Year 12s: what will be the first way you research your future options? >>

Help with naming - aromatic compounds and N-substituted amines

I'm struggling with some of the naming conventions, mainly with aromatic compounds.

In one of the past papers (AQA January 2008 CHM4 Unit 4 exam) they ask a question about "methyl benzenecarboxlate" (C6H5COOCH3) and it's highlighted something I really don't understand - how benzene and phenyl are used when naming esters.

I don't have a great grasp on when Phenyl vs Benzene are used as it is (I know that generally Benzene is for one non-functional group attached where-as phenyl is when there is another functional group...except instances like Benzene-1,4-carboxylic acid?), but this seems even harder to understand for esters!

Could the above ester also be called "methyl phenyl ethanoate"? From googling the phenyl + -oate format they seem to refer to when the phenyl group is the alcohol, rather than the acid in the ester...

Any help with this? What rules are there when naming esters with benzene in - or am I missing a fundamental rule of when to use phenyl vs. benzene?

The other question I had was around N-substituted amines. The text books I have seem to only mention N-substituted amides, but this paper (same as before, AQA January 2008 CHM4 Unit 4 exam) has an answer for question 7.b) as [b]/b]N-Phenyl ethyl amine. The books seem to say that secondary or tertiary amines don't need the "N-" prefix so I wasn't sure who to believe. Has this been changed since 2008?

Thanks for any help at all.

Reply 1

username2434011

http://www.chemguide.co.uk/basicorg/conventions/names3.html hopefully this can help with that naming issue

Reply 2

Bacardigan

Thanks! I did have a read of that but unfortunately find the answers to the 2 things above. Namely how to name esters with a phenyl group when they are a) joined to the acid or b) joined to the alcohol (only the alcohol example in there), and it doesn't mention anything about N-substituted amines.

Any idea about those 2?