Facile synthesis of tetrazoles catalyzed by the new copper nano-catalyst

Figures & data

Scheme 1. Synthesis of the new Cu nano-catalyst.

Scheme 2. Synthesis of diverse tetrazoles.

Figure 1. Comparison of the FT-IR spectra of five compounds (A, B, C, D and E).

Figure 2. The XRD patterns of B (blue,), C (red), D (purple) and E (green).

Figure 3. The EDX analysis of the catalyst.

Figure 4. The SEM images of the catalyst.

Figure 5. The TEM images of the catalyst.

Figure 6. The particle size distribution histograms of the Cu nano-catalyst.

Figure 7. The TGA-DTA patterns of the catalyst in N₂ atmosphere.

Figure 8. The VSM analyses of A, B, C, D and E.

Table 1. Effect of the amount of the catalyst on the synthesis of 1-(4-nitrophenyl)-1H-tetrazole in solvent-free condition at 100°C.

Entry	Catalyst (mg)	Time (h)	Yield (%)
1	10	2	Trace
2	20	2	30
3	30	2	55
4	40	2	70
5	50	2	94

Table 2. Effect of solvent on the synthesis of 1-(4-nitrophenyl)-1H-tetrazole at 100°C.

Entry	Solvent	Time (h)	Yield (%)
1	H2O	2	Trace
2	EtOH	2	15
3	DMF	2	70
4	Toluene	2	46
5	DMSO	2	57
6	Solvent-free	2	94

Table 3. Effect of temperature on the synthesis of 1-(4-nitrophenyl)-1H-tetrazole in solvent-free condition.

Entry	T (°C)	Time (h)	Yield (%)
1	rt	2	Trace
2	40	2	51
3	80	2	75
4	100	2	94

Table 4. Synthesis of various tetrazoles (2a–j).

Entry	Substrate	Product	Time (min)	Yield (%)	Mp (°C) Found, (Lit) ( 24)
1			85	89	63–66 (64–65)
2			90	83	132–134 (133–135)
3			90	91	93–95 (94–95)
4			100	92	113–115 (114–115)
5			100	88	174–177 (177)
6			180	78	176–180 (183–185)
7			90	87	127–131 (127–131)
8			180	90	156–158 (157–158)
9			120	94	199–203 (201–202)
10			120	83	124–128 (125–127)

Scheme 3. The suggested mechanism for the synthesis of tetrazoles.

Figure 9. The reusability of the Cu nano-catalyst.

Habibi, D.; Nasrollahzadeh, M.; Kamali, T.A. Green Chem. 2011, 13, 3499–3504. doi: 10.1039/c1gc15245a

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