Synthesis of novel N-protected hydrophobic phenylalanines and their application in potential antibacterials

Article abstract of DOI:10.1016/j.ejmech.2008.07.001

An efficient synthesis of two new N-acetyl-4′-arylphenylalanines is described together with their incorporation into a number of cationic peptoid antibacterial agents, one of which had an MIC of 7.8 μg/mL against Staphylococcus aureus. Crown Copyright

Full text of DOI:10.1016/j.ejmech.2008.07.001

European Journal of Medicinal Chemistry 44 (2009) 1001–1009
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
Synthesis of novel N-protected hydrophobic phenylalanines and their
application in potential antibacterials
,
b
b
a,
*
Timothy P. Boyle a, John B. Bremner a , Jonathan A. Coates , John Deadman , Paul A. Keller
,
*
,
a
Stephen G. Pyne a , Kittiya Somphol
*
a School of Chemistry, University of Wollongong, Wollongong, NSW 2522, Australia
b Avexa Ltd, 576 Swan St, Richmond, Vic 3121, Australia
a r t i c l e i n f o
a b s t r a c t
An efficient synthesis of two new N-acetyl-40-arylphenylalanines is described together with their
incorporation into a number of cationic peptoid antibacterial agents, one of which had an MIC of 7.8 mg/
mL against Staphylococcus aureus.
Article history:
Received 5 June 2008
Received in revised form 24 June 2008
Accepted 2 July 2008
Available online 9 July 2008
Crown Copyright Ó 2008 Published by Elsevier Masson SAS. All rights reserved.
Keywords:
Anthracenyl phenylalanines
Phenanthrenyl phenylalanines
Cationic peptoids
Antibacterials
1. Introduction
aspects of their in vitro antibacterial activity are reported in this
paper [12].
With the increasing spread of antibacterial resistance [1–3],
including resistance by pathogenic bacteria to vancomycin [4,5],
there is a compelling imperative for new antibacterials [6,7]. In
this context, we have undertaken a program investigating the
design and synthesis of cyclic cationic peptoids linked by
a hydrophobic scaffold as potential antibacterial agents, and thus
far, have shown the binaphthyl [8] and carbazole scaffolds [9,10]
within these cyclic peptoids to produce antibacterial agents,
whilst the smaller indole based cyclic peptoids [11] failed to
inhibit bacterial growth. Therefore, as part of this program tar-
geting new peptoid derivatives as antibacterial agents and
attempting to address the resistance mechanism against vanco-
mycin, we investigated the synthesis of novel hydrophobic amino
acids and their subsequent incorporation into acyclic cationic
peptides. These peptides were designed to further explore the
effect of hydrophobicity and the role of cationic residues within
the peptide. The synthesis and methodology of the novel hydro-
phobic amino acids, their incorporation into cationic peptides and
2. Chemistry
The strategy employed to prepare the two hydrophobic amido
acids proceeded via a common trimethylstannyl amido acid 5,
which was prepared from phenylalanine in four steps (Scheme 1).
This common intermediate was then coupled to either 9-bro-
moanthracene or 9-bromophenanthrene via a Stille coupling [13]
protocol followed by subsequent saponification to yield the
hydrophobic amido acids 7a and 7b (Scheme 1).
Therefore, iodination of phenylalanine was performed as
previously described [14] to produce p-iodophenylalanine 2, which
was isolated in quantitative yield. Esterification of 2 with MeOH/
SOCl2 afforded the methyl ester 3 as the hydrochloride salt in
excellent yield, which was carried forward to the N-acetyl deriva-
tive 4 without further purification (Scheme 1). The key trimethyl-
stannyl intermediate 5 was prepared following the procedure of
Morera and Ortar [15] in 76% yield. This methodology was favoured
over previously reported methods [16], due to the faster reaction
time in preparing the aryltrimethylstannane over the aryltributyl-
stannane, significantly decreasing the possibility of racemization at
the
The hydrophobic amido esters 6a and 6b were prepared via
a Stille coupling methodology [14,15] in 67% and 59% yields,
a position of the amido ester.
* Corresponding authors. Tel.: þ61 2 4221 3509; fax: þ61 2 4221 4287.
E-mail addresses: keller@uow.edu.au (P.A. Keller), spyne@uow.edu.au (S.G.
Pyne).
0223-5234/$ – see front matter Crown Copyright Ó 2008 Published by Elsevier Masson SAS. All rights reserved.
doi:10.1016/j.ejmech.2008.07.001

1002
T.P. Boyle et al. / European Journal of Medicinal Chemistry 44 (2009) 1001–1009
I
I
I
(c)
(a)
(b)
O
HOOC
NH2
HOOC
H3COOC
H3COOC
N
H
NH2
NH3Cl
2
1
3
4
Me3Sn
Ar
(d)
(e)
O
O
H3COOC
N
H
H3COOC
N
H
5
6
a. Ar = 9-anthracenyl
b. Ar = 9-phenanthrenyl
(f)
O
O
HOOC
N
H
HOOC
N
H
7b
7a
Scheme 1. Reagents and conditions: (a) NaIO3, AcOH, H2SO4, 70 ꢀC, 16 h, 100%; (b) SOCl2, MeOH, 0 ꢀC–RT, 16 h, 99%; (c) Ac2O, AcONa(aq), 0 ꢀC, 56%; (d) (SnMe3)2, Pd(OAc)2, PPh3,
PhMe, 100 ꢀC, 30 min, 76%; (e) a. 9-bromoanthracene, Pd(OAc)2, P(o-tol)3, DMF, 70 ꢀC, 16 h, 6a: 67%; b. 9-bromophenanthrene, Pd(OAc)2, P(o-tol)3, DMF, 70 ꢀC, 16 h, 6b: 59%; (f)
LiOH, THF/H2O, RT, 16 h, 7a: 90%, 7b: 55%.
respectively (Scheme 1). The ligand of choice for this reaction was
tri-o-tolylphosphine, as phenyl transfer to the amino acid was
observed when triphenylphosphine was present as the ligand. It
was found that increasing the temperature above 85 ꢀC resulted in
faster reaction times and also resulted in partial racemization of the
a
O
-stereocentre of the amido ester. However, at 70 ꢀC, no racemi-
(a)
(b)
MeO
NHFmoc
MeO
N
H
zation was observed. Partial racemization of these products formed
at the higher temperature was detected from 1H NMR analysis of
their products 12a, and 12b (Scheme 2) that showed NMR signals
for a minor diastereomer. The desired free acid form was obtained
by saponification to afford 7a and 7b in 90% and 55% yields,
respectively.
NH3Cl
O
O
9
8
NHBoc
Ar
The peptide fragment 10 was prepared by employing a well-
established EDCI peptide coupling methodology and an Fmoc
protection/deprotection protocol [8–11]. This fragment was
coupled to 7a and 7b to give the protected tripeptoids 11a and 11b,
respectively (Scheme 2). N-Boc deprotection of 11a and 11b by
exposure to TFA, followed by anion exchange with HCl provided the
hydrochloride salts 12a and 12b, respectively (Scheme 2).
This chemistry was further expanded to include the dicationic
tetrapeptoids 20a and 20b, which also incorporated the hydro-
phobic amido acids 7a and 7b and the less hydrophobic O-allyltyr-
osine peptoid analogue 20c (Scheme 3). Allyl glycine 13 was
O
H
O
O
(c)
MeO
N
MeO
NH2
N
H
N
H
N
H
O
O
O
11
10
NHBoc
NHBoc
Ar
a. Ar = 9-anthracenyl
converted to its benzyl ester 14 which was coupled to Fmoc-D-
arginine(Pmc)OH to give the dipeptide 15. Selective base catalysed
removal of the N-Fmoc protecting group of 15 gave the free amine 16
b. Ar = 9-phenanthrenyl
O
O
(d)
H
N
MeO
N
H
N
H
O
O
that was coupled to Fmoc-D-lysine(Boc)OH to give the protected
tripeptoid 17. N-Fmoc removal from 17 and coupling of the resulting
amine 18 with 7a or 7b gave the protected tetrapeptoids 19a and
19b, respectively. Coupling of 18 with N-acetyl-O-allyl-L-tyrosine
12
NH3 Cl
[17] gave the tetrapeptoid 19c. Acid catalysed deprotection of 19a,
19b and 19c, followed by anion exchange with HCl, gave the bis-
hydrochloride salts of tetrapeptoids 20a, 20b and 20c, respectively
(Scheme 3).
Scheme 2. Reagents and conditions: (a) Fmoc-L-lysine(Boc)OH, EDCI, HOBt, CH2Cl2,
DMAP, RT, 16 h, 87%; (b) 1% piperidine, MeCN, RT, 3 h, 100%; (c) 7a, EDCI, HOBt, DMF,
RT, 16 h, 11a: 59%, 11b: 50%; (d) TFA/CH2Cl2 (1:1), RT, 3 h, then HCl/ether, 12a: 61%, 12b:
69%.

T.P. Boyle et al. / European Journal of Medicinal Chemistry 44 (2009) 1001–1009
1003
O
(a)
(b)
BnO
NHFmoc
BnO
NH3+Cl-
NH3+Cl-
N
H
HOOC
O
O
13
14
HN
HN
NHPmc
15
NHBoc
O
BnO
O
NH2
O
(d)
(e)
(c)
N
H
H
N
BnO
N
H
NHFmoc
O
O
HN
HN
HN
NHPmc
HN
NHPmc
16
17
NHBoc
NHBoc
O
O
H
O
H
(f)
H
N
BnO
N
N
BnO
N
H
NH2
N
H
N
H
O
O
O
O
O
HN
HN
19
18
R
HN
NHPmc
Pmc
N
NH
H
NH3+Cl-
4"'
3'
O
O
H
N
H
N
14
(g)
1
a; R = 9-anthracenyl
BnO
N
N
H
2
b; R = 9-phenanthrenyl
c; R = O-allyl
H
O
O
O
3"
HN
HN
NH3+Cl-
20
R
Scheme 3. Reagents and conditions: (a) BnOH, SOCl2, 16 h, RT, 68%; (b) Fmoc-D-arginine(Pmc)OH, EDCI, HOBt, DMF, 16 h, RT, 51%; (c) 1% piperidine, MeCN, RT, 3 h, 70%; (d) Fmoc-D-
lysine(Boc)OH, EDCI, HOBt, DMF, 16 h, RT, 51%; (e) 1% piperidine, MeCN, RT, 3 h, 93%; (f) 7a or 7b or N-Ac-O-allyl-L-tyrosine, EDCI, HOBt, DMF, 16 h, RT, 19a: 36%, 19b: 80%, 19c: 85%;
(g) TFA/CH2Cl2 (1:1), RT, 3 h, then HCl/ether, 20a: 88%, 20b: 79%, 20c: 85%.
2.1. In vitro antibacterial activity
[12] for peptide compounds which indicates that two hydrophobic
and two cationic sites are important for antibacterial activity. In
our case the benzyl ester moiety in 20a and 20b would represent
the second, albeit considerably smaller, hydrophobic group.
In contrast to the activity shown against S. aureus, the cationic
peptoids 12a, 12b, 20a, and 20b, were not active against Entero-
coccus faecalis strains (both vancomycin sensitive and resistant
The synthesized hydrophobic and cationic peptoids 12a, 12b,
20a, 20b and 20c were tested against the Gram-positive bacterium
Staphylococcus aureus (ATCC6538) and it showed MIC values of
31.3, 15.6, 15.6, 7.8 and >125 mg/mL, respectively. The positive
control, vancomycin, showed an MIC value of 1.95 mg/mL. In stark
contrast to 12a, 12b and 20a, 20b the less hydrophobic tetra-
peptoid 20c was not active (MIC > 125 mg/mL). 9-Phenanthrenyl
peptoids, 12b and 20b, were more active than their respective 9-
anthracenyl counterparts, 12a and 20a. The dicationic peptoids,
20a and 20b were more active than their respective monocationic
analogues 12a and 12b. However, it should be noted that peptides
strains); MIC values > 125 mg/mL were obtained against these
strains and the same results were seen with the peptoid 20c.
3. Conclusions
We have developed a useful method for preparing the novel
biaryl hydrophobic amido acids 7a and 7b via Stille coupling
reactions. This method could potentially be employed to prepare
other novel biaryl phenylalanine derivatives. We have shown that
incorporation of these hydrophobic amido acid residues into
cationic peptides resulted in peptoids having significant
12a, 12b have a
L-lysine residue whereas peptides 20a and 20b
have a -lysine residue. These differences limit further structure–
D
activity comparisons to be made between the tripeptides 12a and
12b and tetrapeptides 20a and 20b. These biological results are
consistent with the pharmacophore model proposed by Svendsen

1004
T.P. Boyle et al. / European Journal of Medicinal Chemistry 44 (2009) 1001–1009
antibacterial activity against S. aureus when compared to a less
hydrophobic, O-allyltyrosine analogue 20c. These results highlight
the importance of hydrophobicity within the peptoid for antibac-
terial activity and provide a platform for further development of
antimicrobial agents with improved activity against S. aureus.
removed under reduced pressure and the crude product was
purified by flash column chromatography (15:1, CH2Cl2/MeOH) to
yield the free amine.
4.2.4. (S)-2-Amino-3-(4-iodophenyl)propanoic acid 2
To a solution of (S)-2-amino-3-phenylpropanoic acid (4.01 g,
24.3 mmol) in acetic acid (22 mL) were added sulfuric acid (2.9 mL,
5.14 mmol), iodine (2.47 g, 4.7 mmol) and sodium iodate (1.02 g,
5.14 mmol). The mixture was heated to 70 ꢀC and allowed to stir at
this temperature for 16 h before an additional portion of sodium
iodate (1.02 g, 5.14 mmol) was added. The reaction was left for
a further 2 h before being concentrated, dissolved in MeOH (20 mL)
and treated with NaOH (60 mL). The mixture was left to precipitate
out of the basic solution overnight and the resulting solid was
filtered by vacuum filtration to yield the title compound 2 (7.07 g,
4. Experimental
4.1. Chemistry
Chemical ionization (CI) mass spectra were obtained on a Shi-
madzu QP-5000 mass spectrometer by a direct insertion technique
(electron beam density, 70 eV). Electrospray ionization (ESI) mass
spectra were obtained on a VG Quattro spectrometer. High-reso-
lution mass spectra (HRMS) were determined on a VG Autospec
spectrometer or on a micromass QTof2 spectrometer using poly-
ethylene glycol as the internal standard. The m/z values are stated
with their peak intensity percentages in parentheses. Optical
rotations were measured using a Jasco DIP-370 digital polarimeter
with a 10-mm path length. Proton and carbon nuclear magnetic
resonance (NMR) spectra were determined in CDCl3 solution at
300 MHz (1H NMR) or 75 MHz (13C NMR) unless otherwise stated,
using a Varian Mercury 300 MHz or Varian Inova 500 MHz spec-
trometer. TMS was used as the internal standard and all chemical
24.3 mmol, 100%) as a pink solid, which had spectral data in
21
agreement with that reported [14]. [
258–260 ꢀC (lit. 261–262 ꢀC) [14].
a
]
ꢁ10.6 (c. 0.3, HCl). Mp
D
4.2.5. Methyl (2S)-2-amino-3-(4-iodophenyl)propanoate
hydrochloride 3
To a solution of 2 (2.00 g, 6.87 mmol) in MeOH (10 mL) at 0 ꢀC
was added thionyl chloride (2 mL) and the resulting solution was
allowed to stir for 16 h whilst equilibrating to RT. The reaction was
evaporated to dryness in vacuo to yield the title compound 3
shifts
(d) were measured relative to the internal standard.
Analytical thin layer chromatography (TLC) was carried out on
Merck Silica gel 60 F254 pre-coated aluminium plates with a 0.2-
mm adsorbant thickness. All column chromatography was
performed under ‘flash’ conditions on Merck Silica gel 60 (230–
400 mesh). 1H NMR assignments were achieved with the aid of
gCOSY, and in some cases NOESY and TOCSY experiments. 13C NMR
assignments were based upon DEPT, gHSQC and sometimes
gHMBC experiments. All compounds were homogeneous by TLC
analysis and judged to be of >95% purity based upon 1H NMR
analysis. Compound numbering is based on that of compound 20
as shown in Scheme 3. All compounds were judged to be greater
than 95% purity based upon 1H NMR and TLC analyses. Solvent
ratios are vol/vol.
(2.25 g, 6.80 mmol, 99%) as a white solid, which had spectral data in
21
agreement with that reported [14]. [
198 ꢀC (lit. 199.5–200.5 ꢀC) [14].
a]
ꢁ9.3 (c. 0.15, HCl). Mp 195–
D
4.2.6. Methyl (2S)-2-acetamido-3-(4-iodophenyl)propanoate 4
To a solution of 3 (2.25 g, 6.80 mmol) in 10% HCl (10 mL) at 0 ꢀC
was added 4 M sodium acetate (115 mL) and the resulting solution
was allowed to stir whilst equilibrating to 0 ꢀC. Acetic anhydride
(50 mL) was added and the reaction allowed to proceed with
vigorous stirring. After 1 h the product was collected by vacuum
filtration, dissolved in ethyl acetate (30 mL) and washed with 2 M
sodium bicarbonate (2 ꢂ 30 mL). The organic layer was dried and
evaporated to yield the title compound 4 (1.31 g, 3.79 mmol, 56%)
27
as a white solid. Mp 118–120 ꢀC. [
a]
þ93.8 (c. 0.1, CHCl3). 1H NMR
D
4.2. General procedures
(CDCl3, 300 MHz)
d
: 7.61 (d, J ¼ 8.4 Hz, 2H, ArH20 and ArH60); 6.84
(d, J ¼ 8.1 Hz, 2H, ArH30 and ArH50); 5.92 (d, J ¼ 7.2 Hz, 1H, NH);
4.2.1. General synthetic procedure for N-Boc and Pmc
deprotection (procedure A)
4.87 (m, 1H, H2); 3.73 (s, 3H, OCH3); 3.11 (dd, J ¼ 6.0, 13.8 Hz, 1H,
H3a); 3.03 (dd, J ¼ 5.4, 13.8 Hz, 1H, H3b); 1.99 (s, 3H, NCOCH3). 13
C
The N-Boc or Pmc protected amine was stirred for 3 h in 1:1
CH2Cl2/TFA (5 mL/0.1 mmol of substrate) solution at RT. The solvent
was removed under reduced pressure, and the residue was resus-
pended in a minimal volume of methanol. The solution was then
treated with an excess of 1 M HCl/ether solution and the solvent
evaporated. The crude product was purified by precipitation from
CH2Cl2 and/or MeOH by addition of diethyl ether.
NMR (CDCl3, 75 MHz) d
: 171.8, C1; 169.5, NCO; 137.6, ArCH20 and
ArCH60; 135.5, ArC40; 131.2, ArCH30 and ArCH50; 94.1, ArC10; 52.9,
C2; 52.4, OCH3; 37.4, C3; 23.1, NCOCH3. Mass spectrum (CIþ) m/z:
348 (100%) [MHþ]. HRMS calcd for C12H15NO3I, 348.0097; found,
348.0104.
4.2.7. Methyl (2S)-2-acetamido-3-(4-
trimethylstannylphenyl)propanoate 5
4.2.2. General synthetic procedure for peptide coupling
(procedure B)
A solution of 4 (590 mg, 1.7 mmol), hexamethyldistannane
(781 mg, 2.38 mmol), palladium acetate (20 mg, 0.085 mmol), and
triphenylphosphine (45 mg, 0.17 mmol) in toluene (7 mL) was
flushed with nitrogen for 15 min and then heated at 100 ꢀC for
30 min under N2. The brown mixture was filtered through a short
pad of silica, diluted with diethyl ether (40 mL) and washed twice
To a solution of the acid (1 equiv.) in DMF (10 mL/1 mmol of
substrate) at room temperature were added HOBt (1.1 equiv.), EDCI
(1 equiv.) and the amine (1.2 equiv.). If the amine was a hydro-
chloride salt, DIPEA (1 equiv.) was also added. The mixture was
allowed to stir for 16 h before dilution with EtOAc (30 mL) and
washing with water (30 mL) and brine (30 mL). The organic fraction
was dried (MgSO4) and further purified by column chromatography
if required.
with water. The organic layer was dried and evaporated to yield
27
the title compound 5 (497 mg, 1.29 mmol, 76%) as a clear oil. [a]
D
þ13.7 (c. 0.3, CHCl3). 1H NMR (CDCl3, 300 MHz)
d: 7.41 (d,
J ¼ 7.5 Hz, 2H, ArH20 and ArH60); 7.07 (d, J ¼ 7.8 Hz, 2H, ArH30 and
ArH50); 6.25 (d, J ¼ 7.8 Hz, 1H, NH); 4.87 (m, 1H, H2); 3.72 (s, 3H,
OCH3); 3.12 (dd, J ¼ 5.7, 14.1 Hz, 1H, H3a); 3.04 (dd, J ¼ 6.0, 13.9 Hz,
1H, H3b); 1.98 (s, 3H, NCOCH3); 0.27 (t, J ¼ 27.6 Hz, 9H, Sn(CH3)3).
4.2.3. General synthetic procedure for N-Fmoc deprotection
(procedure C)
The Fmoc protected amine was stirred in 1% piperidine/aceto-
nitrile (5 mL/1 mmol of substrate) for 3 h at RT. The solvent was
13C NMR (CDCl3, 75 MHz) : 172.1, C1; 169.7, NCO; 140.6, ArC40;
d
135.9, ArCH20 and ArCH60; 135.9, ArC10; 128.7, ArCH30 and ArCH50;

T.P. Boyle et al. / European Journal of Medicinal Chemistry 44 (2009) 1001–1009
1005
53.0, C2; 52.1, OCH3; 37.5, C3; 23.9, NCOCH3; ꢁ9.7, Sn(CH3)3. Mass
spectrum (CIþ) m/z: 386 (50%) [MHþ], 382 (10%) [MHþ] (112Sn), 85
(100%). HRMS calcd for C15H24NO3Sn (112Sn), 382.0754; found,
382.0756.
phase was acidified with 10% HCl and the resulting precipitate was
extracted with CH2Cl2 (3 ꢂ 40 mL). The combined organics were
dried and evaporated to yield the title compound 7a (69 mg,
20
0.18 mmol, 90%) as a white solid. Mp 76 ꢀC. [
a
]
þ29.7 (c. 0.1,
D
EtOH). 1H NMR (CDCl3, 300 MHz) : 8.47 (s, 1H, ArH1000); 8.02 (d,
d
4.2.8. Methyl (2S)-2-acetamido-3-(4-[9-anthracenyl]phenyl)-
propanoate 6a
J ¼ 8.4 Hz, 2H, ArH300 and ArH600); 7.59 (d, J ¼ 8.7 Hz, 2H, ArH800 and
ArH100); 7.45 (m, 2H, ArH400 and ArH500); 7.35 (m, 6H, ArH200 and
ArH700, 4 ꢂ ArH0); 6.27 (d, J ¼ 6.6 Hz, 1H, NH); 5.00 (m, 1H, H2); 3.39
(dd, J ¼ 4.8, 12.9 Hz, 1H, H3a); 3.26 (dd, J ¼ 6.3, 14.4 Hz, 1H, H3b);
A solution of 5 (192 mg, 0.50 mmol), 9-bromoanthracene
(141 mg, 0.55 mmol), palladium acetate (6 mg, 0.025 mmol), and
tri-o-tolylphosphine (15 mg, 0.05 mmol) in DMF (2 mL) was
flushed with N2 for 15 min, then heated to 70 ꢀC and allowed to
stir for 16 h. The reaction was diluted with diethyl ether (20 mL)
and washed with water (5 ꢂ 20 mL), dried and evaporated. The
crude product was purified by flash column chromatography (15%
2.07 (s, 3H, COCH3). 13C NMR (CDCl3, 75 MHz)
d: 174.2, C1; 171.2,
COCH3; 137.5, ArC900; 136.4, ArC40; 135.0, ArC10; 131.4, ArC8a00;
131.2, ArC9a00; 130.1, ArCH200 and ArCH700; 129.3, ArCH20 and
ArCH60; 128.8, ArCH30 and ArCH50; 128.3, ArCH400 and ArCH500;
126.6, ArC4a00 and ArC10a00; 125.3, ArCH800 and ArCH100; 125.0,
ArCH300 and ArCH600, ArC1000; 53.5, C2; 37.3, C3; 22.9, COCH3. Mass
spectrum (ESIþ) m/z: 383 (70%) [MHþ]. HRMS calcd for C25H22NO3,
384.1600; found, 384.1610.
EtOAc/hexane then 5% MeOH/CH2Cl2) to yield the title compound
27
6a (133 mg, 0.33 mmol, 67%) as an orange oil. [
a
]
þ66.9 (c. 0.1,
D
CHCl3). 1H NMR (CDCl3, 300 MHz)
d
: 8.48 (s, 1H, ArH1000); 8.03 (dd,
J ¼ 0.9, 8.7 Hz, 2H, ArH300 and ArH600); 7.63 (dd, J ¼ 0.6, 9.0 Hz, 2H,
ArH800 and ArH100); 7.45 (m, 2H, ArH400 and ArH500); 7.36 (m, 6H,
ArH200 and ArH700, 4 ꢂ ArH0); 5.40 (d, J ¼ 7.8 Hz, 1H, NH); 5.04 (m,
1H, H2); 3.79 (s, 3H, OCH3); 3.32 (dd, J ¼ 5.7, 13.8 Hz, 1H, H3a);
3.25 (dd, J ¼ 6.3, 13.8 Hz, 1H, H3b); 2.08 (s, 3H, COCH3). 13C NMR
4.2.11. (2S)-2-Acetamido-3-(4-[9-phenanthrenyl]phenyl)propanoic
acid 7b
To a solution of 6b (124 mg, 0.31 mmol) in THF/water, 2:1 (9 mL)
was added lithium hydroxide monohydrate (26 mg, 0.62 mmol)
and the resulting suspension was allowed to stir for 16 h. The
reaction mixture was diluted with water (30 mL) and the THF was
removed by evaporation. The aqueous layer was washed with
CH2Cl2 (40 mL) to remove unreacted starting material. The aqueous
phase was acidified with 10% HCl and the resulting precipitate was
extracted with CH2Cl2 (3 ꢂ 40 mL). The combined organics were
(CDCl3, 75 MHz) d
: 172.2, C1; 169.8, COCH3; 137.4, ArC900; 136.4,
ArC40; 135.2, ArC10; 132.0, ArC8a00 and ArC9a00; 131.9, ArCH200 and
ArCH700; 131.3, ArCH20 and ArCH60; 129.2, ArCH30 and ArCH50;
128.3, ArCH400 and ArCH500; 126.5, ArC4a00 and ArC10a00; 125.3,
ArCH800 and ArCH100; 125.0, ArCH300 and ArCH600, ArCH1000; 53.3,
C2; 52.3, OCH3; 37.8, C3; 23.1, COCH3. Mass spectrum (CIþ) m/z:
398 (100%) [MHþ]. HRMS calcd for C26H23NO3, 397.1678; found,
397.1675.
dried and evaporated to yield the title compound 7b (65 mg,
20
0.17 mmol, 55%) as a white solid. Mp 128–132 ꢀC. [
a
]
þ36.8 (c. 0.1,
D
EtOH). 1H NMR (CD3OD, 300 MHz)
d
: 8.71 (d, J ¼ 8.1 Hz, 1H, ArH400);
4.2.9. Methyl (2S)-2-acetamido-3-(4-[9-
phenanthrenyl]phenyl)propanoate 6b
8.66 (d, J ¼ 8.4 Hz, 1H, ArH300); 7.79 (s, 1H, ArH100); 7.76 (s, 1H,
ArH1000); 7.51 (m, 5H, ArH700, ArH600, ArH500, ArH200 and ArH100); 7.32
(m, 2H, Ar0H); 4.76 (dd, J ¼ 5.1, 9.0 Hz, 1H, H2); 3.29 (dd, J ¼ 4.8,
13.5 Hz, 1H, H3a); 3.03 (dd, J ¼ 8.7, 13.5 Hz, 1H, H3b); 1.95 (s, 3H,
A solution of 5 (259 mg, 0.67 mmol), 9-bromophenanthrene
(190 mg, 0.74 mmol), palladium acetate (8 mg, 0.034 mmol), and
tri-o-tolylphosphine (20 mg, 0.067 mmol) in DMF (2 mL) was
flushed with N2 for 15 min, then heated to 70 ꢀC and allowed to
stir for 16 h. The reaction was diluted with diethyl ether (20 mL)
and washed with water (5 ꢂ 20 mL), dried and evaporated. The
crude product was purified by flash column chromatography (15%
COCH3). 13C NMR (CD3OD, 75 MHz)
d: 174.8, C1; 173.2, COCH3;
140.5, ArC40; 139.7, ArC10; 137.7, ArC900; 132.9, ArC4b00; 132.2,
ArC8a00; 131.9, ArC4a00; 131.2, ArC10a00; 131.1, ArCH20 and ArCH60;
130.2, 0A0 rCH30 and ArCH50; 129.6, ArCH100; 128.3, ArCH300; 127.9,
ArCH6 ; 127.7, ArCH100; 127.7, ArCH500; 127.6, ArCH1000; 127.5,
ArCH200; 124.0, ArCH400; 123.5, ArCH300; 55.2, C2; 38.2, C3; 22.4,
COCH3. Mass spectrum (ESIþ) m/z: 384 (50%) [MHþ]. HRMS calcd
for C25H22NO3, 384.1600; found, 384.1628.
EtOAc/hexane then 5% MeOH/CH2Cl2) to yield the title compound
27
6b (157 mg, 0.40 mmol, 59%) as a clear oil. [
a
]
þ94.6 (c. 0.1,
D
CHCl3). 1H NMR (CDCl3, 300 MHz)
d
: 8.77 (d, J ¼ 9.0 Hz, 1H, ArH400);
8.71 (d, J ¼ 8.1 Hz, 1H, ArH300); 7.89 (m, 2H, ArH100 and ArH1000);
7.61 (m, 5H, ArH700, ArH600, ArH500, ArH200 and ArH100); 7.48 (d,
J ¼ 8.4 Hz, 2H, ArH20 and ArH60); 7.26 (d, J ¼ 8.1 Hz, 2H, ArH30 and
ArH50); 6.25 (d, J ¼ 7.5 Hz, 1H, NH); 5.00 (m, 1H, H2); 3.79 (s, 3H,
OCH3); 3.30 (dd, J ¼ 5.7, 13.8 Hz, 1H, H3a); 3.20 (dd, J ¼ 6.0, 13.8 Hz,
4.2.12. Methyl (2S,5S)-2-allyl-3-aza-9-(tert-butoxycarboxamido)-
5-(9H-9-fluorenylmethyloxycarboxamido)-4-oxononanoate 9
To a solution of 8 [18] (430 mg, 2.61 mmol) and Fmoc-L-lysi-
ne(Boc)OH (1.22 g, 2.61 mmol) in CH2Cl2 (10 mL) were added EDCI
(500 mg, 2.61 mmol) and a catalytic quantity of DMAP. The
resulting mixture was allowed to stir at RT for 16 h. The reaction
was diluted with CH2Cl2 (25 mL), then the organic layer was
washed with brine (2 ꢂ 25 mL) and water (2 ꢂ 25 mL) and dried,
before being concentrated. The crude product was purified by flash
column chromatography (25:1 CH2Cl2/MeOH) to afford the title
compound 9 (1.31 g, 2.27 mmol, 87%) as a cream coloured solid. Mp
1H, H3b); 2.05 (s, 3H, COCH3). 13C NMR (CDCl3, 75 MHz)
d: 172.1,
C1; 169.7, COCH3; 139.5, ArC40; 138.2, ArC10; 135.0, ArC900; 131.4,
ArC4b00; 130.9, ArC9a00; 130.6, ArC4a00; 130.1, ArCH20 and ArCH60;
129.9, ArC10a00; 129.1, ArCH30 and ArCH50; 128.5, ArCH100; 127.4,
ArCH700; 126.8, ArCH600; 126.7, ArCH100; 126.5, ArCH500; 126.4,
ArCH1000; 126.3, ArCH200; 122.9, ArCH400; 122.4, ArCH300; 53.2, C2;
52.3, OCH3; 37.6, C3; 23.0, COCH3. Mass spectrum (CIþ) m/z: 398
(100%) [MHþ]. HRMS (EI) calcd for C26H23NO3, 397.1678; found,
397.1680.
123–126 ꢀC. 1H NMR (CDCl3, 300 MHz)
d: 7.76 (d, J ¼ 7.6 Hz, 2H,
ArH100 and ArH800); 7.59 (d, J ¼ 7.6 Hz, 2H, ArH400 and ArH500); 7.40 (t,
J ¼ 7.6 Hz, 2H, ArH300 and ArH600); 7.31 (ddd, J ¼ 9.0, 7.2, 1.2 Hz, 2H,
ArH200 and ArH700); 6.46 (br s,1H, NH); 5.64 (m, 1H, H20); 5.44 (s, 1H,
NH); 5.10 (m, 2H, H30); 4.65 (m, 1H, H2); 4.39 (d, J ¼ 7.2 Hz, 2H,
OCH2–H900); 4.22 (m, 1H, H5); 4.17 (br s, 1H, H900); 3.74 (s, 3H,
OCH3); 3.11 (m, 2H, H9); 2.55 (m, 2H, H10); 1.85 (m, 2H, H7); 1.65
(m, 2H, H6); 1.50 (m, 2H, H8); 1.44 (s, 9H, C(CH3)3). 13C NMR (CDCl3,
4.2.10. (2S)-2-Acetamido-3-(4-[9-anthracenyl]phenyl)propanoic
acid 7a
To a solution of 6a (80 mg, 0.20 mmol) in THF/water, 2:1 (3 mL)
was added lithium hydroxide monohydrate (17 mg, 0.40 mmol)
and the resulting suspension was allowed to stir for 16 h. The
reaction mixture was diluted with water (30 mL) and the THF was
removed by evaporation. The aqueous layer was washed with
CH2Cl2 (40 mL) to remove unreacted starting material. The aqueous
75 MHz) d
: 171.9, C4; 171.6, C1; 156.2, NCO2; 143.7, ArC8a00 and
ArC9a00; 142.7, ArC4a00 and ArC4b00; 131.9, C20; 127.7, ArCH300 and
ArCH600; 127.0, ArCH200 and ArCH700; 125.0, ArCH100 and ArCH800;

1006
T.P. Boyle et al. / European Journal of Medicinal Chemistry 44 (2009) 1001–1009
119.9, C30; 119.3, ArCH400 and ArCH500; 79.1, C(CH3)3; 67.0, CH2–C900;
54.5, C5; 52.4, OCH3; 50.6, C2; 47.0, C900; 39.8, C9; 36.1, C10; 32.0, C6;
29.9, C8; 28.3, C(CH3)3; 22.2, C7. Mass spectrum (ESIþ) m/z: 580.5
(10%) [MHþ], 130.5 (100%) [MHþ (less allylgly)]. HRMS calcd for
C32H42N3O7, 580.3023; found, 580.3025.
4.2.16. Benzyl (2S,5R)-2-allyl-5-amino-3-aza-8-[(2,2,5,7,8-
pentamethyl-3,4-dihydro-2H-6-chromenylsulfonamido)guanidino]-
4-oxooctanoate 16
The title compound was synthesized using the general N-Fmoc
deprotection procedure (procedure C), from 15 (278 mg,
0.33 mmol) to yield 16 (144 mg, 0.23 mmol, 70%) as a cream semi-
4.2.13. Methyl (2S,5S)-2-allyl-5-amino-3-aza-9-(tert-
butoxycarboxamido)-4-oxononanoate 10
The title compound was synthesized using the general N-Fmoc
deprotection procedure (procedure C), from 9 (1.27 g, 2.19 mmol) to
yield 10 (778 mg, 2.18 mmol, 100%) as a cream oil. 1H NMR (CDCl3,
solid. Mp 66–68 ꢀC. 1H NMR (CDCl3, 300 MHz)
d
: 7.85 (d, J ¼ 7.8 Hz,
1H, NH); 7.60 (d, J ¼ 7.8 Hz, 1H, NH); 7.32 (m, 5H, ArH); 6.33 (m, 2H,
NH2); 5.63 (s, 1H, H20); 5.14 (m, 4H, ArCH2 and H30); 4.56 (m, 1H,
H2); 3.40 (m, 1H, H5); 3.16 (m, 2H, H8); 3.09 (m, 2H, H10); 2.61 (t,
J ¼ 6.9 Hz, 2H, H400); 2.56 (s, 3H, 700-CH3); 2.55 (s, 3H, 500-CH3); 2.09
(s, 3H, 800-CH3); 1.78 (t, J ¼ 7.2 Hz, 2H, H300); 1.68 (m, 4H, H6 and
NH2); 1.54 (m, 2H, H7); 1.29 (s, 6H, 2 ꢂ 200-CH3). 13C NMR (CDCl3,
300 MHz)
d
: 7.81 (d, J ¼ 8.0 Hz, 1H, NH); 5.69 (m, 1H, H20); 5.11 (m,
2H, H30); 4.76 (br s, 1H, NH); 4.67 (m, 1H, H2); 3.75 (s, 3H, OCH3);
3.39 (dd, J ¼ 4.6, 7.6 Hz,1H, H5); 3.12 (d, J ¼ 6.3 Hz, 2H, H9); 2.54 (m,
2H, H10); 1.52 (m, 8H, H6, H7, H8 and NH2); 1.44 (s, 9H, C(CH3)3). 13C
75 MHz) d
: 171.4, C1; 171.2, C4; 156.2, ArC600; 153.4, ArC8a00; 146.0,
CN3; 135.2, ArC700; 135.1, ArC500; 134.7, C20; 128.5, ArC; 128.3, ArC;
128.3, ArC; 128.2, ArC; 123.9, ArC800; 119.2, C30; 117.8, ArC4a00; 73.5,
C200; 67.1, ArCH2; 54.2, C5; 53.4, C2; 40.8, C8; 35.9, C10; 32.7, C400;
30.8, C6; 29.3, C7; 26.6, 200-CH3; 21.3, C300; 18.4, C700–CH3; 17.4, C500–
CH3; 12.0, C800–CH3. Mass spectrum (ESIþ) m/z: 628 (100%) [MHþ].
HRMS calcd for C32H46N5O6S, 628.3169; found, 628.3157.
NMR (CDCl3, 75 MHz) d: 174.8, C4; 172.1, C1; 156.0, NCO2; 132.2,
C20; 118.9, C30; 78.9, C(CH3)3; 54.8, C5; 52.2, C2; 51.1, OCH3; 40.0, C9;
36.4, C10; 34.4, C6; 29.7, C8; 28.3, C(CH3)3; 22.6, C7. Mass spectrum
(ESIþ) m/z: 358.5 (85%) [MHþ], 258.4 (100%) [MHþ (less Boc)].
HRMS calcd for C17H32N3O5, 358.2342; found, 358.2339.
4.2.14. Benzyl (2S)-2-amino-4-pentenoate hydrochloride 14
4.2.17. Benzyl (2S,5R,8R)-2-allyl-3,6-diaza-12-(tert-
To a solution of 13 (225 mg, 1.96 mmol) in benzyl alcohol (5 mL)
was added thionyl chloride (2 mL) and the resulting mixture was
allowed to stir for 16 h before addition of diethyl ether (30 mL) and
extraction with water (3 ꢂ 30 mL). The aqueous layer was concen-
trated, diluted with 2 M sodium bicarbonate (20 mL), and extracted
with CH2Cl2 (3 ꢂ 30 mL). The combined organic fractions were
dried and acidified with 1 M HCl/diethyl ether (2 mL) and evapo-
rated. The crude product was dissolved in a minimal volume of
butoxycarboxamido)-8-(9H-9-fluorenylmethyloxycarboxamido)-5-
([{2,2,5,7,8-pentamethyl-3,4-dihydro-2H-6-
chromenylsulfonamido}guanidino]propyl)-4,7-dioxododecanoate 17
The title compound was synthesized using the general peptide
coupling procedure (procedure B), from 16 (200 mg, 0.32 mmol) and
Fmoc-D-lysine(Boc)OH (151 mg, 0.32 mmol) to afford 17 (202 mg,
0.19 mmol, 59%) as a white solid. Mp 116 ꢀC. 1H NMR (CDCl3,
300 MHz)
d
: 7.72 (d, J ¼ 7.8 Hz, 2H, ArH10000 and ArH80000); 7.55 (d,
MeOH and precipitated with diethyl ether to yield the title
J ¼ 7.8 Hz, 2H, ArH40000 and ArH50000); 7.45 (m, 1H, NH); 7.29 (m, 11H,
ArH); 6.25 (m, 3H, NH); 5.64 (m, 1H, H20); 5.03 (m, 4H, ArCH2, H30);
4.59 (m, 1H, H2); 4.51 (m, 1H, H5); 4.29 (m, 1H, H8); 4.20 (m, 2H,
OCH2–H90000); 3.98 (m,1H, H90000); 3.18 (m, 2H, H300); 3.05 (m, 2H, H12);
2.55 (s, 3H, 7000-CH3); 2.52 (s, 3H, 5000-CH3); 2.50 (m, 4H, H4000 and H10);
2.03(s, 3H, 8000-CH3);1.95 (m, 4H, H100 and H9); 1.74 (m, 2H, H3000);1.67
(m, 4H, H200 and H10); 1.59 (m, 2H, H11); 1.41 (s, 6H, 2 ꢂ 2000-CH3). 13C
20
compound 14 (322 mg, 1.34 mmol, 68%) as a white solid. [a]
D
ꢁ40.6 (c. 0.1, H2O). Mp 186–191 ꢀC. 1H NMR (D2O, 300 MHz)
d: 7.28
(m, 5H, ArH); 5.51 (m, 1H, H4); 5.11 (m, 4H, H5 and ArCH2); 4.08 (t,
J ¼ 5.4 Hz, 1H, H2); 2.55 (m, 2H, H3). 13C NMR (D2O, 75 MHz)
d:
172.1, C1; 137.3, C4; 132.5, ArC10; 131.7, ArC40; 131.6, ArCH0; 131.4,
ArCH0; 124.4, C5; 71.3, ArCH2; 54.9, C2; 36.8, C3. Mass spectrum
(CIþ) m/z: 205 (25%) [MHþ]. HRMS calcd for C12H16NO2, 206.1181;
found, 206.1169.
NMR (CDCl3, 75 MHz) d
: 173.0, C1; 171.7, C4; 170.7, C7; 156.8, ArC6000;
156.2, NCO2; 153.5, NCO2; 144.0, CN3; 143.5, ArC8a0000 and ArC9a0000
;
141.1, ArC4a0000 and ArC4b0000; 135.3, ArC7000; 135.2, ArC5000; 134.8, C20;
128.4, ArC; 128.2, ArC; 128.1, ArC; 127.5, ArC; 126.9, ArCH20000 and
4.2.15. Benzyl (2S,5R)-2-allyl-3-aza-5-(9H-9-
fluorenylmethyloxycarboxamido)-4-oxo-8-[(2,2,5,7,8-pentamethyl-
3,4-dihydro-2H-6-chromenylsulfonyl)guanidino]octanoate 15
The title compound was synthesized using the general peptide
coupling procedure (procedure B), from 14 (155 mg, 0.65 mmol)
ArCH70000; 125.2, ArCH30000 and ArCH60000; 125.0, ArCH40000 and ArCH50000
;
124.0, ArC8000; 119.8, ArC10000 and ArC80000; 118.9, C30; 117.9, ArC4a000;
79.0, C(CH3)3; 73.5, C2000; 67.2, CH2–C90000; 67.0, ArCH2; 55.4, C5; 53.0,
C2; 52.0, C8; 46.7, C90000; 40.6, C300; 39.9, C12; 35.8, C10; 32.5, C3000; 31.8,
C200; 29.4, C9; 28.3, C(CH3)3; 26.6, C10; 25.3, 2000-CH3; 22.6, C11; 21.2,
C4000; 17.5, C7000–CH3; 15.2, C5000–CH3; 12.0, C8000–CH3. Mass spectrum
(ESIþ) m/z: 1078 (10%) [MHþ]; 288 (100%). HRMS calcd for
C58H76N7O11S, 1078.5324; found, 1078.5333.
and Fmoc-D-arginine(Pmc)OH (431 mg, 0.65 mmol) to afford 15
(280 mg, 0.33 mmol, 51%) as a white solid. Mp 78–74 ꢀC. 1H NMR
(CDCl3, 300 MHz)
d
: 7.69 (d, J ¼ 7.5 Hz, 2H, ArH100 and ArH800); 7.51
(d, J ¼ 7.5 Hz, 2H, ArH400 and ArH500); 7.28 (m, 9H, ArH); 6.33 (m,
3H, NH); 5.68 (m, 1H, H20); 5.61 (m, 1H, NH); 4.99 (m, 4H, ArCH2
and H30); 4.58 (m, 1H, H2); 4.24 (m, 3H, OCH2–H900and H5); 4.05
(dd, J ¼ 7.2, 7.2 Hz, 1H, H900); 3.20 (m, 2H, H8); 2.57 (s, 3H, 7000-CH3);
4.2.18. Benzyl (2S,5R,8R)-2-allyl-8-amino-3,6-diaza-12-(tert-
butoxycarboxamido)-5-([{2,2,5,7,8-pentamethyl-3,4-dihydro-2H-6-
chromenylsulfonamido}guanidino]propyl)-4,7-dioxododecanoate 18
The title compound was synthesized using the general N-Fmoc
deprotection procedure (procedure C), from 17 (202 mg,
0.19 mmol) to yield 18 (157 mg, 0.18 mmol, 93%) as a cream oil. 1H
2.54 (s, 3H, 5000-CH3); 2.52 (m, 4H, H3000 and H10); 2.05 (s, 3H, 8000
-
CH3); 1.85 (m, 2H, H6); 1.69 (dd, J ¼ 6.3, 6.3 Hz, H4000); 1.58 (m, 2H,
H7); 1.22 (s, 6H, 2 ꢂ 2000-CH3). 13C NMR (CDCl3, 75 MHz)
d: 172.2,
C1; 171.4, C4; 156.4, ArC6000; 156.3, NCO2; 153.5, ArC8a000; 143.7,
CN3; 143.6, ArC8a00 and ArC9a00; 141.0, ArC4a00 and ArC4b00; 135.3,
ArC7000; 135.1, ArC5000; 134.8, C20; 128.5, ArC; 128.4, ArC; 128.3, ArC;
128.2, ArC; 127.6, ArCH200 and ArCH700; 127.0, ArCH300 and ArCH600;
125.1, ArCH400 and ArCH500; 124.0, ArC8000; 119.8, ArCH100 and
ArCH800; 119.0, C30; 117.9, ArC4a000; 73.5, C2000; 67.0, ArCH2; 66.7,
CH2–C900; 54.7, C5; 53.8; 53.4, C2; 46.8, C900; 39.0, C8; 35.7, C10;
NMR (CDCl3, 300 MHz)
d
: 8.00 (d, J ¼ 7.2 Hz, 1H, NH); 7.58 (d,
J ¼ 7.2 Hz,1H, NH); 7.32 (m, 5H, ArH); 6.44 (m, 3H, NH); 5.63 (m,1H,
H20); 5.09 (m, 4H, ArCH2 and H30); 4.61 (m, 2H, H2 and H5); 3.36
(m, 1H, H8); 3.22 (m, 2H, H300); 3.05 (m, 2H, H12); 2.62 (m, 2H,
H4000); 2.58 (s, 3H, 7000-CH3); 2.56 (s, 3H, 5000-CH3); 2.47 (m, 2H, H10);
2.15 (m, 2H, H100); 2.10 (s, 3H, 8000-CH3); 1.89 (m, 2H, H9); 1.80 (t,
J ¼ 6.3 Hz, H3000); 1.72 (m, 4H, H200 and H10); 1.58 (m, 4H, H11 and
NH2); 1.42 (s, 9H, C(CH3)3); 1.31 (s, 6H, 2 ꢂ 2000-CH3). 13C NMR
32.6, C4000; 29.8, C6; 26.6, 200-CH3; 22.4, C7; 21.3, C3000; 18.5, C7000
–
CH3; 17.5, C5000–CH3; 12.0, C8000–CH3. Mass spectrum (ESIþ) m/z:
850 (100%) [MHþ]. HRMS calcd for C47H56N5O8S, 850.3850; found,
850.3855.
(CDCl3, 75 MHz)
NCO2; 153.4, ArC8000; 135.2, ArC7000; 135.1, ArC5000; 133.3, ArC; 132.2,
d
; 175.7, C1; 171.6, C4; 171.3, C7; 156.2, ArC6000 and

T.P. Boyle et al. / European Journal of Medicinal Chemistry 44 (2009) 1001–1009
1007
C20; 128.4, ArC; 128.2, ArC; 128.0, ArC; 123.8, ArC8000; 118.9, C30;
0.028 mmol) to yield 12a (13 mg, 0.017 mmol, 61%) as a light yellow
solid. Mp 194–202 ꢀC. 1H NMR (CD3OD, 300 MHz)
: 8.53 (s, 1H,
117.8, ArC4a000; 78.9, C(CH3)3; 73.5, C2000; 66.9, ArCH2; 54.8, C8; 53.3,
d
C2; 51.8, C5; 40.3, C300; 40.0, C12; 35.9, C10; 34.5, C200; 32.6, C4000
;
ArH100000); 8.26 (m, 3H, exchanging NH’s); 8.06 (d, J ¼ 8.1 Hz, 2H,
ArH2000 and ArH6000); 7.64 (d, J ¼ 9.0 Hz, 2H, ArH3000 and ArH5000); 7.38
(m, 8H, ArH0000); 5.68 (m, 1H, H20); 5.02 (m, 2H, H30); 4.67 (m, 1H,
H8); 4.45 (m, 2H, H2 and H5); 3.69 (s, 3H, OCH3); 2.93 (m, 4H, H400
and ArCH2); 2.44 (m, 2H, H10); 2.00 (s, 3H, H11); 1.69 (m, 4H, H100
29.6, C9; 28.3, C(CH3)3; 26.6, 2000-CH3; 25.4, C10; 22.6, C11; 21.3,
C4000; 18.4, 7000-CH3; 17.4, 5000-CH3; 15.3, C100; 12.0, 8000-CH3. Mass
spectrum (ESIþ) m/z: 856 (100%) [MHþ]. HRMS calcd for
C43H66N7O9S, 856.4643; found, 856.4655.
and H300); 1.50 (m, 2H, H200). 13C NMR (CD3OD, 75 MHz)
d: 174.4, C7;
4.2.19. Methyl (2S,5S,8S)-2-allyl-8-(4-[9-anthracenyl]benzyl)-
3,6,9-triaza-5-(4-[tert-butoxycarboxamido]butyl)-4,7,10-
trioxoundecanoate 11a
The title compound was synthesized using the general peptide
coupling procedure (procedure B), from 10 (35 mg, 0.098 mmol) and
7a (20 mg, 0.052 mmol) to afford the title compound 11a (22 mg,
0.030 mmol, 59%) as a cream solid. Mp 128 ꢀC. 1H NMR (CDCl3,
173.7, C1; 173.6, C4; 173.5, C10; 138.7, ArC4000; 137.8, ArC1000; 137.7,
ArC90000; 134.1, C20; 132.9, ArCH2000 and ArCH6000; 132.4, ArC4a0000 and
ArC10a0000
; ;
131.5, ArC8a0000 and ArC9a0000 130.4, ArCH40000 and
ArCH50000; 130.1, ArCH3000 and ArCH5000; 129.5, ArCH100000; 127.7,
ArCH80000 and ArCH10000 126.5, ArCH20000 and ArCH70000
126.2,
;
;
ArCH30000 and ArCH60000; 118.8, C30; 56.7, C5; 53.8, OCH3; 53.6, C8;
52.7, C2; 40.5, C400; 38.6, ArCH2; 36.6, C10; 32.8, C100; 28.1, C300; 23.4,
C11; 22.4, C200. Mass spectrum (ESIþ) m/z: 623 (100%) [Mþ]. HRMS
calcd for C37H43N4O5, 623.3233; found, 623.3215.
300 MHz)
d
: 8.49 (s,1H, ArH100000); 8.04 (d, J ¼ 8.7 Hz, 2H, ArH2000 and
ArH6000); 7.64 (d, J ¼ 8.4 Hz, 2H, ArH3000 and ArH5000); 7.38 (m, 8H,
ArH0000); 6.72 (d, J ¼ 7.2 Hz, 1H, NH); 6.48 (d, J ¼ 7.2 Hz, 1H, NH); 6.37
(br s, 1H, NH); 5.59 (m, 1H, H20); 5.06 (m, 2H, H30); 4.82 (m, 1H, H8);
4.60 (dd, J ¼ 6.9,14.1 Hz,1H, H2); 4.45 (m,1H, H5); 3.73 (s, 3H, OCH3);
3.24 (m, 2H, ArCH2); 3.08 (m, 2H, H400); 2.47 (m, 2H, H10); 2.07 (s, 3H,
H11); 1.93 (m, 2H, H100); 1.68 (m, 2H, H300); 1.50 (m, 2H, H200); 1.44 (s,
4.2.22. Methyl (2S,5S,8S)-2-allyl-5-(4-aminobutyl)-3,6,9-triaza-5-
butylamino-4,7,10-trioxo-8-(4-[9-
[phenanthrenyl]benzyl)undecanoate hydrochloride 12b
The title compound was synthesized using the general N-Boc
deprotection procedure (procedure A), from 11b (24 mg,
0.033 mmol) to yield 12b (15 mg, 0.023 mmol, 69%) as a light
9H, C(CH3)3). 13C NMR (CDCl3, 75 MHz)
171.1, C10; 170.4, C7; 156.2, NCOOC; 137.3, ArC900; 136.5, ArC4000
d: 171.9, OCH3; 171.3, C4;
;
135.7, ArC1000; 131.9, ArC8a0000; 131.4, ArC9a0000; 131.3, C20; 130.1,
ArCH20000 and ArCH70000; 129.2, ArCH40000 and ArCH60000; 129.1, ArCH2000
and ArCH6000; 128.3, ArCH3000 and ArCH5000; 126.8, ArCH100000; 126.5,
ArCH4a0000 and ArC10a0000; 125.3, ArCH80000 and ArCH10000; 123.4,
ArCH30000 and ArCH60000; 119.2, C30; 79.0, C(CH3)3; 54.4, C8; 52.9,
OCH3; 52.4, C2; 51.8, C5; 40.0, C400; 38.2, ArCH2; 36.1, C10; 32.2, C100;
29.7, C300; 29.3, C200; 28.4, C(CH3)3; 23.1, C11. Mass spectrum (ESIþ)
m/z: 745 (50%) [MNaþ], 723 (20%) [MHþ], 623 (100%) [M ꢁ Boc].
HRMS calcd for C44H49N4O7, 745.3601; found, 745.3590.
yellow solid. Mp 198 ꢀC. 1H NMR (CD3OD, 300 MHz)
d: 8.84 (d,
J ¼ 7.8 Hz, 1H, ArH40000); 8.78 (d, J ¼ 8.1 Hz, 1H, ArH50000); 8.30 (d,
J ¼ 7.2 Hz, 1H, exchanging NH); 8.15 (d, J ¼ 8.1 Hz, 1H, exchanging
NH); 7.90 (m, 2H, ArH10000 and ArH100000); 7.60 (m, 5H, ArH70000
,
ArH60000, ArH50000, ArH20000 and ArH10000); 7.45 (d, J ¼ 8.4 Hz, 2H, ArH2000
and ArH6000); 7.40 (d, J ¼ 8.7 Hz, 2H, ArH3000 and ArH5000); 5.68 (m,
1H, H20); 4.98 (m, 2H, H30); 4.61 (m, 1H, H8); 4.40 (m, 2H, H2 and
H5); 3.67 (s, 3H, OCH3); 2.93 (t, J ¼ 7.5 Hz, 2H, H400); 2.40 (m, 2H,
H10); 1.99 (s, 3H, H11); 1.83 (m, 4H, H100 and ArCH2); 1.69 (m, 2H,
H300); 1.49 (m, 2H, H200). 13C NMR (CD3OD, 75 MHz)
173.6, C1; 173.5, C4; 173.4, C10; 140.7, ArC4000; 139.8, ArC1000; 137.5,
ArC90000; 134.0, C20; 133.0, ArC8a00’’; 132.3, ArC4b0000; 132.0, ArC4a0000
d: 173.7, C7;
4.2.20. Methyl (2S,5S,8S)-2-allyl-3,6,9-triaza-5-(4-[tert-
butoxycarboxamido]butyl)-4,7,10-trioxo-8-(4-[9-
;
phenanthrenyl]benzyl)undecanoate 11b
131.3, ArCH2000 and ArCH6000; 131.2, ArC10a0000; 130.3, ArCH3000 and
ArCH5000; 129.7, ArCH10000; 128.5, ArCH70000; 128.0, ArCH60000; 127.9,
ArCH10000; 127.8, ArCH50000; 127.7, ArCH100000; 127.6, ArCH20000; 124.2,
ArC40000; 124.1, ArCH30000; 118.8, C30; 56.7, C5; 53.7, OCH3; 53.6, C8;
52.7, C2; 40.5, C400; 38.5, ArCH2; 36.5, C10; 32.8, C100; 28.0, C300; 23.3,
C11; 22.4, C200. Mass spectrum (ESIþ) m/z: 623 (100%) [MHþ]. HRMS
calcd for C37H43N4O5, 623.3233; found, 623.3262.
The title compound was synthesized using the general peptide
coupling procedure (procedure B), from 10 (28 mg, 0.078 mmol) and
7b (15 mg, 0.039 mmol) to afford 11b (14 mg, 0.019 mmol, 50%) as
a cream solid. Mp 132–134 ꢀC. 1H NMR (CDCl3, 300 MHz)
d: 8.76 (d,
J ¼ 8.1 Hz, 1H, ArH40000); 8.71 (d, J ¼ 8.4 Hz, 1H, ArH30000); 7.88 (m, 2H,
ArH10000 and ArH100000); 7.60 (m, 5H, ArH70000, ArH60000, ArH50000, ArH20000
and ArH10000); 7.45 (d, J ¼ 7.8 Hz, 2H, ArH2000 and ArH6000); 7.33 (d,
J ¼ 7.8 Hz, 2H, ArH3000 and ArH5000); 7.10 (d, J ¼ 8.4 Hz, 1H, NH); 6.94
(d, J ¼ 8.7 Hz, 1H, NH); 6.74 (d, J ¼ 8.1 Hz, 1H, NH); 5.61 (m, 1H, H20);
5.06 (m, 2H, H30); 4.90 (m, 1H, H8); 4.57 (m, 2H, H2 and H5); 3.72 (s,
3H, OCH3); 3.20 (m, 2H, ArCH2); 3.08 (m, 2H, H400); 2.47 (m, 2H, H10);
2.04 (s, 3H, H11); 1.92 (m, 2H, H100); 1.68 (m, 2H, H300); 1.48 (m, 2H,
4.2.23. Benzyl (2S,5R,8R,11S)-2-allyl-11-(4-[9-anthracenyl]benzyl)-
3,6,9,12-tetraaza-8-(4-[tert-butoxycarboxamido]butyl)-5-
([{2,2,5,7,8-pentamethyl-3,4-dihydro-2H-6-
chromenylsulfonyl}guanidino]propyl)-4,7,10,13-
tetraoxotetradecanoate 19a
H200); 1.42 (s, 9H, C(CH3)3). 13C NMR (CDCl3, 75 MHz)
d
: 171.9, OCH3;
The title compound was synthesized using the general peptide
coupling procedure (procedure B), from 18 (40 mg, 0.045 mmol)
and 7a (17 mg, 0.045 mmol) to afford 19a (20 mg, 0.016 mmol, 36%)
171.4, C4; 171.0, C10; 170.4, C7; 156.1, NCOOC; 139.4, ArC4000; 138.3,
ArC1000; 135.6, ArC90000; 132.0, ArC4b0000; 131.5, ArC8a0000; 131.0,
ArC4a0000; 130.6, ArC10a0000; 130.2, ArCH2000 and ArCH6000; 129.9,
ArCH3000 and ArCH5000; 129.2, ArCH10000; 128.6, ArCH30000; 127.5,
ArCH60000; 126.8, ArCH10000; 126.6, ArCH50000; 126.5, ArCH100000; 122.8,
ArCH20000; 122.5, ArCH40000; 119.3, ArCH30000; 79.1, C(CH3)3; 54.4, C8;
52.9, OCH3; 52.4, C2; 51.8, C5; 40.0, C400; 38.0, ArCH2; 36.1, C10; 32.1,
C100; 29.7, C300; 29.3, C200; 28.4, C(CH3)3; 23.1, C11. Mass spectrum
(ESIþ) m/z: 745 (60%) [MNaþ], 723 (20%) [MHþ], 623 (100%)
[M ꢁ Boc]. HRMS calcd for C42H51N4O7, 723.3758; found, 723.3767.
as a white solid. Mp 108–110 ꢀC. 1H NMR (CDCl3, 300 MHz)
d: 8.48
(s, 1H, ArH1000000); 8.03 (m, 2H, ArH); 7.58 (m, 2H, ArH); 7.44 (m, 2H,
ArH); 7.30 (m, 11H, ArH); 6.82 (br s, 1H, NH); 6.36 (br s, 2H, NH2);
5.77 (m, 1H, H20); 5.12 (m, 4H, H30 and PhCH2O); 4.85 (m, 1H, H11);
4.59 (m, 1H, H2); 4.44 (m, 1H, H5); 4.31 (m, 1H, H8); 3.19 (m, 2H, 11-
CH2); 2.95 (m, 4H, H40000 and H300); 2.56 (s, 3H, 7000-CH3); 2.54 (s, 3H,
5
000-CH3); 2.52 (m, 4H, H4000 and H10); 2.06 (s, 3H, 8000-CH3); 1.97 (m,
2H, H30000); 1.94 (s, 3H, H14); 1.74 (m, 4H, H100 and H10000); 1.71 (m,
2H, H3000); 1.62 (m, 2H, H200); 1.38 (m, 2H, H20000); 1.36 (s, 9H,
4.2.21. Methyl (2S,5S,8S)-2-allyl-5-(4-aminobutyl)-8-(4-[9-
anthracenyl]benzyl)-3,6,9-triaza-5-butylamino-4,7,10-
trioxoundecanoate hydrochloride 12a
The title compound was synthesized using the general N-Boc
deprotection procedure (procedure A), from 11a (20 mg,
C(CH3)3); 1.23 (s, 6H, 2 ꢂ 2000-CH3). 13C NMR (CDCl3, 75 MHz)
d
:
;
173.0, C13; 172.2, C1; 172.0, C4; 171.8, C7; 170.6, C10; 156.3, ArC6000
156.2, NCO2; 153.6, ArC8a000; 142.8, CN3; 140.0, ArC; 139.9, ArC;
136.5, ArC7000; 135.4, ArC5000; 133.2, ArC; 132.5, C20; 131.5, ArC; 131.3,
2 ꢂ ArCH; 130.1, ArCH; 129.2, ArCH; 128.1, ArCH; 127.9, ArCH; 127.6,

1008
T.P. Boyle et al. / European Journal of Medicinal Chemistry 44 (2009) 1001–1009
ArCH; 127.5, ArCH; 126.6, ArC; 125.3, ArCH; 125.1, ArCH; 124.1, ArC;
123.5, ArC8000; 119.0, C30; 118.0, ArC4a000; 79.0, C(CH3)3; 73.7, C2000
54.5, C5; 53.1, C8; 52.2, C2; 41.2, C300; 40.0, C40000; 37.2,11-CH2; 35.9, C10;
34.0, C4000; 32.7, C20000; 31.1, C20; 29.4, C10000; 28.4, C(CH3)3; 26.7, 2000-CH3;
22.9, C30000; 22.6, C14; 21.4, C3000; 18.5, 7000-CH3; 17.5, 5000-CH3; 12.1, 8000-
CH3. Mass spectrum (ESIþ) m/z: 1101 (30%) [MHþ]; 288 (100%). HRMS
calcd for C57H81N8O12S, 1101.5695; found, 1101.5731.
;
67.0, CH2-ester; 57.7, C11; 54.6, C2; 53.2, C5; 52.3, C8; 40.7, C300;
39.8, C40000; 37.5, C10; 36.0, C200; 32.7, C4000; 29.7, C10000; 29.3, 11-CH2;
28.4, C(CH3)3; 27.1, C100; 26.7, 2000-CH3; 25.3, C20000; 22.9, C14; 22.8,
C30000; 21.4, C3000; 18.6, 7000-CH3; 17.5, 5000-CH3; 12.1, 8000-CH3. Mass
spectrum (ESIþ) m/z: 1221 (10%) [MHþ]; 282 (100%). HRMS calcd
for C68H85N8O11S, 1221.6059; found, 1221.6089.
4.2.26. Benzyl (2S,5R,8R,11S)-2-allyl-8-(4-aminobutyl)-11-(4-[9-
anthracenyl]benzyl)-3,6,9,12-tetraaza-5-(3-guanidinopropyl)-
4,7,10,13-tetraoxotetradecanoate 20a
4.2.24. Benzyl (2S,5R,8R,11S)-2-allyl-3,6,9,12-tetraaza-8-(4-[tert-
butoxycarboxamido]butyl)-5-([{2,2,5,7,8-pentamethyl-3,4-dihydro-
2H-6-chromenylsulfonyl}guanidino]propyl)-4,7,10,13-tetraoxo-11-
(4-[9-phenanthrenyl]benzyl)tetradecanoate 19b
The title compound was synthesized using the general N-Boc
deprotection procedure (procedure A), from 19a (20 mg,
0.016 mmol) to yield 20a (13 mg, 0.014 mmol, 88%) as a white solid.
Mp 218–220 ꢀC. 1H NMR (CD3OD, 300 MHz)
d: 7.68 (m, 17H, ArH);
The title compound was synthesized using the general peptide
coupling procedure (procedure B), from 18 (38 mg, 0.044 mmol)
and 7b (16 mg, 0.042 mmol) to afford 19b (41 mg, 0.034 mmol,
5.77 (m, 1H, H20); 5.15 (m, 4H, H30 and PhCH2O); 4.82 (m, 1H, H11);
4.42 (m, 1H, H2); 4.25 (m, 1H, H5); 4.07 (m, 1H, H8); 3.18 (m, 2H, 11-
CH2); 2.88 (m, 4H, H40000 and H300); 2.55 (m, 2H, H10); 1.95 (s, 3H,
H14); 1.85 (m, 2H, H100); 1.65 (m, 2H, H1000); 1.53 (m, 2H, H200); 0.94
80%) as a white solid. Mp 108 ꢀC. 1H NMR (CDCl3, 300 MHz)
d: 8.72
(m, 2H, ArH); 7.58 (m, 16H, ArH); 6.40 (br s, 2H, NH); 5.71 (m, 1H,
H20); 5.13 (m, 2H, PhCH2O); 5.03 (m, 2H, H30); 4.83 (m, 1H, H11);
4.60 (m, 1H, H2); 4.59 (m, 1H, H5); 4.29 (m, 1H, H8); 3.12 (m, 2H, 11-
CH2); 2.94 (m, 4H, H40000 and H300); 2.56 (s, 3H, 7000-CH3); 2.54 (s, 3H,
(m, 2H, H2000). 13C NMR (CD3OD, 75 MHz)
d: 175.2, C13; 174.4, C1;
174.2, C4; 174.1, C10; 172.5, C7; 158.6, CN3; 140.0, ArC; 139.9, ArC;
138.1, ArC; 137.4, ArC; 134.3, C20; 133.2, ArC; 131.5, ArC; 131.3, ArCH;
130.1, ArCH; 129.2, ArC; 128.1, ArC; 127.9, ArCH; 127.6, ArCH; 127.5,
ArCH; 126.6, ArCH; 125.9, ArCH; 125.8, ArCH; 125.6, ArCH; 124.2,
ArCH; 119.1, C30; 68.1, CH2-ester; 57.9, C11; 55.3, C8; 54.7, C5; 54.2,
5
000-CH3); 2.53 (m, 4H, H4000 and H10); 2.07 (s, 3H, 8000-CH3); 1.91 (s,
3H, H14); 1.82 (m, 4H, H100 and H10000); 1.72 (t, J ¼ 6.6 Hz, 2H, H3000);
1.62 (m, 4H, H200 and H30000); 1.39 (m, 2H, H20000); 1.34 (s, 9H,
C2; 42.1, C300; 40.3, C4000; 38.1, 11-CH2; 36.7, C10; 31.4, C100: 29.4, C1000
;
C(CH3)3); 1.23 (s, 6H, 2 ꢂ 2000-CH3). 13C NMR (CDCl3, 75 MHz)
d
:
27.3, C14; 26.5, C200; 23.6, C3000; 22.5, C2000. Mass spectrum (ESIþ) m/
z: 855 (50%) [M2þ]; 428 (100%). HRMS calcd for C49H59N8O6,
855.4558; found, 855.4539.
173.0, C13; 172.4, C1; 172.0, 171.9, C10, C4; 171.7, C7; 156.3, ArC6000
;
156.1, NCO2; 153.6, CN3; 139.3, ArC8a000; 138.2, ArC; 135.3, ArC and
ArC7000; 134.7, ArC5000; 133.2, C20; 132.7, ArC; 132.5, ArC; 131.4, ArC;
130.8, ArC; 130.6, ArCH; 130.2, ArCH; 129.8, ArC; 129.2, ArC; 128.6,
ArCH; 128.5, ArCH; 128.3, ArCH; 128.1, ArCH; 127.4, ArCH; 126.8,
ArCH; 126.6, 2 ꢂ ArCH; 126.4, ArCH; 126.2, ArCH; 124.0, ArCH;
122.9, ArC8000; 122.4, ArCH; 118.9, C30; 118.0, ArC4a000; 78.9, C(CH3)3;
73.6, C200000; 66.9, CH2-ester; 55.4, C11; 54.5, C8; 53.2, C5; 52.2, C2;
40.6, C3 ; 39.8, C40000; 37.6, 11-CH2; 36.0, C4000; 32.6, H10; 30.6, H100;
29.6, C10000; 29.4, H14; 28.3, C(CH3)3; 26.7, 2000-CH3; 25.4, C200; 22.9,
4.2.27. Benzyl (2S,5R,8R,11S)-2-allyl-8-(4-aminobutyl)-3,6,9,12-
tetraaza-5-(3-guanidinopropyl)-4,7,10,13-tetraoxo-11-(4-[9-
phenanthrenyl]benzyl)tetradecanoate 20b
The title compound was synthesized using the general N-Boc
deprotection procedure (procedure A), from 19b (42 mg,
0.034 mmol) to yield 20b (25 mg, 0.027 mmol, 79%) as a white solid.
Mp 215–220 ꢀC. 1H NMR (CD3OD, 300 MHz)
d: 8.82 (m, 2H, ArH);
C30000; 22.8, C20000; 21.5, 7000-CH3; 18.6, 5000-CH3; 17.5, C3000; 12.1, 8000
-
7.60 (m, 16H, ArH); 5.81 (m, 1H, H20); 5.15 (m, 4H, PhCH2O and H30);
4.58 (m,1H, H11); 4.43 (m,1H, H2); 4.35 (dd, J ¼ 4.8, 9.0 Hz,1H, H5);
4.17 (dd, J ¼ 4.8, 9.6 Hz,1H, H8); 3.17 (m, 4H, H40000 and H300); 2.72 (m,
2H, 11-ArCH2); 2.59 (m, 1H, H10); 1.96 (s, 3H, H14); 1.80 (m, 4H, H100
and H1000); 1.65 (m, 2H, H3000); 1.51 (m, 2H, H200); 1.22 (m, 2H, H2000).
CH3. Mass spectrum (ESIþ) m/z: 1221 (100%) [MHþ]. HRMS calcd
for C68H85N8O11S, 1221.6059; found, 1221.6045.
4.2.25. Benzyl (2S,5R,8R,11S)-2-allyl-11-(4-allyloxybenzyl)-
3,6,9,12-tetraaza-8-(4-[tert-butoxycarboxamido]butyl)-5-
([{2,2,5,7,8-pentamethyl-3,4-dihydro-2H-6-
chromenylsulfonamido}guanidino]propyl)-4,7,10,13-
tetraoxotetradecanoate 19c
13C NMR (CD3OD, 75 MHz)
d: 175.2, C13; 174.4, C1; 174.2, C4; 174.1,
C10; 172.5, C7; 158.6, CN3; 140.7, ArC; 139.6, ArC; 137.4, ArC; 137.2,
ArC; 134.3, C20; 132.9, ArC; 132.1, ArC; 131.3, ArCH; 130.5, ArCH;
129.7, ArC; 129.6, ArC; 129.4, 2 ꢂ ArCH; 128.5, ArCH; 128.1, ArCH;
127.9, ArCH; 127.8, ArCH; 127.6, ArCH; 124.2, ArCH; 123.7, ArCH;
12.4, ArCH; 122.1, ArCH; 121.8, ArCH; 119.0, C30; 68.0, CH2-ester; 57.7,
C11; 55.2, C8; 54.7, C5; 54.0, C2; 42.0, C300; 40.1, C4000; 38.1, 11-CH2;
36.6, C10; 31.3, C100; 29.6, C1000; 27.8, C14; 26.4, C200; 23.8, C3000; 22.6,
C2000. Mass spectrum (ESIþ) m/z: 855 (30%) [M2þ], 428 (100%). HRMS
calcd for C49H59N8O6, 855.4558; found, 855.4528.
The title compound was synthesized using the general peptide
coupling procedure (procedure B), from N-acetyl-O-allyl-L-tyrosine
[17] (60 mg, 0.069 mmol) and 16 (18 mg, 0.068 mmol) to afford 19c
(65 mg, 0.058 mmol, 85%) as a white solid. Mp 94–102 ꢀC. 1H NMR
(CDCl3, 300 MHz)d: 7.76 (br s,1H, NH); 7.54 (br s,1H, NH); 7.41 (br s,1H,
NH); 7.31 (m, 5H, ArH); 7.09 (d, J ¼ 8.7 Hz, 2H, ArH200000 and ArH600000);
6.77 (d, J ¼ 8.4 Hz, 2H, ArH300000 and ArH500000); 6.39 (br s, 3H, 3 ꢂ NH);
6.02 (m, 1H, H2000000); 5.70 (m, 1H, H20); 5.39 (dd, J ¼ 1.5, 17.1 Hz, 1H,
H3a000000); 5.26 (dd, J ¼ 1.2, 10.5 Hz, 1H, H3b000000); 5.06 (m, 2H, H30); 5.05
(m, 2H, PhCH2O); 4.65 (dd, J ¼ 6.9, 13.5 Hz, 1H, H11); 4.57 (dd, J ¼ 8.1,
13.5 Hz, 1H, H2); 4.50 (m, 1H, H5); 4.45 (d, J ¼ 5.4 Hz, 2H, H1000000); 4.41
(m,1H, H8); 4.14 (br s,1H, NH); 3.15 (m, 2H, H300); 2.92(m, 4H, H40000 and
11-CH2); 2.58 (m, 4H, H10 and H4000); 2.53 (s, 3H, 7000-CH3); 2.52 (s, 3H,
5000-CH3); 2.08 (s, 3H, H14); 1.94 (m, 4H, H100 and H10000); 1.84 (s, 3H, 8000-
CH3); 1.78 (m, 2H, H3000); 1.69 (m, 4H, H200 and H20000); 1.55 (m, 2H,
H30000); 1.40 (s, 9H, C(CH3)3); 1.30 (s, 6H, 2 ꢂ 2000-CH3). 13C NMR (CDCl3,
4.2.28. Benzyl (2S,5R,8R,11S)-2-allyl-11-(4-allyloxybenzyl)-8-(4-
aminobutyl)-3,6,9,12-tetraaza-5-(3-[guanidino]propyl)-4,7,10,13-
tetraoxotetradecanoate hydrochloride 20c
The title compound was synthesized using the general N-Boc
deprotection procedure (procedure A), from 19c (65 mg,
0.059 mmol) to yield 20c (39 mg, 0.048 mmol, 82%) as a cream
solid. Mp 108 ꢀC. 1H NMR (CDCl3, 300 MHz)
d: 7.35 (m, 5H, ArH);
7.16 (d, J ¼ 8.7 Hz, 2H, ArH2000 and ArH6000); 6.87 (d, J ¼ 8.7 Hz, 2H,
ArH3000 and ArH5000); 6.02 (m, 1H, H2000); 5.78 (m, 1H, H20); 5.39 (dd,
J ¼ 1.8, 17.1 Hz, 1H, H3a00000); 5.24 (dd, J ¼ 1.8, 10.5 Hz, 1H, H3b00000);
5.10 (m, 4H, H30 and PhCH2O); 4.52 (m, 2H, H100000); 4.39 (m, 2H, H13
and H2); 4.24 (dd, J ¼ 4.8, 9.0 Hz, 1H, H5); 3.98 (dd, J ¼ 3.9, 9.9 Hz,
1H, H8); 3.16 (m, 2H, H300); 2.94 (m, 2H, 11-CH2); 2.84 (m, 2H, H4000);
2.55 (m, 2H, H10); 1.94 (s, 3H, H14); 1.87 (m, 2H, H100); 1.73 (m, 2H,
H1000); 1.54 (m, 4H, H200 and H2000); 1.03 (m, 2H, H3000). 13C NMR
75 MHz) d: 172.2, C1; 172.0, C4; 171.6, C7; 157.5, C10; 156.2, C13 and
NCO2; 156.1, ArC6000; 153.5, ArC8a000; 135.3, ArC7000; 134.7, ArC5000; 133.1,
C2000000; 132.5, C20; 130.5, ArC400000,130.2, ArCH200000 and ArCH600000; 128.5,
ArC100000; 128.4, ArCH; 128.3, ArCH; 128.2, ArCH; 128.1, ArC; 124.0,
ArC8000; 118.8, C30; 118.0, C3000000; 117.6, ArC4a000; 114.7, ArCH300000 and
ArCH500000; 78.9, C(CH3)3; 73.7, C2000; 68.7, C1000000; 66.9, ArCH2; 55.6, C11;

T.P. Boyle et al. / European Journal of Medicinal Chemistry 44 (2009) 1001–1009
1009
(CDCl3, 75 MHz)
d
: 175.4, C1; 174.4, C4; 174.2, C7; 172.5, C10; 159.0,
(Development Grant 404528) for their support, and Drs Susan Cox
and David Rhodes for their support in the initial development of
this project.
C13; 158.5, NCO; 137.2, ArC40000; 134.9, C200000; 134.3, C20; 131.5, ArC;
130.0, ArCH20000 and ArCH60000; 129.6, ArCH; 129.4, ArCH; 129.4,
ArCH; 128.5, ArC01000000; 119.0, C30; 117.6, C300000; 115.9, ArCH3000 and
ArCH5000; 69.8, C1 ; 67.9, CH2-ester; 57.8, C11; 55.3, C5; 54.8, C8;
References
54.0, C2; 41.9, C300; 40.3, C4000; 37.4, 11-CH2; 36.5, C10; 31.2, C1000
;
29.5, C200; 28.0, C2000; 26.5, C14; 23.8, C3000; 22.5, C100. Mass spectrum
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We thank Amrad and Avexa Limited, the University of Wol-
longong, the Australian Research Council (PhD scholarship to
TPB), and the National Health and Medical Research Council