Question

Provide the experimental conditions for the preparation of Salicylic acid. (step by step procedure to create the substance)(the recipe for the compound in other words)

Answer 1

Dissolve 10 g of NaOH solid in 15 ml water. Gradually add 23 g of phenol. Heat the resulting mixture with stirring, so that water is evaporated. The caked mass is then powdered as it cools. The powder is heated, until it is dry enough to form dust.

It is then itransfered to a 250 ml distillation flask and heated to 140 deg C in presence of dry hydrogen.

After about 1 hour, the mass is cooled gradually in the current of hydrogen, and powdered.

This gives perfectly dry, uncharred, well-powdered sodium phenate.

Carbon dioxide, is passed over sodium phenate through the distillation apparatus and heated. It is then cooled, and the phenol is melted heating the outside of the neck. The crude reaction product is taken into a large beaker. It is boiled, and 100 ml conc. hydrochloric acid are added. It is then cooled ice-water, and crude salicylic acid is precipitated by rubbing the sides of the vessel with a glass rod.

The precipitate is filtered, washed with a little cold water, and dried on a porous plate.