Laboratory Experiments of B.Sc. II Sem BT/FS/CBZ - Experiment: 7

  Laboratory Experiments of B.Sc. II Sem BT/FS/CBZ

 

Dr. Navdeep Sharma
Institute of Sciences
SAGE University, Indore (M.P.)

 

Experiment: 7


Objective:

Benzoylation of Phenols

Principle:

Benzoylation is an acylation reaction in which the hydrogen atom of –OH group is replaced by a benzoyl group (C₆H₅CO–).
This reaction is carried out in the presence of aqueous NaOH to neutralize the HCl formed.

The general reaction is:

C6H5OH + C6H5COCl → NaOHC6H5OCOC6H5 + HCl

This reaction is also called the Schotten–Baumann reaction.

Materials Required:

Chemicals

Apparatus

Phenol or Aniline

Beaker (100 mL)

Benzoyl chloride

Measuring cylinder

Sodium hydroxide (NaOH)

Stirring rod

Distilled water

Funnel and filter paper

Ice (optional)

Conical flask

 

Procedure:

  1. Dissolve 2 g of phenol in 10 mL of 10% NaOH solution in a beaker.
  2. Cool the solution in an ice bath.
  3. Slowly add 2.5 mL of benzoyl chloride with continuous stirring.
  4. Stir vigorously for 15–20 minutes until the white solid appears.
  5. Filter the product, wash with cold water to remove unreacted materials.
  6. Recrystallize the product from hot ethanol.
  7. Dry and note the melting point of phenyl benzoate.

Observation Table:

Compound Used

Product Formed

Appearance

Melting Point (°C)

Phenol

Phenyl benzoate

White crystals

~69–70 °C

 

Result:

The benzoylation reaction of phenol was successfully carried out to yield the corresponding benzoyl derivative.

Precautions:

  • Benzoyl chloride is corrosive and irritating—handle with care.
  • Carry out the experiment in a well-ventilated area or fume hood.
  • Maintain low temperature using ice during addition.
  • Stir continuously to ensure complete reaction.

Comments

Post a Comment

Popular posts from this blog

Laboratory Experiments of B.Sc. II Sem BT/FS/CBZ - Experiment: 1

Laboratory Experiments of B.Sc. II Sem BT/FS/CBZ   Dr. Navdeep Sharma Institute of Sciences SAGE University, Indore (M.P.)   Experiment 1 Objective: Synthesis of 2, 4-Dinitrophenylhydrazone Derivative   Material  Required 2,4-Dinitrophenylhydrazine (DNP or DNPH) Carbonyl compound (Aldehyde or Ketone) Ice bath Beaker (100 mL) Stirring rod Filter paper Funnel Principle The reaction between 2,4-dinitrophenylhydrazine (DNPH) and a carbonyl compound (aldehyde or ketone) is a condensation reaction that forms a 2,4-dinitrophenylhydrazone derivative with the elimination of water. The reaction occurs due to the nucleophilic attack of the hydrazine's -NH₂ group on the electrophilic carbonyl carbon , leading to the formation of a stable C=NNH bond. This reaction is widely used for the identification of aldehydes and ketones, as the resulting yellow, orange, or red precipitate has a distinct melting point, which helps in compound characterization.   R 2 ​ C = O + H...
Read more

Laboratory Experiments of B.Sc. II Sem BT/FS/CBZ - Experiment: 2

  Laboratory Experiments of B.Sc. II Sem BT/FS/CBZ   Dr. Navdeep Sharma Institute of Sciences SAGE University, Indore (M.P.)   Experiment 2 Objective: Synthesis of Oxime from a Carbonyl Compound                                                 Objective: To synthesize an oxime from an aldehyde or ketone using hydroxylamine hydrochloride (NH₂OH·HCl) . Materials Required: Carbonyl compound (aldehyde or ketone) – 2 mL Hydroxylamine hydrochloride (NH₂OH·HCl) – 2 g Sodium hydroxide (NaOH) solution (10%) – 5 mL Ethanol (or methanol) – 10 mL Distilled water – 10 mL Ice bath Beaker (50 mL or 100 mL) Glass rod Filter paper & funnel Watch glass Ste...
Read more

Laboratory Experiments of B.Sc. II Sem BT/FS/CBZ - Experiment: 3

  Laboratory Experiments of B.Sc. II Sem BT/FS/CBZ   Dr. Navdeep Sharma Institute of Sciences SAGE University, Indore (M.P.)   Experiment 3 Objective: To calibrate a pH meter using standard buffer solutions of known pH values. Apparatus and Materials Required: Digital pH meter Standard buffer solutions (pH 4.00, pH 7.00, and pH 9.20 or 10.00) Distilled water Beakers (3) – 50 mL each Wash bottle Tissue paper or filter paper Glass rod Measuring cylinder Theory: A pH meter measures the hydrogen ion concentration (acidity or basicity) of a solution. Calibration ensures accurate and reliable readings by setting the pH meter to known pH values before use. Buffer solutions with known pH values are used for calibration. Usually, a 2-point or 3-point calibration is performed. Procedure: Preparation: Switch on the pH meter and allow it to warm up for 5–10 minutes. Rinse the electrode wit...
Read more