Question

What's ortho, para, and meta?

Answer 1

@Somy

This is toluene, which is just the common name for methylbenzene. For benzene rings with only two substituents, this is a special naming convention we can use to describe one relative to the other.

So for instance at the place where I drew an arrow at the bottom, if we put a bromine there then we can say that the bromine is para to the methyl group or that the methyl group is para to the bromine. If you named that compound it would be called, p-methylbromobenzene. Since this is a special naming, the ordinary way to name it would just be to make the highest priority substituent 1 and name to give the lowest ordering, so 1-bromo-4-methylbenzene.

Answer 2

ohhh IUPAC
lowest numbers
and these para and the rest are just showing no of carbon

Answer 3

ohkaaay

Answer 4

For instance, what's the name of this compound?

Answer 5

hmmm sec

Answer 6

meta-ethylebromobenzene

Answer 7

i guess?>

Answer 8

so much typing.....kinda scares me....was i wrong?? lol

Answer 9

Yeah, exactly. Alright, now the reason you should know these names is because there are substituents that are ortho/para directors and ones that are meta directors. I have a kind of "math" way of memorizing the names too that might be helpful to you. para is "para"llel to the group, ortho is "ortho"gonal to the group and meta is in the mittle lol.

One sec, I can explain o/p and m directors more but I need to do something real quick.

Answer 10

ooooookay

Answer 11

Alright so now here's the fun part of aromatics. When you want to make a compound, certain groups contribute certain effects.

So if we want to make 4-bromo-3-nitrobenzoic acid from toluene what do we do?

Well we need to know a few things. Alkyl groups and halogens are ortho/para directors, while nitro groups and carboxylic acids are meta directing groups. There's also a reaction you should know about, which is that KMnO4 reacts with primary and secondary alkyl groups to make them into carboxylic acids.

So for instance, in synthesizing this we can attempt to add the bromine, nitrogen, or turn the methyl into a carboxylic acid. But the groups we try to add are affected by where the other groups point them to be.

See if you can try it on your own, or if you need more information to get started.

Answer 12

Well we need to know a few things. Alkyl groups and halogens are ortho/para directors, while nitro groups and carboxylic acids are meta directing groups. There's also a reaction you should know about, which is that KMnO4 reacts with primary and secondary alkyl groups to make them into carboxylic acids.

Answer 13

ok so

Answer 14

alkyl and halogens can be attached ONLY to ortho and para?

Answer 15

hot concentrated acidified KMnO4 oxidation taking place when there is a double bond, i know this one

Answer 16

By directing I mean that after they're attached then other groups you add on after that are directed to places that are ortho/para to them. So kind of the other way around.

Example:

Bromobenzene will not have anything on the meta spot after you react it with something.

Answer 17

if 1 R group =>aldahyde- carboxylic acid
2 R groups- ketone
no R groups- CO2

Answer 18

This is a different reaction though of KMnO4 because you're not breaking a double bond, you're breaking a sigma bond. Not only that, KMnO4 can't break the benzene ring because it is conjugated and too stable.

Answer 19

owhhh this one i don't know

Answer 20

but does it work same way?

Answer 21

like this?