Effect of different solvents on the model reaction^a.

Entry	Solvent	Temperature (°C)	Yieldb (%)
1	Water	80	79
2	Methanol	Reflux	84
3	Ethanol	80	96
4	Propanol	80	67
5	Dioxane	80	28
6	THF	Reflux	16
7	Acetonitrile	Reflux	38
8	Ethyl acetate	Reflux	41
9	Chloroform	Reflux	N.R
10	Solvent free	80	N.R

^aReaction conditions: 4-bromobenzaldehyde (1 mmol), benzil (1 mmol), ammonium acetate (3 mmol), MC–SO₃H (20 mg), solvent (4 mL), 2 h.

^bIsolated yield.