Synthesis of isoxazole-lactams 3(a–r)^aa.

Entry	Acids (R1)	Amines (R2)	Time (h)	Yield (%)b
1	Me (2a)	4-Ts	24	78 (3a)
2	nPr (2b)	4-Ts	24	80 (3b)
3	Ph (2c)	4-Ts	18	82 (3c)
4	4-MeC6H4 (2d)	4-Ts	12	82 (3d)
5	4-OMeC6H4 (2e)	4-Ts	12	79 (3e)
6	4-FC6H4 (2f)	4-Ts	12	85 (3f)
7	4-ClC6H4 (2g)	4-Ts	12	88 (3g)
8	2,6-di-Cl-C6H3 (2h)	4-Ts	12	80 (3h)
9	4-BrC6H4 (2i)	4-Ts	12	86 (3i)
10	4-lC6H4 (2j)	4-Ts	12	79 (3j)
11	4-CF3C6H4 (2k)	4-Ts	12	88 (3k)
12	CO2Et (2l)	4-Ts	24	78 (3l)
13	Me (2a)	PMB	18	80 (3m)
14	Ph (2c)	PMB	18	85 (3n)
15c	Ph (2o)	PMB	18	87 (3o)
16	Me (2a)	4-Csd	24	89 (3p)
17	nPr (2b)	4-Csd	24	89 (3q)
18	Ph (2c)	4-Csd	12	88 (3r)

^aDMAP (1.4 equiv.) was added to a suspension of EDC (1.3 equiv.) in DCM (1 M). The corresponding carboxylic acid (1 equiv.) and amine (1.2 equiv.) were then added at 0 °C. The mixture was stirred at room temperature for (12–24) hours.

^bIsolated yield based on 2.

^c n = 2.

^d(4-Cs = 4-ClC₆H₄SO₂).