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Naming Benzene Ring Derivatives - Aromatic Compounds



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in this video we're gonna focus on

naming benzene derivatives so let's

start with the mono substituted benzene

derivatives so how can we name in this

molecule

let's say if we have a benzene ring with

an no.2 group attached to it what's the

name of this molecule the no.2 group

it's called nitro and so combined this

is called nitro benzene by the way I

recommend having a piece of paper or

something to write these names down

because these parent names you need to

commit them to memory now what about the

next one let's say if we have a benzene

ring with an O H group what do you think

the name is called the name is called

phenol that's the common name for this

and for this example we're gonna have a

benzene ring with an O ch3 group so

basically this is an ether the parent

name that you want to be familiar with

is Anusol so that's the name for that

molecule next up we're going to have a

benzene ring with an nh-2 group and so

if you see this this is called aniline

now this one I'm sure you've seen before

let's say if we have a benzene ring with

a carbocylic acid

so this is called benzoic acid now

sometimes you may see it like this too

so you may see the COOH group and so

it's the same this is also benzoic acid

now let's move on to our next example

what is the name of this molecule

what's the parent name now we can also

write it like this too so instead of CH

oh it's gonna be C with a double bond oh

and the hydrogen attached to it so we

have a benzene ring and an aldehyde

functional group so this is going to be

called instead of benzene it's

benzaldehyde

now what is the common name for this

molecule let's say if we have a benzene

ring and a carbon-carbon double bond

attached to it

the common name is styrene this is also

called vinnil benzene because this is a

vinta group now what if we have a ketone

next to a benzene ring like this one

this is called acetyl phenol when you

hear the word acetyl think of two

carbons this is the acetyl group and

then when you hear the word phenyl

phenyl has to do with a benzene ring

with six carbons and their own tells you

add in little for ketone

now what if we have a halogen attached

to a benzene ring so let's say if we

have a chlorine atom compared to a

bromine atom how can we name these two

benzene derivatives so for the molecule

on the left this is called plural

benzene and for the one on the right you

can guess what it is that's going to be

called bromo benzene

now what if we have an ethyl group

attached to a benzene ring what's the

name for this molecule now this one is

pretty straightforward this is simply

called ethyl benzene that's it for this

example

now what if we have a methyl group

attached to let's say a benzene ring so

what's the name of this one can we say

that it's methyl benzene that would make

sense but this one has a common name

that you need to know and it's called

toluene you'll see that one a lot so

make sure you know this common name next

up we have a benzene ring with an amide

functional group so what's the name for

this molecule so benzene plus an amide

this is called benzene ID now what if we

have a benzene ring with a nitro

functional group what's the name for

this molecule so this one is simply

called benzyl nitro

now what about having a benzene ring and

a ch2 group followed by a chlorine atom

what's the name for this molecule so

this is a phenyl group if it's just the

benzene ring but the phenyl group Plus

this extra carbon which totals seven

carbons

that's called benzyl and so this is

called benzyl chloride so remember a

phenyl group has six carbons a benzyl

group has seven carbons it has the

benzene ring plus this additional carbon

now what about this one how can we name

this molecule so here we have an

isopropyl group and so we can call this

isopropyl benzene it also has another

name the common name is Q me

so if you see cumin is not cumin but you

mean it's isopropyl benzene now let's

move on to our next example so here we

have a butyl group attached to a benzene

ring and so this is going to be called

tert-butyl benzene

now what if we have a benzene ring

attached to a sulfur atom that has two

double bonded oxygen atoms attached to

it and an H group so if you see this

group this is called a sulphonic acid

combined this is benzene so phonic acid

kind of like a car boat like a

carboxylic acid but instead of that it's

a sulphonic acid now let's move on to

name in die substituted benzene

derivatives so we saw that if we have

one methyl group it's called toluene

what if we have two methyl groups

attached to a benzene ring how was the

name going to be different if you have

two benzene I mean two methyl groups

rather attached to a benzene ring it's

gonna be called a xylene

now this specifically is known as ortho

xylene it's also called run to dimethyl

benzene so let's call this carbon one

this will be number two three and four

so with respect to the first methyl

group the second methyl group is at the

ortho position ortho is one two meta is

one three para is one four now what

about this example

what is the name of this molecule go

ahead and try it so this is still going

to be xylene but instead of 1 2 its 1 3

so we can call it 1 3 dimethyl benzene

or we know that 1 3 is the same as meta

so we could say this is meta xylene you

could write it as M xylene or you can

actually write out meta xylene so both

ways are acceptable

so what do you think the name for this

compound is going to be so let's call

this carbon one two three four so we can

call it 1 comma four dimethyl benzene or

we know that one 4 is the same as para

and so we can call it para xylene or we

could just say P - xylene now let's move

on to our next example so now we have

two different groups attached to a

benzene ring so how can we name this

compound well first we need to identify

the parent name we know that a benzene

ring plus a methyl group is called

toluene and so that's going to be the

parent name therefore we're gonna count

the methyl group is going to be carbon

one because it's part of the parent name

so therefore we're gonna call this -

bromo

toluene or we could say ortho bromo

totten you can use ortho meta and para

for any time you have a dive substituted

benzene derivative that's when you have

only two groups attached to it so let's

try another example so let's say we have

CH o group and a CL go ahead and name

this benzene derivative so a benzene

ring with a CH o group that's called

benzaldehyde so that's the parent name

which means that the aldehyde functional

group is on carbon one so we can call

this three plural benzaldehyde or we

could say it's meta chloro benzene

because meta

corresponds to the run three positions

now let's try another example so let's

say we have an O ch3 group and at the

same time we have an NL two group so

what is the name of this aromatic

compound so the NL two group is called

nitro and the benzene ring with an O ch3

group is called Anusol so the parent

name is going to be an assault and the

Nitro group is on carbon two so we can

call this two nitro a nasaw or ortho

nitro anisole now let's move on to try

substituted benzene derivatives

so go ahead and name the molecule so the

parent name is going to be phenyl

because that's the benzene ring with the

O H group it doesn't make sense to use

Nitro benzene as the parent name

especially when is two of them so we

need to count this like this in a

clockwise direction so that we can get

the lowest numbers so this is going to

be called 2 comma 4 die nitrile because

we have two of them on carbons 2 & 4 and

then phenol now for our next example

we're going to have a carbocylic acid a

bromine atom and a nitro group attached

to the benzene ring so feel free to

pause the video and try this example so

let's start with a parent name the

parent name is going to include the

benzene ring and the carbocylic acid so

combined we know that to be benzoic acid

which means this is carbon one now how

should we count it in the clockwise

direction or in the counterclockwise

direction so if we try the

counterclockwise direction notice that

the bromine atom is on carbon 3 and the

nitro group is on carbon 6 but if we

count in clockwise the nitros on carbon

2 the bromine is on carbon 5 and so 2 is

less than 3 therefore we're going to

count it in the clockwise direction now

we need to put it in alphabetical order

so bromo comes before nitro so it's

gonna be 5 - bromo - 2 - nitro benzoic

acid and so that's how we can name this

molecule

let's try one more example and so for

this example we're gonna have a bromine

atom a nitro group and at the same time

a chlorine atom so what do you think the

name of this aromatic compound will be

and how should we count it well if we

count it this way one two three four so

the numbers will be one three four if we

count it this way we will get lower

numbers one two four instead of one

three four and we don't want to start

with a nitro group because if we count

it this way this is going to be one two

five and so we don't want that or if we

count it this way it's gonna be one

three six which is even worse so this is

the best option so this is going to be

one two three four now we have a four

bromo we have a one chloro and a two

nitro so we need to put the substituents

in alphabetical order so it's gonna be

four bromo and then one chloro become

c4c and then - two - nitro benzene so

that's how we can name this particular

aromatic compound and so that's it for

this video now you know how to name

benzene derivatives thanks for watching