Journal of Medicinal Chemistry
Article
v/v formic acid in acetonitrile. The electrospray mass spectrometer
was operated in switching mode to obtain both positive and negative
ion spectra.
Method 2. This method utilized the same column, flow rate, solvent
systems and MS switching mode as for Method 1 but a different linear
gradient: 95:5 v/v solvent A/B at time 0 to 5:95 v/v A/B at 3 min after
sample injection, then maintained at 5:95 v/v until 5 min.
method 4, tR = 8.57 min. MS, m/z (ES+): 715 (M• + H +). Calcd for
C34H38N10O8, 715.2974. Found, 715.2956 (M• + H+).
Ethyl 4-({4-[4-(7-Methoxy-5-oxo-2,3,5,11a-tetrahydro-5H-
pyrrolo[2,1-c][1,4]benzodiazepine-8-yloxy)butyrylamino]-1-
methyl-1H-pyrrole-2-carbonyl]amino)-1-methyl-1H-imidazole-
2-carbonyl]amino}-1-methyl-1H-imidazole-2-carboxylate (3d).
The Alloc-THP-PBD-pyrrole-imidazole-imidazole conjugate 10d (145
mg, 0.16 mmol) was deprotected as described in the general procedure
to yield the imine product 3d (16 mg, 14%). 1H NMR (acetone-d6): δ
9.46 (s, 1H, N-H), 9.29 (s, 1H, N-H), 9.19 (s, 1H, N-H), 7.75 (d, 1H,
J = 4.4 Hz, H-11), 7.59 (s, 1H, Im-H), 7.58 (s, 1H, Im-H), 7.42 (s, 1H,
H-6), 7.36 (d, 1H, J = 1.7 Hz, Py-H), 6.99 (d, 1H, J = 1.7 Hz, Py-H),
6.81 (s, 1H, H-9), 4.34 (q, 2H, J = 7.1 Hz, OCH2CH3), 4.15 (m, 2H,
side chain H-1), 4.10 (s, 3H, O/N-CH3), 4.04 (s, 3H, O/N-CH3), 3.94
(s, 3H, O/N-CH3), 3.87 (s, 3H, O/N-CH3), 3.68 (m, 1H, H-11a),
3.58 (m, 1H, H-3), 3.46 (m, 1H, H-3), 2.54 (m, 2H, side chain H-3),
2.36 (m, 2H, H-1), 2.21 (m, 2H, side chain H-2), 2.09 (m, 2H, H-2),
1.36 (t, 3H, J = 7.1 Hz, OCH2CH3). LCMS: method 1, tR = 2.62 min;
method 3, tR = 9.98 min; method 4, tR = 8.17 min. MS, m/z (ES+):
729 (M• + H+). Calcd for C35H40N10O8, 729.3104. Found, 729.3115
(M• + H+).
Ethyl 4-({4-[4-(7-Methoxy-5-oxo-2,3,5,11a-tetrahydro-5H-
pyrrolo[2,1-c][1,4]benzodiazepine-8-yloxy)butyrylamino]-1-
methyl-1H-pyrrole-2-carbonyl]amino)-1-methyl-1H-pyrrole-2-
carbonyl]amino}-1-methyl-1H-imidazole-2-carboxylate (3e).
The Alloc-THP-PBD-pyrrole-pyrrole-imidazole conjugate 10e (210
mg, 0.23 mmol) was deprotected as described in the general procedure
to yield the imine product 3e (28 mg, 17%). 1H NMR (acetone-d6) δ
9.40 (s, 1H, N-H), 9.29 (s, 1H, N-H), 9.07 (s, 1H, N-H), 8.15 (s, 1H,
Im-H), 7.74 (d, 1H, J = 4.4 Hz, H-11), 7.59 (s, 1H, H-9), 7.48 (d, 1H,
J = 1.6 Hz, Py-H), 7.42 (d, 1H, J = 2.1 Hz, Py-H), 7.16 (d, 1H, J = 1.6
Hz, Py-H), 6.83 (d, 2H, J = 1.8 Hz, Py-H, H-6), 4.33 (q, 2H, J = 7.1
Hz, OCH2CH3), 4.13 (m, 2H, side chain H-1), 4.01 (s, 3H, O/N-
CH3), 3.96 (s, 3H, O/N-CH3), 3.91 (s, 3H, O/N-CH3), 3.87 (s, 3H,
O/N-CH3), 3.69 (m, 2H, H-11a, H-3), 3.47 (m, 1H, H-3), 2.55 (m,
2H, side chain H-3), 2.36 (m, 2H, H-1), 2.15 (m, 2H, side chain H-2),
2.09 (m, 2H, H-2), 1.37 (t, 3H, J = 7.1 Hz, OCH2CH3). LCMS:
method 1, tR = 2.60 min; method 3, tR = 9.80 min; method 4, tR = 7.97
min. MS, m/z (ES+): 728 (M• + H+). Calcd for C36H41N9O8,
728.3151. Found, 728.3151 (M• + H+).
Ethyl 4-({4-[4-(7-Methoxy-5-oxo-2,3,5,11a-tetrahydro-5H-
pyrrolo[2,1-c][1,4]benzodiazepine-8-yloxy)butyrylamino]-1-
methyl-1H-imidazole-2-carbonyl]amino)-1-methyl-1H-pyrrole-
2-carbonyl]amino}-1-methyl-1H-imidazole-2-carboxylate (3f).
The Alloc-THP-PBD-imidazole-pyrrole-imidazole conjugate 10f (120
mg, 0.13 mmol) was deprotected as described in the general procedure
to yield the imine product 3f (26 mg, 27%). 1H NMR (acetone-d6): δ
9.52 (s, 1H, N-H), 9.42 (s, 1H, N-H), 9.27 (s, 1H, N-H), 7.74 (d, 1H,
J = 4.4 Hz, H-11), 7.60 (s, 1H, Im-H), 7.49 (d, 1H, J = 1.7 Hz, Py-H),
7.44 (s, 1H, Im-H), 7.42 (s, 1H, H-6), 7.27 (d, 1H, J = 1.8 Hz, Py-H),
6.82 (s, 1H, H-9), 4.33 (q, 2H, J = 7.1 Hz, OCH2CH3), 4.16 (m, 1H,
side chain H-1), 4.06 (m, 1H, side chain H-1), 4.02 (s, 3H, O/N-
CH3), 3.98 (s, 3H, O/N-CH3), 3.88 (s, 3H, O/N-CH3), 3.80 (s, 3H,
O/N-CH3), 3.69 (m, 2H, H-11a, H-3), 3.48 (m, 1H, H-3), 2.65 (m,
2H, side chain H-3), 2.35 (m, 2H, H-1), 2.18 (m, 2H, side chain H-2),
2.09 (s, 2H, H-2), 1.38 (t, 3H, J = 7.1 Hz, OCH2CH3). LCMS:
method 1, tR = 2.60 min; method 3, tR = 9.22 min; method 4, tR = 8.12
min. MS, m/z (ES+): 729 (M• + H+). Calcd for C35H40N10O8,
729.3104. Found, 729.3075 (M• + H+).
Ethyl 4-({4-[4-(7-Methoxy-5-oxo-2,3,5,11a-tetrahydro-5H-
pyrrolo[2,1-c][1,4]benzodiazepine-8-yloxy)butyrylamino]-1-
methyl-1H-imidazole-2-carbonyl]amino)-1-methyl-1H-imida-
zole-2-carbonyl]amino}-1-methyl-1H-imidazole-2-carboxylate
(3g). The Alloc-THP-PBD-imidazole-imidazole-imidazole conjugate
10g (135 mg, 0.15 mmol) was deprotected using the general
procedure to give imine product 3g (24 mg, 22%). 1H NMR
(DMSO-d6): δ 10.53 (m, 1H, N-H), 10.16 (s, 1H, N-H), 9.54 (s, 1H,
N-H), 7.78 (d, 1H, J = 4.4 Hz, H-11), 7.71 (s, 1H, Im-H), 7.64 (s, 1H,
Im-H), 7.54 (s, 1H, Im-H), 7.32 (s, 1H, H-6), 6.83 (s, 1H, H-9), 4.29
(q, 2H, J = 7.1 Hz, OCH2CH3), 4.16 (m, 2H, side chain H-1), 4.00 (s,
3H, O/N-CH3), 3.98 (s, 3H, O/N-CH3), 3.95 (s, 3H, O/N-CH3),
Methods 3 and 4. These Methods utilized Phenomenex Luna 5 μm
C18(2) (250 mm × 4.6 mm) and Gemini 5 μm C18 (100 mm × 4.6
mm) columns, respectively. The solvent composition for both
Methods was (A) 0.1% v/v formic acid in water and (B) 0.1% v/v
formic acid in acetonitrile, with a flow rate of 1.5 mL/min. The
gradient elution conditions for both Methods were: 95:5 v/v solvent
A/B at time 0 to 5:95 v/v A/B at 18 min after sample injection,
maintained at 5:95 v/v A/B until 22 min, reverted to 95:5 v/v A/B at
23 min, and then maintained at 95:5 v/v A/B until 30 min.
Analytical Data for PBD Conjugates 3a−i and 3k−n. Methyl
4-({4-[4-(7-Methoxy-5-oxo-2,3,5,11a-tetrahydro-5H-pyrrolo-
[2,1-c][1,4]benzodiazepine-8-yloxy)butyrylamino]-1-methyl-
1H-imidazole-2-carbonyl]amino)-1-methyl-1H-pyrrole-2-
carbonyl]amino}-1-methyl-1H-pyrrole-2-carboxylate (3a). The
Alloc-THP-PBD-imidazole-pyrrole-pyrrole conjugate 10a (200 mg,
0.22 mmol) was deprotected as described in the general procedure to
1
yield the imine product 3a (45 mg, 29%). H NMR (acetone-d6): δ
9.38 (s, 1H, N-H), 9.37 (s,1H, N-H), 9.22 (s, 1H, N-H), 7.73 (d, 1H, J
= 4.4 Hz, H-11), 7.50 (d, 1H, J = 1.9 Hz, Py-H), 7.47 (s, 1H, Im-H),
7.43 (s, 1H, H-6), 7.28 (d, 1H, J = 1.8 Hz, Py-H), 7.00 (d, 1H, J = 1.8
Hz, Py-H), 6.94 (d, 1H, J = 2.0 Hz, Py-H), 6.82 (s, 1H, H-9), 4.20 (m,
1H, side chain H-1), 4.10 (m, 1H, side chain H-1), 4.06 (s, 3H, O/N-
CH3), 4.00 (s, 3H, O/N-CH3), 3.95 (s, 3H, O/N-CH3), 3.91 (s, 3H,
O/N-CH3), 3.76 (s, 3H, O/N-CH3), 3.68 (m, 2H, H-11a, H-3), 3.44
(m, 1H, H-3), 2.64 (m, 2H, side chain H-3), 2.33 (m, 2H, H-1), 2.19
(m, 2H, side chain H-2), 2.09 (s, 2H, H-2). LCMS: method 1, tR =
2.67 min; method 3, tR = 10.22 min; method 4, tR = 8.35 min. MS, m/z
(ES+): 714 (M• + H+). Calcd for C35H39N9O8, 714.2994. Found,
714.3011 (M• + H+).
Methyl 4-({4-[4-(7-Methoxy-5-oxo-2,3,5,11a-tetrahydro-5H-
pyrrolo[2,1-c][1,4]benzodiazepine-8-yloxy)butyrylamino]-1-
methyl-1H-pyrrole-2-carbonyl]amino)-1-methyl-1H-imidazole-
2-carbonyl]amino}-1-methyl-1H-pyrrole-2-carboxylate (3b).
The Alloc-THP-PBD-pyrrole-imidazole-pyrrole conjugate 10b (260
mg, 0.29 mmol) was deprotected as described in the general procedure
to yield the imine product 3b (34 mg, 16%). 1H NMR (acetone-d6): δ
9.88 (s, 1H, N-H), 9.69 (s, 1H, N-H), 9.53 (s, 1H, N-H), 7.76 (d, 1H,
J = 4.4 Hz, H-11), 7.60 (d, 1H, J = 1.1 Hz, Py-H), 7.50 (s, 1H, Im-H),
7.43 (s, 1H, H-6), 7.19 (d, 1H, J = 2.2 Hz, Py-H), 7.01 (d, 1H, J = 1.5
Hz, Py-H), 6.98 (d, 1H, J = 1.3 Hz, Py-H), 6.83 (s, 1H, H-9), 4.21 (m,
2H, side chain H-1), 4.06 (s, 3H, O/N-CH3), 3.90 (s, 6H, O/N-CH3),
3.88 (s, 3H, O/N-CH3), 3.76 (s, 3H, O/N-CH3), 3.67 (m, 2H, H-11a,
H-3), 3.50 (m, 1H, H-3), 2.53 (m, 2H, side chain H-3), 2.36 (m, 2H,
H-1), 2.19 (m, 2H, side chain H-2), 2.09 (s, 2H, H-2). LCMS: method
1, tR = 2.65 min; method 3, tR = 10.18 min; method 4, tR = 8.32 min.
MS, m/z (ES+): 714 (M• + H+). Calcd for C35H39N9O8, 714.2994.
Found, 714.2999 (M• + H+).
Methyl 4-({4-[4-(7-Methoxy-5-oxo-2,3,5,11a-tetrahydro-5H-
pyrrolo[2,1-c][1,4]benzodiazepine-8-yloxy)butyrylamino]-1-
methyl-1H-imidazole-2-carbonyl]amino)-1-methyl-1H-imida-
zole-2-carbonyl]amino}-1-methyl-1H-pyrrole-2-carboxylate
(3c). The Alloc-THP-PBD-imidazole-imidazole-pyrrole conjugate 10c
(130 mg, 0.14 mmol) was deprotected as described in the general
procedure to afford imine product 3c (28 mg, 28%). 1H NMR
(acetone-d6): δ 9.71 (s, 1H, N-H), 9.42 (s, 1H, N-H), 9.05 (s, 1H, N-
H), 8.02 (s, 1H, Im-H), 7.73 (d, 1H, J = 4.4 Hz, H-11), 7.56 (s, 1H,
Im-H), 7.50 (d, 1H, J = 5.0 Hz, Py-H), 7.42 (s, 1H, H-6), 7.18 (d, 1H,
J = 1.2 Hz, Py-H), 6.83 (s, 1H, H-9), 4.14 (m, 2H, side chain H-1),
4.10 (s, 3H, O/N-CH3), 4.07 (s, 3H, O/N-CH3), 3.94 (s, 3H, O/N-
CH3), 3.92 (s, 3H, O/N-CH3), 3.78 (s, 3H, O/N-CH3), 3.67 (m, 1H,
H-11a), 3.52 (m, 1H, H-3), 3.39 (m, 1H, H-3), 2.52 (m, 2H, side
chain H-3), 2.31 (m, 2H, H-1), 2.21 (m, 2H, side chain H-2), 2.09 (s,
2H, H-2). LCMS: method 1, tR = 2.70 min; method 3, tR = 10.45 min;
I
dx.doi.org/10.1021/jm4001852 | J. Med. Chem. XXXX, XXX, XXX−XXX