To a RBF add 2 g of sodium cyanide and 6 mL of water, 20 g of benzaldehyde and 20 mL of ethanol. Reflux gently for 2 h, then remove the condenser and heat until some solid starts to form, then let it stand for 1 h. Filter wash the filtrate with 2x 10 mL of cold water and 30 mL of cold ethanol. The product is quite pure but should be recrystallized from ethanol.
The reagents were combined
After the reflux, the solution turned more yellow
On cooling the benzoin starts to crystallize
The benzoin crystallized out
Filtering and washing
The almost pure benzoin