Chapter 6: Problem 107

How are the following conversions carried out? (i) Ethyl amine to methyl amine (ii) Benzene to phenyl hydrazine (iii) meta dinitrobenzene to meta bromo phenol

Short Answer

Expert verified

Question: Describe the process of converting meta-dinitrobenzene to meta-bromo phenol. Answer: The conversion of meta-dinitrobenzene (1,3-C6H4(NO2)2) to meta-bromo phenol (1,3-C6H4(OH)(Br)) involves two main steps: 1. Replace one nitro group with a bromo group using bromine (Br2) and acetic acid (CH3COOH) under sunlight. This results in m-nitro phenol (1,3-C6H4NO2Br). 2. Reduce the remaining nitro group in m-nitro phenol to a hydroxyl group using Zinc (Zn) and hydrochloric acid (HCl). This forms the final product, meta-bromo phenol (1,3-C6H4(OH)Br).

Step by step solution

(i) Conversion of ethyl amine to methyl amine: Reaction Sequence)

In order to convert ethyl amine (C2H5NH2) to methyl amine (CH3NH2), we will first need to remove the ethyl group from the nitrogen atom and replace it with a methyl group. This can be done in two steps: 1. Convert ethyl amine to ethyl isocyanate 2. Hydrolyze ethyl isocyanate to yield methyl amine

(i.1) Convert ethyl amine to ethyl isocyanate)

To convert ethyl amine (C2H5NH2) to ethyl isocyanate (C2H5NCO), we can use chloroform (CHCl3) and an alkali, such as potassium hydroxide (KOH). The reaction takes place under basic conditions and the formed product is ethyl isocyanate: C2H5NH2 + CHCl3 + 3KOH ⟶ C2H5NCO + 3KCl + 3H2O

(i.2) Hydrolyze ethyl isocyanate to yield methyl amine)

The final step is to hydrolyze ethyl isocyanate (C2H5NCO) to produce methyl amine (CH3NH2) and ethanol (C2H5OH). This is done by adding H2O under acidic conditions (HCl): C2H5NCO + H2O + HCl ⟶ CH3NH2 + C2H5OH

(ii) Conversion of benzene to phenyl hydrazine: Reaction Sequence)

In order to convert benzene (C6H6) to phenyl hydrazine (C6H5NHNH2), we will first need to introduce a nitro group, followed by reducing it to an amine and finally converting the amine group to phenyl hydrazine. This can be done in three steps: 1. Nitration of benzene to form nitrobenzene 2. Reduction of nitrobenzene to form aniline 3. Formation of phenyl hydrazine from aniline

(ii.1) Nitration of benzene to form nitrobenzene)

To convert benzene (C6H6) to nitrobenzene (C6H5NO2), we can use a mixture of concentrated nitric acid (HNO3) and concentrated sulfuric acid (H2SO4). This is an electrophilic substitution reaction, and the nitro group substitutes one of the hydrogen atoms in the benzene ring: C6H6 + HNO3 ⟶ C6H5NO2 + H2O

(ii.2) Reduction of nitrobenzene to form aniline)

To reduce nitrobenzene (C6H5NO2) to aniline (C6H5NH2), we can use Tin (Sn) and concentrated hydrochloric acid (HCl) followed by neutralization with sodium hydroxide (NaOH). This reaction involves reduction of the nitro group to an amine group: C6H5NO2 + 6[H] ⟶ C6H5NH2 + 2H2O

(ii.3) Formation of phenyl hydrazine from aniline)

The final step is to convert aniline (C6H5NH2) to phenyl hydrazine (C6H5NHNH2). This can be achieved by treating aniline with sodium nitrite (NaNO2) and hydrochloric acid (HCl) to form diazonium salt, which is then reacted with hydrazine sulfate (N2H4.H2SO4) to form phenyl hydrazine: C6H5NH2 + NaNO2 + HCl ⟶ C6H5N2+Cl- ⟶ C6H5NHNH2 + H2O

(iii) Conversion of meta-dinitrobenzene to meta bromo phenol: Reaction Sequence)

In order to convert meta-dinitrobenzene (1,3-C6H4(NO2)2) to meta-bromo phenol (1,3-C6H4(OH)(Br)), we will need to replace one of the nitro groups with a bromo group, followed by reducing the remaining nitro group to a hydroxyl group. This can be achieved in two steps: 1. Replace one nitro group with a bromo group 2. Reduce the remaining nitro group to a hydroxyl group

(iii.1) Replace one nitro group with a bromo group)

In order to replace one nitro group in meta-dinitrobenzene with a bromo group to form m-nitro phenol (1,3-C6H4NO2Br), the reaction is carried out using bromine (Br2) with acetic acid (CH3COOH) under sunlight. The Br+ ion substitutes the NO2 group via nucleophilic aromatic substitution: 1,3-C6H4(NO2)2 + Br2 ⟶ 1,3-C6H4NO2Br + HBr

(iii.2) Reduce the remaining nitro group to a hydroxyl group)

To reduce the remaining nitro group in m-nitro phenol (1,3-C6H4NO2Br) to a hydroxyl group, forming meta-bromo phenol (1,3-C6H4(OH)Br), we can use Zinc (Zn) and hydrochloric acid (HCl) in a reduction reaction: 1,3-C6H4NO2Br + 6[H] ⟶ 1,3-C6H4(OH)Br + 2H2O

Unlock Step-by-Step Solutions & Ace Your Exams!

Full Textbook Solutions
Get detailed explanations and key concepts
Unlimited Al creation
Al flashcards, explanations, exams and more...
Ads-free access
To over 500 millions flashcards
Money-back guarantee
We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

Recommended explanations on Chemistry Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

How are the following conversions carried out? (i) Ethyl amine to methyl amine (ii) Benzene to phenyl hydrazine (iii) meta dinitrobenzene to meta bromo phenol

Short Answer

Step by step solution

(i) Conversion of ethyl amine to methyl amine: Reaction Sequence)

(i.1) Convert ethyl amine to ethyl isocyanate)

(i.2) Hydrolyze ethyl isocyanate to yield methyl amine)

(ii) Conversion of benzene to phenyl hydrazine: Reaction Sequence)

(ii.1) Nitration of benzene to form nitrobenzene)

(ii.2) Reduction of nitrobenzene to form aniline)

(ii.3) Formation of phenyl hydrazine from aniline)

(iii) Conversion of meta-dinitrobenzene to meta bromo phenol: Reaction Sequence)

(iii.1) Replace one nitro group with a bromo group)

(iii.2) Reduce the remaining nitro group to a hydroxyl group)

One App. One Place for Learning.

Most popular questions from this chapter

Recommended explanations on Chemistry Textbooks

The Earths Atmosphere

Making Measurements

Chemistry Branches

Chemical Analysis

Ionic and Molecular Compounds

Chemical Reactions

Study anywhere. Anytime. Across all devices.