Aim: Preparation of p-bromo Aniline from acetanilide

Requirements:

  • Acetanilide
  • Acetic acid
  • Bromine
  • Ethanol
  • Potassium hydroxide

Procedure:

Step 1: Preparation of p-bromo acetanilide from acetanilide

Take 5.0 g acetanilide in 22 mL gla. Acetic acid dissolves the substance in beaker this solution is (I) another beaker takes 12.0 mL of bromine in 11.0 mL gla. Acetic acid in beaker this solution is (II) Solution (II) slowly add dropwise in beaker (I) shaking well when some bromine solution added the solutions color orange this solution stand at room temperature for 15 minutes than pour the solution in to cold water stirring well and filtrate and get product recrystallized in Rectified sprite.

Step 2: Preparation of p-bromo Aniline from p-bromo acetanilide

Dissolve 5.0 g p- bromo acetanilide in 15 mL of boiling ethanol + add 2.7 g mL of KOH pallets in 5 mL water reflux for 30 minutes on sand bath and then dilute with 60 ml water then these solutions pour in cold water filtrate and wash it dry it and recrystallized in methylated sprite.

.

Results:

Step 1.

  • Theoretical Yield: ______________g.
  • Practical Yield: ________________g.
  • % Yield of the product: _____________%.
  • M.P of p-bromo acetanilide: ___________°C

Step 2.

  • Theoretical Yield: ______________g.
  • Practical Yield: ________________g.
  • % Yield of the product: _____________%.
  • M.P of p-bromo Aniline: ___________°C

Chemical Reaction:

Mechanism:

Calculation:

Step 1.

  • Theoretical Yield

Acetanilide: C8H9NO (135.0 g.) p-bromo acetanilide: C8H8BrNO (214.0 g.)

From Chemical Reaction

135.0 g. Acetanilide             =                      214.0 g. p-bromo acetanilide

∴ 5.00 g. Acetanilide            =                      (?) g p-bromo acetanilide

                        = \frac{5.0 \times 214.0}{135.0}

                        = 7.92 g.

  • Practical Yield:

Actual weight of the dried product = ________________g.

  • % of Yield =\frac{\text { Practical Yield } \times 100}{\text { Theoretical Yield }}

                             = _______________%

Step 1.

  • Theoretical Yield

p-bromo acetanilide: C8H8BrNO (214.0 g.) p-bromo Aniline: C6H6BrN (172 g.)

From Chemical Reaction

214.0 g. p-bromo acetanilide                      =                      172.0 g. p-bromo Aniline

∴ 5.0 g. p-bromo acetanilide                       =                      (?) g p-bromo Aniline

                        = \frac{5.0 \times 172.0}{214.0}

                        = 4.01 g.

  • Practical Yield:

Actual weight of the dried product = ________________g.

  • % of Yield =\frac{\text { Practical Yield } \times 100}{\text { Theoretical Yield }}

                             = _______________%