PAPER
Synthesis of Pyrrolo[2,1-c][1,4]benzodiazepin-5-ones
4091
Anal. Calcd for C18H13ClN2O: C, 70.02; H, 4.24; N, 9.07. Found: C,
70.05; H, 4.25; N, 9.09.
1H NMR (300 MHz, CDCl3): d = 8.16 (d, J = 2.4 Hz, 1 H, ArH),
7.67–7.65 (m, 1 H, ArH), 7.40–7.28 (m, 5 H, ArH), 6.70 (d, J = 8.6
Hz, 1 H, ArH), 6.20 (t, J = 3.3 Hz, 1 H, ArH), 5.51 (s, 1 H, ArH),
5.34 (s, 1 H, ArH), 4.77 (br s, 1 H, NH).
13C NMR (50 MHz, CDCl3): d = 167.2, 148.2, 147.6, 137.3, 134.8,
133.7, 130.7, 129.4, 129.3, 125.5, 122.9, 121.5, 121.1, 118.4, 115.5,
113.3, 111.9, 58.4.
11-(4-Nitrophenyl)-10,11-dihydro-5H-pyrrolo[2,1-c][1,4]ben-
zodiazepin-5-one (4b)
Yellow solid; yield: 0.237 g (92%); mp 170–172 °C; Rf = 0.32
(EtOAc–hexane, 2:8).
IR (KBr): 3309, 1714, 1630, 1485, 1434, 1328 cm–1.
MS (ES+): m/z = 343.2 [M+ + 1].
1H NMR (300 MHz, CDCl3): d = 8.37 (dd, J = 8.4, 1.4 Hz, 1 H,
ArH), 8.22 (dd, J = 7.1, 1.8 Hz, 2 H, ArH), 7.72–7.70 (m, 1 H,
ArH), 7.53 (d, J = 8.5 Hz, 2 H, ArH), 7.42–7.36 (m, 1 H, ArH), 6.98
(td, J = 7.1, 1.0 Hz, 1 H, ArH), 6.81–6.78 (m, 1 H, ArH), 6.23 (t,
J = 3.3 Hz, 1 H, ArH), 5.59–5.54 (m, 2 H, ArH), 4.89 (br s, 1 H,
NH).
13C NMR (75 MHz, CDCl3): d = 163.5, 148.5, 146.8, 134.7, 134.3,
131.9, 128.6, 123.6, 122.3, 119.7, 119.6, 115.8, 111.4, 111.2, 56.7.
MS (ES+): m/z = 320.2 [M+ + 1].
Anal. Calcd for C18H12Cl2N2O: C, 62.99; H, 3.52; N, 8.16. Found:
C, 62.97; H, 3.52; N, 8.16.
11-(4-Bromophenyl)-7-chloro-10,11-dihydro-5H-pyrrolo[2,1-
c][1,4]benzodiazepin-5-one (6b)
Yellow solid; yield: 0.176 g (67%); mp 166–167 °C; Rf = 0.38
(EtOAc–hexane, 2:8).
IR (KBr): 3313, 1627, 1481, 1407, 1310, 1164 cm–1.
1H NMR (300 MHz, CDCl3): d = 8.35 (d, J = 2.5 Hz, 1 H, ArH),
7.67–7.65 (m, 1 H, ArH), 7.54 (dd, J = 6.6, 1.8 Hz, 2 H, ArH), 7.32–
7.28 (m, 3 H, ArH), 6.70 (d, J = 8.7 Hz, 1 H, ArH), 6.20 (t, J = 3.3
Hz, 1 H, ArH), 5.51 (t, J = 2.0 Hz, 1 H, ArH), 5.33 (s, 1 H, ArH),
4.77 (br s, 1 H, NH).
13C NMR (50 MHz, CDCl3): d = 162.7, 147.6, 137.8, 134.8, 133.7,
133.6, 132.3, 129.7, 125.4, 122.9, 122.8, 121.1, 117.3, 111.9, 111.8,
58.4.
Anal. Calcd for C18H13N3O3: C, 67.71; H, 4.10; N, 13.16. Found: C,
67.72; H, 4.11; N, 13.14.
7-Methyl-11-(4-nitrophenyl)-10,11-dihydro-5H-pyrrolo[2,1-
c][1,4]benzodiazepin-5-one (5a)
Yellow solid; yield: 0.212 g (85%); mp 186–188 °C; Rf = 0.38
(EtOAc–hexane, 2:8).
IR (KBr): 3308, 1724, 1631, 1507, 1409, 1330 cm–1.
MS (ES+): m/z = 387.2 [M+ + 1].
1H NMR (300 MHz, CDCl3): d = 8.23–8.20 (m, 2 H, ArH), 8.14 (s,
1 H, ArH), 7.73–7.71 (m, 1 H, ArH), 7.53–7.50 (m, 2 H, ArH),
7.27–7.19 (m, 1 H, ArH), 6.73–6.68 (m, 1 H, ArH), 6.22 (t, J = 3.3
Hz, 1 H, ArH), 5.58 (d, J = 1.9 Hz, 1 H, ArH), 5.51 (s, 1 H, ArH),
4.76 (br s, 1 H, NH), 2.31 (s, 3 H, CH3).
13C NMR (50 MHz, CDCl3): d = 163.7, 147.9, 146.6, 146.3, 136.3,
134.4, 132.8, 130.2, 128.9, 124.1, 123.0, 119.8, 116.7, 111.7, 111.6,
58.3, 20.4.
Anal. Calcd for C18H12BrClN2O: C, 55.77; H, 3.12; N, 7.23. Found:
C, 55.78; H, 3.10; N, 7.25.
8-Chloro-11-(4-chlorophenyl)-10,11-dihydro-5H-pyrrolo[2,1-
c][1,4]benzodiazepin-5-one (7a)
Yellow solid; yield: 0.203 g (87%); mp 144–146 °C; Rf = 0.45
(EtOAc–hexane, 2:8).
IR (KBr): 3308, 1627, 1478, 1415, 1322 cm–1.
1H NMR (300 MHz, CDCl3): d = 8.33 (d, J = 8.8 Hz, 1 H, ArH),
7.67–7.66 (m, 1 H, ArH), 7.41–7.31 (m, 4 H, ArH), 6.92 (dd,
J = 8.8, 1.9 Hz, 1 H, ArH), 6.78 (d, J = 1.9 Hz, 1 H, ArH), 6.20 (t,
J = 3.3 Hz, 1 H, ArH), 5.51 (s, 1 H, ArH), 5.36 (s, 1 H, CH), 4.79
(br s, 1 H, NH).
13C NMR (75 MHz, CDCl3): d = 163.1, 149.7, 140.9, 137.2, 136.5,
134.8, 133.6, 129.4, 129.3, 122.9, 120.8, 118.8, 114.9, 111.8, 58.2.
MS (ES+): m/z = 334.2 [M+ + 1].
Anal. Calcd for C19H15N3O3: C, 68.46; H, 4.54; N, 12.61. Found: C,
68.43; H, 4.56; N, 12.62.
11-(4-Chlorophenyl)-7-methyl-10,11-dihydro-5H-pyrrolo[2,1-
c][1,4]benzodiazepin-5-one (5b)
Yellow solid; yield: 0.196 g (81%); mp 168–170 °C; Rf = 0.66
(EtOAc–hexane, 2:8).
MS (ES+): m/z = 343.2 [M+ + 1].
IR (KBr): 3332, 2930, 1629, 1491, 1316 cm–1.
Anal. Calcd for C18H12Cl2N2O: C, 62.99; H, 3.52; Cl, 20.66; N,
8.16. Found: C, 62.97; H, 3.54; N, 8.18.
1H NMR (300 MHz, CDCl3): d = 8.17 (s, 1 H, ArH), 7.70–7.68 (m,
1 H, ArH), 7.39–7.32 (m, 4 H, ArH), 7.20–7.16 (m, 1 H, ArH), 6.65
(d, J = 8.2 Hz, 1 H, ArH), 6.18 (t, J = 3.3 Hz, 1 H, ArH), 5.46 (s, 1
H, ArH), 5.30 (s, 1 H, CH), 5.58 (br s, 1 H, NH), 2.31 (s, 3 H, CH3).
13C NMR (75 MHz, CDCl3): d = 163.9, 147.2, 137.9, 136.1, 134.7,
134.4, 129.9, 129.5, 129.3, 122.8, 121.6, 119.7, 116.6, 112.7, 111.5,
111.4, 107.0, 58.9, 20.5.
11-(4-Bromophenyl)-8-chloro-10,11-dihydro-5H-pyrrolo[2,1-
c][1,4]benzodiazepin-5-one (7b)
Yellow solid; yield: 0.205 g (78%); mp 154–155 °C; Rf = 0.40
(EtOAc–hexane, 2:8).
IR (KBr): 3350, 1638, 1478, 1419, 1323 cm–1.
MS (ES+): m/z = 323.2 [M+ + 1].
1H NMR (300 MHz, CDCl3): d = 8.33 (d, J = 8.8 Hz, 1 H, ArH),
7.67–7.66 (m, 1 H, ArH), 7.55 (d, J = 8.4 Hz, 2 H, ArH), 7.27 (d,
J = 8.4 Hz, 2 H, ArH), 6.93 (dd, J = 8.8, 1.9 Hz, 1 H, ArH), 6.78 (d,
J = 1.9 Hz, 1 H, ArH), 6.20 (t, J = 3.3 Hz, 1 H, ArH), 5.52 (s, 1 H,
ArH), 5.35 (s, 1 H, CH), 4.79 (br s, 1 H, NH).
13C NMR (50 MHz, CDCl3): d = 163.1, 149.7, 140.9, 137.8, 136.5,
133.5, 132.3, 129.7, 122.9, 122.8, 120.8, 118.8, 114.9, 111.8, 58.2.
Anal. Calcd for C19H15ClN2O: C, 70.70; H, 4.68; N, 8.68. Found: C,
70.74; H, 4.66; N, 8.66.
7-Chloro-11-(4-chlorophenyl)-10,11-dihydro-5H-pyrrolo[2,1-
c][1,4]benzodiazepin-5-one (6a)
Yellow solid; yield: 0.182 g (78%); mp 150–152 °C; Rf = 0.38
(EtOAc–hexane, 2:8).
IR (KBr): 3312, 1628, 1605, 1479, 1409, 1312, 1120 cm–1.
MS (ES+): m/z = 387.2 [M+ + 1].
Anal. Calcd for C18H12BrClN2O: C, 62.99; H, 3.52; N, 8.16. Found:
C, 62.98; H, 3.53; N, 8.15.
Synthesis 2010, No. 23, 4087–4095 © Thieme Stuttgart · New York