Amines and nitriles
Naming amines and nitriles: Practice exercises
How to name amines with -amine and N-substituents, and nitriles with -nitrile, including the nitrile carbon in the chain, with exercises and worked answers.
Amines contain a nitrogen joined by single bonds to one, two or three carbon groups. Nitriles contain a carbon triple-bonded to a nitrogen, –C≡N. Both are nitrogen compounds, but their names work differently.
The rules you need
- Amines: replace the final e of the alkane with -amine and give the locant of the carbon bonded to the nitrogen: propan-1-amine, propan-2-amine.
- Other groups on the nitrogen are prefixes with the locant N. The largest carbon group is the parent: N-methylethanamine; two groups on the nitrogen give N,N-: N,N-dimethylpropan-2-amine.
- Primary, secondary and tertiary amines have one, two or three carbon groups on the nitrogen. Many books also use names such as ethylamine, diethylamine and triethylamine.
- Nitriles: add -nitrile to the full alkane name. The C≡N carbon is C1 of the chain: butanenitrile has four carbons. On a ring the ending is -carbonitrile, and the C≡N carbon is not counted in the ring.
- A nitrile outranks aldehydes, ketones, alcohols and amines, which then become prefixes; next to an OH, the amine becomes the prefix amino-: 2-aminoethan-1-ol.
Two names, read step by step
N-Methylpropan-2-amine
The nitrogen carries two carbon groups, so this is a secondary amine. The larger group, with three carbons bonded to the nitrogen through the middle carbon, gives the parent propan-2-amine. The methyl group on the nitrogen gets the locant N.
Pentanenitrile
Five carbons in a chain, the last one triple-bonded to nitrogen: pentane plus -nitrile. The nitrile carbon is C1 and needs no locant, and the e of pentane stays because -nitrile starts with a consonant.
Watch out for
- Count the nitrile carbon: butanenitrile has four carbons, not five.
- An amine nitrogen has only single bonds; a C≡N is a nitrile, not an amine.
- If the nitrogen is bonded to a C=O carbon, the compound is an amide, named with the carboxylic acid derivatives.
Draw from the name: 17 exercises
Each name opens its exercise. Draw the structure and check it: any correct drawing is accepted, and hints and a worked answer help when you are stuck.
- propan-1-amine Beginner
- ethanamine Beginner
- propan-2-amine Beginner
- ethanenitrile Beginner
- cyclohexanamine Beginner
- N-methylethanamine Intermediate
- butanenitrile Intermediate
- N,N-dimethylmethanamine Intermediate
- N-ethylethanamine Intermediate
- 2-methylpropan-2-amine Intermediate
- N-methylpropan-1-amine Intermediate
- N,N-dimethylpropan-2-amine Advanced
- N-ethyl-N-methylpropan-1-amine Advanced
- hexane-1,6-diamine Advanced
- 3-methylbutanenitrile Advanced
- cyclohexanecarbonitrile Advanced
- 2-aminoethan-1-ol Advanced
Name the structure
17 structures of this family to name, each with four names to choose from and an explanation of every wrong choice.
Printable worksheet
For practice on paper: names to draw and structures to name, with an answer key to check your work.
The full guide
The guide Amines and nitriles explains these names in more detail, with more worked examples and the most common mistakes.