Table 1.

Optimization of the reaction conditions ^[a].

Entry	Base	Solvent	T (°C)	Yield (%) [b]
1	tBuOK	DMF [c]	110	77
2	tBuOK [d]	DMF [c]	110	75
3	tBuOK	DMF	110	81
4	tBuOK	DMF	110	48
				80
5	K2CO3	DMF	110	34
6	K3PO4	DMF	110	55
7	KOH	DMF	110	27
8	tBuOLi	DMF	110	75
9	NaOMe	DMF	110	55
10	tBuONa	DMF	110	74
11	tBuOK	DMF	90	73
12	tBuOK	DMF	130	41
13	tBuOK	DMAc	110	54
14	tBuOK	DMSO	110	30
15	tBuOK	Toluene	110	9
16	tBuOK	o-xylene	110	12
17	tBuOK	1,4-dioxane	110	15

^[a] Reaction conditions: 1 (1 mmol), 2 (1.5 mmol), base (2.0 equiv.), solvent (1 mL), 110 °C, 16 h. ^[b] Isolated yields. ^[c] DMF (2 mL). ^{[d] t}BuOK (3 equiv.).