Synthesis of p-Bromoaniline A student starts with 1.15 g of acetanilide and isolates 1.55 g of the product. Determine the percentage yield for the reaction. 1.15 g of the acetanilide and 4.8 mL acetic acid were placed in a 50 mL Erlenmeyer flask  2.80 mL of 4.1 M bromine in acetic acid (1:4) were added dropwise with a Pasteur pipette. product- 1.55 g of the product

Chemistry
10th Edition
ISBN:9781305957404
Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Chapter1: Chemical Foundations
Section: Chapter Questions
Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...
icon
Related questions
Question

Synthesis of p-Bromoaniline

A student starts with 1.15 g of acetanilide and isolates 1.55 g of the product. Determine the percentage yield for the reaction.

1.15 g of the acetanilide and 4.8 mL acetic acid were placed in a 50 mL Erlenmeyer flask

 2.80 mL of 4.1 M bromine in acetic acid (1:4) were added dropwise with a Pasteur pipette.

product- 1.55 g of the product

 

**Experiment 6: Synthesis of p-Bromoaniline**

**Introduction**

Since the amino group of aniline is a strong activator of the aromatic ring, direct bromination is impractical because it leads to several products (Equation 1) that are difficult to separate. To make the desired product, the amino group needs to be protected as the acetamide, which also maintains the direction of the incoming electrophile into ortho and para position. It slows down the rate of reaction and introduces steric hindrance for the ortho positions (Equation 2). Both factors lead to an increased selectivity for the desired para product (Equation 3). The acetamide can be hydrolyzed back to the amine (Equation 4). This strategy of protection and deprotection is a very important tool in organic chemistry, especially in multi-step synthesis. In this experiment, p-bromoaniline was synthesized in three steps starting from aniline.

**Equation 1:**
- Depicts the reaction of aniline with bromine (Br₂), resulting in various mono- and disubstitution products.

**Equation 2:**
- Shows aniline reacting with acetic anhydride to form acetanilide. This transformation protects the amino group by converting it into an amide.

**Equation 3:**
- Describes the bromination of acetanilide. Bromine adds specifically to the para position relative to the amide group, creating p-bromoacetanilide due to steric hindrance and electronic effects.

**Equation 4:**
- Illustrates the acidic hydrolysis of the brominated amide, regenerating the amino group to produce p-bromoaniline.

These equations collectively highlight the strategy of using protection and deprotection of functional groups to achieve selectivity in multi-step organic synthesis.
Transcribed Image Text:**Experiment 6: Synthesis of p-Bromoaniline** **Introduction** Since the amino group of aniline is a strong activator of the aromatic ring, direct bromination is impractical because it leads to several products (Equation 1) that are difficult to separate. To make the desired product, the amino group needs to be protected as the acetamide, which also maintains the direction of the incoming electrophile into ortho and para position. It slows down the rate of reaction and introduces steric hindrance for the ortho positions (Equation 2). Both factors lead to an increased selectivity for the desired para product (Equation 3). The acetamide can be hydrolyzed back to the amine (Equation 4). This strategy of protection and deprotection is a very important tool in organic chemistry, especially in multi-step synthesis. In this experiment, p-bromoaniline was synthesized in three steps starting from aniline. **Equation 1:** - Depicts the reaction of aniline with bromine (Br₂), resulting in various mono- and disubstitution products. **Equation 2:** - Shows aniline reacting with acetic anhydride to form acetanilide. This transformation protects the amino group by converting it into an amide. **Equation 3:** - Describes the bromination of acetanilide. Bromine adds specifically to the para position relative to the amide group, creating p-bromoacetanilide due to steric hindrance and electronic effects. **Equation 4:** - Illustrates the acidic hydrolysis of the brominated amide, regenerating the amino group to produce p-bromoaniline. These equations collectively highlight the strategy of using protection and deprotection of functional groups to achieve selectivity in multi-step organic synthesis.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps with 2 images

Blurred answer
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
Chemistry
Chemistry
Chemistry
ISBN:
9781305957404
Author:
Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning
Chemistry
Chemistry
Chemistry
ISBN:
9781259911156
Author:
Raymond Chang Dr., Jason Overby Professor
Publisher:
McGraw-Hill Education
Principles of Instrumental Analysis
Principles of Instrumental Analysis
Chemistry
ISBN:
9781305577213
Author:
Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:
Cengage Learning
Organic Chemistry
Organic Chemistry
Chemistry
ISBN:
9780078021558
Author:
Janice Gorzynski Smith Dr.
Publisher:
McGraw-Hill Education
Chemistry: Principles and Reactions
Chemistry: Principles and Reactions
Chemistry
ISBN:
9781305079373
Author:
William L. Masterton, Cecile N. Hurley
Publisher:
Cengage Learning
Elementary Principles of Chemical Processes, Bind…
Elementary Principles of Chemical Processes, Bind…
Chemistry
ISBN:
9781118431221
Author:
Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
Publisher:
WILEY