Journal of Medicinal Chemistry
Brief Article
raphy (gradient 0−90% EtOAc/hexanes) to give 35 (2.41 g, 63%). 1H
NMR (500 MHz, DMSO-d6) δ 8.34−8.21 (m, 1H), 8.10−7.79 (m,
1H), 7.38−7.28 (m, 1H), 7.22 (br d, J = 7.3 Hz, 1H), 7.17−7.01 (m,
7H), 6.96−6.83 (m, 1H), 6.62−6.38 (m, 1H), 4.97 (br s, 1H), 4.81 (br
s, 1H), 4.59−4.38 (m, 2H), 4.32−4.15 (m, 1H), 3.97−3.76 (m, 1H),
3.30−3.22 (m, 4H), 3.19−2.95 (m, 2H), 2.81−2.57 (m, 5H), 1.86 (br
s, 4H), 1.75−1.55 (m, 4H), 1.52−1.32 (m, 18H). MS(ESI+) m/z 749.5
(M + H)+.
(S)-2-((S)-3,3-Dimethyl-2-((S)-2-(methylamino)-
propanamido)butanoyl)-7-((3R,5S)-1-((S)-3,3-dimethyl-2-((S)-2-
(methylamino)propanamido)butanoyl)-5-(((R)-1,2,3,4-tetrahy-
dronaphthalen-1-yl)carbamoyl)pyrrolidin-3-yl)-N-((R)-1,2,3,4-
tetrahydronaphthalen-1-yl)-1,2,3,4-tetrahydroisoquinoline-3-
carboxamide, 2 HCl (17). Following the general procedure for N-
Boc deprotection, 35 (1.10 g, 1.47 mmol) was converted to a crude oil.
Following the general procedure for amide coupling, the crude oil and
N-Boc-L-tert-leucine (644 mg, 2.78 mmol) were converted to Boc-
precursor I (945 mg, 66%) after purification using flash column
chromatography (gradient 0−100% EtOAc/hexanes). MS(ESI+) m/z
975.6 (M + H)+.
Author Contributions
All authors have given approval to the final version of the
manuscript.
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
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We thank Robert Schmidt, Chunlei Wang, and Yingru Zhang
for purification and analytical support; Gregory Locke for
completion of cIAP1 assays, and Henry Shen for caspase-3
rescue assays; Robin Moore, Georgia Cornelius, and Celia
D’Arienzo for bioanalytical support; and Anuradha Gupta,
Thirupala Reddy, Arun Akunuri, Manivel Pitchai, Rick
Rampulla, and Arvind Mathur for contributions to the synthesis
of 17.
ABBREVIATIONS USED
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Following the general procedure for N-Boc deprotection, Boc-
precursor I (1.05 g, 1.08 mmol) was converted to a crude bis-amine.
Following the general procedure for amide coupling, the crude bis-
amine and Boc-N-methyl-L-alanine (450 mg, 2.22 mmol) were
converted to Boc-precursor II (0.99 g, 82%) after purification using
flash column chromatography (gradient 0−80% EtOAc/CH2Cl2).
MS(ESI+) m/z 1146.2 (M + H)+.
IAP, inhibitor of apoptosis protein; BIR, baculovirus inhibitor
of apoptosis repeat; XIAP, X-linked inhibitor of apoptosis
protein; cIAP, cellular inhibitor of apoptosis; TNF, tumor
necrosis factor; RIP, receptor-interacting protein; NIK, NF-κB-
inducing kinase; Smac, second mitrochondria-derived activator
of caspases; DIABLO, direct IAP-binding protein with low pI;
THIQ, tetrahydroisoquinoline; EDC, N-(3-(dimethylamino)-
propyl)-N′-ethylcarbodiimide hydrochloride; HOAt, 1-hy-
droxy-7-azabenzotriazole; NMM, N-methylmorpholine; DMF,
dimethyl formamide; rt, room temperature; THF, tetrahy-
drofuran; TFA, trifluoroacetic acid; DCE, dichloroethane; Boc,
tert-butyloxycarbonyl; NaHMDS, sodium bis(trimethylsilyl)-
amide; PhNTf2, N-phenyl-bis(trifluoromethanesulfonimide);
DMSO, dimethyl sulfoxide; N-Boc-L-tert-leucine, (S)-2-((tert-
butoxycarbonyl)amino)-3,3-dimethylbutanoic acid; Boc-N-
methyl-L-alanine, (S)-2-((tert-butoxycarbonyl)(methyl)amino)-
propanoic acid; DMAP, 4-(dimethylamino)pyridine; ADDP,
1,1′-(azodicarbonyl)-dipiperidine; PSA, polar surface area; PK,
pharmacokinetic; TGI, tumor growth inhibition
To a solution of Boc-precursor II (447 mg, 0.39 mmol) in CH2Cl2
(5.0 mL) was added TFA (1.5 mL). The reaction mixture was stirred
at rt for 1 h, then concentrated in vacuo, purified by preparative
HPLC, and lyophilized. The resulting white solid was dissolved in
EtOAc (50 mL), washed with 1N NaOH (3 × 10 mL) and water (5
mL) and then dried over MgSO4. Filtration and concentration in
vacuo gave 17 (free base, 265 mg, 72%) as a white solid. To a
suspension of 17 (free base, 120 mg, 0.13 mmol) in water (5.0 mL) at
0 °C was added 1 N HCl (0.64 mL, 0.64 mmol) dropwise. The
resulting clear solution was stirred at rt for 20 min and then lyophilized
1
give 17 (2 HCl, 115 mg, 88%) as a white solid. H NMR (500 MHz,
DMSO-d6, mixture of amide rotamers) δ 9.33 (br s, 2H), 8.86 (br s,
2H), 8.72−8.62 (m, 2H), 8.50 (d, J = 8.8 Hz, 1H), 8.13 (d, J = 8.8 Hz,
1H), 7.39 (d, J = 7.9 Hz, 1H), 7.26 (s, 1H), 7.22 (s, 1H), 7.19 (s, 1H),
7.16−7.10 (m, 2H), 7.11−7.02 (m, 3H), 6.99 (t, J = 7.6 Hz, 1H), 6.92
(d, J = 7.7 Hz, 1H), 5.01 (d, J = 9.0 Hz, 1H), 5.00−4.93 (m, 1H),
4.90−4.82 (m, 2H), 4.78 (t, J = 6.2 Hz, 1H), 4.75−4.69 (m, 1H), 4.57
(d, J = 8.3 Hz, 1H), 4.47−4.40 (m, 1H), 4.28 (t, J = 8.5 Hz, 1H), 3.97
(d, J = 5.1 Hz, 2H), 3.52−3.43 (m, 1H), 3.42−3.36 (m, 1H), 3.06 (d, J
= 6.2 Hz, 2H), 2.78−2.67 (m, 4H), 2.56−2.50 (m, 1H), 2.50−2.44 (m,
6H), 2.01−1.91 (m, 1H), 1.90−1.83 (m, 1H), 1.80−1.73 (m, 1H),
1.72−1.65 (m, 2H), 1.65−1.59 (m, 1H), 1.63−1.56 (m, 2H), 1.58−
1.52 (m, 1H), 1.35 (d, J = 6.8 Hz, 3H), 1.29 (d, J = 7.0 Hz, 3H), 1.09
(s, 9H), 1.05 (s, 9H); HRMS (ESI+) m/z calcd for C55H77N8O6 (M
+H)+: 945.59668, obsd 945.59463.
REFERENCES
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(1) Elmore, S. Apoptosis: a review of programmed cell death. Toxicol.
Pathol. 2007, 35, 495−516.
(2) Igney, F. H.; Krammer, P. H. Death and anti-death: tumor
resistance to apoptosis. Nature Rev. Cancer 2002, 2, 277−288.
(3) Fesik, S. W. Promoting apoptosis as a strategy for cancer drug
discovery. Nature Rev. Cancer 2005, 5, 876−885.
(4) Salvensen, G. S.; Duckett, C. S. IAP proteins: blocking the road
to death’s door. Nature Rev. Mol. Cell Biol. 2002, 3, 401−410.
(5) Shiozaki, E. N.; Chai, J.; Rigotti, D. J.; Riedl, S. J.; Li, P.;
Srinivasula, S. M.; Alnemri, E. S.; Fairman, R.; Shi, Y. Mechanism of
XIAP-mediated inhibition of caspase-9. Mol. Cell 2003, 11, 519−527.
(6) Scott, F. L.; Denault, J.-B.; Riedl, S. J.; Shin, H.; Renatus, M.;
Salvesen, G. S. XIAP inhibits caspase-3 and -7 using two bindingsites:
evolutionarily conserved mechanism of IAPs. EMBO J. 2005, 24, 645−
655.
ASSOCIATED CONTENT
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S
* Supporting Information
General methods, full experimental procedures for 15 and 17,
and characterization data for all new compounds; procedures
for binding assays, caspase-3 rescue assay, MDA-MB-231 and
A875 cell proliferation assays; pharmacokinetic experiments;
tumor growth inhibition and body weight change graphs for in
vivo efficacy studies and charaterization of 17 by Western blot.
This material is available free of charge via the Internet at
(7) Wang, C. Y.; Mayo, M. W.; Korneluk, R. G.; Goeddel, D. V.;
Baldwin, A. S. NFκB antiapoptosis: induction of TRAF1 and TRAF2
and c-IAP1 and c-IAP2 to suppress caspase-8 activation. Science 1998,
281, 1680−1683.
(8) Gyrd-Hansen, M.; Meier, P. IAPs: from caspase inhibitors to
modulators of NF-kappaB, inflammation and cancer. Nature Rev.
Cancer 2010, 10, 561−574.
(9) Du, C.; Fang, M.; Li, Y.; Li, L.; Wang, X. Smac, a mitochondrial
protein that promotes cytochrome c-dependent caspase activation by
eliminating IAP inhibition. Cell 2000, 102, 33−42.
AUTHOR INFORMATION
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Corresponding Author
(10) Verhagen, A. M.; Ekert, P. G.; Pakusch, M.; Silke, J.; Connolly,
L. M.; Reid, G. E.; Moritz, R. L.; Simpson, R. J.; Vaux, D. L.
F
J. Med. Chem. XXXX, XXX, XXX−XXX