Table 3.

Three-component heterocyclization of 5-amino-3-methylisoxazole (1), salicylaldehyde (2) and N-aryl-3-oxobutanamides (3a–h).

Entry	Amide	Conditions	Product	Yield, %
1	3a	EtOH, ))), rt, 4 h	4a	58
2		EtOH, Yb(OTf)3 (5 mol %), rt, 48 h	5a	69
3		EtOH, Yb(OTf)3 (5 mol %), ))), rt, 4 h	6a	66
4	3b	EtOH, ))), rt, 4 h	4b	54
5		EtOH, Yb(OTf)3 (5 mol %), rt, 48 h	5b	70
6		EtOH, Yb(OTf)3 (5 mol %), ))), rt, 4 h		69
7	3c	EtOH, ))), rt, 4 h	4c	51
8		EtOH, Yb(OTf)3 (5 mol %), rt, 48 h	5c	68
9		EtOH, Yb(OTf)3 (5 mol %), ))), rt, 4 h	6c	64
10	3d	EtOH, ))), rt, 4 h	4d	58
11		EtOH, Yb(OTf)3 (5 mol %), rt, 48 h	5d	61
12		EtOH, Yb(OTf)3 (5 mol %), ))), rt, 4 h		65
13	3e	EtOH, ))), rt, 4 h	4e	57
14		EtOH, Yb(OTf)3 (5 mol %), rt, 48 h	9e	72
15		EtOH, Yb(OTf)3 (5 mol %), ))), rt, 4 h		81
16	3f	EtOH, ))), rt, 4 h	4f	59
17		EtOH, Yb(OTf)3 (5 mol %), rt, 48 h	9f	77
18		EtOH, Yb(OTf)3 (5 mol %), ))), rt, 4 h		75
19	3g	EtOH, ))), rt, 4 h	4g	63
20		EtOH, Yb(OTf)3 (5 mol %), rt, 48 h	9g	76
21		EtOH, Yb(OTf)3 (5 mol %), ))), rt, 4 h		82
22	3h	EtOH, ))), rt, 4 h	4h	55
23		EtOH, Yb(OTf)3 (5 mol %), rt, 48 h	5h	61
24		EtOH, Yb(OTf)3 (5 mol %), ))), rt, 4 h		63