Advances in Chemistry

Research Article

A Simple and Advantageous Synthesis of the Privileged 1,4-Benzodiazepine Nucleus

Table 1

Physical and spectral data of the compounds 2(a–i) and 4(a–i).


Entry	Molecular formula	M.W.	M.P. (°C)^a	Yield (%)	IR (KBr) cm⁻¹	¹H NMR (CDCl₃-DMSO-d₆) ppm	Elemental analysis
Entry	Molecular formula	M.W.	M.P. (°C)^a	Yield (%)	IR (KBr) cm⁻¹	¹H NMR (CDCl₃-DMSO-d₆) ppm	C (cald/exp.)	H (cald/exp.)	N (cald/exp.)

2a	C₁₀H₆ClNO₃	223.61	210–12	91	1735, 1680, 1675	7.56–7.19 (m, 4H, ArH), 4.32 (s, 2H, CH₂)	53.71/53.67	2.70/2.65	6.26/6.18
2b	C₁₀H₅ClFNO₃	241.60	165–66	88	1755, 1725, 1700	7.81–7.23 (m, 3H, ArH), 4.33 (s, 2H, CH₂)	49.71/49.67	2.49/2.40	5.80/5.69
2c	C₁₀H₅Cl₂NO₃	258.06	153–55	94	1785, 1740, 1720	7.81–7.53 (m, 3H, ArH), 4.32 (s, 2H, CH₂)	46.54/46.42	1.95/1.90	5.43/531
2d	C₁₀H₅BrClNO₃	302.51	178–79	90	1780, 1735, 1710	7.96–7.61 (m, 3H, ArH), 4.32 (s, 2H, CH₂)	39.70/39.62	1.67/1.56	4.63/4.59
2e	C₁₀H₅ClINO₃	349.51	206–07	89	1770, 1725, 1690	7.80–7.50 (m, 3H, ArH), 4.28 (s, 2H, CH₂)	28.95/28.89	1.21/1.17	3.38/3.27
2f	C₁₁H₈ClNO₃	237.64	185–86	92	1765, 1720, 1690	7.72–7.03 (m, 3H, ArH), 4.32 (s, 2H, CH₂), 2.85 (s, 3H, CH₃)	55.60/55.51	3.39/3.28	5.89/5.80
2g	C₁₁H₈ClNO₄	253.64	223–25	90	1780, 1740, 1705	7.72–7.03 (m, 3H, ArH), 4.32 (s, 2H, CH₂), 3.73 (s, 3H, OCH₃)	52.09/51.97	3.18/3.12	5.52/5.42
2h	C₁₀H₅ClN₂O₅	268.61	130–32	91	1785, 1745, 1710	8.72–8.09 (m, 3H, ArH), 4.52 (s, 2H, CH₂)	44.71/44.56	1.88/1.71	10.43/10.37
2i	C₁₂H₁₀ClNO₃	251.67	168–70	92	1740, 1700, 1685	7.40–7.12 (m, 2H, ArH), 4.32 (s, 2H, CH₂), 2.35 (s, 6H, CH₃)	57.27/57.19	4.01/3.97	5.57/5.46
4a	C₁₁H₁₀N₂O₃	218.21	172–75	85	3190, 1725, 1675	8.0 (s, 1H, NH), 7.98–7.65 (m, 4H, ArH), 4.48 (s, 2H, CH₂), 3.65 (s, 3H, OCH₃) MS: (%) 218.21 (M+, 100%), 210.20 (75%), 107.16 (35%)	60.55/60.48	4.62/4.52	12.84/12.79
4b	C₁₁H₉FN₂O₃	236.20	198–200	87	3220, 1735, 1690	8.2 (s, 1H, NH), 8.08 (d, 1H, ArH), 7.78 (d, 1H, ArH), 7.66 (s, 1H, ArH), 4.56 (s, 2H, CH₂), 3.78 (s, 3H, OCH₃) MS: (%) 236.20 (M+ 75%), 205.17 (100%), 177.16 (35%)	55.93/55.88	3.84/3.79	11.86/11.76
4c	C₁₁H₉ClN₂O₃	252.65	176–78	84	3215, 1728, 1684	8.1 (s, 1H, NH), 7.90 (s, 1H, ArH), 7.81 (d, 1H, ArH), 7.60 (d, 1H, ArH), 4.48 (s, 2H, CH₂), 3.70 (s, 3H, OCH₃) MS: (%) 252.65 (M+, 100%), 254.57 (M+2, 33%)	52.29/52.23	3.59/3.51	11.09/11.00
4d	C₁₁H₉BrN₂O₃	297.98	243–45	86	3208, 1721, 1675	8.0 (s, 1H, NH), 7.90 (s, 1H, ArH), 7.75 (d, 1H, ArH), 7.50 (d, 1H, ArH), 4.32 (s, 2H, CH₂), 3.12 (s, 3H, OCH₃) MS: (%) 297.98 (M+, 100%), 299.90 (M+2, 100%), 177.16 (35%)	44.47/44.41	3.05/2.99	9.43/9.36
4e	C₁₁H₉IN₂O₃	344.11	187–88	90	3200, 1710, 1670	8.0 (s, 1H, NH), 7.85 (s, 1H, ArH), 7.66 (d, 1H, ArH), 7.40 (d, 1H, ArH), 4.32 (s, 2H, CH₂), 3.12 (s, 3H, OCH₃) MS: (%) 344.11 (M+ 75%), 205.17 (100%), 147.16 (35%)	38.39/38.29	2.64/2.59	8.14/8.07
4f	C₁₂H₁₂N₂O₃	232.24	205–06	85	3188, 1723, 1672	8.0 (s, 1H, NH), 7.84 (s, 1H, ArH), 7.56 (d, 1H, ArH), 7.42 (d, 1H, ArH), 4.32 (s, 2H, CH₂), 3.12 (s, 3H, OCH₃), 2.34 (s, 3H, CH₃) MS: (%) 232.24 (M+ 72%), 177.25 (25%), 149.17 (100%)	62.60/62.52	5.21/5.17	12.06/11.96
4g	C₁₂H₁₂N₂O₄	248.08	182–85	87	3202, 1728, 1677	8.0 (s, 1H, NH), 7.88 (d, 1H, ArH), 7.75 (d, 1H, ArH), 7.43 (s, 1H, ArH), 4.33 (s, 2H, CH₂), 3.12 (s, 3H, OCH₃), 3.63 (s, 3H, OCH₃) MS: (%) 248.08 (M+ 68%), 240.11 (100%), 163.45 (36%)	58.06/57.98	4.87/4.79	11.29/11.19
4h	C₁₁H₉N₃O₅	263.05	202–05	83	3228, 1735, 1698	8.0 (s, 1H, NH), 8.12 (s, 1H, ArH), 7.98 (d, 1H, ArH), 7.66 (d, 1H, ArH), 4.55 (s, 2H, CH₂), 3.42 (s, 3H, OCH₃) MS: (%) 263.05 (M+ 65%), 201.17 (100%), 170.80 (35%)	50.20/50.13	3.45/3.34	15.96/15.89
4i	C₁₃H₁₄N₂O₃	246.26	215–17	88	3185, 1720, 1670	8.0 (s, 1H, NH), 7.40 (s, 2H, ArH), 4.30 (s, 2H, CH₂), 3.10 (s, 3H, OCH₃), 2.34 (s, 3H, for two CH₃) MS: (%) 246.26 (M+ 100%), 145.17 (86%), 104.16 (27%)	63.40/63.31	5.73/5.69	11.38/11.33

All the melting points (M.P.) were found to be identical to the authentic samples prepared according to the procedure reported in the literature [22].
M.W.: Molecular Weight; cald./exp.: calculated/experimental.