[NewtoAtoms]

Hello Organic Chemists.

When naming aromatic hydrocarbons, do halides (such as Cl) take precedence over alkyl groups?

For example:
When naming a aromatic hydrocarbon with 1 Chloro substitutent, 1 pentyl substitutent, and 1 ethyl substitutent. 
DOES chloro assume the #1 carbon position, as it is more prevalent than the ethyl or pentyl. 
I can't figure out how to draw on here, but I am assuming that a would be correct.

But I'll try this below, please note that I can't make the double bonds. Therefore I have highlighted the lines which have the double bonds,

Ch3Ch2
          \ __
      Cl_/     \
          \     /
            __
                \
                  Ch2Ch2Ch2Ch2Ch3

a. 1-Chloro-2-ethyl-5-pentylbenzene
b. 1-Chloro-6-ethyl-3-pentylbenzene
c. 2-Chloro-1-ethyl-4-pentylbenzene
d. 3-Chloro-4-ethyl-1-pentylbenzene
e. 5-Chloro-4-ethyl-1-pentylbenzene

I would choose 'a' to be correct, because I am assuming Cl would take the #1 C spot
AM I CORRECT?

Thank you so much organic chemists

HAPPY NEW YEAR

[macman104]

Yes, they do take precedence.

[muse]

Hi

I don't agree. Naming aromatic hydrocarbons one is suppose to get the lowest number for the substituents. Chloro will not take precedence. So the right name would be 2-chloro-1-ethyl-4-pentylbenzene, in my opinion. (ChemDraw agrees with me)

If you had a benzenering with a chloro and a methylgroup next to each other, it would be named 1-chloro-2-methylbenzene. But that is because the substituents are in alphabetic order.

-m

[nj_bartel]

I'm familiar with muse's way as well.

[macman104]

Whoops.