Table 1.

Optimization of reaction conditions.

Entry	2a (equiv.)	Pyrrolidine (equiv.)	Base	Solvent	T (°C)	t (min)	Yield of 3a (%)
1	1	2	K2CO3	DMSO	189	30	16b
2	1	2	K2CO3	DMSO	189	180	22b
3	1	2	K2CO3	DMF	120	30	22c
4	1	2	K2CO3	NMP	200	30	55c
5	1	2	K2CO3	DMSO	200	30	93c
6	1	2	DBU	DMSO	200	30	30c
7	1	2	NaOH	DMSO	200	30	80c
8	1	1	K2CO3	DMSO	200	30	30c
9	1	2	K2CO3	DMSO	180	30	71c
10	1	2	K2CO3	DMSO	220	30	83c
11	1	2	K2CO3	DMSO	200	20	70c

^a The yields were determined by HPLC and LC–MS spectroscopy of the crude reaction mixture.

^b The reactions were carried out with stirring under refluxing in an oil bath.

^c The reactions were carried out with stirring under microwave irradiation.