# Amines

> CIE A-Level Chemistry · 9701
> Source: https://www.owlsprep.com/study/cie-9701-u23-overview/
> Weight: n/a

This unit covers the structure, preparation and key chemical properties of amines, an important class of nitrogen-containing organic compounds relevant to biochemistry and industrial synthesis.

**Prerequisites:** Basic organic nomenclature rules; Nucleophilic substitution reactions of haloalkanes; Acid-base chemistry of weak bases

## Learning objectives

- Classify amines as primary, secondary, tertiary or quaternary based on their structure
- Describe common laboratory and industrial methods for preparing different types of amines
- Explain how structure affects the basicity of amines
- Predict products of key reactions of amines and interpret common distinguish tests

## Unit at a Glance

Amines are derivatives of ammonia where one or more hydrogen atoms are replaced by alkyl or aryl groups. They play critical roles in biological systems (as components of amino acids and proteins) and are widely used in pharmaceutical and polymer manufacturing.

This unit follows a logical learning sequence: we first cover standard methods to synthesize different classes of amines, then explore their characteristic properties and key reaction patterns.

This unit includes two core sub-topics:
- [Preparation of amines](https://www.owlsprep.com/study/cie-9701-u23-preparation-of-amines/) — Covers reduction of nitro compounds, nitriles and amides, and nucleophilic substitution routes to synthesize amines.
- [Properties and reactions of amines](https://www.owlsprep.com/study/cie-9701-u23-properties-and-reactions-of-amines/) — Explores amine basicity, nucleophilic reactions, acylation, and tests to distinguish different amine classes.

## Common pitfalls

- **Wrong:** Confusing amine classification with alcohol/haloalkane classification
  - Why it fails: Amine classification depends on groups bonded directly to nitrogen, not the carbon chain
  - Correct: Count the number of alkyl/aryl groups attached to N to assign 1°, 2° or 3° classification
- **Wrong:** Claiming aryl amines are more basic than alkyl amines
  - Why it fails: The nitrogen lone pair in aryl amines is delocalized into the benzene ring, so it is less available to accept protons
  - Correct: Remember the standard basicity order: secondary alkyl amines > primary alkyl amines > ammonia > aryl amines

## Cheatsheet

| Key Concept / Formula | Core Note |
| --- | --- |
| Amine classification | 1° = 1 R group on N, 2° = 2 R groups, 3° = 3 R groups, quaternary = 4 R groups on N |
| Reduction of nitrobenzene | $\text{C}_6\text{H}_5\text{NO}_2 \xrightarrow{\text{Sn / conc HCl}} \text{C}_6\text{H}_5\text{NH}_2$ |
| Basicity order (aqueous) | $\text{R}_2\text{NH} > \text{RNH}_2 > \text{NH}_3 > \text{ArNH}_2$ |
| Diazonium salt formation | Primary aryl amines form stable diazonium salts only at 0-5°C; aliphatic diazonium salts decompose immediately |
| Nucleophilic property | Amines act as nucleophiles due to the lone pair of electrons on the nitrogen atom |

## What's next

Begin this unit by studying the first sub-topic on preparation methods for amines, then move on to learn about their properties and reactions. Once you complete all content in this unit, you can progress to the next unit covering amino acids, proteins, and nucleic acids.

- [Preparation of amines](https://www.owlsprep.com/study/cie-9701-u23-preparation-of-amines/)
- [Properties and reactions of amines](https://www.owlsprep.com/study/cie-9701-u23-properties-and-reactions-of-amines/)
- [Polymers](https://www.owlsprep.com/study/cie-9701-u24-overview/)

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