M. Keller et al. / Bioorg. Med. Chem. xxx (2015) xxx–xxx
19
derivative (ratio ca 7:1) as a white glass-like solid (2.67 g, 70%). A
portion (0.97 g) of this material was re-chromatographed (eluent:
as above) to yield pure product 60 as a white glass-like solid
(0.50 g) mp 69–73 °C. Rf = 0.4 (CH2Cl2/MeOH 10:1). Anal. calcd for
4.1.45. 5-((4-(4-(4-(((N-(2-Propionamidoethyl))-3-amino-3-oxo)-
propyl)1H-imidazol-1-yl)butyl)piperidin-1-yl)acetyl)-5H-dibenzo-
[b,e][1,4]diazepin-11(10H)-one (62)
Amine 61 (0.31 g, 0.34 mmol, included a minor amount of the
respective 1,5-disubstitued imidazole derivative (ratio 7:1), cf.
prep. of 61) and diisopropylethylamine (0.17 g, 1.29 mmol) were
dissolved in DMF (2 mL). N-Succinimidyl propionate (51 mg,
0.30 mmol) dissolved in DMF (0.3 mL) was added and the mixture
was stirred at rt for 2.5 h. The solvent was removed under reduced
pressure at 60 °C, the residue was dried in vacuo, then taken up in
CH2Cl2 (35 mL) and washed with 5% aq NaOH (10 mL). As the prod-
uct was evident in the aq phase by TLC analysis, it was extracted
from the aq phase with CH2Cl2 (20 and 15 mL). The organic layers
were combined, washed with brine/water (2:1 v/v, 8 mL) and dried
over Na2SO4. The volatiles ware evaporated and the residue was
subjected to column chromatography (eluent: CH2Cl2/MeOH 40:1
to 7.5:1). Pure product 62 was obtained from the first fraction of
the eluate. The residual eluate afforded 62 as major component
and the respective 1,5-disubstitued imidazole derivative as minor
component (ca 30%). The solvent was removed from the eluates
under reduced pressure, the residues were dried in vacuo and redis-
solved in CH2Cl2 (4 and 5 mL, respectively). The solutions were fil-
tered through a cotton wool packed Pasteur pipette, the solvent was
removed in vacuo and the residue taken up in CH2Cl2/n-pentane
(1:1 v/v, 2 mL) and CH2Cl2 (5 mL), respectively. Removal of the sol-
vent in vacuo afforded pure 62 (103 mg, 55%) mp >80 °C (turned to
a resin) as well as a mixture of 62 and the above mentioned by-
product (ratio 2.5:1) (68 mg, 36%), each as a white glass. Rf = 0.5
(CH2Cl2/MeOH 5:1). Anal. calcd for C35H45N7O4ꢆ0.2H2O: C, 66.58;
H, 7.18; N, 15.53; found: C, 66.34; H, 7.67; N, 15.08. IR (Nujol)
3295 br, 1655, 1600, 1545, 1500 cmꢁ1. Ratio of isomers evident in
the NMR spectra: ca 1.2:1. 1H NMR (600 MHz, CD3OD) d (ppm)
0.96–1.12 (m, 2H), 1.14 (t, 3H, J 7.6 Hz), 1.24 (br s, 5H), 1.45 (br d,
0.5H, J ca 11 Hz), 1.53 (br d, 1H, J ca 12 Hz), 1.60 (br d, 0.5H, J ca
12 Hz), 1.69–1.76 (m, 2H), 1.87–2.05 (m, 2H), 2.21 (q, 2H, J
7.6 Hz), 2.46–2.53 (m, 2.45H), 2.66 (br d, 0.55H, J ca 10 Hz), 2.79–
2.89 (m, 3H), 3.07 (br d, 0.55H, J ca 15 Hz), 3.17 (br d, 0.45H, J ca
15 Hz), 3.21–3.31 (m, 5H), 3.94 (t, 2H, J 6.9 Hz), 6.87 (s, 1H), 7.23–
7.32 (m, 2H), 7.35 (t, 0.45H, J 7.1 Hz), 7.42 (t, 0.55H, J 7.2 Hz),
7.45–7.56 (m, 3H), 7.56–7.61 (m, 1H), 7.64–7.70 (m, 1H), 7.89 (d,
0.55H, J 7.4 Hz), 7.92 (d, 0.45H, J 7.3 Hz). 13C NMR (150 MHz, CD3-
OD) d (ppm) 11.6, 25.4/25.5, 26.0, 31.0, 33.0, 33.4/33.65/33.74,
37.1, 37.7, 37.8, 40.8, 40.9, 48.7, 55.5/55.8, 61.8/62.2, 117.8,
123.8/123.9, 127.4, 127.8, 128.6, 129.77, 129.82, 130.3, 130.7,
131.4, 132.0, 132.8/133.0, 135.1/135.5, 136.76, 136.83, 137.8,
138.7, 142.6, 144.6/144.7, 170.0/170.2, 172.0/172.2, 176.4, 178.1.
MS (ESI, MeOH) m/z (%) 1277 (22) [2M+Na]+, 650 (100) [M+Na]+,
628 (44) [M+H]+. HRMS (ESI, MeOH) m/z calcd for [C35H46N7O4]+
628.3611, found: 628.3602. C35H45N7O4 (627.78).
C37H49N7O5ꢆ0.5H2O: C, 65.27; H, 7.25; N, 14.40; found: C, 64.97;
H, 7.57; N, 14.11. IR (Nujol) 1660, 1600, 1500 cmꢁ1. Ratio of iso-
mers evident in the NMR spectra: ca 1.2:1. 1H NMR (600 MHz, CD3-
OD) d (ppm) 0.95–1.17 (m, 2H), 1.24 (br s, 5H), 1.45 (s, 9H), 1.48–
1.55 (m, 1.5H), 1.60 (d, 0.5H, J 12.1 Hz), 1.73 (p, 2H, J 6.8 Hz), 1.87–
2.03 (m, 2H), 2.45–2.53 (m, 2.45H), 2.65 (br d, 0.55H, J ca 9.5 Hz),
2.78–2.88 (m, 3H), 3.05 (d, 0.55H, J 15.5 Hz), 3.10–3.18 (m,
2.45H), 3.20–3.27 (m, 3H), 3.94 (t, 2H, J 7.0 Hz), 6.86 (s, 1H),
7.23–7.31 (m, 2H), 7.35 (t, 0.45H, J 7.0 Hz), 7.41 (t, 0.55H, J
7.3 Hz), 7.45–7.56 (m, 3H), 7.56–7.61 (m, 1H), 7.64–7.70 (m, 1H),
7.87–7.95 (m, 1H). 13C NMR (150 MHz, CD3OD) d (ppm) 25.5,
26.0, 29.6, 33.0, 33.5/33.7/33.8, 37.1, 37.7, 37.8, 41.3, 41.8, 48.7,
55.5/55.8, 61.8/62.2, 81.0, 117.8, 123.9, 127.4, 127.8, 128.6,
129.77, 129.83, 130.3, 130.7, 131.4, 132.0, 132.9/133.0, 135.1/
135.5, 136.8, 137.8, 138.7, 142.57/142.60, 144.7, 159.3, 170.0/
170.2, 172.1/172.3, 176.4. MS (ESI, MeOH) m/z (%) 1365 (10)
[2M+Na]+, 694 (64) [M+Na]+, 672 (100) [M+H]+, 364 (20). HRMS
(ESI, MeOH) m/z calcd for [C37H50N7O5]+ 672.3873, found:
672.3871. C37H49N7O5 (671.83).
There followed a 5:1 mixture of 60 and the respective 1,5-
disubstitued 1H-imidazole derivative as a white glass (0.38 g).
4.1.44. 5-((4-(4-(4-(((N-2-Aminoethyl)-3-amino-3-oxo)propyl)-
1H-imidazol-1-yl)butyl)piperidin-1-yl)acetyl)-5H-dibenzo[b,e]-
[1,4]diazepin-11(10H)-one tris(hydrotrifluoroacetate) (61)
Compound 60 (1.70 g, 2.52 mmol, included a minor amount
of the respective 1,5-disubstitued imidazole derivative (ratio ca
7:1), cf. prep. of 60) was dissolved in MeOH (8 mL) and water
(2 mL). TFA (1 mL) was added, the mixture was stirred for
2 min and then water (8 mL) and TFA (1.5 mL) were added. Stir-
ring was continued at rt for 24 h, the mixture was concentrated
under reduced pressure at 50 °C to a volume of about 8 mL and
filtered through a 0.45 lm filter (for filter type cf. exp. protocol
of 49). The filtrate was diluted with water (200 mL) and lyophil-
isation afforded a mixture of product 61 and the respective 1,5-
disubstitued 1H-imidazole derivative (ratio ca 7:1) as a white
fluffy, highly hygroscopic solid (2.37 g, 94%). Applying the same
procedure another batch of compound 61 was prepared from
isomerically pure carbamate 60 (434 mg, 0.65 mmol) to yield
pure product 61 as a white fluffy, highly hygroscopic solid
(570 mg, 96%). Ratio of configurational isomers evident in the
NMR spectra: ca 1.8:1. 1H NMR (700 MHz, CD3OD) d (ppm)
1.38 (br s, 4H), 1.44–1.52 (m, 1H), 1.52–1.60 (m, 2H), 1.86–
1.95 (m, 3H), 1.98 (br d, 1H, J ca 10.8 Hz), 2.67 (t, 2H,
7.4 Hz), 2.91–3.00 (m, 1H), 3.02 (t, 2H, J 7.1 Hz), 3.05–3.11 (m,
3H), 3.45–3.52 (m, 3H), 3.72–3.84 (m, 2H), 4.20 (t, 2H,
J
J
7.4 Hz), 4.44 (d, 0.65H, J 16.7 Hz), 4.48 (d, 0.35H, J 16.7 Hz),
7.27–7.33 (m, 0.8H), 7.34–7.39 (m, 1.2H), 7.39–7.44 (m, 1.35H),
7.51 (dt, 0.65H, J 7.7 1.3 Hz), 7.52–7.57 (m, 1.65H), 7.63–7.68
(m, 1H), 7.68–7.74 (m, 1H), 7.78 (dt, 0.35H, J 7.7 1.3 Hz), 7.93
(dd, 0.65H, J 8.2 1.4 Hz), 8.00 (dd, 0.35H, J 7.8 1.3 Hz), 8.85 (d,
1H, J 1.5 Hz). 13C NMR (150 MHz, CD3OD) d (ppm) 22.1, 25.0,
31.3, 31.9, 35.1, 35.6, 36.9, 39.1, 41.6, 51.2, 55.8/56.2, 58.9,
118.0 (TFA), 120.0 (TFA), 120.7, 123.9, 124.5, 127.7, 128.4,
128.8, 129.4, 129.7, 130.3, 131.0, 131.4, 131.8, 132.1, 132.6,
132.8, 133.2/133.8, 134.3, 135.4, 135.8, 136.2, 136.3, 136.6,
137.9, 141.9, 143.6, 162.9 (TFA), 163.1 (TFA), 163.4 (TFA),
163.6 (TFA), 165.8/166.3, 169.4/169.7, 175.7. MS (ESI, MeOH)
4.1.46. N,N0-Bis(4-((1-(2-(5H-dibenzo[b,e][1,4]diazepin-11(10H)-
one-5-yl)-2-oxo)ethyl)piperidin-4-yl)butyl)piperazineꢆ0.5H2O (63)
Compound 63 was prepared from amine 39 (186 mg,
0.51 mmol) and chloride 43 (307 mg, 1.07 mmol) using the proce-
dure for the preparation of 29. Potassium carbonate: 0.56 g,
4.08 mmol. Eluent for column chromatography: CH2Cl2/MeOH
100:1 to 10:1. Removal of the solvent from the eluate under
reduced pressure, drying in vacuo, re-uptake in CH2Cl2 (5 mL), fil-
tration of the solution with a cotton wool packed Pasteur pipette,
evaporation, re-uptake in CH2Cl2 (1 mL) and n-pentane (2 mL) fol-
lowed by removal of the solvent in vacuo afforded product 63 as a
pale tan colored glass (165 mg, 37%) mp >170 °C (turned to a resin).
Rf = 0.5 (CH2Cl2/MeOH 5:1). Anal. calcd for C52H64N8O4ꢆ0.5H2O: C,
71.45; H, 7.38; N, 12.82; found: C, 71.40; H, 7.49; N, 12.78. IR
(Nujol) 1660, 1600 cmꢁ1. Ratio of configurational isomers evident
in the NMR spectra: ca 1.2:1. 1H NMR (400 MHz, CD3OD) d (ppm)
m/z (%) 572 (7) [M+H]+, 286.5 (100) [M+2H]2+
. HRMS (ESI,
MeOH) m/z calcd for [C32H42N7O3]+ 572.3349, found: 572.3338,
m/z calcd for [C2F3O2]ꢁ 112.9850, found 112.9868. C32H41N7O3-
ꢆ3ꢅC2HF3O2 (571.71 + 3 ꢅ 114.025).