Effect of temperature on the synthesis of 2,4,6-triphenylpyridine^a.

Entry	Temp. (°C)	Yieldb (%)
1	Room temp.	—
2	45	36
3	60	67
4	80	93
5	85	93

^aReaction condition: benzaldehyde (1 mmol), acetophenone (2 mmol), ammonium acetate (1.5 mmol), HNTf₂ (1 mol%) at different temperature for 50 min under solvent-free conditions.

^bIsolated yield.