Table 3.

Synthesis of compounds 5^a

Entry	2	R	Time (h)	Yield (%)b
1	2a	Ph	5	5a (68)
2	2b	4-MeOC6H4	5	5b (77)
3	2c	4-ClC6H4	6	5c (71)
4	2d	3-NO2C6H4	5	5d (76)
5	2e	3-MeC6H4	6.5	5e (52)
6	2f	4-MeC6H4	5.5	5f (73)
7	2g	3,4-(Me)2C6H4	7	5g (55)
8	2h	3-MeOC6H4	5	5h (74)
9	2i	4-BrC6H4	5.5	5i (65)
10	2j	3,4-(MeO)2C6H4	7	5j (71)

^aThe reactions were carried out with 2(1 mmol), pyridine(0.1 mL), acetic anhydride(1 mL) under reflux at 85 °C.

^bAll the yields were isolated yields.