Non-thiol farnesyltransferase inhibitors: N-(4-acylamino-3-benzoylphenyl)-3-[5-(4-nitrophenyl)-2-furyl]acrylic acid amides.

Article abstract of DOI:10.1016/S0968-0896(03)00064-6

We have designed the nitrophenylfurylacryl-substituted benzophenone 4f as a non-thiol farnesyltransferase inhibitor utilizing a novel aryl binding site of farnesyltransferase. Variation of the 2-acylamino substituent at the benzophenone core structure of

Full text of DOI:10.1016/S0968-0896(03)00064-6

Bioorganic & Medicinal Chemistry 11 (2003) 1521–1530
Non-thiol Farnesyltransferase Inhibitors: N-(4-Acylamino-3-
benzoylphenyl)-3-[5-(4-nitrophenyl)-2-furyl]acrylic Acid Amides
Katja Kettler,a Jacek Sakowski,a Katrin Silber,b Isabel Sattler,c
Gerhard Klebeb and Martin Schlitzera,*
aDepartment fur Pharmazie, Ludwig-Maximilians-Universitat Munchen, Butenandtstr. 5-13, D-81377 Munchen, Germany
¨
¨
¨
¨
bInstitut fur Pharmazeutische Chemie, Philipps-Universitat Marburg, Marbacher Weg 6, D-35032 Marburg, Germany
¨
¨
cHans-Knoll-Institut fur Naturstoff-Forschung e.V., Beutenbergstr. 11, D-07745 Jena, Germany
¨
¨
Received 1 March 2002; accepted 23 January 2003
Abstract—We have designed the nitrophenylfurylacryl-substituted benzophenone 4f as a non-thiol farnesyltransferase inhibitor
utilizing a novel aryl binding site of farnesyltransferase. Variation of the 2-acylamino substituent at the benzophenone core struc-
ture of our initial lead 4f yielded several non-thiol farnesyltransferase inhibitors with improved activity. These compounds display
activity in the low nanomolar range.
# 2003 Elsevier Science Ltd. All rights reserved.
Introduction
involved in the action of farnesyltransferase inhibitors.
Although the exact mechanism of the antiproliferative
In the past years, farnesyltransferase has become a
major target in the development of potential anti-cancer
drugs. Farnesyltransferase catalyzes the transfer of a
farnesyl residue from farnesylpyrophosphate to the thiol
of a cysteine side chain of proteins which carry at the C-
terminus the so called CAAX-sequence. C represents a
cysteine whose side chain is farnesylated, A amino acids
which normally, but not neccessarily, carry aliphatic
side chains and X mostly methionine or serine.1,2
effect of farnesyltransferase inhibitors remains to be
determined, farnesyltransferase inhibitors are regarded
as a major emerging strategy in cancer therapy.3ꢀ12
Most inhibitors described in literature are peptidomi-
metics resembling the CAAX-tetrapeptide recognition
sequence of farnesylated proteins. The majority of these
CAAX-peptidomimetics exhibit a free thiol group
which is shown to coordinate the enzyme-bound zinc
ion. However, free thiols are associated with several
adverse drug effects13 and, therefore, the development
of farnesyltransferase inhibitors is clearly directed
towards the so-called non-thiol farnesyltransferase inhi-
bitors. The most frequently used replacements for
cysteine are nitrogen-containing heterocycles. The ring
nitrogen is supposed to coordinate to the enzyme-bound
zinc similarly to the cysteine thiol group.14 However, it
has been shown that nitrogen heterocycles can be
replaced by aryl residues lacking the ability to coordinate
metal atoms without loosing too much of their
farnesyltransferase inhibitory activity.15,16 Therefore,
the existence of at least one hitherto unknown aryl
binding region in the farnesyltransferase’s active site has
been postulated.17,18
Although farnesyltransferase inhibitors have demon-
strated their efficiency in various cancer cell culture
assays, animal models and first clinical studies, it turned
out that their mechanism of action is much more com-
plicated than initially anticipated. Farnesyltransferase
inhibitors display multiple effects as the inhibition of
anchorage independent cell growth, reversal of the pheno-
type of cancer cells back to that of non-transformed
cells, cell-cycle arrest and induction of apoptosis. It
became obvious that these multiple effects cannot be
attributed solely to the prevention of ras farnesylation.
Several different farnesylated proteins as for instance
ras, rhoB, and centromer binding proteins seem to be
Using docking studies of model compounds of non-thiol
farnesyltransferase inhibitors as well as GRID analysis
*Corresponding author. Tel.: +49-89-2180-77804; fax: +49-89-2180-
79992; e-mail: martin.schlitzer@cup.uni-muenchen.de
0968-0896/03/$ - see front matter # 2003 Elsevier Science Ltd. All rights reserved.
doi:10.1016/S0968-0896(03)00064-6

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K. Kettler et al. / Bioorg. Med. Chem. 11 (2003) 1521–1530
protected as trifluoroacetamide (5). After reduction of
the 5-nitro group, the resulting amine 6 was acylated
with 3-[5-(4-nitrophenyl)-2-furyl]arylic acid chloride.
After removal of the protective group from 7 the
resulting intermediate 8 could by acylated by 2- and
4-trifluoromethylphenylacetic acid chloride and 4-nitro-
phenylacetic acid chloride, respectively, yielding com-
pounds 4m–o. The 4-fluoro compound 4i was prepared
in the same manner.
Farnesyltransferase inhibition assay
Scheme 1. (I) R-CO–Cl, toluene/dioxane, reflux, 2 h; (II) SnCl2ꢁ2H2O,
EtOAc, reflux 2 h; (III) 3-[5-(4-nitrophenyl)-2-furyl]acrylic acid chloride,
toluene/dioxane, reflux, 2 h.
The inhibitory activity of the inhibitors was determined
using the fluorescence enhancement assay as described by
Pompliano.21 The assay employed yeast farnesyltransfer-
ase (FTase) fused to Glutathione S-transferase at the
N-terminus of the b-subunit.22 Farnesylpyrophosphate
and the dansylated pentapeptide Ds-GlyCysValLeuSer
were used as substrates. Upon farnesylation of the cysteine
thiol the dansyl residue is placed in a lipophilic environ-
ment which results in an enhancement of fluorescence at
505 nm which is used to monitor the enzyme reaction.-
Table 1
of farnesyltransferase’s active site, we have identified two
different aryl binding clefts in the farnesyltransferase’s
active site which we suggest to be the postulated aryl
binding regions.19
We have designed the nitrophenylfurylacryl-substituted
benzophenone 4f as a non-thiol farnesyltransferase
inhibitor utilizing one of these aryl binding sites.19 In
this study, we addressed the question how the replace-
ment of the p-tolylacetyl residue at the 2-amino group
of the benzophenone core structure of 4f would influ-
ence farnesyltransferase inhibitory activity.
Flexible docking
Flexible docking of selected compounds was performed
using the program FlexX.23 Based on the coordinates of
the published crystal structure24 of a ternary complex of
farnesyltransferase, a farnesylpyrophosphate analogue
and N-acetyl-Cys-Val-Ile-selenoMetOH (PDB-code
1QBQ), we have calculated the solvent accessible sur-
face of the farnesyltransferase’s active site using the
program MOLCAD which is implemented in the molec-
ular modeling software package SYBYL.25 The nitro-
phenyl residue of the terminal biaryl moiety was placed
into the region we have previously suggested to be the
far aryl binding site.19 Subsequently, the remaining
fragments of the inhibitors were placed in the active site
using the incremental construction algorithm of FlexX.
The docking runs provided sets of solutions which were
inspected according to their calculated energy score.
Chemistry
Synthesis of most of the target compounds 4a–x was
accomplished by acylation of appropriate 2-acylamino-
5-aminobenzophenones 3 using 3-[5-(4-nitrophenyl)-2-
furyl]acrylic acid chloride. Intermediates 3 were prepared
as described previously20 form 2-amino-5-nitrobenzo-
phenone 1 (Scheme 1). However, since acylation of 1 by
2- or 4-trifluoromethylphenylacetic acid chloride failed
and because of the reductions stepinvolved in the
synthesis according to Scheme 1, an alternative route
had to be followed for the preparation of compounds
4m–o (Scheme 2). First, the 2-amino groupof 1 was
Scheme 2. (I) TFAA, DCM/pyridine, 0 ꢂC, 2 h; (II) SnCl2ꢁ2H2O, EtOAc, reflux 2 h; (III) 3-[5-(4-nitrophenyl)-2-furyl]acrylic acid chloride, toluene/
dioxane, reflux, 2 h; (IV) K2CO3, dioxane/H2O, reflux, 3 h; (V) R-C6H4–CH2–COCl, toluene/dioxane, reflux, 2 h.

K. Kettler et al. / Bioorg. Med. Chem. 11 (2003) 1521–1530
1523
Figure 1. Docking solution of inhibitors 4f (a) and 4a (b) showing the terminal aryl of 4f in a binding pocked (indicated by a blue arrow) while the
phenyl residue of 4a does not reach into this pocket.
Selected docking solutions were minimised with the
MAB force field26 and the resulting geometries were
evaluated using the knowledge based scoring function
DrugScore,27 which was also used to locate areas of
favoured binding of moieties with selected properties.
to focus our attention on the variation of the phenyl-
acetic acid substructure and postpone the investigation
of other cinnamic acid derivatives to a separate study.
Introduction of a p-methoxy (4e; IC50=35 nM) or a
p-methyl group( 4f; IC50=35 nM) resulted in a 6-fold
reduction in activity in comparison to the unsubstituted
phenylacetic acid derivative 4b. Shifting the methyl
groupfrom the para to the meta (4g; IC50=58 nM) and
ortho position (4h; IC50=206 nM), respectively, resulted
in an increasing reduction of activity which is especially
pronounced with the ortho derivative 4h. Flexible dock-
ing might provide a rationale for this difference. Intro-
duction of halogen substituents into the para position of
the terminal phenyl residue resulted in all cases in a
decreased activity in comparison to the unsubstituted
derivative 4b. This effect is at least pronounced with the
fluoro derivative 4i (IC50=15 nM) what might be
explained on the basis that the fluoro substituent is
more similar to the hydrogen than the chloro or bromo
substituent. These two substituents caused a consider-
able reduction in activity which is more pronounced
with the chloro substituent (4j; IC50=102 nM) than
with the bromo substituent (4k; IC50=50 nM). Surpris-
ingly, shifting the bromo substituent from the para to
the ortho position resulted in a more active inhibitor 4l,
(IC50=15 nM). This result is in marked difference to the
situation observed with the methyl substituents where
the shift from the para to the ortho position caused a
decrease in activity. Introduction of a trifluoromethyl
groupinto the para position of the terminal phenyl
resulted in an inhibitor 4m which is slightly more potent
(IC50=26 nM) than the lead derivative 4f. Again, shift-
ing this substituent from the para to the ortho position
resulted in an increase in activity (4n; IC50=14 nM).
These structure activity relationships are not easily
understood. Especially disturbing is the different influ-
ence of the ortho position on the activity. In case of the
methyl substituent this position strongly reduces activ-
ity, while in case of bromo or trifluoromethyl the ortho
substituted derivatives are more active than their para
analogoues. However, molecular modelling methods
can provide some insight into these structure activity
relationships. The first ranking FlexX docking results of
Results and Discussion
Having developed compound 4f as a novel non-thiol
farnesyltransferase inhibitor which was specifically
designed to make use of an aryl binding site of farnesyl-
transferase,19 we then turned our attention towards the
question how variations of the acyl substituent at the
2-amino groupof the benzohpenone core structure
would influence the inhibitory activity of this class of
compounds. Starting from the p-tolylacetic acid sub-
stituted lead 4f we first turned to moieties with an
unsubstituted phenyl residue and varied the distance
between the amide carbonyl groupand the terminal
phenyl residue. Here it turned out that deviation from
the original methylene spacer resulted in a considerable
dropin inhibitory activity. While the unsubstituted
phenylacetic acid compound 4b is about 6-fold more
active (IC50=6 nM) than the original lead 4f (IC50=35
nM), the shorter benzoic acid compound 4a (IC50=123
nM) is markedly less active. This difference may be
explained using flexible docking. Direct comparison of
the docking solutions of the benzoic acid compound 4a
and the tolylacetic acid derivative 4f shows the aryl
residue of 4f in a binding cleft indicated by a blue arrow
in Fig. 1a while the phenyl residue of 4a cannot reach
into this cleft (Fig. 1b). This may be an explanation for
the lower activity of the benzoic acid compound 4a. As
4a also the longer phenylpropionic acid compound 4c
(IC50=40 nM) is less active than the lead 4f. However,
introduction of a trans-configurated double bond into
the ethylene spacer of 4c resulted in an inhibitor (4d)
which was equipotent (IC50=5 nM) to the phenylacetic
acid derivative 4b. The next steptowards the establish-
ment of systematic structure–activity relationships
would have been the addition of substituents to the
terminal phenyl residue of the phenylacetic acid deriva-
tive 4b and the cinnamic acid derivative 4d. We decided

1524
K. Kettler et al. / Bioorg. Med. Chem. 11 (2003) 1521–1530
Figure 2. Comparison of the docking solutions of the para methyl
substituted inhibitor 4f (yellow) and the ortho methyl substituted
inhibitor 4h (margenta). Areas which according to DrugScore pre-
Figure 3. Comparison of the docking solutions of the para bromo
substituted inhibitor 4k (margenta) and the ortho bromo substituted
inhibitor 4l (yellow) Areas which according to DrugScore prevalently
bind hydrogen bond acceptors are indicated by a violet-green-white
cloud (increasing prevalence). It is clearly visible that the ortho bromo
substituent points to such an area while the para bromo substituent
cannot reach such an area.
valently bind methyl are indicated by
a blue-yellow-red cloud
(increasing prevalence). The para methyl groupof inhibitor 4f (yellow)
is located in such an area while the ortho methyl groupof 4h (mar-
genta) is directed in no such region.
inhibitors 4f, 4h (para and ortho methyl) and 4k, 4l (para
and ortho bromo) were post-optimised with the MAB
force field, minimising the ligands in the rigid binding
pocket. Rescoring the resulting geometries of the methyl
derivatives 4f and 4h with DrugScore clearly indicates
the preference for the para derivative 4f. As can be seen
in Fig. 2 the para methyl groupof inhibitor 4f points
into an area which favours binding of a methyl group
indicated by a so called DrugScore hot spot. In con-
trast, the ortho methyl groupof 4h is not located in such
an area what may explain its lower activity. In case of
the bromo derivatives 4k and 4l, the ortho bromo sub-
stituent of 4l is located in an area in which according to
DrugScore binding of a hydrogen bond acceptor is
favoured while the para substituent of 4k cannot reach
into such an area (Fig. 3). Since bromo as well as tri-
fluoromethyl possess some weak hydrogen bond acceptor
properties this may be the explanation for the pre-
valence of the ortho derivatives in this cases.
placed in a lipophilic chanal which was recently shown
to bind the farnesyl residue the enzyme’s reaction pro-
duct, the farnesylated protein.28
Finally, we turned back to the ring-unsubstituted phenyl-
acetic acid and introduced a substituent into the
a-position. While the decrease observed with a methyl
groupin this position is small ( 4v; IC50=16 nM), this
effect is pronounced with the bulkier phenyl group (4w;
IC50=660 nM).
Although structure–activity relationships in this series
of farnesyltransferase inhibitors are difficult to interpret,
variation of the 2-acylamino substituent at the benzo-
phenone core structure of our initial lead 4f yielded
several non-thiol farnesyltransferase inhibitors with
improved activity. These compounds display activity in
the low nanomolar range and will be used as starting
points for further structural variation which led to inhi-
bitors with improved properties as will be reported in
due course.
From all substituents placed into the para position the
nitro groupproduced the largest decrease in activity ( 4o;
IC50=136 nM) in comparison to the unsubstituted
derivative 4b. Introduction of an additional chloro sub-
stituent into the ortho position of the p-chloro derivative
4j (IC50=102 nM) had no significant effect on the inhi-
bitory activity (4p; IC50=92 nM).
Then, we turned our attention to bigger aromatic
structures. Naphthyl residues connected via the 1- or
2-position directly to the amide carbonyl yielded com-
pounds of medium activity (4q; IC50=465 nM; 4r;
IC50=185 nM). As seen with the phenyl derivatives 4a,b
introduction of a methylene spacer markedly improved
activity. The 1- and 2-naphthylacetic acid derivatives
(4s; IC50=6 nM; 4t; IC50=8 nM) are as active as the
phenylacetic acid derivative 4b. Equal activity was
found for the biphenylylacetic acid derivative 4u
(IC50=7 nM). Docking of this inhibitor (Fig. 4) pro-
vided an interesting solution with the biaryl moiety
Figure 4. Docking solution of the biphenyl substituted inhibitor 4u
showing the biphenyl residue in a lipophilic chanal which normally
habours the farnesyl residue of the farnesylated protein.

K. Kettler et al. / Bioorg. Med. Chem. 11 (2003) 1521–1530
1525
Table 1. Farnesyltransferase inhibitory activity of compounds 4a–x
uncorrected. Column chromatography was carried out
using silica gel 60 (0.062–0.200 mm) from Merck. The
preparation of following compounds has been descri-
bed20: 2a-c, e-h, j, k, p, q, s-w, 3a-c, e-h, j, k, p, q, s-w, 5
and 6.
General procedure 1: activation of various acids as acid
chlorides and reaction with aromatic amines
Compd.
R
IC50
(nM)
Compd.
R
IC50
(nM)
The various carboxylic acids were dissolved in toluene
and 0.1 mL SOCl2 per mmol acid was added. The mix-
ture was heated under reflux for 2 h and the volatiles
were evaporated in vacuo. The resulting acyl chlorides
were dissolved in toluene or dioxane (approx. 10 mL)
and added to a solution of the appropriate aromatic
amine in hot toluene (approx. 50 mL). The mixtures
were heated under reflux for 2 h. Then, the solvent was
removed in vacuo to give the crude products.
4a
123ꢃ19
4m
26ꢃ6
4b
4c
4d
4e
4f
6ꢃ3
40ꢃ4
5ꢃ2
4n
4o
4p
4q
4r
4s
4t
14ꢃ3
136ꢃ11
92ꢃ3
465ꢃ20
185ꢃ11
6ꢃ3
General procedure 2: reduction of aromatic nitro
compounds
Aromatic nitro compounds 2 were dissolved in EtOAc
(50–100 mL) and SnCl2ꢁ2H2O (1.125 g per mmol nitro
compound) was added. The mixture was heated under
reflux for 2 h. Then, NaHCO3–solution was added until
pH 7–8 was reached and the organic layer was sepa-
rated. The aqueous layer was extracted two times with
EtOAc. The combined organic layers were washed with
brine and dried over MgSO4.
35ꢃ1
35ꢃ5
58ꢃ5
206ꢃ27
15ꢃ3
102ꢃ39
4g
4h
4i
N-3-Benzoyl-4-(benzoylamino)phenyl-3-[5-(4-nitrophenyl)-
2-furyl]acrylic acid amide (4a). From 3-[5-(4-nitro-
phenyl)-2-furyl]acrylic acid chloride (195 mg, 0.75
mmol) and N-(4-amino-2-benzoylphenyl)benzoic acid
amide (237 mg, 0.75 mmol) according to general pro-
cedure 1. Purification: recrystallisation from ethanol.
Yield: 261 mg, (62%); mp: 252 ꢂC. IR (KBr): n=3436,
8ꢃ2
4u
4v
7ꢃ2
1
1628, 1599, 1548, 1510, 1334 cmꢀ1. H NMR (DMSO-
4j
16ꢃ2
d6): d=6.78 (d, J=16 Hz, 1H,¼CH), 7.03–7.04 (m, 1H,
Ar), 7.42–7.49 (m, 3H, Ar and d, J=16 Hz, 1H,¼CH),
7.50–7.61 (m, 4H, Ar), 7.70–7.74 (m, 4H, Ar), 7.83–8.01
(m, 5H, Ar), 8.31–8.33 (m, 2H, Ar), 10.42 (s, 1H, –NH),
10.61 (s, 1H, –NH). MS (EI): m/z=557 (33) [M+], 316
(100), 105 (77), 242 (51), 91 (34). Anal. (C33H23N3O6): C,
71.09; H, 4.16; N, 7.54; found C, 71.17; H, 4.17; N, 7.52.
4k
4l
50ꢃ11
15ꢃ4
4w
4x
660ꢃ60
117ꢃ13
N-3-Benzoyl-4-(phenylacetylamino)phenyl-3-[5-(4-nitro-
phenyl)-2-furyl]acrylic acid amide (4b). From 3-[5-(4-
nitrophenyl)-2-furyl]acrylic acid chloride (195 mg, 0.75
mmol) and N-(4-amino-2-benzoylphenyl)phenylacetic
acid amide (248 mg, 0.75 mmol) according to general
procedure 1. Purification: recrystallisation from ethanol.
Yield: 307 mg, (72%); mp: 211 ꢂC. IR (KBr): n=3383,
Experimental
1H NMR spectra were recorded on a Jeol JMN-GX-400
and a Jeol JMN-LA-500 spectrometer. Mass spectra
were obtained with a Vacuum Generators VG 7070H
using a Vector 1 data acquisition system from Teknivent
or a AutoSpec mass spectrometer from Micromass. IR
spectra were recorded on a Nicolet 510P FT-IR-spectro-
meter. Microanalyses were obtained from a CH analy-
zer according to Dr. Salzer from Labormatic and from
a Hewlett Packard CHN-analyzer type 185. Melting
points were obtained with a Leitz-microscope and are
1670, 1629, 1598, 1545, 1512, 1330 cmꢀ1 1H NMR
.
(DMSO-d6): d=3.19 (s, 2H, –CH2), 6.75 (d, J=16 Hz,
1H,=CH), 7.02–7.25 (m, 6H, Ar), 7.39–7.50 (m, 3H, Ar
and d, J=16 Hz, 1H,¼CH), 7.60–7.69 (m, 4H, Ar),
7.87–8.00 (m, 4H, Ar), 8.30–8.32 (m, 2H, Ar), 10.05 (s,
1H, –NH), 10.36 (s, 1H, –NH). MS (EI): m/z=571 (8)
[M+], 212 (100), 330 (81), 211 (48), 331 (24), 312 (23).
Anal. (C34H25N3O6): C, 71.45; H, 4.41; N, 7.35; found
C, 71.46; H, 4.42; N, 7.44.

1526
K. Kettler et al. / Bioorg. Med. Chem. 11 (2003) 1521–1530
N-3-Benzoyl-4-(3-phenylpropionyl)aminophenyl-3-[5-(4-
nitrophenyl)-2-furyl]acrylic acid amide (4c). From 3-[5-
(4-nitrophenyl)-2-furyl]acrylic acid chloride (195 mg,
0.75 mmol) and N-(4-amino-2-benzoylphenyl)-3-phenyl-
propionic acid amide (258 mg, 0.75 mmol) according to
general procedure 1. Purification: recrystallisation from
ethanol. Yield: 221 mg, (50%); mp: 204 ꢂC. IR (KBr):
3H, Ar), 7.40 (m, 2H, Ar), 7.49 (m, 2H, Ar), 7.60 (m,
2H, Ar), 7.67 (m, 2H, Ar), 7.77 (m, 1H, Ar), 7.88 (m,
1H, Ar), 7.99 (m, 2H, Ar), 8.31 (m, 2H, Ar), 10.06 (s,
1H, –NH), 10.42 (s, 1H, NH). MS (EI): m/z=601
(1) [M+], 212 (100), 121 (64), 360 (53), 148 (34), 211
(32), 135 (31), 239 (25). Anal. (C35H27N3O7): C, 69.88;
H, 4.52; N, 6.98; found C, 69.55; H, 4.69; N, 7.05.
n=3379, 1598, 1511, 1402, 1332, 853, 798 cmꢀ1 1H
.
NMR (DMSO-d6): d=2.31 (s, 2H, –CH2), 2.60 (s, 2H,
–CH2), 6.77 (d, J=16 Hz, 1H,¼CH), 7.04–7.14 (m, 6H,
Ar), 7.40–7.52 (m, 4H, Ar and d, J=16 Hz, 1H,¼CH),
7.61–7.80 (m, 4H, Ar), 7.88–7.90 (m, 3H, Ar), 8.31–8.33
(m, 2H, Ar), 9.87 (s, 1H, –NH), 10.37 (s, 1H, –NH). MS
(EI): m/z=585 (8) [M+], 212 (100), 344 (69), 211 (41),
213 (22), 345 (21). Anal. (C35H27N3O6): C, 71.79; H,
4.65; N, 7.18; found C, 71.88; H, 4.61; N, 7.19.
N-3-Benzoyl-4-(3-methylphenyl)acetylaminophenyl-3-[5-
(4-nitrophenyl)-2-furyl]acrylic acid amide (4g). From
3-[5-(4-nitrophenyl)-2-furyl]acrylic acid chloride (195
mg, 0.75 mmol) and N-(4-amino-2-benzoylphenyl)-3-
methylphenylacetic acid amide (258 mg, 0.75 mmol)
according to general procedure 1. Purification: recrys-
tallisation from ethanol. Yield: 292 mg, (67%); mp:
222 ꢂC. IR (KBr): n=3379, 1597, 1510, 1330, 1108, 852,
752 cmꢀ1. 1H NMR (DMSO-d6): d=2.27 (s, 3H, –CH3),
3.38 (s, 2H, –CH2), 6.75 (d, J=16 Hz, 1H, ¼CH), 6.90–
7.13 (m, 5H, Ar), 7.40–7.47 (m, 4H, Ar), 7.48 (d, J=16
Hz, 1H, ¼CH), 7.61–7.80 (m, 7H, Ar), 8.30–8.32 (m,
2H, Ar), 10.03 (s, 1H, –NH), 10.36 (s, 1H, –NH). MS
(EI): m/z=585 (58) [M+], 242 (100), 212 (79), 344 (69),
453 (19), 345 (17), 243 (16). Anal. (C35H27N3O6): C,
71.79; H, 4.65; N, 7.18; found C, 71.69; H, 4.72; N, 7.48.
N-(2-Benzoyl-4-nitrophenyl)cinnamic acid amide (2d).
From cinnamic acide chloride (666 mg, 4.0 mmol) and
2-amino-5-nitrobenzophenone (969 mg, 4.0 mmol)
according to general procedure 1. Purification: recrys-
tallisation from ethanol. Yield: 698 mg (47%); mp:
145 ꢂC. IR (KBr): n=3239, 1627, 1579, 1502, 1344,
1
1276, 1149, 762 cmꢀ1. H NMR (CDCl3): d=6.65 (d,
J=16 Hz, 1H,¼CH), 7.34–7.54 (m, 7H, Ar), 7.61–7.68
(m, 3H, Ar), 7.74 (d, J=16 Hz, 1H,¼CH), 8.38–8.47 (m,
2H, Ar), 9.01–9.03 (m, 1H, Ar), 11.41 (s, 1H, –NH). MS
(EI): m/z=372 (30)M+, 131 (100), 103 (16), 131 (11).
N-3-Benzoyl-4-(2-methylphenyl)acetylaminophenyl-3-[5-
(4-nitrophenyl)-2-furyl]acrylic acid amide (4h). From
3-[5-(4-nitrophenyl)-2-furyl]acrylic acid chloride (195
mg, 0.75 mmol) and N-(4-amino-2-benzoylphenyl)-2-
methylphenylacetic acid amide (258 mg, 0.75 mmol)
according to general procedure 1. Purification: recrys-
tallisation from ethanol. Yield: 303 mg, (69%); mp:
221 ꢂC. IR (KBr): n=3361, 1598, 1508, 1332, 1108, 853,
752 cmꢀ1. 1H NMR (DMSO-d6): d=2.12 (s, 3H, –CH3),
3.43 (s, 2H, –CH2), 6.72 (d, J=16 Hz, 1H, ¼CH), 7.06–
7.08 (m, 5H, Ar), 7.36–7.45 (m, 3H, Ar), 7.45 (d, J=16
Hz, 1H, ¼CH), 7.59–7.75 (m, 5H, Ar), 7.85–7.95 (m,
3H, Ar), 8.20–8.29 (m, 2H, Ar), 9.98 (s, 1H, –NH),
10.33 (s, 1H, –NH). MS (EI): m/z=585 (9) [M+], 212
(100), 344 (82), 211 (38), 141 (37), 238 (27), 105 (24).
Anal. (C35H27N3O6): C, 71.79; H, 4.65; N, 7.18; found
C, 71.56; H, 4.79; N, 7.28.
N-(4-Amino-2-benzoylphenyl)cinnamic acid amide (3d).
From 2d (633 mg, 1.7 mmol) according to general pro-
cedure 2. Yield: 535 mg (92%). 1H NMR (CDCl3):
d=3.65 (s, 2H, –NH2), 6.56 (d, J=16 Hz, 1H,¼CH),
7.22–7.38 (m, 3H, Ar), 7.49–7.70 (m, 7H, Ar), 7.71 (d,
J=16 Hz, 1H,¼CH), 8.38–8.47 (m, 2H, Ar), 9.01–9.03
(m, 1H, Ar), 11.41 (s, 1H, –NH).
N-3-Benzoyl-4-(cinnamoylamino)phenyl-3-[5-(4-nitro-
phenyl)-2-furyl]acrylic acid amide (4d). From 3-[5-(4-
nitrophenyl)-2-furyl]acrylic acid chloride (195 mg, 0.75
mmol) and 3d (257 mg, 0.75 mmol) according to general
procedure 1. Purification: recrystallisation from ethanol.
Yield: 247 mg (56%); mp: 265 ꢂC. IR (KBr): n=3373,
1
1559, 1335, 1243, 1171, 971, 854, 752 cmꢀ1. H NMR
N-3-Benzoyl-4-(trifluoroacetylamino)phenyl-3-[5-(4-nitro-
phenyl)-2-furyl]acrylic acid amide (7). From N-(4-
amino-2-benzoylphenyl)-trifluoracetamide (6)xy (0.616
g, 2.0 mmol) und 3-[5-(4-nitrophenyl)-2-furyl]acrylic
acid chloride (554 mg, 2.0 mmol) according to general
procedure 1. Purification: recrystallisation from toluene.
Yield: 1002 mg (90%); mp: 244 ꢂC. IR (KBr): n=3426,
(DMSO-d6): d=6.65 (d, J=16 Hz, 1H,¼CH), 6.76 (d,
J=16 Hz, 1H,¼CH), 7.01–7.12 (m, 1H, Ar), 7.32–7.40
(m, 10H, Ar), 7.40 (d, J=16 Hz, 1H,¼CH), 7.50 (d,
J=16 Hz, 1H,¼CH), 7.53–8.07 (m, 6H, Ar), 8.30–8.32
(m, 2H, Ar), 10.71 (s, 1H, –NH), 10.39 (s, 1H, –NH).
MS (EI): m/z=583 (21) [M+], 212 (100), 242 (95), 131
(88), 342 (73), 40 (28), 211 (21). Anal. (C35H25N3O6): C,
72.03; H, 4.32; N, 7.20; found C, 72.06; H, 4.41; N, 7.15.
1626, 1599, 1520, 1332 cmꢀ1 1H NMR (DMSO-d6):
.
d=6.74 (d, J=16 Hz, 1H, ¼CH), 7.06 (m, 1H, Ar), 7.38
(m, 2H, Ar), 7.47 (m, 2H, Ar and d, J=16 Hz, 1H,
¼CH), 7.61 (m, 1H, Ar), 7.64 (m, 2H, Ar), 7.83 (m, 1H,
Ar), 7.95 (m, 3H, Ar), 8.27 (m, 2H, Ar), 10.53 (s, 1H,
–NH), 11.24 (s, 1H, –NH). MS (EI): m/z=549 (24)
[M+], 242 (100), 243 (15), 196 (14), 550 (8), 308 (6), 139
(5), 212 (2).
N-3-Benzoyl-4-(4-methoxyphenyl)acetylaminophenyl-3-
[5-(4-nitrophenyl)-2-furyl]acrylic acid amide (4e). From
3-[5-(4-nitrophenyl)-2-furyl]acrylic acid chloride (277
mg, 1.0 mmol) and N-(4-amino-2-benzoylphenyl)-4-
methyloxyphenylacetic acid amide (360 mg, 1.0 mmol)
according to general procedure 1. Purification: recrys-
tallisation from toluene. Yield: 500 mg (83%); mp:
>250 ꢂC. IR (KBr): n=3427, 1665, 1631, 1598, 1551,
N-4-Amino-3-benzoylphenyl-3-[5-(4-nitrophenyl)-2-furyl]-
acrylic acid amide (8). From 7 (559 mg, 1.0 mmol)
according to general procedure 2. Yield: 385 mg (85%);
mp: 257 ꢂC. IR (KBr): n=3487, 1622, 1598, 1550, 1511,
1
1507, 1334 cmꢀ1. H NMR (CDCl3): d=3.33 (s, 2H,
–CH2), 3.70 (s, 3H, –CH3), 6.78 (m, 3H, Ar), 7.02 (m,

K. Kettler et al. / Bioorg. Med. Chem. 11 (2003) 1521–1530
1527
1330 cmꢀ1
.
1H NMR (DMSO-d6): d=6.70 (d, J=16
(935 mg, 4.0 mmol) and 2-amino-5-nitrobenzophenone
(969 mg, 4.0 mmol) according to general procedure 1.
Purification: recrystallisation from ethanol. Yield: 1032
mg (58%); mp: 96 ꢂC. IR (KBr): n=3203, 3108, 1701,
Hz, 1H,¼CH), 6.86 (m, 2H, Ar), 6.95 (m, 1H, Ar), 7.32
(d, J=16 Hz, 1H, ¼CH), 7.37 (m, 1H, Ar), 7.51 (m, 2H,
Ar), 7.58 (m, 3H, Ar), 7.67 (m, 1H, Ar), 7.71 (m, 1H,
Ar), 7.96 (m, 2H, Ar), 8.29 (m, 2H, Ar), 9.95 (s, 1H,
–NH). MS (EI): m/z=453 (100) [M+], 212 (83), 242
(52), 454 (30), 211 (13), 213 (13), 243 (8), 455 (5).
1642, 1597, 1579, 1539, 1506, 1348 cmꢀ1 1H NMR
.
(CDCl3): d=3.96 (s, 2H, –CH2), 7.23 (m, 1H, Ar), 7.37
(m, 1H, Ar), 7.41 (m, 1H, Ar), 7.52 (m, 2H, Ar), 7.60
(m, 1H, Ar), 7.66 (m, 3H, Ar), 8.38 (m, 1H, Ar), 8.42
(m, 1H, Ar), 8.89 (m, 1H, Ar), 11.01 (s, 1H, –NH). MS
(EI): m/z=438 (0.5) [M+], 359 (100), 269 (43), 169 (32),
171 (32), 105 (29), 191 (26).
N-3-Benzoyl-4-(4-fluorophenyl)acetylaminophenyl-3-[5-
(4-nitrophenyl)-2-furyl]acrylic acid amide (4i). From
4-flourophenylacetic acid chloride (93 mg, 0.6 mmol)
and N-4-amino-3-benzoylphenyl-3-[5-(4-nitrophenyl)-2-
furyl]acrylic acid amide (8) (272 mg, 0.6 mmol) accord-
ing to general procedure 1. Purification: recrystallisation
from ethanol. Yield: 260 mg (74%); mp: 212 ꢂC. IR
N-(4-Amino-2-benzoylphenyl)-2-bromophenylacetic acid
amide (3l). From 2l (1008 mg, 2.3 mmol) according to
general procedure 2. Yield: 847 mg (87%); IR (KBr):
(KBr): n=3314, 1599, 1508, 1333 cmꢀ1
.
1H NMR
n=3438, 3357, 3282, 1658, 1518s, 1325 cmꢀ1. H NMR
1
(DMSO-d6): d=3.38 (s, 2H, –CH2), 6.73 (d, J=16 Hz,
1H, ¼CH), 7.00–7.13 (m, 5H, Ar), 7.37–7.98 (m, 11H,
Ar and d, J=16 Hz, 1H, ¼CH), 8.28–8.29 (m, 1H, Ar),
10.01 (s, 1H, –NH), 10.34 (s, 1H, –NH). MS (EI): m/z
=589 (37) [M+], 242 (100), 348 (87), 212 (67), 211 (36),
238 (24), 239 (17), 217 (17). Anal. (C34H24FN3O6): C,
69.27; H, 4.10; N, 7.13; found C, 69.31; H, 4.21; N, 6.94.
(CDCl3): d=3.83 (s, 4H, –CH2 and –NH2), 6.73 (m, 1H,
Ar), 6.85 (m, 1H, Ar), 7.15 (m, 1H, Ar), 7.31 (m, 1H,
Ar), 7.36 (m, 1H, Ar), 7.44 (m, 2H, Ar), 7.56 (m, 2H,
Ar), 7.65 (m, 2H, Ar), 8.26 (d, J=9 Hz, 1H, Ar), 10.04
(s, 1H, –NH). MS (EI): m/z=408 (70) [M+], 212 (100),
410 (70), 211 (50), 409 (17), 239 (16), 213 (15).
N-3-Benzoyl-4-(2-bromophenyl)acetylaminophenyl-3-[5-
(4-nitrophenyl)-2-furyl]acrylic acid amide (4l). From
3-[5-(4-nitrophenyl)-2-furyl]acrylic acid chloride (277
mg, 1.0 mmol) and 3l (409 mg, 1.0 mmol) according to
general procedure 1. Purification: recrystallisation from
toluene. Yield: 493 mg (76%); mp: 228 ꢂC. IR (KBr):
N-3-Benzoyl-4-(4-chlorophenyl)acetylaminophenyl-3-[5-
(4-nitrophenyl)-2-furyl]acrylic acid amide (4j). From
3-[5-(4-nitrophenyl)-2-furyl]acrylic acid chloride (195
mg, 0.75 mmol) and N-(4-amino-2-benzoylphenyl)-4-
chlorophenylacetic acid amide (274 mg, 0.75 mmol)
according to general procedure 1. Purification: recrys-
tallisation from ethanol. Yield: 277 mg, (61%); mp:
219 ꢂC. IR (KBr): n=3386, 1599, 1511, 1333, 854, 753
n=3356, 2925, 1666, 1628, 1598, 1553, 1508, 1332 cmꢀ1
.
1H NMR (CDCl3): d=3.57 (s, 2H, –CH2), 6.77 (d,
J=16 Hz, 1H, ¼CH), 7.04 (m, 1H, Ar), 7.17 (m, 2H,
Ar), 7.28 (m, 2H, Ar), 7.41 (m, 2H, Ar), 7.52 (m, 3H,
Ar), 7.62 (m, 2H, Ar), 7.68 (m, 2H, Ar), 7.79 (d, J=16
Hz, 1H, ¼CH), 7.90 (m, 1H, Ar), 7.99 (m, 2H, Ar), 8.32
(m, 2H, Ar), 10.14 (s, 1H, –NH), 10.43 (s, 1H, –NH).
MS (EI): m/z=650 (3) [M+], 212 (100), 410 (66), 408
(65), 211 (50), 242 (24), 238 (23), 105 (19). Anal.
(C34H24BrN3O6): C, 62.78; H, 3.72; N, 6.46; found C,
62.58; H, 4.11; N, 6.47.
cmꢀ1 1H NMR (DMSO-d6): d=3.42 (s, 2H, –CH2),
.
6.71 (d, J=16 Hz, 1H, ¼CH), 7.03–7.29 (m, 5H, Ar),
7.40–7.50 (m, 3H, Ar and d, J=16 Hz, 1H, ¼CH), 7.56–
7.68 (m, 4H, Ar), 7.78–8.00 (m, 4H, Ar), 8.31–8.33 (m,
2H, Ar), 10.05 (s, 1H, –NH), 10.38 (s, 1H, –NH). MS
(EI): m/z=606 (7) [M+], 605 (19) [M+], 40 (100), 242
(98), 212 (77), 364 (58), 213 (38), 365 (35). Anal.
(C34H24ClN3O6): C, 67.36; H, 3.99; N, 6.93; found C,
67.29; H, 4.04; N, 6.89.
N-3-Benzoyl-4-(4-trifluoromethylphenyl)acetylaminophenyl-
3-[5-(4-nitrophenyl)-2-furyl]acrylic acid amide (4m).
From (4-trifluoromethylphenyl)acetic acid chloride
(166 mg, 0.75 mmol) and 8 (325 mg, 0.75 mmol)
according to general procedure 1. Purification: recrys-
tallisation from toluene. Yield: 190 mg (30%); mp:
235 ꢂC. IR (KBr): n=3426, 1684, 1626, 1598, 1511, 1331
N-3-Benzoyl-4-(4-bromophenyl)acetylaminophenyl-3-[5-
(4-nitrophenyl)-2-furyl]acrylic acid amide (4k). From
3-[5-(4-nitrophenyl)-2-furyl]acrylic acid chloride (277 mg,
1.0 mmol) and N-(4-amino-2-benzoylphenyl)-4-bromo-
phenylacetic acid amide (409 mg, 1.0 mmol) according
to general procedure 1. Purification: recrystallisation
from toluene. Yield: 532 mg (82%); mp: 237 ꢂC. IR
(KBr): n=3384, 3302, 1680, 1628, 1597, 1553, 1511,
1
cmꢀ1. H NMR (CDCl3): d=3.52 (s, 2H, –CH2), 6.77
(d, J=16 Hz, 1H, ¼CH), 7.03 (m, 1H, Ar), 7.32 (m, 2H,
Ar), 7.41 (m, 2H, Ar), 7.44 (m, 2H, Ar), 7.58 (m, 4H,
Ar), 7.66 (m, 2H, Ar), 7.78 (d, J=16 Hz, 1H, ¼CH),
7.90 (m, 1H, Ar), 7.99 (m, 2H, Ar), 8.32 (m, 2H, Ar),
10.12 (s, 1H, –NH), 10.39 (s, 1H, –NH). MS (EI): m/z
=639 (1) [M+], 43 (100), 55 (86), 41 (84), 57 (77), 59
(69), 69 (56), 44 (54). Anal. (C35H24F3N3O6): C, 65.73;
H, 3.78; N, 6.57; found C, 65.42; H, 4.09; N, 6.46.
1
1332 cmꢀ1. H NMR (CDCl3): d=3.38 (s, 2H, –CH2),
6.77 (d, J=16 Hz, 1H, ¼CH), 7.04 (m, 3H, Ar), 7.40
(m, 4H, Ar), 7.47 (m, 2H, Ar), 7.55 (m, 1H, Ar), 7.60 (d,
J=16 Hz, 1H, ¼CH), 7.66 (m, 2H, Ar), 7.77 (m, 1H,
Ar), 7.88 (m, 1H, Ar), 7.99 (m, 2H, Ar), 8.30 (m, 2H,
Ar), 10.05 (s, 1H, –NH), 10.37 (s, 1H, –NH). MS (EI):
m/z=650 (4) [M+], 212 (100), 242 (78), 408 (49), 211
(48), 410 (47), 238 (33), 239 (21). Anal.
(C34H24BrN3O6): C, 62.78; H, 3.72; N, 6.46; found C,
62.41; H, 4.10; N, 6.44.
N-3-Benzoyl-4-(2-trifluoromethylphenyl)acetylaminophenyl-
3-[5-(4-nitrophenyl)-2-furyl]acrylic acid amide (4n).
From (2-trifluormethylphenyl)acetic acid chloride (133
mg, 0.6 mmol) and 8 (260 mg, 0.6 mmol) according to
general procedure 1. Purification: recrystallisation from
N-(2-Benzoyl-4-nitrophenyl)-2-bromophenylacetic acid
amide (2l). From (2-bromophenyl)acetic acid chloride

1528
K. Kettler et al. / Bioorg. Med. Chem. 11 (2003) 1521–1530
toluene. Yield: 155 mg (40%); mp: 220 ꢂC. IR (KBr):
N-(2-Benzoyl-4-nitrophenyl)-2-naphthoic acid amide (2r).
From 2-naphthoic acid chloride (763 mg, 4.0 mmol) and
2-amino-5-nitrobenzophenone according to general
procedure 1. Purification: recrystallisation from ethanol.
Yield: 941 mg, (59%); mp: 206 ꢂC. IR (KBr): n=3135,
1634, 1617, 1547, 1510, 1411, 1335, 1233, 1197, 963,
773, 696 cmꢀ1. 1H NMR (CDCl3): d=7.60–7.74 (m, 7H,
Ar), 7.91–8.10 (m, 4H, Ar), 8.50–8.60 (m, 3H, Ar), 9.18–
9.19 (m, 1H, Ar), 12.41 (s, 1H, –NH).
1
n=3437, 1654, 1627, 1598, 1554, 1511, 1332 cmꢀ1. H
NMR (CDCl3): d=3.60 (s, 2H, –CH2), 6.75 (d, J=16
Hz, 1H, ¼CH), 7.00 (m, 1H, Ar), 7.23 (m, 1H, Ar), 7.37
(m, 1H, Ar), 7.39 (m, 1H, Ar), 7.47 (m, 3H, Ar), 7.53
(m, 1H, Ar), 7.59 (m, 3H, Ar), 7.65 (m, 2H, Ar), 7.77 (d,
J=16 Hz, 1H, ¼CH), 7.86 (m, 1H, Ar), 7.96 (m, 2H,
Ar), 8.28 (m, 2H, Ar), 10.05 (s, 1H, –NH), 10.36 (s, 1H,
–NH). MS (EI): m/z=639 (20) [M+], 242 (100), 212
(69), 139 (44), 398 (42), 43 (38), 159 (32), 196 (31). Anal.
(C35H24F3N3O6): C, 65.73; H, 3.78; N, 6.57; found C,
65.68; H, 3.43; N, 6.77.
N-(4-Amino-2-benzoylphenyl)-2-naphthoic acid amide
(3r). From 2q (605 mg, 1.5 mmol) according to general
1
procedure 2. Yield: 488 mg, (89%). H NMR (CDCl3):
d=3.68 (s, 2H, –NH2), 6.90–7.01 (m, 2H, Ar), 7.46–7.80
(m, 11H, Ar), 8.53–8.67 (m, 2H, Ar), 11.59 (s, 1H, –NH).
N-3-Benzoyl-4-(4-nitrophenyl)acetylaminophenyl-3-[5-(4-
nitrophenyl)-2-furyl]acrylic acid amide (4o). From
4-nitrophenylacetic acid chloride (109 mg, 0.6 mmol)
and N-(4-amino-3-benzoylphenyl)- 3-[5-(4-nitrophenyl)-
2-furyl]acrylic acid amide (272 mg, 0.6 mmol) according
to general procedure 1. Purification: recrystallisation
from ethanol. Yield: 309 mg, (84%); mp: 240 ꢂC. IR
(KBr): n=3377, 1686, 1598, 1516, 1332 cmꢀ1. 1H NMR
(DMSO-d6): d=3.52 (s, 2H, –CH2), 6.71 (d, J=16 Hz,
1H, ¼CH), 6.97–6.98 (m, 1H, Ar), 7.30–7.62 (m, 10H,
Ar and d, J=16 Hz, 1H, ¼CH), 7.72–8.04 (m, 5H, Ar),
8.25–8.27 (m, 2H, Ar), 10.08 (s, 1H, –NH), 10.33 (s, 1H,
–NH). MS (EI): m/z=616 (1) [M+], 212 (100), 357 (79),
242 (64) 211 (53), 44 (53), 356 (43), 453 (34). Anal.
(C34H23N4O8): C, 66.23; H, 3.92; N, 9.09; found C,
66.47; H, 3.87; N, 8.87.
N-3-Benzoyl-4-(2-naphthoylamino)phenyl-3-[5-(4-nitro-
phenyl)-2-furyl]acrylic acid amide (4r). From 3-[5-(4-
nitrophenyl)-2-furyl]acrylic acid chloride (195 mg, 0.75
mmol) and 3r (275 mg, 0.75 mmol) according to general
procedure 1. Purification: recrystallisation from ethanol.
Yield: 227 mg, (50%); mp: 279 ꢂC. IR (KBr): n=3370,
1599, 1507, 1333, 966, 853, 753 cmꢀ1
.
1H NMR
(DMSO-d6): 6.79 (d, J=16 Hz, 1H, ¼CH), 7.04–7.05
(m, 1H, Ar), 7.41–7.63 (m, 6H, Ar and d, J=16 Hz, 1H,
¼CH), 7.75–8.01 (m, 11H, Ar), 8.23–8.33 (m, 3H, Ar),
10.44 (s, 1H, –NH), 10.72 (s, 1H, –NH). MS (EI): m/z
=607 (1) [M+], 155 (100), 366 (57), 392 (29), 127 (19),
242 (17). Anal. (C37H25N3O6): C, 73.14; H, 4.15; N,
6.92; found C, 73.30; H, 4.30; N, 6.85.
N-3-Benzoyl-4-(2,4-dichlorophenyl)acetylaminophenyl-3-
[5-(4-nitrophenyl)-2-furyl]acrylic acid amide (4p). From
3-[5-(4-nitrophenyl)-2-furyl]acrylic acid chloride (277 mg,
1.0 mmol) and 3p (399 mg, 1.0 mmol) according to general
procedure 1. Purification: recrystallisation from toluene.
Yield: 515 mg (80%); mp: 245ꢂC. IR (KBr): n=3365,
3109, 1669, 1628, 1597, 1549, 1512, 1479, 1403, 1332
cmꢀ1. 1H NMR (DMSO-d6): d=3.42 (s, 2H, –CH2), 6.78
(d, J=16 Hz, 1H, ¼CH), 7.05 (m, 2H, Ar), 7.33 (m, 1H,
Ar), 7.44 (m, 6H, Ar), 7.59 (m, 1H, Ar), 7.64 (m, 2H, Ar),
7.77 (d, J=16 Hz, 1H, ¼CH), 7.88 (m, 1H, Ar), 7.99 (m,
2H, Ar), 8.31 (m, 2H, Ar), 10.12 (s, 1H, –NH), 10.44
(s, 1H, –NH). MS (EI): m/z=212 (100), 380 (62), 242
(62), 453 (46), 382 (41), 211 (40), 379 (38), 381 (37), 398
N-3-Benzoyl-4-(1-naphthyl)acetylaminophenyl-3-[5-(4-nitro-
phenyl)-2-furyl]acrylic acid amide (4s). From 3-[5-(4-
nitrophenyl)-2-furyl]acrylic acid chloride (195 mg, 0.75
mmol) and N-(4-amino-2-benzoylphenyl)-1-naphthyl-
acetic acid amide (286 mg, 0.75 mmol) according to
general procedure 1. Purification: recrystallisation from
ethanol. Yield: 322 mg, (69%); mp: 227 ꢂC. IR (KBr):
n=3360, 1598, 1510, 1402, 1333, 967, 863 cmꢀ1 1H
.
NMR (DMSO-d6): 3.89 (s, 2H, –CH2), 6.71 (d, J=16
Hz, 1H, ¼CH), 6.97– 6.98 (m, 1H, Ar), 7.27–7.57 (m,
7H, Ar and d, J=16 Hz, 1H, ¼CH), 7.59–7.95 (m, 11H,
Ar), 8.26–8.28 (m, 2H, Ar), 10.13 (s, 1H, –NH), 10.32 (s,
1H, –NH). MS (EI): m/z=621 (1) [M+], 212 (100), 380
(78), 239 (39), 211 (37), 141 (25), 238 (24), 381 (23), 156
(22). Anal. (C38H27N3O6): C, 73.42; H, 4.38; N, 6.76;
found C, 73.53; H, 4.53; N, 6.85.
(30), 640 (1) [M+]. Anal. (C34H23Cl N3O6): C, 63.76;
3
H, 3.62; N, 6.56; found C, 63.39; H, 3.94; N, 6.48.
N-3-Benzoyl-4-(1-naphthoylamino)phenyl-3-[5-(4-nitro-
phenyl)-2-furyl]acrylic acid amide (4q). From 3-[5-(4-
nitrophenyl)-2-furyl]acrylic acid chloride (277 mg, 1.0
mmol) and 3q (366 mg, 1.0 mmol) according to general
procedure 1. Purification: recrystallisation from toluene.
Yield: 120 mg (20%); mp:=260 ꢂC. IR (KBr): n=3442,
N-3-Benzoyl-4-(2-naphthyl)acetylaminophenyl-3-[5-(4-nitro-
phenyl)-2-furyl]acrylic acid amide (4t). From 3-[5-(4-
nitrophenyl)-2-furyl]acrylic acid chloride (195 mg, 0.75
mmol) and N-(4-amino-2-benzoylphenyl)-2-naphthyl-
acetic acid amide (286 mg, 0.75 mmol) according to general
procedure 1. Purification: recrystallisation from ethanol.
Yield: 342 mg, (73%); mp: 209 ꢂC. IR (KBr): n=3309,
1676, 1653, 1623, 1598, 1514, 1332 cmꢀ1 1H NMR
.
(CDCl3): d=6.83 (d, J=16 Hz, 1H, ¼CH), 7.04 (m, 1H,
Ar), 7.31 (m, 1H, Ar), 7.42 (m, 2H, Ar), 7.48 (m, 2H,
Ar), 7.53 (m, 3H, Ar), 7.65 (m, 2H, Ar), 7.79 (m, 2H,
Ar), 7.89 (d, J=16 Hz, 1H, ¼CH), 7.94 (m, 1H, Ar),
8.00 (m, 5H, Ar), 8.31 (m, 2H, Ar), 10.49 (s, 1H, –NH),
10.58 (s, 1H, –NH). MS (EI): m/z=607 (5) [M+], 366
(100), 155 (94), 367 (28), 392 (13), 156 (12), 242 (5), 127
(4). Anal. (C37H25N3O6): C, 73.14; H, 4.15; N, 6.92;
found C, 73.13; H, 4.32; N, 6.98.
1
2342, 1598, 1508, 1332, 969, 853, 752 cmꢀ1. H NMR
(DMSO-d6): 3.57 (s, 2H, –CH2), 6.76 (d, J=16 Hz, 1H,
¼CH), 7.03–7.04 (m, 1H, Ar), 7.26–7.28 (m, 1H, Ar), 7.41–
8.00 (m, 17H, Ar and d, J=16 Hz, 1H, ¼CH), 8.31–8.33
(m, 2H, Ar), 10.13 (s, 1H, –NH), 10.38 (s, 1H, –NH). MS
(EI): m/z=621 (1)M+, 212 (100), 380 (74), 156 (41), 211
(37), 155 (31), 238 (27), 141 (27). Anal. (C38H27N3O6): C,
73.42; H, 4.38; N, 6.76; found C, 73.39; H, 4.52; N, 6.84.

K. Kettler et al. / Bioorg. Med. Chem. 11 (2003) 1521–1530
1529
N-3-Benzoyl-4-(4-biphenylyl)acetylaminophenyl-3-[5-(4-
nitrophenyl)-2-furyl]acrylic acid amide (4u). From 3-[5-
(4-nitrophenyl)-2-furyl]acrylic acid chloride (139 mg, 0.5
mmol) and N-(4-amino-2-benzoylphenyl)biphenylyl-
acetic acid amide (203 mg, 0.5 mmol) according to gen-
eral procedure 1. Purification: recrystallisation from
toluene. Yield: 215 mg (34%); mp: 250 ꢂC. IR (KBr):
ethanol. Yield: 257 mg, (73%); mp: 257 ꢂC. IR (KBr):
n=3384, 1678, 1627, 1597, 1546, 1513, 1403, 1333, 1247,
853, 799 cmꢀ1. 1H NMR (DMSO-d6): d=6.70 (d, J=16
Hz, 1H, ¼CH), 7.04–7.05 (m, 1H, Ar), 7.42–7.78 (m,
11H, Ar and d, J=16 Hz, 1H, ¼CH), 7.89–8.02 (m, 4H,
Ar), 8.31–8.33 (m, 2H, Ar), 10.44 (s, 1H, –NH), 10,58 (s,
1H, –NH). MS (EI): m/z=592 (1) [M+], 591 (3) [M+],
139 (100), 350 (97), 352 (37), 351 (34), 211 (34). Anal.
(C33H22ClN3O6): C, 66.95; H, 3.75; N, 7.10; found C,
66.78; H, 3.91; N, 6.89.
n=3390, 1698, 1628, 1597, 1552, 1515, 1402, 1333 cmꢀ1
.
1H NMR (DMSO-d6): d=3.46 (s, 2H, –CH2), 6.79 (d,
J=16 Hz, 1H, ¼CH), 7.04 (m, 1H, Ar), 7.19 (m, 2H,
Ar), 7.34 (m, 1H, Ar), 7.42 (m, 4H, Ar), 7.52 (m, 4H,
Ar), 7.61 (m, 4H, Ar), 7.69 (m, 2H, Ar), 7.79 (d, J=16
Hz, 1H, ¼CH), 7.90 (m, 1H, Ar), 8.00 (m, 2H, Ar), 8.32
(m, 2H, Ar), 10.11 (s, 1H, –NH), 10.40 (s, 1H, –NH).
MS (EI): m/z=647 (1) [M+], 212 (100), 406 (61), 242
(39), 211 (33), 182 (31), 181 (28), 167 (28). Anal.
(C40H29N3O6): C, 74.18; H, 4.51; N, 6.49; found C,
74.18; H, 4.51; N, 6.75.
Enzyme preparation
Yeast farnesyltransferase was used as a fusionprotein to
Glutathione S-transferase at the N-terminus of the
b-subunit. Farnesyltransferase was expressed in Escher-
ichia coli DH5a grown in LB media containing ampicillin
and chloramphenicol for co-expression of pGEX-DPR1
and pBC-RAM2 for farnesyltransferase production.22
The enzyme was purified by standard procedures with
glutathione-agarose beads for selective binding of the
target protein.
N-3-Benzoyl-4-(2-phenylpropionylamino)phenyl-3-[5-(4-
nitrophenyl)-2-furyl]acrylic acid amide (4v). From 3-[5-
(4-nitrophenyl)-2-furyl]acrylic acid chloride (277 mg, 1.0
mmol) and N-(4-amino-2-benzoylphenyl)-2-phenylpro-
pionic acid amide (344 mg, 1.0 mmol) according to
general procedure 1. Purification: recrystallisation from
toluene. Yield: 309 mg (53%); mp: 208 ꢂC. IR (KBr):
n=3374, 3304, 2932, 1686, 1629, 1597, 1548, 1508, 1330
Farnesyltransferase assay
The assay was conducted as described.21 Farnesylpyro-
phosphate (FPP) was obtained as a solution of the
ammonium salt in methanol-10 mM aqueous NH4Cl
(7:3) from Sigma-Aldrich. Dansyl-GlyCysValLeuSer
(Ds-GCVLS) was custom synthesized by ZMBH, Hei-
delberg, Germany. The assay mixture (100 mL volume)
contained 50 mM Tris/HCl pH 7.4, 5 mM MgCl2, 10
cmꢀ1 1H NMR (CDCl3): d=1.14 (d, J=7 Hz, 3H,
.
–CH3), 3.58 (q, J=7 Hz, 2H, –CH2), 6.77 (d, J=16 Hz,
1H, ¼CH), 7.04 (m, 1H, Ar), 7.19 (m, 3H, Ar), 7.24 (m,
2H, Ar), 7.41 (m, 2H, Ar), 7.48 (m, 2H, Ar), 7.55 (m,
1H, Ar), 7.62 (m, 1H, Ar), 7.66 (m, 2H, Ar), 7.79 (d,
J=16 Hz, 1H, ¼CH), 7.89 (m, 1H, Ar), 7.99 (m, 2H,
Ar), 8.32 (m, 2H, Ar), 10.09 (s, 1H, –NH), 10.42 (s, 1H,
–NH). MS (EI): m/z=585 (18) [M+], 242 (100), 344
(34), 212 (31), 105 (25), 40 (15), 196 (9), 586 (4). Anal.
(C35H27N3O6): C, 71.79; H, 4.65; N, 7.18; found C,
71.75; H, 4.50; N, 7.37.
mM ZnCl2,
5 mM dithiothreitol (DTT), 7 mM
Ds-GCVLS, 20 mM FPP and 5 nmol (approx.) yeast
GST-farnesyltransferase and 1% of various concen-
trations of the test compounds dissolved in dimethyl-
sulfoxide (DMSO). The progress of the enzyme reaction
was followed by monitoring the enhancement of the
fluorescence emission at 505 nm (excitation 340 nm).
The reaction was started by addition of the enzyme
and run in a Quartz cuvette thermostatted at 30 ꢂC.
Fluorescence emission was recorded with a Perkin
Elmer LS50B spectrometer. IC50 values (concentra-
tions resulting in 50% inhibition) were calculated from
initial velocity of three independent measurements of
four to five different concentrations of the respective
inhibitor.
N-3-Benzoyl-4-(diphenylacetylamino)phenyl-3-[5-(4-nitro-
phenyl)-2-furyl]acrylic acid amide (4w). From 3-[5-(4-
nitrophenyl)-2-furyl]acrylic acid chloride (277 mg, 1.0
mmol) and N-(4-amino-2-benzoylphenyl)diphenylacetic
acid amide (406 mg, 1.0 mmol) according to general
procedure 1. Purification: recrystallisation from toluene.
Yield: 433 mg (67%); mp: 248 ꢂC. IR (KBr): n=3453,
1
1598, 1516, 1332 cmꢀ1. H NMR (CDCl3): d=4.96.(s,
1H, –CH), 6.74 (d, J=16 Hz, 1H, ¼CH), 6.97 (m, 1H,
Ar), 7.09 (m, 3H, Ar), 7.15 (m, 3H, Ar), 7.19 (m, 4H,
Ar), 7.35 (m, 1H, Ar), 7.40 (m, 3H, Ar), 7.55 (m, 2H,
Ar), 7.62 (m, 2H, Ar), 7.74 (d, J=16 Hz, 1H, ¼CH),
7.83 (m, 1H, Ar), 7.94 (m, 1H, Ar), 8.26 (m, 5H, Ar), 10.24
(s, 1H, –NH), 10.37 (s, 1H, –NH). MS (EI): m/z =647 (5)
[M+], 182 (100), 105 (96), 239 (80), 406 (77), 265 (53), 212
(48), 167 (24). Anal. (C40H29N3O6): C, 74.18; H, 4.51; N,
6.49; found C, 73.98; H, 4.90; N, 6.68.
Molecular modeling
All molecular modeling was carried out using SYBYL25
version 6.7/6.8 running on a Silicon Graphics O2
(R5000). Flexible docking was performed using FlexX23
version 1.10. The FlexX command MAPREF and the
perturbate mode of the PLACEBAS command were
used. Default parameters were employed except the
MAX_ENERGY value which was set to 10 kJ molꢀ1
.
N-3-Benzoyl-4-(4-chlorobenzoylamino)phenyl-3-[5-(4-nitro-
phenyl)-2-furyl]acrylic Acid Amide (4x). From 3-[5-(4-
nitrophenyl)-2-furyl]acrylic acid chloride (195 mg, 0.75
mmol) and N-(4-amino-2-benzoylphenyl)-4-chloro-
benzoic acid amide (263 mg, 0.75 mmol) according to
general procedure 1. Purification: recrystallisation from
Acknowledgements
The pGEX-DPR1 and pBC-RAM2 plasmids were
kindly provided by Professor F. Tamanoi (UCLA).

1530
K. Kettler et al. / Bioorg. Med. Chem. 11 (2003) 1521–1530
Financial support by the Deutsche Pharmazeutische
Gesellschaft is gratefully acknowledged. I.S. wishes to
thank Professor Dr. S. Grabley for generous support
and Ms. S. Egner for technical assistance.
Tahir, S.; Kovar, P.; Ewing, P.; Alder, J.; Mitten, M.; Leal, J.;
Marsh, K.; Bauch, J.; Hoffman, D. J.; Sebti, S. M.; Rosen-
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16. Augeri, D. J.; Janowick, D.; Kalvin, D.; Sullivan, G.;
Larsen, J.; Dickman, D.; Ding, H.; Cohen, J.; Lee, J.; Warner,
R.; Kovar, P.; Cherian, S.; Saeed, B.; Zhang, H.; Tahir, S.;
Ng, S.-C.; Sham, H.; Rosenberg, S. H. Bioorg. Med. Chem.
Lett. 1999, 9, 1069.
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