[CHEKAL]

Hi everyone, im having some difficulty in finding a reagent or catalyst to convert a tertiary amine (with an ester group attached) to a secondary amine replacing the ester with a hydrogen. I was wondering if anyone could give me any guidance? It should only be a single step reaction/catalysis reaction.

Many thanks

[discodermolide]

It is a carbamate. What is the ester group?

[CHEKAL]

It is a carbamate. What is the ester group?

The molecule is RR'NC(O)OCPh so the ester group is just C(O)OCH2Ph

[discodermolide]

Then if the rest of the molecule will allow it use hydrogenation with 5 or 10% Pd/C.

[Dan]

The functional group is called a carbamate:



These are common protecting groups for amines, cleavage of which relies on a chemical reaction that breaks the O-R2 bond:



Spontaneous loss of CO₂ then provides the amine:



See also: http://www.organic-chemistry.org/protectivegroups/amino.shtm

[CHEKAL]

The functional group is called a carbamate:



These are common protecting groups for amines, cleavage of which relies on a chemical reaction that breaks the O-R2 bond:



Spontaneous loss of CO₂ then provides the amine:



See also: http://www.organic-chemistry.org/protectivegroups/amino.shtm

So you would reduced via hydrogenation to carboxylic acid which then undergoes sponatenous loss of carbon dioxide to give the amine product?

[discodermolide]

This depends upon the R² group in Dan's scheme. When it is benzyl you can use hydrogenation, when it is ethyl you can use acid or base to hydrolyse the ester.

[CHEKAL]

The target molecule is piperidine produced from the carbamate version of piperidine where the ester group, as before is where the hydrogen is.

[discodermolide]

As I said already hydrogenate it off.

[CHEKAL]

according to the link that Dan posted, im able to use LiAlH4 to hydrolyse the ester which would induce decarboxylation?

[discodermolide]

The easiest way to remove a benzyl carbamic acid ester is to hydrogenolyse it off. If the rest of your molecule will tolerate that.
Room temperature, H₂/5 or 10% Pd/C, in methanol or the like. The CO₂ can mess up the measurement of H₂ uptake but that's not a problem.
Using LiAlH₄ is like using a sledgehammer to hit nails.