[makaveli416]

Which of the following below is true?

1 - The major product of the nitration of nitrobenzene is p-dinitrobenzene.

2 - The product of the nitration of m-dinitrobenzene is 1,3,5-trinitrobenzene.

3 - Both 1 and 2.

4 - Neither 1 nor 2

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I think option 4 is correct because nitration of nitro benzene gives m-dinitro benzene and nitration of m-dinitro benzene is not a good reaction for production of 1,3,5-trinitrobenzene because m-dinitrobenzene contains two strongly electron withdrawing groups so the electron density on the benzene ring is very less to react. Best method for preparing sym trinitro benzene is prolonged heating of benzene with fuming nitric acid and nitrating mixture.

What do you all think?

[Rabn]

I think you are wrong.  Draw the resonant structures of m-dinitrobenzene.

[Kryolith]

Your argumentation sounds good, but one way to synthesize TNB is #2. Max. yield is 50 % when using nitrating acid.

[makaveli416]

Hmmm...

So would the answer be:

2 - The product of the nitration of m-dinitrobenzene is 1,3,5-trinitrobenzene?

[Kryolith]

2 - The product of the nitration of m-dinitrobenzene is 1,3,5-trinitrobenzene?

That's true. See my previous post. But I don't know, what the program thinks....

[sjb]

2 - The product of the nitration of m-dinitrobenzene is 1,3,5-trinitrobenzene?

That's true. See my previous post. But I don't know, what the program thinks....

I'd agree, if only because the question makes no reference to the ease (or otherwise) of the transformation. I think we're agreed the product is not 1,2,4- or 1,2,3-trinitrobenzenes due to the directing effects...