Table 2.

Preparation method II of bis-1,2,4-oxadiazoles 4a-4h.

Product 4	R	Method I		Method II
		Reaction Time (h)	Yield (%)[a]	Reaction Time (h)	Yield (%)[a]
4a	Ph	6	85	10	63
4b	4-CH3C6H4	6	92	10	71
4c	4-ClC6H4	6	81	10	65
4d	4-FC6H4	6	83	10	61
4e	3-ClC6H4	6	79	10	59
4f	4-BrC6H4	6	86	10	69
4g	4-NO2C6H4	6	82	10	58
4h	Cyclohexyl	6	72	10	53

Note: [a] Isolated yield.