Bromobenzene Nitration

Chemistry Level 2

You perform the nitration reaction of bromobenzene. In the image above, bromobenzene is shown to be nitrated in either the ortho ( $o$ ), meta ( $m$ ), and para ( $p$ ) position(s). In which positions will the major products of bromobenzene nitration be nitrated?

David's Organic Chemistry Set

David's Physical Chemistry Set

o,p o o,m,p p m,p o,m m

1 solution

David Hontz
Jun 2, 2016

The $Br$ group on bromobenzene will act as either an $ortho$ or $para$ directing group during nitration. Therefore, bromobenzene will be nitrated at both the $o$ and $p$ positions; separately.

But the question does not specify about Major Product. Halogens majorly direct incoming groups to ortho para positions but meta product will be obtained (it will be less) . the question clearly which position will actually be nitrated!

Prakhar Bindal - 5 years ago

yep you are correct that it is ortho and para director but it seems from you ques that o,p implies 2 NO2 on the same benzene. moreover since no heat is mentioned so kinetically controlled product ie ortho is the major(slightly more than para)

aryan goyat - 5 years ago

Should not the major product be only the ortho?? Since the relative velocity of the reaction in the ortho position is greater than para

João Vitor Cordeiro de Brito - 4 years, 11 months ago

Bromine is an ortho/para directing group. A mixture of ortho and para substituted products will be made due to the nature of the directing group.

David Hontz - 4 years, 11 months ago

Yes, that is true, but it is ortho/para dirigent, but the relative velocity of the substitution in the ortho position is greater than para. Nevertheless, you have two carbons available for "ortho" substitution and only one for "para"

João Vitor Cordeiro de Brito - 4 years, 11 months ago

@João Vitor Cordeiro de Brito – It has been determined experimentally that nitration of $\ce{phenyl~bromide}$ yields the nitro group ortho 36%, para 62%, and meta 2% of the time $^{[1]}$ . Therefore the product made most is in reality the $\ce{p-nitro-phenyl~bromide}$ ; however, because both the para and ortho products are produced at yields above 5%, they can't be considered negligible and are therefore considered major products.

Source: http://www.saplinglearning.com/media/loudon/loudon5ech16sec05.pdf on page 762

David Hontz - 4 years, 11 months ago

It should be para Para products are always major products in these types of reaction

Subhra Patra - 3 years, 11 months ago

Yes, due to the steric hindrance between Br and NO2

Md Zuhair - 3 years, 4 months ago

Bromobenzene Nitration

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