Table 2. Investigation of the catalyst loading effect on the synthesis of compound 3a^a.

Entry	Amount of the catalyst system	Yieldb (%)
1	FeCl3·6H2O (5 mol%)	78
2	FeCl 3 ·6H 2 O (10 mol%)	84
3	FeCl3·6H2O (15 mol%)	84

^aReaction conditions: methyl arene 1a (1.0 mmol), acetophenone 2a (1.0 mmol), and iron as the catalyst 3a (10 mmol).

^bIsolated yields.