Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
Author: Subject: phenylalanine and carboxylic acid reduction
azoth
Harmless
*




Posts: 5
Registered: 2-4-2006
Member Is Offline

Mood: No Mood

[*] posted on 2-4-2006 at 11:54
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.
View user's profile View All Posts By User
CherrieBaby
Hazard to Self
**




Posts: 91
Registered: 4-3-2005
Location: London
Member Is Offline

Mood: No Mood

[*] posted on 2-4-2006 at 12:04


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.
View user's profile View All Posts By User
azoth
Harmless
*




Posts: 5
Registered: 2-4-2006
Member Is Offline

Mood: No Mood

[*] posted on 2-4-2006 at 12:29


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?
View user's profile View All Posts By User
runlabrun
Hazard to Others
***




Posts: 172
Registered: 4-12-2004
Member Is Offline

Mood: No Mood

[*] posted on 4-4-2006 at 05:20


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
View user's profile View All Posts By User
Madandcrazy
Hazard to Others
***




Posts: 117
Registered: 11-5-2005
Member Is Offline

Mood: annoyed

[*] posted on 6-4-2006 at 07:42


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.
View user's profile View All Posts By User
praseodym
Hazard to Others
***




Posts: 137
Registered: 25-7-2005
Location: Schwarzschild Radius
Member Is Offline

Mood: crazy

[*] posted on 6-4-2006 at 17:43


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.
View user's profile View All Posts By User This user has MSN Messenger
Nicodem
Super Moderator
*******




Posts: 4230
Registered: 28-12-2004
Member Is Offline

Mood: No Mood

[*] posted on 7-4-2006 at 03:30


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!
View user's profile View All Posts By User
solo
International Hazard
*****




Posts: 3813
Registered: 9-12-2002
Location: Estados Unidos de La Republica Mexicana
Member Is Offline

Mood: ....getting old and drowning in a sea of knowledge

[*] posted on 7-4-2006 at 13:05


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.
View user's profile View All Posts By User
praseodym
Hazard to Others
***




Posts: 137
Registered: 25-7-2005
Location: Schwarzschild Radius
Member Is Offline

Mood: crazy

[*] posted on 7-4-2006 at 23:46


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.
View user's profile View All Posts By User This user has MSN Messenger

  Go To Top