Practice Problem: Electrophilic Aromatic Substitution Multi-Step Pathway

[@SaeedNeamati]

From 2016, until now (2022), 6 years of hard work. You deserve this success. Congratulations.

[@HeyImLucious]

My final was yesterday... fate is cruel.

[@Pink_DoT]

Very clear! Thank you so much❤️

[@DarlinaLiu]

What happens when the two substituents don't agree? Which effect ultimately "wins"?

[@ProfessorDaveExplains]

+Darlina Liu good question! one will probably have stronger directing capacity than another. check out a list of donating and withdrawing groups and see that they are ranked by strength. of course if you have two that are roughly of similar magnitude but opposite, you'll just get a big mixture of different products.

[@BardiaSaeedi]

If I had chosen the NO3 to be on the meta position when we did the nitration, does that mean that the final bromination, the bromine ends up para to the isoethyl group? ie the Br and NO3 are swapped compared to yours.

[@BardiaSaeedi]

Ps, really like ur videos.

[@ProfessorDaveExplains]

but alkyl groups are ortho/para! so your only options are to put the nitro group on an ortho or para position, you won't get nearly any meta substitution. perhaps you meant ortho, in which case yes you'd get bromination at the para predominately, as it is sterically preferred, though some on the other ortho spot could also work.

[@BardiaSaeedi]

Ah whoops, yes I meant ortho. And ah yes, I see. Br could also go on the other ortho spot (1 left of the alkyl group), but I'm guessing that would be a much lower yield since it has steric hindrance. Thanks for the quick response.

[@vaibhavrao8485]

Well that was easy