[workingundergrad1896]

I'm completely new here so I hope i've posted this in the right place!
I'm having trouble answering this practise question, I'm generally pretty good at organic nomenclature, but this has just stumped me.
The compound is:

I need to give the IUPAC name from the following:
(a)2,6-Dimethyl-1-bromo-3-ethylbenzene
(b)1-Bromo-2,6-dimethyl-3-ethylbenzene
(c)1-Ethyl-3-bromo-2,4-dimethylbezene
(d)1-Methyl-2-bromo-3-methyl-4-ethylbenzene
(e)2,6-Dimethyl-3-ethyl-bromobenzene

I know it's obviously not d, I thought maybe it's C as this uses the lowest numbers, but I don't have an answer sheet to check from.

If anyone knows which answer would be correct, and can give a brief explanation of how you ordered the carbon atoms on the ring to determine which position each substituent is on, that would be massively appreciated! Thanks!

[OCSaviour]

I doubt these options, but if that's what has been given to you then follow this rule:

Substituents are listed in alphabetical order.

[workingundergrad1896]

So the answer would be B, although D is the same, just doesn't include position of bromo, I think technically for IUPAC you have to include the position? not really sure

I'll consult my lecturer next week, thanks for your help

[discodermolide]

apart from alphabetical order the sum of the determinants is also important. They should add up to the lowest total.
Now ChemDraw gives me 2-bromo-4-ethyl-1,3-dimethylbenzene, compare that with your choices.

[OCSaviour]

apart from alphabetical order the sum of the determinants is also important. They should add up to the lowest total.
Now ChemDraw gives me 2-bromo-4-ethyl-1,3-dimethylbenzene, compare that with your choices.

Exactly, that's why I was doubting the options.

[vnaraya3]

I believe it should be c.

In IUPAC nomenclature, you first have to prioritize the substituents. Alkyl groups actually have higher priority than halo groups. So, you know that either one of the methyl groups or the ethyl groups needs to be on C1.

To decide which of these three groups is C1, look at which will give the lowest numbers. You can either designate C1 as the ethyl group, or as the methyl group farthest away from the ethyl:

Either: 2-bromo-4-ethyl-1,3-dimethylbenzene
Or: 3-bromo-1-ethyl-2,4-dimethylbenzene
(Note that IUPAC substituents must always be alphabetized and that the "di" doesn't count in alphabetization.)

The first one is correct. Why? Because the options are equal in every other way, look at which of the substituents comes first in alphabetical order. Because the bromo group comes first, you choose the option that gives the bromo group C2.

So, based on my understanding of IUPAC Rules (which is limited) I believe it should be 2-bromo-4-ethyl-1,3-dimethylbenzene.

EDIT: I just realized I misread the options! c is what I said except they put the ethyl in front even though it comes later in alphabetical order for some reason... And e would be right if you considered it a substituted derivative of bromobenzene, except in that case dimethyl should still come before ethyl...None of these look right to me!

EDIT: I changed my original answer because I mis-copied the name