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Amines help please!!

"Amine F can be prepared in a three-step synthesis starting from methylbenzene. Suggest the structures of the two intermediate compounds. For each step, give reagents and conditions only. Equations and mechanisms are not required. [5marks]"

So I looked at this question and thought it would be about making phenyl amine from benzene, so thought it was to do with the process of going from benzene to nitrobenzene to phenyl amine. However, the mark scheme states something completely different and I don't understand it at all:

"Intermediate compounds
Product of step 1 C6H5CH2Cl1
Product of step 2 C6H5CH2CN
Reagents/conditions
Step 1
Cl2& UV
Step 2
KCN alcoholic & aq (both reqd)
Step 3H2 / Ni or Ptor Pd"

Can someone please explain
1.) Free Radical Substitution of methyl Benzene with a halogen (chlorine)
2.)Nucleophilic Substitution of Halogenoalkane
3.) Catalytic Hydrogenation/ Reduction of a nitrile
The questions says "starting from methylbenzene " so you cannot start with Benzene. Also your answer is 2 step where as the question specifies 3 steps.
Hope this helps
Am I the only one that read this as anime..
Original post by Themysticalegg
Am I the only one that read this as anime..

yes
Original post by Mr.noname
1.) Free Radical Substitution of methyl Benzene with a halogen (chlorine)
2.)Nucleophilic Substitution of Halogenoalkane
3.) Catalytic Hydrogenation/ Reduction of a nitrile
The questions says "starting from methylbenzene " so you cannot start with Benzene. Also your answer is 2 step where as the question specifies 3 steps.
Hope this helps

Thank you, but I have never come across this particular process before, is there a name for it? Could you maybe provide more information on this process please? Could you provide the mechanisms?
(edited 5 years ago)
How would you prepare phenylethylamine in a three-step synthesis starting from methylbenzene?

What mechanisms are involved? Is there a specific name for this process? I can't find much about it online and have never come across an example of a reaction like this in my AQA textbook?
Original post by anactualmess
Thank you, but I have never come across this particular process before, is there a name for it? Could you maybe provide more information on this process please? Could you provide the mechanisms?

Follow this diagram on aliphatic synthetic routes: https://imgur.com/a/UuOJn0X
Original post by anactualmess
How would you prepare phenylethylamine in a three-step synthesis starting from methylbenzene?

What mechanisms are involved? Is there a specific name for this process? I can't find much about it online and have never come across an example of a reaction like this in my AQA textbook?

The benzene ring is just a distraction. You could just as easily transform methane into ethylamine.

PhCH3 --- free radical substitution of chlorine using u.v. light --> PhCH2Cl

Now you need to lengthen the carbon chain. At 'A' level the accepted way is nucleophilic substitution using cyanide ions.

PhCH2Cl + CN- --> PhCH2CN

Now you just have to add hydrogen across the CN triple bond. Use a nickel catalyst and hydrogen gas at 150ºC.

PhCH2CH2NH2
Original post by charco
The benzene ring is just a distraction. You could just as easily transform methane into ethylamine.

PhCH3 --- free radical substitution of chlorine using u.v. light --> PhCH2Cl

Now you need to lengthen the carbon chain. At 'A' level the accepted way is nucleophilic substitution using cyanide ions.

PhCH2Cl + CN- --> PhCH2CN

Now you just have to add hydrogen across the CN triple bond. Use a nickel catalyst and hydrogen gas at 150ºC.

PhCH2CH2NH2

thank you so much I get it now
Original post by anactualmess
Thank you, but I have never come across this particular process before, is there a name for it? Could you maybe provide more information on this process please? Could you provide the mechanisms?


The have named the mechanisms and the reagents and conditions have already been mentioned in the markscheme. Use synthetic routes to determine which three steps would make the desired product starting from a given compound.
The flashcards at www.alevelrevisioncards.co.uk are helping me greatly with things like this. Maybe check them out?
Original post by anactualmess
Thank you, but I have never come across this particular process before, is there a name for it? Could you maybe provide more information on this process please? Could you provide the mechanisms?
Original post by Mr.noname
The have named the mechanisms and the reagents and conditions have already been mentioned in the markscheme. Use synthetic routes to determine which three steps would make the desired product starting from a given compound.

I've already answered this in your other thread (on the same topic - :naughty:)

In fact, I'll merge them ...
Original post by Mr.noname
1.) Free Radical Substitution of methyl Benzene with a halogen (chlorine)
2.)Nucleophilic Substitution of Halogenoalkane
3.) Catalytic Hydrogenation/ Reduction of a nitrile
The questions says "starting from methylbenzene " so you cannot start with Benzene. Also your answer is 2 step where as the question specifies 3 steps.
Hope this helps


A little bit late on the trend but could someone please answer? I just did this question and am so confused because product F is an amine with the formula: C6H5(CH2CH2NH2) But the mark scheme says C6H5CH2CL so there are two carbons attached but in the mark scheme there is only one carbon attached. Am I going insane or what. Also instead of doing the free radical substitution and then nucleophilic substitution to get the bromine could you not have done the free radial substitution with the bromine originally?

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