This document describes the preparation of p-nitro acetanilide from acetanilide. Acetanilide is nitrated using nitric and sulfuric acid. This produces p-nitro acetanilide as the major product along with a minor amount of o-nitro acetanilide. The p-nitro acetanilide product is purified by recrystallization from ethanol, yielding colorless crystals. Percent yield of the product is calculated and the melting point is obtained and compared to literature values.

1. SPP-1.8 (1.4A) Practical Organic Chemistry
DOS & R in Organic Chemistry, TUT Page 1
Prepared by
Dr. Krishna swamy
Faculty
DOS & R in Organic Chemistry
Tumkur University

2. SPP-1.8 (1.4A) Practical Organic Chemistry
DOS & R in Organic Chemistry, TUT Page 2
Experiment No: 2
Preparation of p-nitro acetanilide from acetanilide
AIM:
To prepare p-nitro acetanilide from acetanilide.
PRINCIPLE:
The nitration of aniline is difficult to carry out with nitrating mixture
since amino group gets oxidized and also mixture of products will be
formed. Hence, the amino group is first protected by acylation to form
acetanilide which is then nitrated to get p-nitroacetanilide as a major
product and o-nitro acetanilide as a minor product because the
acetamido group is less powerful ortho and para directing group than
amino group due to electron withdrawing carbonyl group and also it
blocks the ortho position by steric hindrance. Recrystallization from
ethanol readily removes the more soluble ortho compound and the pure
crystal of p-nitro acetanilide is obtained.
CHEMICALS REQUIRED:
Acetanilide, conc. HNO3, conc.H2SO4, CH3COOH, Ethanol.
APPARATUS:
Conical flask, Thermometer, Beaker, Funnel, Measuring cylinder,
Filter paper.

3. SPP-1.8 (1.4A) Practical Organic Chemistry
DOS & R in Organic Chemistry, TUT Page 3
PROCEDURE:
• Add 2.5 g of acetanilide into 100 mL beaker containing 3 mL of
glacial acetic acid and 2 mL of con.H2SO4. Stir the mixture by the
use of glass rod. Cool the resulting mixture in ice bath.
• Place 1.5 mL conc.HNO3 in a clean test tube and cool it in a
freezing mixture (ice + salt). Then carefully add 1.5 mL
conc.H2SO4 drop by drop with constant stirring.
• Place the test tube in a freezing mixture and wit until the
temperature becomes less than 5oC.
• To the cooled content in the beaker add nitrating mixture drop
wise with constant stirring. During the addition temperature of
the mixture should not rise above 10oC.
• After complete addition remove the beaker from the freezing
mixture and allow it to stand for 30 minutes at lab temperature.
• Pour the reaction mixture into cold water taken in a beaker with
stirring. Crude nitro acetanilide separates out at once.
• Filter the crude product and wash thoroughly with cold water till
it is free of acid.
• Dissolve the crude product in about 20 mL of ethanol. Warm the
content to get clear solution.
• Filter while hot and cool the filtrate in ice, colorless crystals of p-
nitro acetanilide were obtained.
• Collect the crystals by filtration and wash with cold ethanol.
• After drying, weigh the product, calculate the yield and obtain
melting point.

4. SPP-1.8 (1.4A) Practical Organic Chemistry
DOS & R in Organic Chemistry, TUT Page 4
REACTION:
HN
NO2
O
HN
O
Con.HNO3
Con.H2SO4
HN
O
0-5o
C
NO2
(Major) (Minor)
CALCULATIONS:
Compound Amount
Molecular
Weight
Moles Equivalent
Acetanilide 2.5 g 135.1 0.018 1
HNO3 1.5 mL - - -
H2SO4
2 mL +
1.5 mL
- - -
CH3COOH 3 mL - - -
THEORETICAL CALCULATION:
135 g of Acetanilide gives 180.1 g of p-nitroacetanilide
2.5 g of Acetanilide will forms X g of p-nitroacetanilide
Theoretical yield =
Practical yield =
% Yield = (Practical yield) / (Theoretical yield) X 100

5. SPP-1.8 (1.4A) Practical Organic Chemistry
DOS & R in Organic Chemistry, TUT Page 5
MECHANISM:
Step-1: Generation of Electrophile
HNO3 H2SO4
H2NO3 HSO4
NO2
-H2O
Step-2: Attack on Electrophile
HN
N
O
HN
NO2
H
HN HN
H
O2N
Ortho-substituion
Para-substituion
O O
O O
O
N
O
O

6. SPP-1.8 (1.4A) Practical Organic Chemistry
DOS & R in Organic Chemistry, TUT Page 6
Step-2: Loss of proton and formation of product
HN HN
H
O2N
O O
N
O
O
HSO4
HN
NO2
O
CHEMICAL TESTS:
Reduction and Diazotization test
Acetanilide: Does not undergo reduction with Sn and no dye
formation (-Ve)
p-nitro acetanilide: Undergo reduction with Sn and dye formation
(+Ve)

7. SPP-1.8 (1.4A) Practical Organic Chemistry
DOS & R in Organic Chemistry, TUT Page 7
REPORT:
Structure and
name of the
compound
Theoretical
yield
Practical
yield
Percentage
yield
Theoretical
Melting
point
Experimental
Melting
point
HN
NO2
O
p-nitro acetanilide
214oC
REFERENCES:
1. https://www.learncbse.in/to-prepare-a-sample-of-p
nitroacetanilide-from-acetanilide/
2. https://labmonk.com/synthesis-of-p-nitroaniline-from-
acetanilide