Naming Acid Chlorides

(Chemical) Definition of Acid Chlorides - also known as Acyl Chlorides:

Names of Acid Chlorides in General

Acid chlorides are also known generically as acyl chlorides (link to equivalent page about naming acyl chlorides).

Acid chlorides are named according to the same system as other organic compounds. In the simplest case of linear acid chlorides, the suffix -oyl chloride is added to the stem used to indicate the number of carbon atoms in the longest chain within the molecule. That is, when naming acid chlorides the first step is to consider the number of carbon atoms forming the longest chain within the molecule. The simplest situation is when all the carbon atoms in the molecule are attached together in a linear (i.e. unbranched) configuration. In that case the number of carbon atoms forming that single chain is the same as the total number of carbon atoms in the molecule. After identifying the longest carbon chain in the molecule use the number of carbon atoms forming that chain to look-up the most likely* stem of the name of the molecule using the same system as used for naming alkanes (see also the examples listed in the table below).
*Note that some organic compounds have multiple names so we refer to the "most likely" stem of the name of the compound because some variants may also be referred to by older or simply non-standard names based on a slightly different stem - the the "synonyms" column in the table below for examples.

Rememer that if the carbon atoms do not form a linear chain but include branches, the longest linear chain of carbon atoms within the molecule usually determines the base of the standard name of the compound, onto which is added information about the branches incl. their lengths in terms of the number of carbon atoms in each branch (i.e. methyl- indicates a branch consisting of just one carbon atom attached to the main chain, ethyl- indicates a branch of two carbon atoms in length, etc.) and their positions along the longest linear carbon chain (e.g. attached to the 2nd carbon, 3rd carbon, etc.).

The simplest linear acid chlorides are named and their structures drawn in the following table.
More complex acid chloride molecules follow afterwards.

Names and Structures of simple Linear Acid Chlorides

The first ten members of the homologous series of linear acid chlorides are represented below.

Number carbons in chain	Name	Simple Structure	Other Names = Synonyns (*Examples not complete lists)
	and simple formula	showing bond types but not accurate bond angles
1	formyl chloride (CHClO) CHOCl
2	ethanoyl chloride (C2H3ClO) CH3COCl		acetyl chloride acetic chloride acetylchloride acetic acid, chloride
3	propanoyl chloride (C3H5ClO) CH3CH2COCl		propionyl chloride propionic chloride propionic acid chloride
4	butanoyl chloride (C4H7ClO) CH3CH2CH2COCl		butyryl chloride butyric chloride butyroyl chloride butyric acid chloride n-butyryl chloride
5	pentanoyl chloride (C5H9ClO) CH3CH2CH2CH2COCl		valeryl chloride
6	hexanoyl chloride (C6H11ClO) CH3CH2CH2CH2CH2COCl		n-hexanoyl chloride caproyl chloride
7	heptanoyl chloride (C7H13ClO) CH3CH2CH2CH2CH2CH2COCl		n-heptanoyl chloride
8	octanoyl chloride (C8H15ClO) CH3CH2CH2CH2CH2CH2CH2COCl		n-octanoyl chloride capryloyl chloride octanoic chloride caprylyl chloride caprylic acid chloride octanoic acid chloride
9	nonanoyl chloride (C9H17ClO) CH3CH2CH2CH2CH2CH2CH2CH2COCl		n-nonanoyl chloride pelargonoyl chloride nonanoic acid chloride
10	decanoyl chloride (C10H19ClO) CH3CH2CH2CH2CH2CH2CH2CH2CH2COCl		n-decanoyl chloride
Why stop at ten carbon atoms (in the chain) ? It doesn't, there are more similar linear acid chlorides. We stopped here due to page width.
Important Note: *The synonyms indicated for compounds listed above are just some examples of alternative names found online and believed to have been used to refer to the substance indicated. They have not all been verified and may include common (non-scientific) names, trade names specific to particular suppliers, and perhaps errors. The purpose of these lists is to give a general indication of the range of names by which acid chlorides are known - both generally, and specifically.

Note: This is one of many pages about types of organic compounds in our Organic Chemistry Section. Similar and related pages describe hydrocarbons, alkanes, haloalkanes, alkenes, alkynes, cycloalkanes, aromatic hydrocarbons (arenes), alcohols, esters, ethers, aldehydes, ketones, carboxylic acids, acid chlorides, acid anhydrides, azo dyes, amines, amides, nitriles, amino acids (chemistry), peptides, proteins (chemistry), polypeptides and others. If you need further information ask your chemistry tutor.