Synthesis and antibacterial activity of some 5-(4-biphenylyl)-7-Aryl[3,4-d]-1,2,3-benzoselenadiazoles

Figures & data

Table I.  Physical and analytical data for 7(a–j).

				Elemental analysis %
Compound. No.	m.p°C	Yield* %	Molecular formula	Carbon found/calcd.	Hydrogen found/calcd.	Nitrogen found/calcd.
7a	118–120	38	C24H16N2Se	70.26 / 70.07	3.98 / 3.89	7.02 / 6.81
7b	151–159	49	C24H15N2BrSe	67.86 / 67.13	3.65 / 3.49	5.99 / 5.39
7c	176–177	44	C24H15N2SeCl	64.99 / 64.71	3.70 / 3.37	6.51 / 6.29
7d	164–165	37	C24H15N2ClSe	63.82 / 64.71	3.49 / 3.37	6.73 / 6.29
7e	128–129	35	C24H15N2FSe	58.51 / 58.77	3.22 / 3.06	5.28 / 5.71
7f	179–181	40	C24H15N3O2Se	62.97 / 63.15	3.51 / 3.28	9.45 / 9.21
7 g	122–124	50	C24H15N3O4Se	63.71 / 63.15	3.74 / 3.28	9.71 / 9.21
7 h	177–179	36	C24H18N2OSe	68.69 / 68.02	4.59 / 4.08	6.56 / 6.34
7i	160–161	41	C25H18N2Ose	69.07 / 68.02	4.39 / 4.08	6.92 / 6.34
7j	163–165	52	C30H20N2O2Se	70.27 / 69.36	3.38 / 3.85	6.56 / 6.34

*Isolated yield of purified product

Table II.  ¹H and ¹³C NMR spectral data for 7(a–j).

	^1H NMR (δ, ppm)					^13C NMR (δ, ppm)
Compound No.	CH3	H-4	H-6	Ar-H	CH3	C-9	C-8	C-7	C-5	C-4	ipso carbons	Aromatic carbons and C-6
7a	–	8.90 (d)	8.00 (d)	7.26–7.85 (m)	–	162.9	144.1	141.1	142.6	123.0	140.4, 138.3	127.1–129.3
7b	–	8.90 (d)	7.95 (d)	7.19–7.84 (m)	–	161.7	144.1	140.2	141.1	123.0	137.2, 138.0, 138.7	125.7–130.7
7c	–	8.94–8.95 (d)	7.95 (d)	7.23–7.85 (m)	–	162.2	145.7	140.4	141.2	123.4	138.1, 137.7, 135.6	127.0–130.3
7d	–	8.90 (d)	7.95–7.96 (d)	7.25–7.84 (m)	–	162.9	141.3	140.3	141.1	123.3	138.1, 137.1, 135.0	127.1–129.5
7e	–	8.91 (d)	8.00 (d)	7.26–7.86 (m)	–	160.1	145.4	138.2	144.6	122.0	134.9, 136.6, 137.0	127.0–130.5
7f	–	8.97 (d)	8.03–8.04 (d)	7.25–7.86 (m)	–	163.1	144.2	140.3	141.6	124.1	137.7, 135.9, 132.8	127.1–130.3
7 g	–	8.97 (d)	8.03 (d)	7.25–7.88 (m)	–	163.1	148.1	141.5	143.9	124.5	140.2, 137.6, 136.0	127.1–128.9
7 h	3.82 (s)	8.91 (d)	7.97–7.98 (d)	7.04–7.85 (m)	55.3	162.2	141.0	140.3	140.5	122.7	156.2, 138.5, 135.3	111.5–130.9
7i	3.89 (s)	8.86 (d)	7.95 (d)	7.03–7.77 (m)	55.3	162.7	143.9	140.3	141.0	122.4	160.1, 138.3, 138.0, 135.0	114.6–128.8
7j	–	8.89 (d)	7.98 (d)	7.01–7.83 (m)	–	163.5	144.9	141.8	144.6	120.1	159.0, 141.0, 138.8, 138.3	117.6–131.3

Scheme 1 Synthetic pathway to compounds 7a–j.

Table III.  In vitro antibacterial activity of 7a–j and standard (MIC μg ml⁻¹).

Compounds	S. aureus	B. subtilis	E. coli	K. pneumoniae
7a	0.64	0.50	>60	>60
7b	0.20	0.16	11	45
7c	0.43	0.41	>60	>60
7d	0.32	0.29	26	55
7e	0.25	0.22	18	48
7f	0.55	0.51	>60	>60
7 g	0.41	0.38	37	51
7 h	0.55	0.45	44	>60
7i	0.68	0.58	>60	>60
7j	0.58	0.52	49	>60
Norfloxacin	0.51	0.018	0.15	0.05