Aromatic Ring Question

[Chrono]

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How would you guys name this ring? (Letter E). Please write how you got the name.

I thought it could be 1-Bromo-2-Chloro-3-ethyl-5-Nitrobenzene. Why isn't this right?

According to the text the solution is: 3 bromo - 2 chloro - 5 nitro ethyl benzene. Why does the ethyl get numbered 1?

 

[casper22]

According to CHAD,

The methyl carbon attached to the main chain automatically gets number 1, irrespective of any halogen group.

 

[rnbaxter]

lol is that 6.23 relating to your question? If so toss what ever material you are attempting to learn nomenclature from.

 

[Chrono]

lol is that 6.23 relating to your question? If so toss what ever material you are attempting to learn nomenclature from.

No that question is unrelated and that mark was their before I got this book. It's funny you say that cause this ochem book is amazing, best I've ever used as things are explained extremely well with no extra bs. Of course, their will always be something that needs clarifying in any book.

 

[Chrono]

According to CHAD,

The methyl carbon attached to the main chain automatically gets number 1, irrespective of any halogen group.

Interesting, any idea why this is?

 

[casper22]

Don't know if there was any explanation to this logic..actually he mentioned this while naming a hydrocarbon that had complex substituent and a methyl group...

I am wondering if this is a correct statement in this context and would like to know if I am not confusing things...

Please correct me if I am wrong..

 

[Baylor2011]

Number the ring so that the sum of the substituents is the lowest possible number. Starting from the top and going clockwise you get 1, 2, 3, 5 for a total of 11. If you started with the nitro group youd get 1, 3, 4, 5 for a total of 13. 11's lower than 13 so you use that numbering scheme.

Like person above said you start with alkyl groups in complex structures regardless of alphabetizing

 

[casper22]

Ahh...I had no idea about the summing concept...

Thanks Baylor

 

[DQLEUCD]

How would you guys name this ring? (Letter E). Please write how you got the name.

I thought it could be 1-Bromo-2-Chloro-3-ethyl-5-Nitrobenzene. Why isn't this right?

According to the text the solution is: 3 bromo - 2 chloro - 5 nitro ethyl benzene. Why does the ethyl get numbered 1?

Following Priorities it would be 3-bromo, 2-chloro, 5-nitro, 1-ethylbenzene

http://www.lavcchem212.com/files/FGPR.PDF shows a list of priorities for the majority of the groups and Nitro has the lowest priority while halogens are second lowest and alkanes are above both.