Chemistry help please!

tres

tres

tres

Soldato
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Clever OCUK,

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For the first one, I'm guessing a substitution reaction occurs, with a Cl swapping with the hydroxide group. But why? Oxygen finds the Phosphorus less electronegative than the carbon, and therefore would have a greater affinity? So the negative Cl which has been kicked from the P joins with the C?

For the second one, I looked at the answers. I can't quite work out why.

For the third one, I am desperately stuck
 
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you are right for the first one it will form the alkylchloride
the second will form the hydrochloride salt
the third will form an ester
 
The amine nitrogen is basic so will become protonated forming R-NH3+ Cl-.

The third could also form an amide depending on the sight of greatest reactivity. Both reactions occur through nucleophilic attack of the nitrogen and oxygen respectively, followed by loss of chloride and de-protonation forming HCl
 
flibbage0 said:
Oh ok, didn't know that.

This reminds me I need to revise my synthesis routes.

Quick question, when you have different functional groups like OH and NH2, if you added an acid/acyl chloride do you leave the NH2 group alone?
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the NH2 will always attack an electrophile first due to its lone pair, except in alkaline conditions when the OH will be ionised to O-, or in acidic conditions when the NH2 is protonated as NH3+.
 
When I went straight from doing chemistry A level, into the waste industry, I got the pee royally extracted for using systematic IUPAC names.

In industry it's always the old names.

Acetone
M.E.K.
M.I.B.K.
Toluene
Xylene
Butyl Acetate
Trike
1,1,1-Trike
Meth Chloride
Perk
IPA
Acetic Acid
Caustic (soda)

etc etc
 
aardvark said:
christ that annoys me!

not as much as everybody spelling sulphur compounds with an f and not a ph though!!
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I can't remember what they're called, but the group that essentially oversee naming of compounds decided a while back that it should be f, not ph.

Even professors who have been teaching / in reasearch for decades will have papers rejected / corrected if they spell sulfide / sulfur e.t.c with a ph.
 
int said:
I can't remember what they're called, but the group that essentially oversee naming of compounds decided a while back that it should be f, not ph.

Even professors who have been teaching / in reasearch for decades will have papers rejected / corrected if they spell sulfide / sulfur e.t.c with a ph.
Click to expand...

yeah i have recently started using the f when writing documents, reluctantly.
 
aardvark said:
the NH2 will always attack an electrophile first due to its lone pair, except in alkaline conditions when the OH will be ionised to O-, or in acidic conditions when the NH2 is protonated as NH3+.
Click to expand...

So a compound with bifunctional groups (OH and NH2) will lead to the NH2 attacking the R-COO+ ? So it leaves the OH alone and produces HCl as the by-product?
 
flibbage0 said:
So a compound with bifunctional groups (OH and NH2) will lead to the NH2 attacking the R-COO+ ? So it leaves the OH alone and produces HCl as the by-product?
Click to expand...

i think you mean R-CO+ ??
but basically yes - if you were to have an amino acid (with OH and NH2) and reacted with an acid chloride you would pretty much get the amide and not the ester.
 
aardvark said:
i think you mean R-CO+ ??
but basically yes - if you were to have an amino acid (with OH and NH2) and reacted with an acid chloride you would pretty much get the amide and not the ester.
Click to expand...

Yes sorry that is what I meant.

Thank you very much for helping:) I normally find the exam questions hard when they have two functional groups and ask to add something.
 
Entropy gave you the right answers.

The mechanism involving PCl5, goes through the -OH group reacting first with the Phosphorus, then transfer of one chlorine to the alkyl chain, and liberation of another atom of chlorine, in general:

Ph-CHOH-R' + PCl5 -> Ph-CHCl-R' + POCl3 + HCl

Hope it helps.
 
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