864
S. Goswami, A. Hazra, and S. Jana
Vol 46
Scheme 2. Probable mechanism for the synthesis of pyridodiazepines and benzodiazepines.
7.34 (t, 4H, J ¼ 7.1 Hz), 7.29 (t, 1H, J ¼ 7.1 Hz), 5.22 (bs,
1H), 5.11 (m, 1H), 3.38 (d, 1H, J ¼ 14.0 Hz), 3.07 (dd, 1H, J
¼ 8.7, 13.9 Hz); 13C NMR (CDCl3, 125 MHz): dc (ppm):
168.2, 150.0, 146.6, 144.0, 140.3, 139.2, 132.2, 131.0, 129.4,
128.9, 128.7, 127.5, 126.3, 109.8, 66.1, 39.8; ms (HRMS-ESI):
m/z (%): Calculated for C20H16BrN3 is 378.0625, found
378.0921 [Mþ, 100], 380.0891 [(Mþ2H)þ, 93]. Anal. Calcd.
for C20H16BrN3: C, 63.50; H, 4.26; N, 11.11. Found: C, 63.41;
H, 4.35; N, 11.21.
cmꢂ1 1H NMR (CDCl3, 500 MHz): d (ppm): 8.04 (s, 1H),
;
7.79 (s, 1H), 7.76 (d, 2H, J ¼ 7.1 Hz), 7.52 (s, 1H), 7.39 (m,
4H), 7.32 (d, 1H, J ¼ 7.8 Hz), 7.19 (t, 1H, J ¼ 7.8 Hz), 5.13
(m, 1H), 5.12 (bs, 1H), 3.34 (d, 1H, J ¼ 13 Hz), 3.09 (dd, 1H,
J ¼ 8.9, 13.9 Hz); ms (FIA-MS): m/z (%): 458.1 [(MþH)þ,
97], 458.9 [(Mþ2H)þ, 25], 459.8 [(Mþ3H)þ, 35], 456.0
[(MꢂH)þ, 100], 454.1 [(Mꢂ3H)þ, 50], 356.1 (45), 276.1 (15),
188.1 (40); Anal. Calcd. for C20H15Br2N3: C, 52.55; H, 3.31;
N, 9.19. Found: C, 52.49; H, 3.36; N, 9.23.
7,8-Dibromo-2-(3-bromo-phenyl)-4-phenyl-2,3-dihydro-1H-
benzo[b][1,4]diazepine (3d). Yield: 65%; mp 88–89ꢁC; IR:
7,8-Dibromo-2,4-diphenyl-2,3-dihydro-1H-benzo[b][1,4]-
diazepine (3i). Yield: 68%; mp 71–72ꢁC; IR: 3360, 2918,
3356, 2922, 2863, 1658, 1568, 1248, 1021, 910 cmꢂ1
;
1H
2850, 1608, 1574, 1451, 1272, 1112, 1025, 885 cmꢂ1 1H
;
NMR (CDCl3, 400 MHz): d (ppm): 7.77 (d, 2H, J ¼ 7.1 Hz),
7.52 (s, 1H), 7.37 (m, 6H), 7.19 (m, 2H), 5.13 (m, 1H), 3.80
(bs, 1H), 3.21 (dd, 1H, J ¼ 3.7, 16.6 Hz), 3.03 (q, 1H, J ¼
13.3 Hz); ms (HRMS-ESI): m/z (%): Calculated for
C21H15Br3N2Na is 558.8683, found 558.8696 [(MþNa)þ, 50],
560.8768 [(Mþ2HþNa)þ, 10], 556.8659 [(M-2HþNa)þ, 100],
554.8785 [(M-4HþNa)þ, 50]. Anal. Calcd. for C21H15Br3N2:
C, 47.14; H, 2.83; N, 5.24. Found: C, 47.22; H, 2.69; N, 5.32.
9-Nitro-2,4-diphenyl-2,3-dihydro-1H-benzo[b][1,4]-diazepine
(3e). Yield: 35%; mp 86–88ꢁC; IR: 3062, 2934, 2846, 1680,
NMR (CDCl3, 400 MHz): d (ppm): 7.80 (d, 2H, J ¼ 6.9 Hz),
7.58 (s, 1H), 7.36 (m, 8H), 7.06 (s, 1H), 5.12 (m, 1H), 3.83
(bs, 1H), 3.26 (dd, 1H, J ¼ 3.6, 13.6 Hz), 3.03 (dd, 1H, J ¼
8.9, 13.66 Hz); ms (HRMS): m/z (%): Calcd for C21H16Br2N2
is 456.9766, found 456.9735 [Mþ, 100], 458.9732 [(Mþ2H)þ,
50], 454.9669 [(Mꢂ2H)þ, 50]. Anal. Calcd. for C21H16Br2N2:
C, 55.29; H, 3.54; N, 6.14. Found: C, 55.23; H, 3.62, N, 6.21.
2-(3-Bromophenyl)-9-nitro-4-phenyl-2,3-dihydro-1H-ben-
zo[b][1,4]diazepine (3j). Yield: 32%; mp 94–96ꢁC; IR: 3068,
2922, 2851, 1685, 1595, 1529, 1473, 1207, 1073 cmꢂ1 1H
;
1586, 1445, 1218, 1056, 982 cmꢂ1
;
1H NMR (CDCl3, 500
NMR (CDCl3, 400 MHz): d (ppm): 8.03 (d, 2H, J ¼ 8.3 Hz),
7.97 (t, 1H, J ¼ 8.4 Hz), 7.59 (d, 1H, J ¼ 9.2 Hz), 7.56 (m,
1H), 7.49 (m, 3H), 7.42 (d, 2H, J ¼ 7.0 Hz), 7.34 (m, 1H),
7.18 (t, 1H, J ¼ 7.8 Hz), 6.52 (q, 1H, J ¼ 8.5 Hz), 4.83 (dd,
1H, J ¼ 9.1, 16.9 Hz), 3.87 (dd, 1H, J ¼ 5.1, 17.9 Hz); ms
(FIA-MS): m/z (%): 421.2 [(MꢂH)þ, 20], 408.3 (30), 406.1
(20), 279.2 (100), 262.3 (80). Anal. Calcd. for C21H16BrN3O2:
C, 59.73; H, 3.82; N, 9.95. Found: C, 59.37; H, 4.37; N, 9.81.
2-(3-Bromo-phenyl)-1H-benzoimidazole (4). Yield: 5%; mp
MHz): d (ppm): 7.98 (m, 4H), 7.59 (m, 1H), 7.52 (d, 1H, J ¼
8.4 Hz), 7.44 (m, 2H), 7.42 (m, 1H), 7.40 (m, 2H), 7.32 (t,
2H, J ¼ 7.9 Hz), 6.57 (q, 1H, J ¼ 8.9 Hz), 4.87 (dd, 1H, J ¼
8.7, 18.9 Hz), 3.87 (dd, 1H, J ¼ 4.9, 17.9 Hz); ms (FIA-MS):
m/z (%): 347 [(Mþ4H)þ, 10], 328.2 [(Mþ3H-H2O)þ, 100],
209.2 (70); Anal. Calcd. For C21H17N3O2: C, 73.45; H, 4.99;
N, 12.24. Found: C, 72.95; H, 5.65; N, 12.23.
4-(3-Bromo-phenyl)-2-phenyl-4,5-dihydro-3H-pyrido[2,3-b][1,4]
diazepine (3f). Yield: 70%; mp 138–140ꢁC; IR: 3242, 3068,
1
245–247ꢁC; IR: 3342, 3121, 1621, 1534, 1012 cmꢂ1; H NMR
2910, 1665, 1575, 1448, 1226, 1120, 924 cmꢂ1
;
1H NMR
(CDCl3 þ d6-DMSO, 400 MHz): d (ppm): 8.41 (s, 1H), 8.17
(d, 1H, J ¼ 7.8 Hz), 7.76 (d, 1H, J ¼ 8.1 Hz), 7.56 (d, 1H, J
¼ 7.9 Hz), 7.50 (d, 1H, J ¼ 7.45 Hz), 7.38 (t, 1H, J ¼ 7.9
Hz), 7.23 (m, 2H); ms (FIA): m/z (%): 273.0 (Mþ, 98), 275.0
[(Mþ2)þ, 100].
(CDCl3, 500 MHz): d (ppm): 8.03 (s, 1H), 7.77 (d, 2H, J ¼
6.8 Hz), 7.66 (d, 1H, J ¼ 7.7 Hz), 7.54 (s, 1H), 7.39 (m, 5H),
7.18 (t, 1H, J ¼ 7.8 Hz), 6.92 (dd, 1H, J ¼ 7.7 Hz), 5.17 (m,
1H), 5.12 (bs, 1H), 3.33 (dd, 1H, J ¼ 2.8, 13.8 Hz), 3.10 (dd,
1H, J ¼ 8.2, 13.9 Hz); ms (FIA-MS): m/z (%): 378.1 [Mþ,
100], 380.1 [(Mþ2H)þ, 80], 196.2. Anal. Calcd. for
C20H16BrN3: C, 63.50; H, 4.26; N, 11.11. Found: C, 63.57; H,
4.30; N, 11.02.
Acknowledgment. The authors thank DST [SR/S1/OC-13/
2005], Government of India for financial support and the CSIR,
Government of India for the research fellowship.
2,4-Diphenyl-2,3-dihydro-1H-benzo[b][1,4]diazepine (3g). Yield:
85%; mp 112–114ꢁC; IR: 3336, 3020, 2925, 1610, 1580, 1470,
1
1238, 1125, 940 cmꢂ1; H NMR (CDCl3, 500 MHz): d (ppm):
REFERENCES AND NOTES
7.84 (d, 2H, J ¼ 7.9 Hz), 7.35 (m, 9H), 7.04 (m, 2H), 6.82 (d,
1H, J ¼ 7.6 Hz), 5.18 (q, 1H, J ¼ 9.1 Hz), 3.77 (bs, 1H), 3.24
(dd, 1H, J ¼ 3.8, 13.5 Hz), 3.05 (q, 1H, J ¼ 13.5 Hz); ms
(FIA-MS): m/z (%): 299.3 [(MþH)þ, 100], 284.2, 195.2. Anal.
Calcd. for C21H18N2: C, 84.53; H, 6.08; N, 9.39. Found: C,
84.58, H, 6.17; N, 9.33.
8-Bromo-4-(3-bromo-phenyl)-2-phenyl-4,5-dihydro-3H-pyr-
ido[2,3-b][1,4]diazepine (3h). Yield: 65%; mp 130–132ꢁC; IR:
3239, 3056, 2922, 2852, 1669, 1573, 1472, 1214, 1071, 900
[1] Present address: Department of Chemistry, University of
Victoria, Victoria, Canada.
[2] (a) Randall, L. O.; Kamal, B. In Benzodiazepines; Garattini,
S.; Mussini, E.; Randall, L. O., Eds.; Raven Press: New York, 1973,
p27 and references cited therein; (b) Baun, J. R. D.; Pallos, F. M.;
Baker, D. R. U.S. Pat. 3,978,227 (1976); Baun, J. R. D.; Pallos, F. M.;
Baker, D. R. Chem Abstr 1977, 86, 5498d.
[3] (a) Schutz, H. Benzodiazepines; Springer: Heidelberg, 1982.
(b) Landquist, J. K. In Comprehensive Heterocyclic Chemistry;
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet