To a reflux apparatus add 18 g of β-naphthol, 50 mL of warm water and 5.3 g of NaOH with stirring, after everything has dissolved add 23,3g of methyl tosylate to the solution with vigorous stirring and heat in reflux for 4h. After the reflux, quickly pour the hot solution into 200 mL of ice water with some mechanical stirring, filter and wash with 60 mL of water. Recrystallize the crude product from methanol without heating.
The solution darkens after the addition of the TsCl
Refluxing the solution
The crude product
The recrystallized product