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F324 jan 2011 question help

Hi everyone,

I'm trying to do F324 and I'm finding the papers ridiculously hard to do- I haven't gotten higher than a C in the previous ones. The content I find easy to learn and udnerstand- but the paper is just so difficult for me.

Anyways, can anybody help me with question 4 of F324 JAN 2011 please? Could you please explain how you get the answer and what is going on in the reaction please? thank you!!
F324 JUNE.PNG2.PNG3.PNG
:confused:
Original post by aSunnyDay
Hi everyone,

I'm trying to do F324 and I'm finding the papers ridiculously hard to do- I haven't gotten higher than a C in the previous ones. The content I find easy to learn and udnerstand- but the paper is just so difficult for me.

Anyways, can anybody help me with question 4 of F324 JAN 2011 please? Could you please explain how you get the answer and what is going on in the reaction please? thank you!!
F324 JUNE.PNG2.PNG3.PNG
:confused:


In synthesis 1:

Step 1.
You have to concentrate on what is happening at each end of the molecule.

On the far left the chorine is being substituted by an amine group, by the ammonia nucleophile.

On the far right the basic conditions are deprotonating the carboxylic acid group.

Step 2
The carboxylate ion is being reprotonated to give the carboxylic acid.

In synthesis 2:

The first step is nucleophilic addition of HCN to the carbonyl group and simultaneous substitution of the OH formed by NH2 from the ammonium ions.

The CN group is then hydrolysed to a carboxylic acid.
(edited 9 years ago)
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aSunnyDay
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Original post by charco
In synthesis 1:

Step 1.
You have to concentrate on what is happening at each end of the molecule.

On the far left the chorine is being substituted by an amine group, by the ammonia nucleophile.

On the far right the basic conditions are deprotonating the carboxylic acid group.

Step 2
The carboxylate ion is being reprotonated to give the carboxylic acid.

In synthesis 2:

The first step is nucleophilic addition of HCN to the carbonyl group and simultaneous substitution of the OH formed by NH2 from the ammonium ions.

The CN group is then hydrolysed to a carboxylic acid.


thank you so much!!
I haven't heard of protonation and deprotonation before :/ are you on the OCR syllabus aswell?

Also what would 4aii) and b) be? don't really understand how you get an impurity? :colondollar:
Original post by aSunnyDay
thank you so much!!
I haven't heard of protonation and deprotonation before :/ are you on the OCR syllabus aswell?

Also what would 4aii) and b) be? don't really understand how you get an impurity? :colondollar:


Protonation just means adding a hydrogen ion, and deprotonation the opposite.

No, I'm not on the OCR syllabus.

To see the possible side reactions you have to consider the functional groups you have on the molecule and see which could also react further under the stated conditions.

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