Table 1:

Reaction Development

entry	change to conditions	T (°C)	t (h)	yield 3a (%)b
1	None	100	24	88 (86)
2	CuCl2 (1.0 equiv)	100	24	42
3	CuCl2 (1.5 equiv)	100	24	63
4	None	60	24	20
5	FeCl3 or CuCl instead of CuCl2	100	24	0
6	DMSO instead of MeCN	100	24	40
7	DMF instead of MeCN	100	24	44

^aReaction conditions: 1 (0.10 mmol), 2 (0.25 mmol,), CuCl₂ (0.2 mmol), MeCN (1 mL), 100 °C, 24 h.

^bYields as judged by ¹HNMR spectrocscopy with CH₂Br₂ as internal standard. Yield in parentheses is the isolated yield.