Aqueous NaOH (10 ml of a 1.5 M solution) was added to a stirred
solution of 2-acetyl pyridine (1.20 g; 10 mmol) and 1-
pyrenecarbaldehyde (2.30 g; 10 mmol) in ethanol (20 ml). After
stirring for 4 h at room temperature, the resultant orange precipitate
was isolated by filtration and re-crystallized from ethanol to
give L as yellow needles (3.00 g; 90%). Elemental analyses for
C24H15NO