solid, 568 mg, yield, 85%; Mp: 356e357 ꢀC; HRMS, ESIþ,
m/z: Calcd for C31H32F2N6O5 (M þ H)þ, 625.2381; found, 625.2372;
4.2.18. 8-(3,4-Difluorophenylamino)-1-(3-morpholinopropyl)
oxazolo[4,5-g]quinazolin-2(1H)-one (5r)
1H NMR (500 MHz, DMSO-d6)
d:9.63 (1H, bs), 8.51 (1H, s), 8.32 (2H,
White solid, 387 mg, yield, 82%; Mp: 250e254 ꢀC; HRMS, ESIþ,
m/z: Calcd for C22H22F2N5O3 (M þ H)þ, 442.1685; found, 442.1677;
d, J ¼ 8.3 Hz), 8.02 (1H, d, J ¼ 8.3 Hz), 7.63 (2H, d, J ¼ 8.7 Hz), 7.35
(1H, s), 7.14 (2H, d, J ¼ 8.7 Hz), 6.84 (1H, s), 5.20 (2H, s), 4.91 (2H, q,
J ¼ 8.7 Hz), 3.98 (2H, t, J ¼ 6.0 Hz), 3.47 (4H, m), 3.38 (2H, m), 2.39
(2H, t, J ¼ 6.1 Hz), 2.27 (7H, m), 2.01 (2H, p, J ¼ 6.4 Hz); 13C NMR
1H NMR (500 MHz, DMSO-d6)
d:9.71 (1H, bs), 8.56 (1H, s), 8.19 (1H,
s), 8.06 (1H, m), 7.66 (1H, s), 7.58 (1H, m), 7.47 (2H, dd, J ¼ 9.3 Hz,
10.1 Hz), 3.98 (2H, t, J ¼ 6.4 Hz), 3.40 (4H, m), 2.38 (2H, t, J ¼ 6.4 Hz),
2.23 (4H, m), 1.88 (2H, p, J ¼ 5.6 Hz); 13C NMR (75 MHz, DMSO-d6)
(125 MHz, DMSO-d6) d: 161.35, 158.51, 157.10, 153.62, 152.97, 147.65,
147.10, 146.37, 144.52, 140.32, 131.15, 129.13, 121.30, 114.99, 111.75,
109.66, 109.17, 107.56, 106.81, 106.44, 104.35, 100.46, 70.26, 65.99,
64.38, 55.49, 54.88, 53.26, 40.92, 23.23, 22.87, 9.92.
d:156.84, 153.57, 152.75, 149.70, 147.76, 147.11, 146.46, 144.45,
136.20, 131.24, 118.39, 117.06, 116.92, 111.56, 111.34, 111.17, 106.50,
100.15, 65.93, 55.49, 53.26, 40.92, 22.85.
4.2.24. 1-(3-Morpholinopropyl)-8-(4-(pyridin-2-ylmethoxy)
phenylamino)oxazolo[4,5-g]quinazolin-2(1H)-one (5x)
4.2.19. 8-(3-Isopropoxyphenylamino)-1-(3-morpholinopropyl)
oxazolo[4,5-g]quinazolin-2(1H)-one (5s)
White solid, 482 mg, yield, 88%; Mp: 332e335 ꢀC; HRMS, ESIþ,
m/z: Calcd for C28H29N6O4 (M þ H)þ, 513.2245; found, 513.2235; 1H
White solid, 416 mg, yield, 84%; Mp: 259e262 ꢀC; HRMS, ESIþ, m/
z: Calcd for C25H30F2N5O4 (M þ H)þ, 464.2292; found, 464.2285; 1H
NMR (500 MHz, DMSO-d6)
d
:9.55 (1H, bs), 8.55 (1H, d, J ¼ 4.2 Hz),
NMR (500 MHz, DMSO-d6)
d: 9.53 (1H, bs), 8.54 (1H, s), 8.24 (1H, s),
8.34 (1H, s), 8.22 (1H, s), 7.80 (2H, dt, J ¼ 7.8 Hz, 5.2 Hz), 7.63 (1H, s),
7.48 (1H, d, J ¼ 7.8 Hz), 7.31 (1H, t, J ¼ 5.2 Hz), 6.73 (2H, d, J ¼ 8.8 Hz),
6.52 (1H, d, J ¼ 8.8 Hz), 5.13 (2H, s), 3.99 (2H, t, J ¼ 6.4 Hz), 3.40 (4H,
t, J ¼ 4.3 Hz), 2.38 (2H, t, J ¼ 6.4 Hz), 2.23 (4H, m), 2.00 (2H, p,
7.65 (1H, s), 7.50 (1H, s), 7.36 (1H, d, J ¼ 8.6 Hz), 7.29 (1H, t, J ¼ 8.1 Hz),
6.71 (1H, d, J ¼ 8.6 Hz), 4.62 (1H, m), 3.99 (2H, t, J ¼ 6.4 Hz), 3.41 (4H,
m), 2.38 (2H, t, J ¼ 6.5 Hz), 2.23 (4H, m), 2.00 (2H, p, J ¼ 6.5 Hz),
1.31(6H, s); 13C NMR (125 MHz, DMSO-d6)
d:157.55, 157.07, 153.60,
J ¼ 6.5 Hz); 13C NMR (75 MHz, DMSO-d6)
d:167.96, 161.35, 157.45,
152.99, 147.09, 146.34, 140.28, 131.12, 129.12, 114.34, 111.71, 110.01,
106.44, 100.33, 69.20, 65.92, 55.45, 53.25, 40.00, 22.86, 21.83.
155.38, 154.99, 148.88, 142.71, 136.74, 132.09, 130.94, 122.65, 121.40,
115.60, 115.03, 111.53, 107.56, 106.38, 100.37, 70.89, 65.93, 55.52,
53.26, 40.91, 23.85, 22.87.
4.2.20. 8-(3-Acetylphenylamino)-1-(3-morpholinopropyl)oxazolo
[4,5-g]quinazolin-2(1H)-one (5t)
4.2.25. 8-(4-(4-Chlorobenzyloxy)-3-chlorophenylamino)-1-(3-
morpholinopropyl)oxazolo[4,5-g]quinazolin-2(1H)-one (5y)
White solid, 539 mg, yield, 87%; Mp: 339e340 ꢀC; HRMS, ESIþ,
m/z: Calcd for C29H28Cl2N5O4 (M þ H)þ, 580.1513; found, 580.1511;
White solid, 373 mg, yield, 78%; Mp: 275e278 ꢀC; HRMS, ESIþ,
m/z: Calcd for C24H26N5O4 (M þ H)þ, 448.1979; found, 448.1982; 1H
NMR (500 MHz, DMSO-d6) d:9.79 (1H, bs), 8.56 (1H, s), 8.32 (1H, s),
8.27 (1H, s), 8.23 (1H, d, J ¼ 7.9 Hz), 7.77 (1H, d, J ¼ 7.6 Hz), 7.68 (1H,
s), 7.58 (1H, t, J ¼ 7.9 Hz), 4.00 (2H, t, J ¼ 6.2 Hz), 3.40 (4H, m), 2.63
(3H, s), 2.39 (2H, t, J ¼ 6.3 Hz), 2.23 (4H, m), 2.01 (2H, p, J ¼ 6.3 Hz);
1H NMR (500 MHz, DMSO-d6)
d:9.58 (1H, bs), 8.52 (1H, s), 8.19 (1H,
s), 7.96 (1H, d, J ¼ 2.1 Hz), 7.70 (1H, dd, J ¼ 8.9 Hz, 2.1 Hz), 7.64 (1H,
s), 7.52 (2H, d, J ¼ 8.4 Hz), 7.48 (2H, d, J ¼ 8.4 Hz), 7.28 (1H, d,
J ¼ 8.9 Hz), 5.23 (2H, s), 3.98 (2H, m), 3.41 (4H, m), 2.38 (2H, t,
J ¼ 6.4 Hz), 2.24 (4H, m), 2.00 (2H, p, J ¼ 6.4 Hz); 13C NMR (125 MHz,
13C NMR (125 MHz, DMSO-d6)
d:197.67, 157.06, 153.60, 152.88,
147.17, 146.46, 139.61, 137.18, 131.24, 128.84, 126.78, 123.70, 121.20,
111.68, 106.49, 100.32, 65.92, 55.52, 53.27, 40.94, 26.73, 22.83.
DMSO-d6) d:157.00, 153.59, 152.99, 149.69, 147.01, 146.35, 135.68,

J. Lin et al. / European Journal of Medicinal Chemistry 55 (2012) 39e48
47
133.07, 132.47, 131.09, 129.24, 128.43, 124.08, 122.26, 121.07, 114.36,
111.52,106.46,100.22, 69.44, 65.99, 55.52, 53.27, 53.12, 40.92, 30.66,
22.85.
brine, dried over MgSO4, and concentrated. Chromatography of the
residue on silica gel with DCMeMeOH (120/1,v/v) gave 348 mg (yield,
75%) of the title compound as pale yellow solid: Mp: 264e267 ꢀC;
HRMS, ESIþ, m/z: Calcd for C24H28N5O3 (M þ H)þ, 434.2187; found,
4.2.26. 8-(4-tert-Butylphenylamino)-1-(3-morpholinopropyl)
oxazolo[4,5-g]quinazolin-2(1H)-one (5z)
434.2184; 1H NMR (300 MHz, DMSO-d6)
d:8.37 (1H, s), 8.27 (1H, d,
J ¼ 7.7 Hz), 8.22 (1H, s), 7.57 (1H, s), 7.46 (2H, d, J ¼ 7.4 Hz), 7.34 (2H, d,
J ¼ 7.4 Hz), 7.24 (1H, t, J ¼ 7.2 Hz), 5.65 (1H, p, J ¼ 7.2 Hz), 3.99 (2H, t,
J ¼ 6.3 Hz), 3.41 (4H, m), 2.39 (2H, t, J ¼ 6.3 Hz), 2.25 (4H, m), 2.01 (2H,
White solid, 414 mg, yield, 84%; Mp: 285e287 ꢀC; HRMS, ESIþ,
m/z: Calcd for C26H32N5O3 (M þ H)þ, 462.2500; found, 462.2503;
1H NMR (500 MHz, DMSO-d6)
d:9.63 (1H, bs), 8.48 (1H, s), 8.28 (1H,
p, J ¼ 6.3 Hz), 1.65 (3H, d, J ¼ 7.0 Hz); 13C NMR (75 MHz, DMSO-d6)
d:
s), 7.70 (2H, d, J ¼ 6.8 Hz), 7.65 (1H, s), 7.43 (2H, d, J ¼ 6.8 Hz), 3.99
(2H, t, J ¼ 6.1 Hz), 3.40 (4H, m), 2.38 (2H, t, J ¼ 6.1 Hz), 2.24 (4H, m),
2.00 (2H, p, J ¼ 6.4 Hz), 1.32 (9H, s); 13C NMR (125 MHz, DMSO-d6)
159.47, 153.30, 152.04, 148.44, 148.32, 144.13, 134.36, 120.79, 106.66,
104.37, 101.66, 66.00, 55.04, 53.17, 40.63, 22.90.
d:167.96,157.19,153.62, 153.14,147.01,146.27,135.44,134.01,130.98,
4.2.30. 8-(Benzylamino)-1-(3-morpholinopropyl)oxazolo[4,5-g]
quinazolin-2(1H)-one (6d)
123.11, 119.07, 111.59, 106.38, 100.37, 65.93, 55.52, 53.26, 40.91,
23.85, 22.87.
White solid, 314 mg, yield, 70%; Mp: 217e220 ꢀC; HRMS, ESIþ, m/
z: Calcd for C23H26N5O3 (M þ H)þ, 420.2030; found, 420.2028; 1H
4.2.27. 8-(Methyl(phenyl)amino)-1-(3-morpholinopropyl)oxazolo
[4,5-g]quinazolin-2(1H)-one (6a)
NMR (500 MHz, DMSO-d6)
d
: 8.61 (1H, t, J ¼ 5.8 Hz), 8.40 (1H, s), 8.07
(1H, s), 7.57 (1H, s), 7.38 (2H, d, J ¼ 7.4 Hz), 7.32 (2H, t, J ¼ 7.4 Hz), 7.25
(1H, t, J ¼ 7.2 Hz), 4.83 (2H, d, J ¼ 5.8 Hz), 3.92 (2H, t, J ¼ 6.6 Hz), 3.37
(2H, t, J ¼ 4.4 Hz), 2.36 (2H, t, J ¼ 6.6 Hz), 2.22 (4H, m), 1.96 (2H, p,
N-methylbenzenamine (95.4 mg, 0.89 mmol) was added to
a solution of compound 13 (300 mg, 1.07 mmol) in isopropanol
(10 ml) and stirred at 50 ꢀC for 24 h. The mixture was cooled to
room temperature and concentrated in vacuo, then the residue was
treated with aqueous NaHCO3 (10 ml) and extracted with EtOAc/
MeOH (20:1, 30 ml). The organic layer was washed with brine,
dried over MgSO4, and concentrated. Chromatography of the
residue on silica gel with DCMeMeOH (90/1,v/v) gave 282 mg
(yield, 63%) of the titlþe compound as pale yellow solid: Mp:
218e221 ꢀC; HRMS, ESI , m/z: Calcd for C23H26ClN5O3 (M þ H)þ,
J ¼ 6.6 Hz); 13C NMR (75 MHz, DMSO-d6)
d:159.44, 157.18, 153.58,
153.07, 147.12, 146.37, 138.97, 130.91, 128.41, 123.77, 122.62, 111.64,
106.42, 100.23, 65.94, 59.81, 55.51, 53.27, 40.90, 22.88.
4.2.31. 8-(trans-4-Hydroxycyclohexylamino)-1-(3-
morpholinopropyl)oxazolo[4,5-g]quinazolin-2(1H)-one (6e)
Trans-4-aminocyclohexanol (148 mg, 1.28 mmol) and TEA
(150 mg, 2.14 mmol) was added to a solution of compound 13
(300 mg, 1.07 mmol) in isopropanol (12 ml) and stirred at 60 ꢀC for
24h. Themixturewas cooled toroom temperatureand concentrated
in vacuo, the residue was treated with aqueous NaHCO3 (10 ml) and
extracted with EtOAc/MeOH (20:1, 30 ml). The organic layer was
washed with brine, dried over MgSO4, and concentrated. Chroma-
tography of the residue on silica gel with DCMeMeOH (90/1,v/v)
gave 361 mg (yield, 79%) of tþhe title compound as pale yellow solid:
Mp: 312e315 ꢀC; HRMS, ESI , m/z: Calcd for C22H30N5O4 (M þ H)þ,
420.2030; found, 420.2041; 1H NMR (500 MHz, DMSO-d6)
d: 8.61
(1H, s), 8.50 (1H, s), 7.80 (1H, d, J ¼ 7.7 Hz), 7.69 (1H, s), 7.44 (2H, t,
J ¼ 7.7 Hz), 7.21 (1H, d, J ¼ 7.4 Hz), 4.00 (2H, t, J ¼ 6.6 Hz), 3.39 (4H,
m), 2.78 (3H, s), 2.38 (2H, t, J ¼ 6.6 Hz), 2.22 (4H, m), 2.00 (2H, m);
13C NMR (75 MHz, DMSO-d6)
d:160.80, 153.43, 152.81, 148.58,
148.11, 145.56, 130.08, 129.58, 126.22, 125.55, 112.83, 106.64, 102.92,
65.94, 55.52, 53.22, 41.92, 40.54, 22.10.
4.2.28. (S)-1-(3-morpholinopropyl)-8-(1-phenylethylamino)
oxazolo[4,5-g]quinazolin-2(1H)-one (6b)
428.2292; found, 428.2295; 1H NMR (500 MHz, DMSO-d6)
d:8.70
(1H, s), 7.80 (1H, s), 7.74 (1H, s), 4.14 (1H, s), 4.00 (2H, t, J ¼ 6.4 Hz),
(S)-1-phenylethanamine (155 mg, 1.28 mmol) and TEA (216 mg,
2.14 mmol) was added to a solution of compound 13 (300 mg,
1.07 mmol) in isopropanol (10 ml) and stirred at 55 ꢀC for 24 h. The
mixture was cooled to room temperature and concentrated in
vacuo, the residue was treated with aqueous NaHCO3 (12 ml) and
extracted with EtOAc/MeOH (20:1, 30 ml). The organic layer was
washed with brine, dried over MgSO4, and concentrated. Chroma-
tography of the residue on silica gel with DCMeMeOH (120/1,v/v)
gave 357 mg (yield, 70%) of tþhe title compound as pale yellow solid:
Mp: 261e265 ꢀC; HRMS, ESI , m/z: Calcd for C24H28N5O3 (M þ H)þ,
3.52 (4H, t, J ¼ 4.2 Hz), 2.33 (2H, t, J ¼ 6.3 Hz), 2.26 (4H, m), 2.00 (2H,
p, J ¼ 6.4 Hz); 13C NMR (75 MHz, DMSO-d6)
d:165.61, 159.43, 153.45,
153.26, 152.57, 152.00, 148.36, 148.27, 147.64, 147.03, 134.26, 132.23,
120.73, 112.49, 106.61, 106.06, 106.38, 101.58, 100.19, 66.00, 65.86,
55.01, 54.77, 54.15, 53.16, 53.12, 40.59, 40.33, 22.19, 22.91.
4.2.32. 8-(4-Methylpiperazin-1-yl)-1-(3-morpholinopropyl)
oxazolo[4,5-g]quinazolin-2(1H)-one (6f)
1-Methylpiperazine (118 mg, 1.18 mmol) and TEA (324 mg,
3.21 mmol) was added to a solution of compound 13 (300 mg,
1.07 mmol) in isopropanol (10 ml) and stirred for 10 h under reflux.
The mixture was cooled to room temperature and concentrated in
vacuo. Chromatography of the residue on silica gel with
DCMeMeOH (20/1,v/v) gave 357 mg (yield, 81%) of the title
compound as pale yellow solid: Mp: >370 ꢀC; HRMS, ESIþ, m/z:
Calcd for C21H29N6O3 (M þ H)þ, 413.2296; found, 413.2305; 1H
434.2187; found, 434.2182; 1H NMR (300 MHz, DMSO-d6)
d:8.37
(1H, s), 8.27 (1H, d, J ¼ 7.7 Hz), 8.22 (1H, s), 7.57 (1H, s), 7.46 (2H, d,
J ¼ 7.4 Hz), 7.34 (2H, d, J ¼ 7.4 Hz), 7.24 (1H, t, J ¼ 7.2 Hz), 5.65 (1H, p,
J ¼ 7.2 Hz), 3.99 (2H, t, J ¼ 6.3 Hz), 3.41 (4H, m), 2.39 (2H, t,
J ¼ 6.3 Hz), 2.25 (4H, m), 2.01 (2H, p, J ¼ 6.3 Hz), 1.65 (3H, d,
J ¼ 7.0 Hz); 13C NMR (75 MHz, DMSO-d6)
d: 160.22, 153.57, 152.05,
146.70, 145.37, 144.13, 131.24, 119.14, 106.66, 104.37, 101.70, 65.98,
54.87, 53.12, 40.29, 23.21.
NMR (500 MHz, DMSO-d6) d: 8.61 (1H, s), 7.70 (1H, s), 7.56 (1H, s),
4.03 (2H, t, J ¼ 6.5 Hz), 3.71 (4H, m), 3.48 (4H, m), 2.64 (4H, m), 2.35
(2H, m), 2.32 (3H, s), 2.25 (4H, m), 1.91 (2H, p, J ¼ 6.4 Hz); 13C NMR
4.2.29. (R)-1-(3-morpholinopropyl)-8-(1-phenylethylamino)
oxazolo[4,5-g]quinazolin-2(1H)-one (6c)
(75 MHz, DMSO-d6) d: 163.78, 153.57, 152.27, 148.60, 146.36, 130.83,
112.99, 106.64, 102.18, 65.88, 55.13, 53.98, 53.92, 53.73, 53.25,
53.13,48.92, 48.74, 44.96, 40.43, 22.96.
(R)-1-phenylethanamine (155 mg, 1.28 mmol) and TEA (216 mg,
2.14 mmol) was added to a solution of compound 13 (300 mg,
1.07 mmol) in isopropanol (10 ml) and stirred at 55 ꢀC for 26 h. The
mixture was cooled to room temperature and concentrated in vacuo,
the residue was treated with aqueous NaHCO3 (15 ml) and extracted
with EtOAc/MeOH (20:1, 30 ml). The organic layer was washed with
4.2.33. 8-(1H-indazol-5-ylamino)-1-(3-morpholinopropyl)oxazolo
[4,5-g]quinazolin-2(1H)-one (6g)
1H-indazol-5-amine (171 mg, 1.28 mmol) was added to a solu-
tion of compound 13 (300 mg, 1.07 mmol) in isopropanol (15 ml)

48
J. Lin et al. / European Journal of Medicinal Chemistry 55 (2012) 39e48
[3,4-d]pyrimidines as irreversible Inhibitors of the erbB family of tyrosine
kinase receptors, J. Med. Chem. 49 (2006) 1475e1485.
and stirred at reflux for 13 h. The mixture was cooled to room
temperature and filtered, the solid was washed with chill iso-
propanol (5 ml), the residue was treated with aqueous NaHCO3
(10 ml) and extracted with EtOAc/MeOH (20:1, 30 ml). The organic
layer was washed with brine, dried over MgSO4, and concentrated.
Chromatography of the residue on silica gel with DCMeMeOH (70/
1,v/v) gave 395 mg (yield, 83%) of the title compound as white
solid: Mp: 346e348 ꢀC; HRMS, ESIþ, m/z: Calcd for C23H24N7O3
(M þ H)þ, 446.1935; found, 446.1939; 1H NMR (500 MHz, DMSO-
[5] F.R. Hirsch, M.V. Garcia, P.A. Bunn Jr., M.V. Dimaria, R. Veve, R.M. Bremmes,
A.E. Baron, C. Zeng, W.A. Franklin, Epidermal growth factor receptor in non-
small-cell lung carcinomas: correlation between gene copy number and
protein expression and impact on prognosis, J. Clin. Oncol. 21 (2003)
3798e3807.
[6] N.E. Hynes, H.A. Lane, ERBB receptors and cancer: the complexity of targeted
inhibitors, Nat. Rev. Cancer 5 (2005) 341e354.
[7] J. Mendelsohn, J. Baselga, Status of epidermal growth factor receptor antag-
onists in the biology and treatment of cancer, J. Clin. Oncol. 21 (2003)
2787e2799.
[8] C.M. Rocha-Lima, H.P. Soares, L.E. Raez, R. Singal, EGFR targeting of solid
tumors, Cancer Control 14 (2007) 295e304.
[9] E. Balius, C. Robert, Quantitative prediction of fold resistance for inhibitors of
EGFR, Biochemistry 48 (2009) 8435e8448.
[10] D.W. Fry, Mechanism of action of erbB tyrosine kinase inhibitors, Exp. Cell Res.
284 (2003) 131e139.
[11] L. Alexander, Protein kinase inhibitors as a therapeutic modality, Acc. Chem.
Res. 36 (2003) 462e469.
d6) d: 9.69 (1H, s), 8.47 (1H, s), 8.27 (1H, s), 8.16 (1H, s), 8.05 (1H, s),
7.93 (1H, s), 7.64 (1H, d, J ¼ 8.8 Hz), 7.63 (1H, s), 7.58 (1H, t,
J ¼ 8.8 Hz), 3.99 (2H, t, J ¼ 6.6 Hz), 3.41 (4H, m), 2.39 (2H, t,
J ¼ 6.3 Hz), 2.25 (4H, m), 2.01 (2H, p, J ¼ 6.6 Hz); 13C NMR (75 MHz,
DMSO-d6) d: 157.67, 153.65, 153.28, 146.95, 146.26, 144.05, 137.41,
133.39, 131.26, 130.96, 123.84, 122.76, 114.01, 113.94, 111.60, 109.86,
106.91, 104.35, 100.44, 65.99, 55.54, 53.28, 53.13, 40.93, 23.23,
22.91.
[12] J.B. Smaill, H.D. Showalter, H.R. Zhou, A.J. Bridges, D.J. McNamara, Tyrosine
kinase inhibitors. 18. 6-Substituted 4-anilinoquinazolines and 4-anilinopyrido
[3,4-d]pyrimidines as soluble, irreversible inhibitors of the epidermal growth
factor receptor, J. Med. Chem. 44 (2001) 429e440.
Acknowledgments
[13] M. Ranson, L.A. Hammond, D. Ferry, M. Kris, A. Tullo, P.I. Murray, V. Miller,
S. Averbuch, J. Ochs, C. Morris, A. Feyereislova, H. Swaisland, E.K. Rowinsky,
ZD1839, a selective oral epidermal growth factor receptor-tyrosine kinase
inhibitor, is well tolerated and active in patients with solid, malignant tumors:
results of a phase I trial, J. Clin. Oncol. 20 (2002) 2240e2250.
[14] F. Ciardiello, G. Tortora, A novel approach in the treatment of cancer: targeting
the epidermal growth factor receptor, Clin. Cancer Res. 7 (2001) 2958e2970.
[15] X. Wenle, R.J. Mullin, B.R. Keith, L.H. Liu, H.D. Ma, W. Rusnak, G. Owens,
K.J. Alligood, N.L. Spector, Anti-tumor activity of GW-572016: a dual tyrosine
kinase inhibitor blocks EGF activation of EGFR/erbB2 and downstream Erk1/2
and AKT pathways, Oncogene 21 (2002) 6255e6263.
We would like to thank Professor Tao Lu and Ms. Yanmin Zhang
for docking study. This study is financially supported by 111 Project
from the Ministry of Education of China and the State Adminis-
tration of Foreign Expert Affairs of China (No. 111-2-07).
Appendix A. Supplementary data
[16] O. Cruz-López, A. Conejo-García, M.C. Núñez, M. Kimatrai, M.E. García-Rubiño,
F. Morales, V. Gómez-Pérez, J.M. Campos, Novel substituted quinazolines for
potent EGFR tyrosine kinase inhibitors, Curr. Med. Chem. 18 (2011) 943e963.
[17] D.D. Li, P.C. Lv, H. Zhang, H.J. Zhang, Y.P. Hou, K. Liu, Y.H. Ye, H.L. Zhu, The
combination of 4-anilinoquinazoline and cinnamic acid: a novel mode of
binding to the epidermal growth factor receptor tyrosine kinase, Bioorg. Med.
Chem. 19 (2011) 5012e5022.
Supplementary data associated with this article can be found, in
the online version, at http://dx.doi.org/10.1016/j.ejmech.2012.06.
055. These data include MOL files and InChiKeys of the most
important compounds described in this article.
[18] P. Ballard, B. Barlaam, R.H. Bradbury, A. Dishington, L.F. Hennequin,
D.M. Kickinson, I.M. Hollinsworth, J.G. Kettle, T. Klinowska, D.J. Ogilvie,
S.E. Pearson, J.S. Scott, A. Suleman, R. Whittaker, E.J. Williams, R. Wood,
L. Wright, Neutral 5-substituted 4-anilinoquinazolines as potent, orally active
inhibitors of erbB2 receptor tyrosine kinase, Bioorg. Med. Chem. Lett. 17
(2007) 6326e6329.
[19] B. Barlaam, P. Ballard, R.H. Bradbury, R. Ducray, H. Germain, D.M. Kickinson,
K. Hudson, J.G. Kettle, T.K. linowska, F. Magnien, D.J. Ogilvie, A. Olivier,
S.E. Pearson, J.S. Scott, A. Suleman, C.B. Trigwell, M. Vautier, R.D. Whittaker,
R. Wood, A new series of neutral 5-substituted 4-anilinoquinazolines as
potent, orally active inhibitors of erbB2 receptor tyrosine kinase, Bioorg. Med.
Chem. Lett. 18 (2008) 674e678.
References
[1] M.A. Lemmon, The EGF receptor family as therapeutic targets in breast cancer,
Breast Dis. 18 (2003) 33e43.
[2] K.K. Ang, N.H. Andratschke, L. Milas, Epidermal growth factor receptor and
response of head-and-neck carcinoma to therapy, Int. J. Radiat. Oncol. Biol.
Phys. 58 (2004) 959e965.
[3] A.P. Meert, B. Martin, M. Paesmans, T. Berghmans, C. Mascaux, J.M. Verdebout,
P. Delmotte, J.J. Lafitte, J.P. Sculier, The role of HER-2/neu expression on the
survival of patients with lung cancer: a systematic review of the literature, Br.
J. Cancer 89 (2003) 959e965.
[20] J.J. Liao, Molecular recognition of protein kinase binding pockets for design of
potent and selective kinase inhibitors, J. Med. Chem. 50 (2007) 409e424.
[4] S.R. Klutchko, H. Zhou, R.T. Winters, T.P. Tran, A.J. Bridges, Tyrosine kinase
inhibitors. 19. 6-Alkynamides of 4-anilinoquinazolines and 4-anilinopyrido