How to convert benzene Diazonium chloride to phenol?

Converting benzene diazonium chloride to phenol involves a reaction called the Sandmeyer reaction. Here are the steps to carry out this transformation:

Materials Needed:

Benzene diazonium chloride (prepared from aniline and nitrous acid)
Sodium nitrite (NaNO2)
Hydrochloric acid (HCl)
Copper(I) chloride (CuCl)
Water (H2O)
Ice
Sodium hydroxide (NaOH)
Sulfuric acid (H2SO4)
Separatory funnel
Procedure:

Preparation of Diazonium Salt:
a. Start with aniline (C6H5NH2).
b. Mix aniline with a cold solution of nitrous acid (HNO2). This will generate benzene diazonium chloride (C6H5N2Cl).
c. Keep the reaction mixture cold by placing it in an ice bath, as diazonium salts are unstable at higher temperatures.
d. Stir the mixture until the diazonium salt is formed.

Conversion to Phenol:
a. In a separate flask, prepare a solution of sodium nitrite (NaNO2) in water (H2O).

Sandmeyer Reaction:
a. Add the sodium nitrite solution dropwise to the cold diazonium salt solution with stirring. This will lead to the formation of phenol and the evolution of nitrogen gas (N2). The reaction can be represented as follows:

C6H5N2Cl + H2O → C6H5OH (Phenol) + N2 + HCl

b. To ensure the reaction proceeds at a controlled rate and to promote the formation of phenol, add a catalytic amount of copper(I) chloride (CuCl) to the mixture.

Isolation of Phenol:
a. Once the reaction is complete, you will have a mixture containing phenol, HCl, and other by-products.
b. Neutralize the mixture by adding a solution of sodium hydroxide (NaOH) until the pH becomes slightly basic.
c. The phenol will separate into the aqueous phase.
d. Extract the phenol from the aqueous solution using a separatory funnel.

Purification of Phenol:
a. The crude phenol obtained from the previous step may contain impurities.
b. To purify it, distill the phenol under reduced pressure (vacuum distillation) or recrystallize it from a suitable solvent like water.

Collection of Pure Phenol:
a. Collect the pure phenol, which will have a melting point of approximately 40-41°C.

Please exercise caution when working with diazonium salts, as they can be hazardous due to their instability. Perform this reaction in a well-ventilated and controlled laboratory environment, and wear appropriate safety gear, including gloves and protective eyewear. Additionally, follow all safety protocols and guidelines for handling chemicals.