azoth
Harmless
Posts: 5
Registered: 2-4-2006
Member Is Offline
Mood: No Mood
|
|
phenylalanine and carboxylic acid reduction
forgive me if this subject has already been discussed, but
i've searched the net and besides a general outline i can't find any specific information about how one would
completely reduce the acyl chloride of phenylalanine using sodium borohydride..
does anyone know any practical methods/links/tips on how much borohydride one would use on an acyl chloride? to reduce everything.
any information would be helpful.
thanks.
|
|
|
CherrieBaby
Hazard to Self
Posts: 91
Registered: 4-3-2005
Location: London
Member Is Offline
Mood: No Mood
|
|
How would you prepare the acid chloride of phenylalanine? Wouldn't the acid Chloride react with the amino group internally? Perhaps the ester may be
easier to reduce.
|
|
|
azoth
Harmless
Posts: 5
Registered: 2-4-2006
Member Is Offline
Mood: No Mood
|
|
The information i've got says that thionyl chloride is used to make the acyl chloride from phenylalanine. what would it be called.
nomenclature is not my strong point
but 1-phenyl-(2-amino-3 propanioyl chloride) perhaps.?
since sod.borohydride isn't strong enough reducing agent to reduce the carboxylic acid directly, i was told that making the acyl chloride first was
the best thing to do.
is sodium borohydride strong enough to competely reduce an ester like you mentioned?
|
|
|
runlabrun
Hazard to Others
Posts: 172
Registered: 4-12-2004
Member Is Offline
Mood: No Mood
|
|
close...
2-amino-3-phenylpropanoyl chloride
LiAlH4 is stronger however its going to take alot of excess agent (whatever you end up using) to go from COOH --> CH3 (as im assuming your looking
at)... this means it will cost you a penny or 6...
-rlr
|
|
|
Madandcrazy
Hazard to Others
Posts: 117
Registered: 11-5-2005
Member Is Offline
Mood: annoyed
|
|
Is the pehnylalanin stable for this synthesis ?
When it threated with HCl, do it converted to
1-chloro-2-amino-propionic acid, to pehnylchloroethylamin or to pehnylacetylalanin  if it exist.
Maybe interested to this the DL-alanin within the -CH3NH2 group.
|
|
|
praseodym
Hazard to Others
Posts: 137
Registered: 25-7-2005
Location: Schwarzschild Radius
Member Is Offline
Mood: crazy
|
|
By use of sodium borohydride in N,N-dimethylformamide solution containing a molar excess of pyridine as a borane scavenger, direct conversion of both
aliphatic and aromatic acid chlorides to the corresponding aldehydes can be achieved in >70% yield with minimal (5-10%) alcohol formation.
Alles sollte so einfach wie möglich gemacht werden aber nicht einfacher.
|
|
|
Nicodem
Super Moderator
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
2-amino-3-phenylpropanoyl chloride does not exists for obvious reasons. Its hydrochloride salt is probably the closest thing you can obtain.
| Quote: | Originally posted by praseodym
By use of sodium borohydride in N,N-dimethylformamide solution containing a molar excess of pyridine as a borane scavenger, direct conversion of both
aliphatic and aromatic acid chlorides to the corresponding aldehydes can be achieved in >70% yield with minimal (5-10%) alcohol formation.
|
Do you mind providing us the reference for such a reduction of acid chlorides to aldehydes.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
|
|
|
solo
International Hazard
Posts: 3967
Registered: 9-12-2002
Location: Estados Unidos de La Republica Mexicana
Member Is Offline
Mood: ....getting old and drowning in a sea of knowledge
|
|
I've read the many ways to reduce the phenylalanine .......thus far one can make an ester and reduce to an alcohol, or use sodium borohydride and a
metal (AlCl3) in water at RT to reduce to the phenylalaninol( the alcohol of phenylalanine) .........and by "all the way " do you mean to the
hydrocarbon? For that you need to either halogenate and reduce or make the OH an easier leaving group to reduce , or dehydrate the alcohol but watch
out for rearrangement , also one thing you should know ......the reduction to the hydrocarbon leads you to a restricted compound ....you should have
a permit or be very careful............solo
It's better to die on your feet, than live on your knees....Emiliano Zapata.
|
|
|
praseodym
Hazard to Others
Posts: 137
Registered: 25-7-2005
Location: Schwarzschild Radius
Member Is Offline
Mood: crazy
|
|
| Quote: | Originally posted by Nicodem
Do you mind providing us the reference for such a reduction of acid chlorides to aldehydes. |
No problem. Here is the link. This website talks about the reduction of acid chlorides to aldehydes using sodium borohydride and pyridine. Hope that it is useful 
Alles sollte so einfach wie möglich gemacht werden aber nicht einfacher.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
