Table 5.

Ultrasound assisted synthesis of compound 3c-j.^a

1; R’, R =	Time	Product (3)	%Yieldb
1a; H, Ph	1.5	3c	67
1b; H, C6H4Me-p	1.5	3d	71
1c; H, t-Bu	2	3e	59
1d; H, CMe2OH	1.5	3f	63
1e; H, n-Bu	1.5	3g	73
1f; H, H	2	3h	60
1g; Me. Ph	4	3i	65
1h; Me, C6H4Me-p	1.5	3j	62

^aAll the reactions were carried out by using 1 (2.5 mmol), 2d (2.8 mmol), Cu(OAc)₂ (0.025 mmol) and Et₃N (3.77 mmol) in DMF (3 mL) under ultrasound.

^bIsolated yield.