A. Bordessa et al. / European Journal of Medicinal Chemistry 70 (2013) 505e524
519
stirred overnight under hydrogen atmosphere at room temperature
and filtered on a celite pad. After the removal of the solvent under
reduced pressure, 18b was obtained as yellow resinous oil (81 mg,
d
¼ 172.0, 158.3, 152.7, 137.1, 134.7, 104.7, 59.9, 55.9, 48.6, 43.8, 34.2.
To a solution of the hydrochloride salt of the amine (1.04 g,
3.28 mmol, 1 eq.) in dry DMF (25 mL) was successively added N
Fmoc-N -Z- -Lys (1.7 g, 3.68 mmol, 1.1 eq.), collidine (2.5 g,
a
-
0.13 mmol, 89%). 1H NMR:
d
¼ 7.55 (bs,1H), 7.23e6.85 (m,15H), 4.80
3
L
(m, 1H), 4.33 (m, 1H), 3.67 (m, 3H), 3.51 (m, 2H), 3.10 (m, 1H), 3.02
(m, 1H), 3.00 (m, 2H), 2.70 (m, 2H), 2.24 (m, 2H), 1.70 (m, 1H), 1.59
21.1 mmol, 7 eq.), EDC (694 mg, 3.68 mmol, 1.1 eq.), and HOBT
(489 mg, 3.68 mmol, 1.1 eq.). The mixture was stirred overnight at
room temperature under argon atmosphere. After removal of the
solvent under reduced pressure, the residue was taken up in EtOAc
(20 mL) and successively washed with 10% aqueous citric acid
(2 ꢂ 20 mL), water (20 mL), 10% aqueous K2CO3 (2 ꢂ 20 mL) and
brine (20 mL). The organic layer was dried over Na2SO4, filtered and
evaporated under reduced pressure to give a crude product that
was purified by column chromatography (EtOAc) to afford 20
(672 mg, 0.92 mmol, 30%) as a white solid. mp: 140e142 ꢀC; 1H
(m, 1H), 1.49 (m, 2H), 1.33 (m, 2H). 13C NMR:
d
¼ 172.9, 171.9, 171.2,
171.0, 157.54, 156.9, 136.7, 136.3, 130.0, 129.8, 129.1, 128.5, 127.0,
124.0, 123.4, 119.7, 118.9, 117.4, 53.5, 52.4, 51.8, 47.5, 43.0, 40.5, 37.5,
34.1, 31.7, 30.0, 22.3. ESIþ MS m/z: 604 [M þ H]þ. Anal. Calcd for
C
33H41N5O6$2.5 H2O: C, 61.13; H, 7.17; N, 10.90; found C, 61.36; H,
6.50; N, 10.07.
4.1.2.5. Methyl
(2S)-2-[3-[2-[(2S)-6-(benzyloxycarbonylamino)-2-
[[2-(2,5-dimethoxyphenyl)acetyl]amino]hexanoyl]hydrazino]prop-
anoylamino]-3-phenyl-propanoate 19a. Compound 19a was syn-
thesized following the same procedure described for 17a.
Deprotection of 17b in DCM/TFA gave the trifluoroacetic salt of the
amine (490 mg, 0.93 mmol, 1 eq.) which was coupled with 2,5-
dimethoxyphenylacetic acid (235 mg, 1.2 mmol, 1.2 eq.). Except,
the crude product was purified by column chromatography (EtOAc/
MeOH, 9:1) to give 19a as a white solid (247 mg, 0.35 mmol, 37%).
NMR:
d
¼ 7.74 (d, 2H, J ¼ 7.6 Hz), 7.55 (d, 2H, J ¼ 7.5 Hz), 7.38 (t, 2H,
J ¼ 7.3 Hz), 7.29 (t, 2H, J ¼ 7.4 Hz), 7.13 (t, 1H, J ¼ 5.3 Hz), 6.52 (s, 2H),
5.58 (m, 1H), 4.71 (m, 1H), 4.37 (m, 2H), 4.35 (m, 2H), 4.17 (m, 1H),
4.06 (m, 1H), 3.81 (s, 6H), 3.80 (s, 3H), 3.11 (m, 2H), 3.06 (m, 2H),
2.36 (m, 2H),1.79 (m,1H),1.66 (m,1H),1.45 (m, 2H),1.41 (s, 9H),1.35
(m, 2H). 13C NMR:
d
¼ 171.6, 171.5, 156.3, 153.3, 143.6, 141.3, 137.1,
134.2, 127.8, 127.1, 124.9, 120.0, 104.9, 80.2, 67.0, 60.1, 56.0, 53.6,
48.1, 47.1, 43.7, 39.7, 34.7, 31.6, 29.5, 28.4, 22.4. IR (cmꢃ1): 2926,
1682, 1650, 1592. ESIþ MS m/z: 756 [M þ 23]þ. Anal. Calcd for
mp: 171e173 ꢀC; 1H NMR (300 MHz, CDCl3):
d
¼ 7.20e7.33 (m,10H),
7.14 (d, 1H, J ¼ 7.3 Hz), 6.82e6.73 (m, 3H), 6.48 (d, 1H, J ¼ 7.3 Hz),
5.10 (s, 2H), 4.83 (dd, 1H, J ¼ 7.5 and 12.2 Hz), 4.28 (dd, 1H, J ¼ 7.2
and 14.0 Hz), 3.72 (s, 6H), 3.79 (s, 3H), 3.52 (s, 2H), 3.16 (m, 1H), 3.13
(m, 2H), 3.03 (m, 1H), 3.02 (m, 2H), 2.21 (t, 2H, J ¼ 5.4 Hz), 1.75 (m,
1H), 1.55 (m, 1H), 1.46 (m, 2H), 1.24 (m, 2H). 13C NMR (75 MHz,
C39H51N5O9 C. 62.71, H. 7.10, N. 9.38 found C. 62.86, H. 7.20, N. 9.24.
4.1.2.8. tert-Butyl
N-[(5S)-5-[[2-(2,5-dimethoxyphenyl)acetyl]ami
no]-6-oxo-6-[2-[3-oxo-3-[(3,4,5-trimethoxyphenyl)methylamino]
propyl] hydrazino]hexyl] carbamate 21a. Compound 21a was syn-
thesized according to the procedure described for the synthesis of
20a from 22 (307 mg, 0.42 mmol, 1 eq.), which was successively
deprotected and coupled with 2,5-dimethoxyphenylacetic acid
(99 mg, 0.50 mmol, 1.2 eq.). 21a was obtained as a white solid
(142 mg, 0.20 mmol, 50%). mp: 138e140 ꢀC; 1H NMR (300 MHz):
CDCl3):
d
¼ 172.9, 171.8, 171.4, 171.1, 156.6, 153.8, 151.1, 136.6, 136.1,
129.1; 128.6, 128.5, 128.0, 127.0, 124.2, 117.2, 113.2, 111.8, 66.6, 56.0,
53.3, 52.5, 51.6, 47.7, 40.5, 38.9, 37.5, 34.3, 31.1, 29.3, 22.3. IR (cmꢃ1):
3283, 1742, 1682, 1638, 1535. APCIþ MS m/z: 706 [M þ H]þ. Anal.
Calcd for C37H47N5O9$1.5 H2O: C, 60.64; H, 6.89; N, 9.56; found C,
60.48; H, 6; 71; N, 9.31.
d
¼ 7.23 (t, 1H, J ¼ 5.0 Hz), 7.18 (m, 1H), 6.79 (m, 1H), 6.78 (m, 1H),
6.77 (m, 1H), 6.54 (s, 2H), 6.41 (d, 1H, J ¼ 6.9 Hz), 4.96 (m, 1H), 4.36
(m, 2H), 4.23 (m, 1H), 3.82 (s, 6H), 3.81 (s, 3H), 3.78 (s, 6H), 3.49 (s,
2H), 3.05 (t, 2H, J ¼ 6.3 Hz), 3.01 (m, 2H), 2.28 (t, 2H, J ¼ 6.3 Hz), 1.78
(m,1H),1.55 (m,1H), 1.42 (s, 9H), 1.41 (m, 2H),1.25 (m, 2H). 13C NMR
4.1.2.6. Methyl (2S)-2-[3-[2-[(2S)-6-amino-2-[[2-(2,5-
dimethoxyphenyl)acetyl]amino] hexanoyl]hydrazino]propanoylami
no]-3-phenyl-propanoate di(hydrochloride) salt 19b. To a solution of
19a (175 mg, 0.24 mmol, 1 eq.) in dry methanol (5 mL) was added
10% Pd/C (17.5 mg). The mixture was stirred overnight under
hydrogen atmosphere at room temperature and filtered on a celite
pad. After removal of the solvent under reduced pressure and
addition of HCl/MeOH, 19b was obtained as a white hygroscopic
solid (110 mg, 0.17 mmol, 73%). 1H NMR (300 MHz, CD3OD):
(75 MHz):
d
¼ 171.7, 171.6, 171.2, 156.2, 153.9, 153.3, 151.1, 137.1,
134.4, 124.2, 117.4, 113.2, 104.8, 79.2, 60.8, 56.1, 55.7, 51.9, 48.2, 43.7,
40.0, 39.0, 34.6, 31.1, 29.6, 28.4, 22.5. IR (cmꢃ1): 2926, 1680, 1591,
1459, 1225. ESIþ MS m/z: 712 [M
þ
23]þ. Anal. Calcd for
C34H51N5O10: C. 57.69, H. 7.56, N. 9.90 found C. 57.73, H. 7.17, N. 9.87.
d
¼ 7.28e7.19 (m, 5H), 6.83 (m, 3H), 4.67 (dd, 1H, J ¼ 5.73 and
4.1.2.9. 3-[2-[(2S)-6-amino-2-[[2-(2,5-dimethoxyphenyl)acetyl]
amino]hexanoyl] hydrazino]-N-[(3,4,5-trimethoxyphenyl)methyl]
8.71 Hz), 4.34 (dd, 1H, J ¼ 5.82 and 8.30), 3.79 (s, 3H), 3.74 (s, 3H),
3.69 (s, 3H), 3.52 (d, 2H, J ¼ 5.06 Hz), 3.17 (dd, 1H, J ¼ 5.63 and
13.82), 3.01e2.88 (m, 5H), 2.31 (m, 2H), 1.39e1.04 (m, 6H). 13C NMR
propanamide di(trifluoroacetic) salt 21b. A solution of 21a (93 mg,
0.13 mmol,1.0 eq.) in DCM/TFA 3:1 (4 mL) was stirred for 2 h at room
temperature. The solvent was evaporated under reduced pressure
and the excess of TFA was coevaporated with methanol to afford 21b
as a white solid (81 mg, 0.13 mmol, quantitative).1H NMR (300 MHz,
(75 MHz, CD3OD):
d
¼ 174.7, 173.4, 172.4, 171.9, 155.0, 153.1, 138.0,
130.3, 129.6, 128.0, 126.0, 118.3, 113.7, 112.7, 68.2, 56.7, 56.2, 55.5,
52.8, 50.0, 40.5, 38.4, 38.2, 32.0, 30.4, 28.0, 23.4. IR (cmꢃ1): 2926,
1682, 1650, 1592. ESIþ MS m/z: 572 [M þ H]þ. Anal. Calcd for
CD3OD):
d
¼ 6.87 (d,1H, J ¼ 8.8 Hz), 6.80 (s,1H), 6.79 (m,1H), 6.62 (s,
C
29H43Cl2N5O7$2.5 H2O: C. 50.50, H. 7.03, N. 10.16 found C. 50.58, H.
2H), 4.32 (m, 1H), 4.31 (m, 2H), 3.82 (s, 6H), 3.77 (s, 3H), 3.73 (s, 6H),
3.60 (s, 2H), 3.44 (m, 2H), 2.91 (m, 2H), 2.68 (m, 2H),1.88 (m,1H),1.78
(m, 1H), 1.68 (m, 2H), 1.44 (m, 2H). 13C NMR (75 MHz, CD3OD):
7.26, N. 9.63.
4.1.2.7. 9H-fluoren-9-ylmethyl
N-[(1S)-5-(tert-butoxycarbonylami
d
¼ 173.2, 170.9, 153.7, 153.2, 151.7, 136.9, 134.4, 124.5, 117.0, 112.2,
no)-1-[[[3-oxo-3-[(3,4,5-trimethoxyphenyl)methylamino]propyl]
amino] carbamoyl]pentyl]carbamate 20. A solution of 36 (1.2 g,
3.28 mmol, 1 eq.) in HCl 4 M in dioxane (25 mL) was stirred for 2 h
at room temperature. The solvent was evaporated under reduced
pressure to afford the hydrochloride salt of the amine (1.14 g,
3.57 mmol, quantitative) as a colorless oil, which was used without
111.3, 104.8, 59.7, 55.3, 55.2, 54.7, 51.9, 47, 43.0, 39.0, 36.8, 30.4, 30.0,
26.6, 22.3. IR (cmꢃ1): 2926, 1682, 1650, 1592. ESIꢃ MS m/z: 624
[M þ 2H2OeH]- and 588 [M ꢃ H]ꢃ. Anal. Calcd for C33H45F6N5O12$4
H2O: C. 44.54, H. 6.02, N. 7.87 found C. 44.17, H. 5.66, N. 7.37.
4.1.2.10. tert-Butyl N-[(5S)-6-oxo-6-[2-[3-oxo-3-[(3,4,5-
trimethoxyphenyl)methylamino] propyl]hydrazino]-5-[[2-(3-
phenoxyphenyl)acetyl] amino]hexyl]carbamate 22a. To 20 (613 mg,
0.84 mmol, 1 eq.) was added a solution of piperidine in DMF (10% v/
further purification. 1H NMR (300 MHz, DMSO-d6):
d
¼ 8.51 (s, 3H),
6.52 (s, 2H), 4.21 (d, 2H, J ¼ 5.5 Hz), 3.79 (s, 6H), 3.61 (s, 3H), 3.15 (t,
2H, J ¼ 6.6 Hz), 2.60 (t, 2H, J ¼ 6.6 Hz). 13C NMR (75 MHz, DMSO-d6):