Potent and selective inhibitors of platelet-derived growth factor receptor phosphorylation. 1. Synthesis, structure-activity relationship, and biological effects of a new class of quinazoline derivatives

Article abstract of DOI:10.1021/jm010428o

A new series of 4-[4-(N-substituted carbamoyl)-1-piperazinyl]-6,7-dimethoxyquinazoline derivatives were found to show potent and selective inhibition of platelet-dervied growth factor (PDGF) receptor phosphorylation. In this exploration of the structure-a

Full text of DOI:10.1021/jm010428o

J . Med. Chem. 2002, 45, 3057-3066
3057
P oten t a n d Selective In h ibitor s of P la telet-Der ived Gr ow th F a ctor Recep tor
P h osp h or yla tion . 1. Syn th esis, Str u ctu r e-Activity Rela tion sh ip , a n d Biologica l
Effects of a New Cla ss of Qu in a zolin e Der iva tives
Kenji Matsuno,*,† Michio Ichimura,† Takao Nakajima,† Keiko Tahara,† Shigeki Fujiwara,† Hiroshi Kase,†
J unko Ushiki,† Neill A. Giese,‡ Anjali Pandey,‡ Robert M. Scarborough,‡ Nathalie A. Lokker,‡ J in-Chen Yu,‡
J unko Irie,† Eiji Tsukuda,† Shin-ichi Ide,† Shoji Oda,† and Yuji Nomoto†
Pharmaceutical Research Institute, Kyowa Hakko Kogyo Company, Ltd., Shimotogari 1188, Nagaizumi-cho, Sunto-gun,
Shizuoka 411-8731, J apan, and Millennium Pharmaceuticals, Inc., 256 East Grant Avenue, San Francisco, California 94108
Received September 10, 2001
A new series of 4-[4-(N-substituted carbamoyl)-1-piperazinyl]-6,7-dimethoxyquinazoline deriva-
tives were found to show potent and selective inhibition of platelet-dervied growth factor (PDGF)
receptor phosphorylation. In this exploration of the structure-activity relationships (SARs) of
the prototype inhibitor KN1022, the 4-nitrophenylurea moiety was probed. We found that
4-substitution on the phenyl ring was optimal and the introduction of more than two
substituents on the phenyl ring decreased activities. Bulky substituents on the phenyl ring
enhanced activities. Thiourea analogues were also prepared, and the SARs were found to be
slightly different from those of the urea derivatives. Through this research, we obtained some
potent KN1022 derivatives such as 4-(4-methylphenoxy)phenyl (36, IC50 0.02 µmol/L), 4-tert-
butylphenyl (16, IC50 0.03 µmol/L), and 4-phenoxyphenyl (21, IC50 0.08 µmol/L) analogues, which
had almost a 10-fold increase in activity against KN1022. These potent compounds retained
their high selectivity against the PDGF receptor family similar to KN1022. We also observed
that these compounds could inhibit the PDGF-BB-induced proliferation of porcine vascular
smooth muscle cells without cell toxicity almost at the same IC50 values observed for PDGF
receptor phosphorylation. To evaluate the biological effects in vivo, we selected some analogues
on the basis of the measurement of the plasma drug concentration after oral administration to
rats. Oral administration of the 4-chlorophenyl (6), 4-bromophenyl (9), or 4-isopropoxyphenyl
(20) analogue to Sprague-Dawley rats (30 mg/kg, twice daily) resulted in significant inhibition
(24-38%) of neointima formation in the carotid artery of the balloon catheter deendothelialized
vessel in the rats. Therefore, 4-[4-(N-substituted carbamoyl)-1-piperazinyl]-6,7-dimethoxy-
quinazoline derivatives, which are potent inhibitors of PDGFR phosphorylation, may be expected
to represent a new therapeutic approach for the treatment of various aspects of atherosclerosis
and other cellar proliferative disorders.
In tr od u ction
which creates the sites for physical interaction with a
number of proteins that contain a Src homology two
(SH-2) domain.11
Platelet-derived growth factor (PDGF) is known to act
as a potent mitogen and chemotactic factor for various
mesenchymal cells such as fibroblasts, smooth muscle
cells (SMCs), mesangial cells, and brain glial cells.
PDGF is a disulfide-linked dimer of two related polypep-
tide chains, designated A and B, which are assembled
as heterodimers (PDGF-AB) or homodimers (PDGF-AA
and PDGF-BB).1-3 PDGF exerts its biological activity
by binding to structurally similar R- or â-PDGF recep-
tors, and inducing receptor dimerization.4,5 The receptor
binding specificity for the PDGF isoforms indicates that
PDGF-AA induces only R/R receptor dimers, PDGF-AB
induces R/R and R/â receptor dimers, and PDGF-BB
induces all three receptor dimer combinations.6-10 Once
dimerized, the PDGF receptor (PDGFR) undergoes
transphosphorylation on cytoplasmic tyrosine residues,
Abnormal PDGF-induced cell proliferation has been
proposed for various proliferative disorders such as
atherosclerosis, restenosis following PTCA, glomerulo-
nephritis, glomerulosclerosis, liver cirrhosis, pulmonary
fibrosis, and cancer.12-22 Additionally, PDGF and its
receptor (PDGFR) are also upregulated in these prolif-
erative disorders. Within restenosis lesions, PDGF plays
a major role in the vascular response to injury.23-27 After
the vascular injury, PDGF induces migration of SMCs
from the media into the intima of the artery wall, and
then subsequent excessive and disorderly proliferation
of intimal SMCs in concert with additional growth
factors. Therefore, an inhibitor of PDGFR phosphoryl-
ation would be expected to represent a therapeutic
benefit for these proliferative disorders.
* To whom correspondence should be addressed at the Kyowa Hakko
Kogyo Co., Ltd., Ohtemachi 1-6-1, Chiyoda-ku, Tokyo 100-8185, J apan.
Phone: +81-3-3282-0064.Fax: +81-3-3284-0407.E-mail: kenji.matsuno@
kyowa.co.jp.
Several inhibitors of PDGFR phosphorylation have
also been previously reported, 3-arylquinoline,28 4-aryl-
oxyquinoline,29 pyridylpyrimidine,30 benzimidazole,31 or
pyrazole32 derivatives, which are illlustrated in Chart
1. Recently we found a new class of potent and selective
† Kyowa Hakko Kogyo Co., Ltd.
‡ Millennium Pharmaceuticals, Inc.; formerly COR Therapeutics,
Inc.
10.1021/jm010428o CCC: $22.00 © 2002 American Chemical Society
Published on Web 06/11/2002

3058 J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 14
Matsuno et al.
Ch a r t 1
Sch em e 1a
Sch em e 2
a
Method A: RPhNCO, solvent. Method B: (i) RPhNH2, CDI,
solvent; (ii) 1. Method C: (i) RPhNH2, triphosgene, Et3N, CH3CN;
(ii) 1, Et3N, CH2Cl2. Method D: (i) RPhNH2, 4-NO2PhOCOCl,
Et3N, NMP; (ii) 1, heat.
inhibitors of PDGFR phosphorylation, the 4-[4-(N-
substituted carbamoyl)-1-piperazinyl]-6,7-dimethoxy-
quinazoline derivatives such as KN1022. In this paper,
we report the synthesis of KN1022 analogues, focused
on the 4-nitrophenylurea moiety, and discuss the struc-
ture-activity relationships (SAR) for inhibition of in
vitro â-PDGFR phosphorylation by this new class of
compounds. Selected analogues were also evaluated for
their kinase selectivity as well as their inhibition of
porcine aorta SMC proliferation induced by PDGF-BB.
Furthermore, selection of analogues for in vivo evalu-
ation by measurement of the plasma drug concentration
after oral administration to Sprague-Dawley rats (SD
rats) and inhibitory activity on neointima formation in
the rat carotid artery is also reported.
mamide (method A). Treatment of amines with N,N′-
carbonyldiimidazole in dichloromethane, followed by
addition of 1 to the reaction mixture in situ, provided
the desired ureas (method B). Sequential carbonylation
of amines with triphosgene in the presence of triethyl-
amine, followed by addition of 1 in situ, gave the ureas
(method C). Heating 1 in N-methylpyrrolidinone (NMP)
with 4-nitrophenylcarbamate, which was prepared from
the corresponding aniline and 4-nitrophenylchlorofor-
mate in the presence of triethylamine, also provided the
ureas (method D).
The dl-sulfoxide 27 and the sulfone 28 were synthe-
sized by oxidation of the methylthio analogue 23 with
differing numbers of equivalents of m-chloroperbenzoic
acid (Scheme 2). The hydroxy analogue 18 was synthe-
sized by catalytic hydrogenation of the benzyloxy ana-
logue 22 (Scheme 3). The carboxy analogue 25 was
obtained by hydrolysis of the ester 24 (Scheme 4).
The widely used synthetic route to the thioureas was
condensation of 1 with commercially available isothio-
cyanates described in Scheme 5 (method E). Addition-
ally, isothiocyanates were also prepared by treatment
of the corresponding amines with thiophosgene in inert
Ch em istr y
General synthetic methods for the ureas are described
in Scheme 1. There are four methods (methods A-D)
which we found useful for preparing analogues from the
known intermediate 4-(1-piperazinyl)-6,7-dimethoxy-
quinazoline (1).33 Condensation of 1 with commercially
available isocyanates was carried out in appropriate
inert solvents such as dichloromethane or dimethylfor-

Inhibitors of PDGF Receptor Phosphorylation
J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 14 3059
Ta ble 1. Synthetic Method and Inhibitory Activity on
â-PDGFR Phosphorylation
Sch em e 3
PDGFP
compd
R
procedure
method A
(µmol/L)a
KN1022
2
3
4
5
6
7
8
9
4-NO2
3-NO2
2-NO2
H
4-F
4-Cl
3-Cl
2-Cl
4-Br
4-I
4-Me
4-Et
0.70
2.57
>30
11.1
6.72
1.10
2.06
>30
0.53
0.29
9.96
1.21
0.11
0.08
0.21
0.03
0.26
>30
5.36
0.23
0.08
0.29
0.48
0.74
>30
0.85
>30
9.42
21.6
1.20
1.47
9.21
>30
method A
method A
method A
method A
method A
method A
method A
method A
method A
method A
method A
method B
method A
method A
method D
method D
hydrogenation of 22
method A
method B
method A
method B
method A
method A
hydrolysis of 24
method A
oxidation of 23
oxidation of 23
method A
method A
method A
method A
method B
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
Sch em e 4
4-nPr
4-iPr
4-nBu
4-tBu
4-Ph
4-OH
4-OMe
4-OiPr
4-OPh
4-OCH2Ph
4-SMe
4-COOEt
4-COOH
4-CN
(dl)-4-SOMe
4-SO2Me
2,4-Cl2
3,4-Cl2
3-NO2, 4-Cl
3,5-Cl2
3,4-(OCH2O)-
a
ΙC50 (µmol/L) of â-PDGFR phosphorylation.
Sch em e 5a
Resu lts a n d Discu ssion
SAR for In h ibition of â-P DGF R P h osp h or yla -
tion . As an initial exploration of the SAR of KN1022
we prepared a series of analogues examining the role
of the phenyl ring of the urea function and substitutions
in this ring on the activity against the PDGFR. All the
analogues prepared were evaluated for their inhibition
of â-PDGFR phosphorylation in accordance with known
whole cell assay,34 and the resulting IC50 values are
listed in Tables 1-3.
Table 1 shows the results that the position and nature
of the substituents on the phenyl ring attached to the
urea moiety have a substantial influence on the inhibi-
tory activity. For urea derivatives, substitution at the
4-position on the phenyl ring was the most favorable
and the activity was reduced at the 3- and 2-positions
with increasing magnitude, respectively. Regarding the
nitrophenyl derivatives, 4-substitution of the nitro group
(KN1022) showed the most potent activity and 3-sub-
stitution (2) yielded moderate activity whereas 2-sub-
stitution (3) completely abolished activity. Additionally,
a
Method E: RPhNCS, solvent. Method F: (i) RPhNH2, CSCl2,
Et3NA, solvent; (ii) 1.
solvent in the presence of triethylamine, and then 1 was
added to the reaction mixture in situ to provide the
desired thioureas (method F, Scheme 5).

3060 J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 14
Matsuno et al.
Ta ble 2. Synthetic Method and Inhibitory Activity on
â-PDGFR Phosphorylation
also showed potent activity, although the 4-phenyl
analogue 17 and 4-benzyloxy analogue 22 displayed
reduced activity just by deletion of an oxygen atom and
addition of a methylene unit, respectively. The ethoxy-
carbonyl (24) and cyano (26) analogues showed similar
IC50 values of KN1022. The hydroxy (18), carboxylic acid
(25), sulfoxide (27), and sulfone (28) analogues were
inactive, therefore suggesting that introduction of hy-
drophilic substituents was unfavorable.
Introduction of two substituents on the phenyl ring
was found to be unfavorable for increasing activity. The
activity of 2,4-dichloro analogue 29 was almost at the
same level as that of 2-substituted analogue 8, which
was weaker than the analogue with monosubstitution
at the 4-position (6). The 3,4-disubstitution almost
retained activity in comparison with 4-substitution (30
vs 6 and 7, 31 vs 6 and 2). The 3,5-disubstitution
reduced activity (32 vs 7). Furthermore, bicyclic deriva-
tive 33 was found to be inactive.
PDGFP
compd
R
procedure
method B
method B
method B
method B
hydrogenation of 37
method C
method C
method B
(µmol/L)a
34
35
36
37
38
39
40
41
42
43
2-(MeO)PhO
4-ClPhO
0.10
0.02
0.02
>30
0.15
2.31
0.05
0.08
0.06
1.04
4-MePhO
4-NO2PhO
4-NH2PhO
4-pyridyl-O
1-naphthyl-O
PhNH
PhCH2
4-pyridyl-CH2
method B
method B
The high potency shown by bulky substituents at the
4-position of the phenyl group prompted us to evaluate
such compounds in more detail. We focused on 21 and
synthesized the related compounds listed in Table 2.
Small substituents on the phenoxy group were found
to be acceptable, such as in the 4-chlorophenoxy (35),
4-methylphenoxy (36), 2-methoxyphenoxy (34), or 4-ami-
nophenoxy (38) analogue; however, 4-nitrophenoxy (37)
substitution completely abolished the activity. Replace-
ment of the oxygen atom was also investigated. Ben-
zylphenyl (42) and anilinophenyl (41) analogues re-
tained potent activity. Regarding exchange of the
phenoxy group, the 1-naphthoxy analogue 40 showed
potent activity; however, 4-pyridyloxy (39) and 4-py-
ridylmethyl (43) analogues were only moderate inhibi-
tors.
a
ΙC50 (µmol/L) of â-PDGFR phosphorylation.
Ta ble 3. Synthetic Method and Inhibitory Activity on
â-PDGFR Phosphorylation
PDGFP
compd
R
procedure
(µmol/L)a
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
4-NO2
3-NO2
2-NO2
H
4-F
4-Cl
3-Cl
2-Cl
4-Br
4-I
4-Me
4-iPr
4-nBu
4-tBu
4-OiPr
4-OPh
4-SMe
3-COOH
3-NO2, 4-Cl
3-Cl, 4-Br
method E
method E
method E
method E
method E
method E
method E
method F
method E
method E
method E
method E
method E
method E
method F
method E
method F
method E
method E
method E
method E
method E
0.33
0.19
1.24
3.18
2.00
0.79
0.44
>10
0.22
0.44
1.26
0.72
0.51
0.29
1.41
0.37
0.44
>30
0.16
0.10
1.14
18.2
The thiourea derivatives also showed inhibitory activ-
ity on â-PDGFR phosphorylation as listed in Table 3.
The SARs were somewhat different from those of the
ureas and thioureas regarding the position and type of
the substituents on the phenyl ring as follows. 2-Sub-
stitution on the phenyl ring showed the weakest activity
in the thiourea series, as was observed for the ureas.
However, 3-substituted derivatives were potent inhibi-
tors similar to 4-substituted derivatives. Regarding
nitrophenyl analogues, the 3-nitro analogue 45 was
found to be potent and the activity was similar to the
4-nitro analogue 44. Although the 2-substituted com-
pound 46 showed the weakest activity among the series,
the magnitude of activity decrease was relatively small
compared to that observed in the urea series. Addition-
ally, the chlorophenyl analogues 49-51 showed similar
SARs.
3,4-(OMe)2
3,4-(OCH2O)-
Next, in accordance with investigation of a variety of
substituents, bulky hydrophobic substitution was also
suitable for potent activity. Among the halogene (48-
53), alkyl (54-57), and alkoxy (58-59) series, the
4-phenoxy (59) and 4-tert-butyl (57) analogues showed
somewhat potent activity; however, the magnitude of
enhancement was not as much and the inhibitory
activity was weaker compared with that of the ureas
possessing the same substituent (21 and 16), respec-
tively. The hydrophilic carboxy analogue 61 was also
inactive like the urea. The inhibitory activity of the 3,4-
disubstituted compounds was similar or more potent
a
ΙC50 (µmol/L) of â-PDGFR phosphorylation.
for the chloro derivatives 6-8, the same order of potency
was observed.
Investigation of a variety of substituents on the
phenyl ring indicated that bulky hydrophobic substitu-
tion at the 4-position increased activity as shown in the
halogene (5-10), alkyl (11-17), and alkoxy (19-22)
series. The activity of the 4-tert-butyl analogue 16 was
significantly improved compared with that of the 4-n-
butyl analogue 15. The bulky 4-phenoxy analogue 21

Inhibitors of PDGF Receptor Phosphorylation
J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 14 3061
Ta ble 4. Kinase Specificitya
IC50 (µmol/L)
Ta ble 5. Inhibitory Activity on the Proliferation of SMCs
Induced by PDGF-BB
IC50
IC50
IC50
kinase
KN1022 compd 9 compd 14 compd 21 compd 26
compd
(µmol/L)
compd
(µmol/L)
compd
(µmol/L)
â-PDGFR
R-PDGFR
EGFR
FGFR
CSF-1R
0.24
0.89
>100
>200
>30
0.27
0.71
>100
0.02
0.09
>30
0.13
0.05
>30
29.7
NT
NT
>30
>30
>30
NT
NT
NT
NT
NT
NT
0.05
0.23
0.45
0.77
>100
KN1022
0.10
0.15
0.08
0.36
14
15
21
24
0.18
0.08
0.25
0.19
45
46
49
0.14
0.74
0.24
6
9
12
>200
>30
>100
>30
>30
>30
>30
>30
>30
>30
>30
>30
>30
NT
NT
>30
>30
>30
NT
NT
NT
NT
NT
NT
>200
>30
>100
>30
>30
>30
>30
>30
>30
>30
>30
>30
VEGFR-2 >100
Src
Ta ble 6. Plasma Concentration after Oral Administration to
>30
>30
>30
>30
>30
>30
>30
>30
>30
Ratsa
PKA
PKC
Mek 1
Mkk 3
Mkk 6
Erk2
J nk1
p38
plasma concn (µg/mL)
compd
1 h
8 h
6
rat 1
rat 2
rat 3
rat 4
rat 5
rat 6
rat 7
rat 8
rat 9
rat 10
rat 11
rat 12
15.8
20.5
<0.1
2.4
63.2
37.0
6.6
7.1
9.3
5.7
21.3
37.7
7.9
20.3
<0.1
1.3
58.6
62.4
0.4
0.1
0.5
<0.1
4.2
49
9
c-Kit
Flt3
0.39
3.3
0.13
11.4
0.05
0.05
0.48
19.7
a
52
12
20
NT ) not tested.
compared with that of the monosubstituted derivatives
at the 3- or 4-position (62, 45, and 49 and 63, 50, and
52). Furthermore, bicyclic 3,4-methylenedioxy analogue
65 was found to be weaker than the 3,4-dimethoxy
analogue 64.
2.5
a
n ) 2.
The 4-anilino-6,7-dimethoxyquinazolines were previ-
ously reported as potent EGF receptor (EGFR) tyrosine
kinase inhibitors by the Parke-Davis and Zeneca
groups.35,36 The EGFR also preferred substitution on the
phenyl ring of the anilino moiety; namely, a hydrophobic
substitutent at the 3-position such as the 3-bromo was
found to be optimal for potent inhibition.35,36 Although
the optimal position for the inhibitory activity of our
series was different from that of these inhibitors of
EGFR, it is interesting that the position of the substitu-
ent on the phenyl ring had great influence on activity
for each inhibitor whose basic skeleton contains the
same 6,7-dimethoxyquinazoline ring system. Unique to
our series is the 4-piperazinyl substitution of the 6,7-
dimethoxyquinazoline ring system, which specifically
yields inhibitors of the PDGFR family of receptor
tyrosine kinases, unlike the 4-anilino substitution,
which provides EGFR kinase inhibitors.
Kin a se Selectivity. We also evaluated several potent
compounds for inhibitory activity on various kinases
including c-Kit and Flt3, which are closely related
PDGFR family tyrosine kinases,37 using previously
reported methods.34,38 As shown in Table 4, the ana-
logues 14 and 21 showed similar inhibitory activity on
PDGFRs, c-Kit, and Flt3 with IC50 values ranging
between 0.05 and 0.23 µmol/L, whereas analogues 9 and
26 inhibited Flt3 with 40-fold higher concentration
compared with PDGFRs and c-Kit. It seems that a less
bulky substituent on the phenyl ring gave specificity for
PDGFR and c-Kit. No significant inhibition was ob-
served on Ser/Thr kinases (PKA, PKC), EGFR, FGFR,
or VEGFR-2 at 100-1000-fold higher concentrations.
Although it was not obvious whether other classes of
inhibitors for PDGFR phosphorylation described in
Chart 1 had inhibitory activity on c-Kit or Flt3, these
studies demonstrate that our synthesized compounds
showed good selectivity for the PDGFR family of recep-
tor tyrosine kinases.
erosclerosis, the abnormal proliferation of SMCs is
observed. We examined several potent compounds
against porcine aorta SMC proliferation induced by
PDGF-BB in vitro using the XTT method.39 As shown
in Table 5, these compounds inhibited the cell prolifera-
tion induced by PDGF-BB at almost the same concen-
tration as observed for inhibition of PDGFR phospho-
rylation. Obvious toxic cell transformation was not
observed in these studies.
P la sm a Dr u g Con cen tr a tion a fter Or a l Ad m in -
istr a tion to SD Ra ts. We initiated an evaluation of
the in vivo biological effects of KN1022 analogues,
especially the inhibition of neointima formation after
balloon injury. We selected the analogues which showed
good oral availability and afforded a high plasma drug
concentration over time for in vivo evaluation. For this
purpose, we measured the plasma drug concentration
of several KN1022 analogues 1 and 8 h after oral
administration to SD rats (n ) 2) as shown in Table 6.
We observed some relationships between the structure
and plasma drug concentration. The plasma drug
concentration of the ureas 6 and 9 was found to be
higher than that of the corresponding thioureas 49 and
52, respectively. Additionally, the high plasma drug
concentration of 6 and 9 was maintained at 8 h
compared with that of 12 and 20. These results sug-
gested that the urea analogues were suitable for oral
absorption and that electron-withdrawing groups on the
phenyl ring lead to a high plasma drug concentration
for a longer period of time.
In h ibitor y Effect on Neoin tim a F or m a tion a fter
Ba lloon In ju r y of th e Ra t Ca r otid Ar ter y. We
evaluated the effect on neointima formation after bal-
loon injury of the rat carotid artery by 6, 9, and 20,
which showed good oral absorption and a high plasma
drug concentration at 8 h. Compounds were suspended
in methylcellulose 400 and were orally administrated
(30 mg/kg) to SD rats twice daily for a period of 15 days
starting on the day before the balloon injury. As shown
in Table 7, all compounds showed significant inhibition
In h ib it ion of SMC P r olifer a t ion In d u ced b y
P DGF -BB. In the blood vessels of patients with ath-

3062 J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 14
Matsuno et al.
Ta ble 7. Inhibitory Activity on Neointima Formation in the
Rat Carotid Artery
was stirred overnight at room temperature. The reaction
mixture was poured into water, and then NaCl was added.
The solid was collected by filtration, washed with water, and
dried under vacuum. Purification by silica gel column chro-
matography eluting with AcOEt/CHCl3/MeOH (50:10:4) gave
5 (630 mg, 1.53 mmol).
no. of animals
compd
I/M ratio
compd
reduction of
I/M ratio (%)
compd vehicle treated vehicle treated
6
9
20
8
10
10
8
10
10
0.93
1.00
0.99
0.67
0.65
0.68
38.5 (p < 0.05)
35.0 (p < 0.05)
24.0 (p < 0.05)
Meth od B. 4-Propylaniline (0.28 mL, 2.25 mmol) was added
slowly to a solution of 1,1′-carbonyldiimidazole (0.36 g, 2.2
mmol) in dichloromethane (15 mL) under cooling with an ice
bath. After the reaction mixture was stirred for 4 h at room
temperature, 1 (0.50 g, 1.8 mmol) was added, and then the
resulting mixture was stirred overnight at room temperature.
The residue after removal of solvent was purified by silica gel
column chromatography eluting with AcOEt/CHCl3/MeOH (50:
10:3) to afford 13 (829 mg, 1.91 mmol).
(24-38%) of neointima formation relative to vehicle-
treated controls (p < 0.05, Student’s t test or Aspin-
Welch test). No obvious affection for rat body weight
was observed (data not shown). On the basis of these
data, 4-[4-(N-substituted carbamoyl)-1-piperazinyl]-6,7-
dimethoxyquinazoline derivatives, which are inhibitors
of PDGFR phosphorylation, may be expected to repre-
sent a new approach for treating various aspects of
atherosclerosis.
Meth od C. To a solution of triphosgene (0.20 g, 0.67 mmol)
in acetonitrile (3 mL) at -5 °C were added an acetonitrile (8
mL) solution of 4-(4-aminophenoxy)pyridine (0.21 g, 1.1 mmol)
and triethylamine (0.2 mL, 1.4 mmol) over a period of 15 min.
The mixture was stirred for an additional 30 min, and then a
dichloromethane solution (5 mL) of 1 (0.31 g, 1.1 mmol) and
triethylamine (0.2 mL, 1.4 mmol) was slowly added. The
reaction mixture was slowly warmed to room temperature and
stirred overnight. The mixture was diluted with ethyl acetate,
washed with water and brine, dried over anhydrous magne-
sium sulfate, filtered, and evaporated to give a crude residue
as an oil. The crude residue was purified by RP-HPLC to afford
39 (0.06 g, 0.12 mmol).
Con clu sion s
Screening for inhibitors of the PDGFR has led to the
discovery of a compound series containing the new
4-piperazinyl-substituted quinazoline nucleus. The posi-
tion and nature of the substituents on the phenyl ring
attached to the (thio)urea moiety were found to be
important for activity in this series. These compounds
showed good selectivity for the PDGFR family of recep-
tor tyrosine kinases and inhibited the proliferation of
porcine aorta smooth muscle cells induced by PDGF-
BB. To evaluate the biological effects in vivo, we selected
some analogues on the basis of the measurement of the
plasma drug concentration after oral administration to
rats. Oral administration of 6, 9, and 20 (30 mg/kg, twice
daily) to SD rats resulted in significant inhibition of
neointima formation in the carotid artery of the balloon
catheter deendothelialized vessel in the rats. These
results indicate that 4-[4-(N-substituted carbamoyl)-1-
piperazinyl]-6,7-dimethoxyquinazolines are expected to
have therapeutic potential for the treatment of cellar
proliferative disorders, especially various aspects of
atherosclerosis such as restenosis following PTCA.
Meth od D. To a solution of 4-tert-butylamine (1.36 mL, 8.54
mmol) in NMP (20 mL) were added 4-nitrophenyl chlorofor-
mate (0.88 g, 4.4 mmol) and triethylamine (3.05 mL, 21.9
mmol) under cooling with an ice bath. After the reaction
mixture was stirred for 2.5 h, 1 (0.60 g, 2.2 mmol) was added,
and the resulting mixture was heated at 80 °C for 4 h, at 100
°C for a further 3 h, and at 140 °C for a further 9 h. The
reaction mixture was cooled to room temperature, poured into
water, extracted with chloroform, and dried over sodium
sulfate. The residue after removal of solvent was purified by
silica gel column chromatography eluting with AcOEt/CHCl3/
MeOH (50:10:3) to give 16 (191 mg, 0.43 mmol).
Meth od E. A mixture of 1 (0.40 g, 1.5 mmol) and 4-chlo-
rophenylisothiocyanate (0.34 g, 2.2 mmol) in DMF (10 mL) was
stirred overnight at room temperature. The reaction mixture
was poured into water, and then NaCl was added. The
precipitated solid was collected by filtration, washed with
water, and dried under vacuum. Purification by silica gel
column chromatography eluting with AcOEt/CHCl3/MeOH (50:
10:1) gave 49 (0.62 g, 1.4 mmol).
Exp er im en ta l Section
Melting points were determined on a Bu¨chi 535 melting
point or Yanaco model MP micro melting point apparatus on
compounds isolated as described in the experimental proce-
dures and are uncorrected. 1H NMR spectra were recorded on
a J EOL J NM-EX270 (270 MHz) FT NMR spectrometer, J EOL
J NM-GX270 (270 MHz) FT NMR spectrometer, or Varian
Unity + 400 spectrometer. Chemical shifts are reported as δ
values (parts per million) downfield from that of internal TMS
in appropriate organic solutions. FAB-mass spectra were
recorded with a J EOL J MS-DX303 mass spectrometer. Low-
resolution ES-mass spectra were recorded with an HP 1100-
MSD LC-MS spectrometer. High-resolution ES-mass spectra
were recorded with a VG ZAB2-EQ high-resolution mass
spectrometer. The IR spectra were recorded with a J ASCO IR-
810 IR spectrometer or HORIBA FT-200 IR spectrometer.
Analytical TLC was carried out on E. Merck 0.25 mm silica
gel precoated glass plates (60 F-254) with detection by UV
light. Normal-phase silica gel (EM Science, silica gel 60) was
used for chromatography. Combustion analyses (CHN) were
performed on a Perkin-Elmer series II CHNS/O analyzer 2400
and agreed with theoretical values to within (0.4%. Support-
ing Information is available.
Meth od F . To a solution of thiophosgene (0.18 mL, 2.4
mmol) in dichloromethane (10 mL) were slowly added 4-(me-
thylmercapto)aniline (0.29 mL, 2.3 mmol) and then triethyl-
amine (0.76 mL, 5.5 mmol) under cooling with an ice bath.
After the reaction mixture was stirred for 4 h, 1 (0.50 g, 1.8
mmol) was added, and then the resulting mixture was stirred
overnight at room temperature. Methanol was added for
quenching excess isothiocyanate, and the residue after removal
of solvent was purified by silica gel column chromatography
eluting with AcOEt/CHCl3/MeOH (50:10:3) to give 60 (634 mg,
1.39 mmol).
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(4-n itr o-
p h en yl)-1-p ip er a zin eca r boxa m id e (KN1022): yield 90% by
method A; mp 272-274 °C (CHCl3-MeOH); 1H NMR, FABMS,
IR, Anal. (C21H22N6O5) C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(3-n itr o-
ph en yl)-1-piper azin ecar boxam ide (2): yield 89% by method
A; mp 123-125 °C (CHCl3-MeOH-iPr2O); 1H NMR, FABMS,
IR, Anal. (C21H22N6O5) C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(2-n itr o-
ph en yl)-1-piper azin ecar boxam ide (3): yield 13% by method
A; mp 217-218 °C (CHCl3-MeOH); 1H NMR, FABMS, IR,
Anal. (C21H22N6O5) C, H, N.
The typical synthetic methods were described as follows.
Meth od A. A mixture of 1 (432 mg, 1.57 mmol) and
4-fluorophenylisocyanate (0.27 mL, 2.4 mmol) in DMF (10 mL)

Inhibitors of PDGF Receptor Phosphorylation
J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 14 3063
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-p h en yl-
1-p ip er a zin eca r boxa m id e (4): yield 44% by method A; mp
121-123 °C (Et2O); 1H NMR, FABMS, IR, Anal. (C21H23N5O3)
C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(4-p h en -
oxyp h en yl)-1-p ip er a zin eca r boxa m id e (21): yield 97% by
method A; mp 218-219 °C (CHCl3-iPr2O); 1H NMR, FABMS,
IR, Anal. (C27H27N5O4) C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(4-flu o-
r op h en yl)-1-p ip er a zin eca r boxa m id e (5): yield 97% by
method A; mp 198-202 °C (CHCl3-iPr2O); 1H NMR, FABMS,
IR, Anal. (C21H22FN5O3) C, H, N.
Da ta for N-(4-Ben zyloxyp h en yl)-4-(6,7-d im eth oxy-4-
qu in a zolin yl)-1-p ip er a zin eca r boxa m id e (22): yield 100%
by method B in the presence of triethylamine; mp 195-196
1
°C (AcOEt); H NMR, FABMS, IR, Anal. (C28H29N5O4) C, H,
Da ta for N-(4-Ch lor op h en yl)-4-(6,7-d im eth oxy-4-qu in a -
zolin yl)-1-piper azin ecar boxam ide (6): yield 100% by method
A; mp 217-219 °C (CHCl3-iPr2O); 1H NMR, FABMS, IR, Anal.
(C21H22ClN5O3) C, H, N.
Da ta for N-(3-Ch lor op h en yl)-4-(6,7-dim eth oxy-4-qu in a -
zolin yl)-1-piper azin ecar boxam ide (7): yield 86% by method
A; mp 223-224 °C (CHCl3-iPr2O); 1H NMR, FABMS, IR, Anal.
(C21H22ClN5O3‚0.25H2O) C, H, N.
Da ta for N-(2-Ch lor op h en yl)-4-(6,7-d im eth oxy-4-qu in a -
zolin yl)-1-p ip er a zin eca r b oxa m id e (8): yield 100% by
method A; mp 186-187 °C (CHCl3-iPr2O); 1H NMR, FABMS,
Anal. (C21H22ClN5O3) C, H, N.
Da ta for N-(4-Br om op h en yl)-4-(6,7-d im eth oxy-4-qu in a -
zolin yl)-1-piper azin ecar boxam ide (9): yield 100% by method
A; mp 223-228 °C (CHCl3-MeOH-iPr2O); 1H NMR, FABMS,
IR, Anal. (C21H22BrN5O3) C, H, N.
N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(4-m eth -
ylth iop h en yl)-1-p ip er a zin eca r boxa m id e (23): yield 84%
by method A; mp 231-233 °C (CHCl3-iPr2O); 1H NMR,
FABMS, IR, Anal. (C22H25N5O3S‚0.25H2O) C, H, N.
Data for 4-(6,7-Dim eth oxy-4-qu in azolin yl)-N-(4-eth oxy-
ca r bon ylp h en yl)-1-p ip er a zin eca r boxa m id e (24): yield
96% by method A; mp 242-246 °C (AcOEt); 1H NMR, FABMS,
IR, Anal. (C24H27N5O5) C, H, N.
N-(4-Car boxyph en yl)-4-(6,7-dim eth oxy-4-qu in azolin yl)-
1-p ip er a zin eca r boxa m id e (25). To a solution of 24 (390 mg,
0.84 mmol) in 1,4-dioxane (10 mL) were added lithium
hydroxide monohydrate (141 mg, 3.36 mmol) and water (1 mL).
The reaction mixture was stirred overnight and evaporated.
The residue was suspended in water and adjusted to pH 4 with
4 mol/L hydrochloric acid, and then the solid was collected by
filtration, washed with water, and dried under vacuum.
Purification by silica gel column chromatography gave the title
compound in 100% yield: 1H NMR, FABMS, IR.
Da ta for N-(4-Cya n op h en yl)-4-(6,7-d im eth oxy-4-qu in a -
zolin yl)-1-piper azin ecar boxam ide (26): yield 90% by method
A; mp 274-275 °C (AcOEt); 1H NMR, FABMS, IR, Anal.
(C22H22N6O3‚0.25H2O) C, H, N.
Data for 4-(6,7-Dimethoxy-4-quinazolinyl)-N-(4-iodophen-
yl)-1-p ip er a zin eca r boxa m id e (10): yield 86% by method A;
mp 238-242 °C (CHCl3-MeOH-iPr2O); 1H NMR, FABMS, IR,
Anal. (C21H22IN5O3) C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(4-tolyl)-
1-p ip er a zin eca r boxa m id e (11): yield 91% by method A; mp
1
225-228 °C (AcOEt-CHCl3-MeOH); H NMR, FABMS, IR,
Anal. (C22H25N5O3) C, H, N.
(dl)-4-(6,7-Dim eth oxy-4-qu in azolin yl)-N-(4-m eth ylsu lfi-
n ylp h en yl)-1-p ip er a zin eca r boxa m id e (27). To a solution
of 23 (647 mg, 1.47 mmol) in dichloromethane (15 mL) was
added m-chloroperbenzoic acid (381 mg, 2.21 mmol) at 0 °C,
and the resulting mixture was stirred for 6 h under an argon
atmosphere. Na2S2O3 solution (0.1 mol/L) was added, and the
mixture was stirred for 30 min. Following separation of
dichloromethane, the mixture was washed with brine, dried
over anhydrous magnesium sulfate, and evaporated. The
residue was purified by silica gel column chromatography to
give the title compound (482 mg, 1.06 mmol, 72% yield): mp
241-244 °C (CHCl3-MeOH); 1H NMR, FABMS, HRMS-FAB,
IR.
4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(4-m eth a n esu lfo-
n ylp h en yl)-1-p ip er a zin eca r boxa m id e (28). Similar reac-
tion of 27 except with 3 equiv of m-chloroperbenzoic acid gave
the title compound: yield 44% yield; mp 266-269 °C (AcOEt);
1H NMR, FABMS, IR, Anal. (C22H25N5O5S‚0.25H2O) C, H, N.
Da ta for N-(2,4-Dich lor op h en yl)-4-(6,7-d im eth oxy-4-
qu in a zolin yl)-1-p ip er a zin eca r boxa m id e (29): yield 100%
by method A; mp 166-167 °C (CHCl3-iPr2O); 1H NMR,
FABMS, IR, Anal. (C21H21Cl2N5O3) C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(4-eth -
ylp h en yl)-1-p ip er a zin eca r boxa m id e (12): yield 92% by
1
method A; mp 251-252 °C (CHCl3-MeOH-iPr2O); H NMR,
FABMS, IR, Anal. (C23H27N5O3) C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(4-p r o-
p ylp h en yl)-1-p ip er a zin eca r boxa m id e (13): yield 100% by
method B; mp 214-215 °C (AcOEt); 1H NMR, FABMS, IR,
Anal. (C24H29N5O3) C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(4-isop r o-
p ylp h en yl)-1-p ip er a zin eca r boxa m id e (14): yield 70% by
method A; mp 252-254 °C (AcOEt-CHCl3-MeOH); 1H NMR,
FABMS, IR, Anal. (C24H29N5O3‚0.25H2O) C, H, N.
Da ta for N-(4-Bu tylp h en yl)-4-(6,7-d im eth oxy-4-qu in a -
zolin yl)-1-piper azin ecar boxam ide (15): yield 83% by method
A; mp 216-222 °C (CHCl3-iPr2O); 1H NMR, FABMS, IR, Anal.
(C25H31N5O3) C, H, N.
Da t a for N-(4-ter t-Bu t ylp h en yl)-4-(6,7-d im et h oxy-4-
qu in a zolin yl)-1-p ip er a zin eca r boxa m id e (16): yield 20% by
method D; mp 109-111 °C (CHCl3-iPr2O); 1H NMR, FABMS,
HRMS-FAB, IR, Anal. (C25H31N5O3‚0.25iPr2O‚0.25H2O) C, H,
N.
Da ta for N-(4-Bip h en yl)-4-(6,7-d im eth oxy-4-qu in a zoli-
n yl)-1-p ip er a zin eca r boxa m id e (17): yield 9% by method
D; mp 221-224 °C (CHCl3-iPr2O); 1H NMR, FABMS, IR, Anal.
(C27H27N5O3‚H2O) C, H, N.
Da ta for N-(3,4-Dich lor op h en yl)-4-(6,7-d im eth oxy-4-
qu in a zolin yl)-1-p ip er a zin eca r boxa m id e (30): yield 100%
by method A; mp 221-222 °C (CHCl3-MeOH-iPr2O); 1H
NMR, FABMS, IR, Anal. (C21H21Cl2N5O3) C, H, N.
4-(6,7-Dim eth oxy-4-qu in azolin yl)-N-(4-h ydr oxyph en yl)-
1-p ip er a zin eca r boxa m id e (18). To a solution of 22 (4.60 g,
9.22 mmol) in acetic acid (30 mL) was added 10% Pd/C (1.50
g, containing 50% water) in acetic acid (20 mL), and the
resulting mixture was hydrogenated at 50 °C. After the
removal of the catalyst by filtration and evaporation, methanol
was added to the residue to give the title compound (2.99 g,
7.31 mmol, 79% yield): mp 152-154 °C (MeOH); 1H NMR,
FABMS, IR, Anal. (C21H23N5O4‚0.25H2O‚MeOH) C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(4-m eth -
oxyp h en yl)-1-p ip er a zin eca r boxa m id e (19): yield 87% by
method A; mp 221-223 °C (Et2O); 1H NMR, FABMS, IR, Anal.
(C22H25N5O4) C, H, N.
Da ta for N-(4-Ch lor o-3-n itr op h en yl)-4-(6,7-d im eth oxy-
4-qu in a zolin yl)-1-p ip er a zin eca r boxa m id e (31): yield 64%
by method A; mp 253-255 °C (AcOEt-CHCl3-MeOH); 1H
NMR, FABMS, IR, Anal. (C21H21ClN6O5) C, H, N.
Da ta for N-(3,5-Dich lor op h en yl)-4-(6,7-d im eth oxy-4-
qu in a zolin yl)-1-p ip er a zin eca r boxa m id e (32): yield 93% by
1
method A; mp 139-140 °C (CHCl3-MeOH-iPr2O); H NMR,
FABMS, IR, Anal. (C21H21Cl2N5O3) C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(3,4-m e-
th ylen edioxyph en yl)-1-piper azin ecar boxam ide (33): quan-
titaive yield by method B; mp 218-219 °C (AcOEt); 1H NMR,
FABMS, IR, Anal. (C22H23N5O5) C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(4-isop r o-
p oxyp h en yl)-1-p ip er a zin eca r boxa m id e (20): yield 67% by
method A; mp 220-222 °C (AcOEt); 1H NMR, FABMS, IR,
Anal. (C24H29N5O4‚0.25H2O) C, H, N.
Data for 4-(6,7-Dim eth oxy-4-qu in azolin yl)-N-[4-(2-m eth -
oxyph en oxy)ph en yl]-1-piper azin ecar boxam ide (34): yield
1
52% by method B; mp 186-187 °C (CHCl3-iPr2O); H NMR,
FABMS, IR, Anal. (C28H29N5O5) C, H, N.

3064 J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 14
Matsuno et al.
Data for N-[4-(4-Ch lor oph en oxy)ph en yl]-4-(6,7-dim eth -
oxy-4-qu in a zolin yl)-1-p ip er a zin eca r boxa m id e (35): yield
97% by method B; mp 204-205 °C (AcOEt); 1H NMR, FABMS,
IR, Anal. (C27H26ClN5O4) C, H, N.
Da ta for N-(2-Ch lor oph en yl)-4-(6,7-dim eth oxy-4-qu in a -
zolin yl)-1-p ip er a zin eth ioca r boxa m id e (51): yield 53% by
method F; mp 166-167 °C (AcOEt); 1H NMR, FABMS, IR,
Anal. (C21H22ClN5O2S) C, H, N.
Da ta for N-(4-Br om op h en yl)-4-(6,7-d im eth oxy-4-qu in a -
zolin yl)-1-p ip er a zin eth ioca r boxa m id e (52): yield 78% by
method E; mp 170-171 °C (AcOEt); 1H NMR, FABMS, IR,
Anal. (C21H22BrN5O2S‚0.25AcOEt) C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-[4-(4-m e-
th ylph en oxy)ph en yl]-1-piper azin ecar boxam ide (36): yield
97% by method B; mp 201-202 °C (AcOEt); 1H NMR, FABMS,
IR, Anal. (C28H29N5O4) C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(4-iod o-
p h en yl)-1-p ip er a zin eth ioca r boxa m id e (53): yield 94% by
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-[4-(4-n i-
tr oph en oxy)ph en yl]-1-p ip er a zin eca r boxa m id e (37): yield
87% by method B; mp 261-262 °C (AcOEt); 1H NMR, FABMS,
IR, Anal. (C27H26N6O6‚0.25H2O) C, H, N.
1
method E; mp 129-132 °C (CHCl3-MeOH-iPr2O); H NMR,
FABMS, IR, Anal. (C21H22IN5O2S‚H2O) C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(4-tolyl)-
1-p ip er a zin eth ioca r boxa m id e (54): yield 82% by method
E; mp 204-205 °C (AcOEt); 1H NMR, FABMS, IR, Anal.
(C22H25N5O2S) C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(4-isop r o-
p ylp h en yl)-1-p ip er a zin eth ioca r boxa m id e (55): yield 84%
by method E; mp 194-195 °C (AcOEt); 1H NMR, FABMS, IR,
Anal. (C24H29N5O2S) C, H, N.
Da ta for N-(4-Bu tylp h en yl)-4-(6,7-d im eth oxy-4-qu in a -
zolin yl)-1-p ip er a zin eth ioca r boxa m id e (56): yield 80% by
method E; mp 171-173 °C (CHCl3-iPr2O); 1H NMR, FABMS,
IR, Anal. (C25H31N5O2S) C, H, N.
N -[4-(4-Am in op h e n oxy)p h e n yl]-4-(6,7-d im e t h oxy-4-
qu in a zolin yl)-1-p ip er a zin eca r boxa m id e (38). To a solution
of 37 (300 mg, 0.57 mmol) in ethanol (25 mL) was added a
suspension of 10% Pd/C (100 mg, containing 50% water) in
ethanol (5 mL) and water (1 mL). The mixture was hydroge-
nated for 5.5 h, then a suspension of 10% Pd/C (50 mg,
containing 50% water) was added, and the mixture was further
hydrogenated for 7.5 h. The catalyst was removed by filtration,
and the residue after removal of solvent was purified by silica
gel column chromatography to give the title compound (172
mg, 0.34 mmol, 61% yield): mp 106-108 °C (CHCl3-MeOH-
1
iPr2O); H NMR, FABMS, IR, Anal. (C27H28N6O4‚H2O) C, H,
Da t a for N-(4-ter t-Bu t ylp h en yl)-4-(6,7-d im et h oxy-4-
q u in a zolin yl)-1-p ip er a zin et h ioca r b oxa m id e (57): yield
N.
Da ta for 4-(6,7-Dim eth oxyqu in a zolin yl)-N-[4-(4-p yr i-
d yloxy)p h en yl]-1-p ip er a zin eca r boxa m id e (39): yield 11%
by method C; mp 163-164 °C; 1H NMR, ESMS, HRMS-ES,
IR.
Data for 4-(6,7-Dim eth oxy-4-qu in azolin yl)-N-[4-(1-n aph -
th yloxy)ph en yl]-1-piper azin ecar boxam ide (40): yield 65%
by method C; mp 178-180 °C; 1H NMR, ESMS, HRMS-ES,
IR.
1
61% by method E; mp 221-224 °C (CHCl3-iPr2O); H NMR,
FABMS, IR, Anal. (C25H31N5O2S‚0.25H2O) C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(4-isop r o-
p oxyp h en yl)-1-p ip er a zin eth ioca r boxa m id e (58): yield
74% by method F; mp 208-209 °C (AcOEt); 1H NMR, FABMS,
IR, Anal. (C24H29N5O3S) C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(4-p h en -
oxyp h en yl)-1-p ip er a zin eth ioca r boxa m id e (59): yield 74%
by method E; mp 242-243 °C (AcOEt-CHCl3-MeOH); 1H
NMR, FABMS, IR, Anal. (C27H27N5O3S‚0.25H2O) C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(4-m eth -
ylth iop h en yl)-1-p ip er a zin eth ioca r boxa m id e (60): yield
77% by method F; mp 214-216 °C (AcOEt); 1H NMR, FABMS,
IR, Anal. (C22H25N5O2S2) C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-[4-p h en -
yla m in op h en yl]-1-p ip er a zin eca r boxa m id e (41): quantita-
tive yield by method B; mp 219-220 °C (CHCl3-MeOH-i-
1
Pr2O); H NMR, FABMS, IR, Anal. (C27H28N6O3) C, H, N.
Da ta for N-(4-Ben zylp h en yl)-4-(6,7-d im eth oxy-4-qu in a -
zolin yl)-1-p ip er a zin eca r boxa m id e (42): quantitative yield
by method B; mp 215-216 °C (AcOEt); 1H NMR, FABMS, IR,
Anal. (C28H29N5O3‚0.25H2O) C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-[4-(4-p y-
r idylm eth yl)ph en yl]-1-piper azin ecar boxam ide (43): yield
59% by method B; mp 174-175 °C (AcOEt); 1H NMR, FABMS,
IR, Anal. (C27H28N6O3‚0.5H2O) C, H, N.
Data for N-(3-Car boxyph en yl)-4-(6,7-dim eth oxy-4-qu in -
a zolin yl)-1-p ip er a zin eth ioca r boxa m id e (61): yield 96% by
1
method E; H NMR, FABMS, HRMS-FAB, IR.
Da ta for N-(4-Ch lor o-3-n itr op h en yl)-4-(6,7-d im eth oxy-
4-qu in a zolin yl)-1-p ip er a zin eth ioca r boxa m id e (62): yield
1
74% by method E; H NMR, FABMS, IR.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(4-n itr o-
p h en yl)-1-p ip er a zin eth ioca r boxa m id e (44): yield 67% by
Data for N-(4-Br om o-3-ch lor oph en yl)-4-(6,7-dim eth oxy-
4-qu in a zolin yl)-1-p ip er a zin eth ioca r boxa m id e (63): yield
1
method E; mp 221-224 °C (CHCl3-MeOH-iPr2O); H NMR,
1
89% by method E; mp 169-172 °C (CHCl3-iPr2O); H NMR,
FABMS, IR, Anal. (C21H22N6O4S‚0.25H2O) C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(3-n itr o-
p h en yl)-1-p ip er a zin eth ioca r boxa m id e (45): yield 83% by
method E; mp 140-143 °C (AcOEt-CHCl3-MeOH); 1H NMR,
FABMS, IR, Anal. (C21H22N6O4S) C, H, N.
FABMS, IR, Anal. (C21H21BrClN5O2S) C, H, N.
Da ta for N-(3,4-Dim eth oxyp h en yl)-4-(6,7-d im eth oxy-
4-qu in a zolin yl)-1-p ip er a zin eth ioca r boxa m id e (64): yield
100% by method E; mp 174-176 °C (CHCl3-iPr2O); 1H NMR,
FABMS, IR, Anal. (C23H27N5O4S) C, H, N.
Data for 4-(6,7-Dim eth oxy-4-qu in azolin yl)-N-(3,4-m eth -
ylen ed ioxyp h en yl)-1-p ip er a zin et h ioca r b oxa m id e (65):
yield 100% by method E; mp 207-211 °C (CHCl3-MeOH-
iPr2O); 1H NMR, FABMS, IR, Anal. (C22H23N5O4S‚0.5H2O) C,
H, N.
P la sm a Con cen tr a tion a fter Or a l Ad m in istr a tion to
SD Ra ts. A suspension of each compound in methylcellulose
(6 mg/mL) was orally administrated to male SD rats (30 mg/
kg, n ) 2), and the plasma was collected via a tail vein by
capillary at 1 and 8 h. DMF (10 µL) and acetonitrile (200 µL)
were added to the plasma (100 µL). The mixture was well
stirred and centrifuged for 5 min. The supernatant was
evaporated under centrifugation to dryness, the mobile phase
of HPLC (acetonitrile-phosphate buffer containing 5 mmol/L
sodium octanesulfonate pH-adjusted by phosphoric acid, 200
µL) was added, and the solution was membrane-filtered. The
concentration of the drug was determined by HPLC, using the
calibration determined previously.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(2-n itr o-
p h en yl)-1-p ip er a zin eth ioca r boxa m id e (46): yield 100% by
method E; mp 177-178 °C (CHCl3-iPr2O); 1H NMR, FABMS,
IR, Anal. (C21H22N6O4S‚0.25H2O) C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-p h en yl-
1-p ip er a zin eth ioca r boxa m id e (47): yield 97% by method
E; mp 230-232 °C (Et2O); 1H NMR, FABMS, IR, Anal.
(C21H23N5O2S‚0.4Et2O‚0.4H2O) C, H, N.
Da ta for 4-(6,7-Dim eth oxy-4-qu in a zolin yl)-N-(4-flu o-
r op h en yl)-1-p ip er a zin eth ioca r boxa m id e (48): yield 56%
by method E; mp 212-217 °C (CHCl3-iPr2O); 1H NMR,
FABMS, IR, Anal. (C21H22FN5O2S‚1.5H2O) C, H, N.
Da ta for N-(4-Ch lor op h en yl)-4-(6,7-d im eth oxy-4-qu in a -
zolin yl)-1-p ip er a zin eth ioca r boxa m id e (49): yield 96% by
method E; mp 199-204 °C (CHCl3-iPr2O); 1H NMR, FABMS,
IR, Anal. (C21H22ClN5O2S‚0.75H2O) C, H, N.
Da ta for N-(3-Ch lor op h en yl)-4-(6,7-d im eth oxy-4-qu in a -
zolin yl)-1-p ip er a zin eth ioca r boxa m id e (50): yield 79% by
method E; mp 222-224 °C (AcOEt); 1H NMR, FABMS, IR,
Anal. (C21H22ClN5O2S‚0.25H2O) C, H, N.
In h ibitor y Effect on Neoin tim a F or m a tion a fter Ba l-
loon In ju r y of th e Ra t Ca r otid Ar ter y. Ma le SD rats (n )

Inhibitors of PDGF Receptor Phosphorylation
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kg, ip). A cervical midline incision was made, the left common
carotid artery was isolated, and a balloon catheter (2F,
Edwards Laboratories) was inserted through the external
branch into the carotid artery to the aortic arch. The balloon
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Ack n ow led gm en t. The technical assistance of Ms.
Kumi Aoki, Miyuki Akimoto, and Chika Okitsu is
acknowledged. We gratefully thank Mrs. Yumiko Aono
for her technical assistance in the chemical synthesis.
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material is available free of charge via the Internet at http://
pubs.acs.org.
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