Table 1. Optimization of the reaction conditions ^a .

#	Base (0.1 eq.)	Solvent	Temp./time	Yield (%)
1	Cs2CO3	DMSO	30 °C/6 h	90 b
2	Cs2CO3	DMSO	80 °C/1 h	87
3	Cs2CO3	DMSO	100 °C/1 h	96
4	KOH	DMSO	100 °C/0.5 h	96 (92 c )
5	K2CO3	DMSO	100 °C/1 h	82
6	NEt3	DMSO	100 °C/1 h	0
7	KOH	DMF	100 °C/0.5 h	60
8	KOH	MeCN	100 °C/0.5 h	55
9	KOH	EtOH	100 °C/0.5 h	35
10	Cs2CO3	EtOH	100 °C/0.5 h	0

^aConditions: 1a (1.15–1.25 mmol), 3a (1 mmol), solvent (2 mL); microwave heating, sealed tube; isolated yield.

^bWorkup with aq. HCl (1 M).

^c 3a (5 mmol).