Naming Amides - Online Tutor, Practice Problems & Exam Prep

Amides are organic compounds featuring a carbonyl group (C=O) linked to a nitrogen atom (N), derived from amines. They can be classified as primary, secondary, or tertiary based on the number of carbon atoms attached to the nitrogen. IUPAC naming involves changing the suffix from "oic acid" to "amide." Common naming follows similar rules, using prefixes for substituents. Understanding amides is crucial in organic chemistry, particularly in the context of functional groups and their reactivity in various chemical reactions.

Intro to Amides Concept 1

Now recall that amides consist of a carbonyl group connected to a nitrogen, which could have its origins from an amine group. Amides can be classified as either being primary, secondary, or tertiary. Here we have an example of an amide: at the far right, we have our carbonyl connected to our nitrogen group. Whether you're primary, secondary, or tertiary is based on how many carbons are directly attached to the nitrogen. In this first example, there is only one carbon directly attached to the nitrogen, so this is a primary amide. For the next one, there are two carbons directly attached to the nitrogen, so this is secondary. And then here there are three, so this is tertiary. That's how we look at the substitution around amides: it's the number of carbons directly attached to the nitrogen.

Intro to Amides Example 1

So here we have to classify each of the given compounds as primary, secondary, or tertiary amides, or neither. Now here, if we take a look, this is an amide because we have a carbonyl connected to a nitrogen directly, and there's only one carbon directly connected to that nitrogen, so it is a primary amide. For the next one, there is no carbonyl present, so it's just sp³ carbons connected to a nitrogen. So this is actually an amine, but we're not asking about amines, so we'll put neither. For the next one, we have our carbonyl directly connected to a nitrogen. So this is an amide and there are 1, 2, 3 carbons directly attached to it. So this is a tertiary amide. Then finally, for this last one, it is also an amide, and it's directly connected to 1, 2 carbons in terms of the nitrogen. So this would be a secondary amide. And that's how we classify each of the given compounds.

IUPAC Rules for Naming Amides Concept 2

So when it comes to the IUPAC naming of amides, we're going to see the carbon chain with the carbonyl group is named as though it was a carboxylic acid. Remember, carboxylic acids end with oic acid. So what we do here is we modify the ending from oic acid to just amide. And our naming convention will be our substituents that are connected to our parent. And we're modifying the ending from again oic acid to amide. So this is the approach we're going to take when it comes to IUPAC naming of different types of amides that we'll see.

IUPAC Rules for Naming Amides Example 2

Provide a systematic name for the following amide. Now, here's step 1: we have to identify the alkyl group or groups connected to the nitrogen atom. So, we're talking about this right here. That is a one-carbon alkyl group, so it's a methyl group. Next, we're going to name the alkyl groups as substituents, which means they're going to go at the beginning of the name. And we're going to say here, n, and this is important, it has to be italicized. This will represent an n substituent, and it's written before the alkyl name to indicate it's connected to the nitrogen atom. Now, when more than one identical substituent, we're going to use the prefix di. Step 3 is we identify the carbon chain connected to the carbonyl group, so C double bond O. Step 4 is we figure out the length of the carbon chain starting from the carbonyl group, and we're going to say the carbonyl group as carbon number 1 is implied. From that point, we use the same rules that we learned in terms of naming esters to name this particular amide. Right. So, if we take a look here, so we have a methyl group here, and it's an n-methyl since it's connected to the nitrogen. Remember, it has to be written in italics. And then we're going to say here, this chain with the carbonyl is 1, 2, 3, 4, and 5. So that's 5 carbons there. And then we have this ethyl group over here that is also another substituent. It's located on carbon number 3. So, in alphabetical order, 'e' comes before 'm', so 3-ethyl-n-methyl. It's a 5 carbon chain, so that's pentane, but here we're going to change the e-ending of pentane to amide, so it's pentanamide. So, this will be the name of this particular amide.

Give IUPAC name for the following amide.

• A. ethylmethylbenzoicamide
• B. N-ethyl-N-methylbenzamide
• C. ethylmethylbenzamide
• D. N-methyl-N-ethylbenzoic amide

Draw structure from provided IUPAC name: 4-hydroxy-N-methyl-N-propylheptanamide.

• A.
• B.
• C.
• D.

Common Naming: Amides Concept 3

So when it comes to the common naming of an amide, we're going to say they follow the same rules as IUPAC, except the parent chain consists of the common name prefixes. Now, the modification of the ending is still going from oic acid to amide. So, if we take a look at this example, it says to provide a common name for the following amide. So if we take a look, we’d say that we have a methyl and then 1, 2, 3, 4, a butyl attached to the nitrogen. Those are our Nsubstituents. Alphabetically, b comes before m. So we’d have N-butylN-methyl, and then the chain with the carbonyl has 1, 2, 3 carbons. Since this is a common name, the prefix will be propion, and then it is an amide, so we just add amide to the end. So this would be the name, the common name, of this particular amide structure.

Assign a common name to the following.

• A. N-pentyl-N-tert-butylacetamide
• B. N-tert-butyl-N-pentylethanamide
• C. N-tert-butyl-N-pentylacetamide
• D. N-hexyl-N-tert-butylethanamide

Draw a structure from the following name: N-cyclopentyl-N-propylvaleramide.

• A.
• B.
• C.
• D.

Here’s what students ask on this topic:

What are the different types of amides and how are they classified?

Amides are classified into three types: primary, secondary, and tertiary. This classification is based on the number of carbon atoms directly attached to the nitrogen atom. In a primary amide, the nitrogen is attached to one carbon atom. In a secondary amide, the nitrogen is attached to two carbon atoms. In a tertiary amide, the nitrogen is attached to three carbon atoms. This classification helps in understanding the structure and reactivity of amides in organic chemistry.

How do you name amides using IUPAC nomenclature?

In IUPAC nomenclature, the naming of amides involves modifying the name of the corresponding carboxylic acid. The suffix 'oic acid' of the carboxylic acid is replaced with 'amide'. For example, if the carboxylic acid is 'ethanoic acid', the corresponding amide would be 'ethanamide'. Additionally, any substituents attached to the nitrogen are named and prefixed with 'N-'. For instance, if there is a methyl group attached to the nitrogen, it would be named 'N-methyl'.

What is the difference between IUPAC and common naming of amides?

The IUPAC naming of amides involves using systematic rules where the suffix 'oic acid' of the corresponding carboxylic acid is replaced with 'amide'. In common naming, the parent chain uses common name prefixes, and the suffix 'amide' is added. For example, the IUPAC name 'propanamide' corresponds to the common name 'propionamide'. Substituents are named similarly in both systems, but the parent chain naming differs.

How do you determine the parent chain in the common naming of amides?

In the common naming of amides, the parent chain is determined by identifying the longest carbon chain that includes the carbonyl group. The chain is named using common name prefixes such as 'form-', 'acet-', 'propion-', etc. For example, a three-carbon chain with a carbonyl group would be named 'propionamide'. Substituents attached to the nitrogen are named and listed alphabetically with the prefix 'N-'.

What is the significance of understanding the classification and naming of amides in organic chemistry?

Understanding the classification and naming of amides is crucial in organic chemistry because it helps in identifying the structure, reactivity, and properties of these compounds. Amides are important functional groups in many biological molecules and synthetic materials. Proper naming conventions allow chemists to communicate effectively about these compounds, predict their behavior in chemical reactions, and understand their role in various chemical processes.