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

Printable Version  
Author: Subject: Leuckart reaction with oxalic acid
njl
Hazard to Self
**




Posts: 65
Registered: 26-11-2019
Member Is Offline

Mood: 20 miles into bat country

[*] posted on 30-3-2020 at 07:27
Leuckart reaction with oxalic acid


Would oxalic acid work as a substitution for formic acid as a reducing agent in the leuckart reaction? Formic acid has the advantage of being oxidized to CO2 but apparently oxalic acid is a stronger reducing agent.

P.S. Searched for this question but didn't find naything, sorry if it's a repeat
View user's profile View All Posts By User
unionised
International Hazard
*****




Posts: 4222
Registered: 1-11-2003
Location: UK
Member Is Offline

Mood: No Mood

[*] posted on 30-3-2020 at 08:09


No.
There's no hydride to transfer.
View user's profile View All Posts By User
clearly_not_atara
International Hazard
*****




Posts: 1796
Registered: 3-11-2013
Member Is Offline

Mood: Big

[*] posted on 30-3-2020 at 09:41


However, there is apparently an oxalic acid Eschweiler-Clarke:

https://www.researchgate.net/profile/Paul_Kosma/publication/...




[Edited on 04-20-1969 by clearly_not_atara]
View user's profile View All Posts By User
Corrosive Joeseph
International Hazard
*****




Posts: 735
Registered: 17-5-2015
Location: The References Forum
Member Is Offline

Mood: Cyclic

[*] posted on 30-3-2020 at 09:51


https://chemistry.mdma.ch/hiveboard/novel/000497428.html


/CJ




MSDS Addict and OTC Slut
View user's profile View All Posts By User
unionised
International Hazard
*****




Posts: 4222
Registered: 1-11-2003
Location: UK
Member Is Offline

Mood: No Mood

[*] posted on 30-3-2020 at 10:39


"Primary and secondary amines are N-methylated by a mixture of paraformaldehyde..."

Just for a start, if you have paraformaldehyde, you can make formic acid.
View user's profile View All Posts By User
clearly_not_atara
International Hazard
*****




Posts: 1796
Registered: 3-11-2013
Member Is Offline

Mood: Big

[*] posted on 30-3-2020 at 11:47


You can also make formic acid from oxalic acid, which I was going to recommend but I thought it was too obvious. But what's the best way to make formic acid from paraformaldehyde?



[Edited on 04-20-1969 by clearly_not_atara]
View user's profile View All Posts By User
njl
Hazard to Self
**




Posts: 65
Registered: 26-11-2019
Member Is Offline

Mood: 20 miles into bat country

[*] posted on 31-3-2020 at 07:22


@All thank you for responses.

@Atara depends on where you are/what you have but basically hydrolyze paraformaldehyde to get a concentrated aqueous solution and then oxidize over KMnO4. Using KMnO4 has the advantage of leaving you with the formate salt after oxidation, so you can easily purify and then recover the acid with HCl. The reason I didn't mention the oxalic acid --> formic acid prep is because I don't have any glycerin at the moment.
View user's profile View All Posts By User
unionised
International Hazard
*****




Posts: 4222
Registered: 1-11-2003
Location: UK
Member Is Offline

Mood: No Mood

[*] posted on 31-3-2020 at 08:27


Quote: Originally posted by clearly_not_atara  
You can also make formic acid from oxalic acid, which I was going to recommend but I thought it was too obvious. But what's the best way to make formic acid from paraformaldehyde?

Hydrolysis to formaldehyde by dissolution in hot water, then this

https://en.wikipedia.org/wiki/Cannizzaro_reaction

to get formate.
View user's profile View All Posts By User
unionised
International Hazard
*****




Posts: 4222
Registered: 1-11-2003
Location: UK
Member Is Offline

Mood: No Mood

[*] posted on 31-3-2020 at 08:29


I'd avoid the oxidation by permanganate since it also attacks formic acid.
View user's profile View All Posts By User
njl
Hazard to Self
**




Posts: 65
Registered: 26-11-2019
Member Is Offline

Mood: 20 miles into bat country

[*] posted on 31-3-2020 at 09:09


I agree the Cannizzaro reaction looks better. I don't have any experience with it which is why I didn't mention it.

@unionised wouldn't the potassium salt be less prone to oxidation to oxidation?
View user's profile View All Posts By User
unionised
International Hazard
*****




Posts: 4222
Registered: 1-11-2003
Location: UK
Member Is Offline

Mood: No Mood

[*] posted on 31-3-2020 at 09:44


Probably, but paraformaldehyde is cheaper than permanganate.
View user's profile View All Posts By User
S.C. Wack
bibliomaster
*****




Posts: 2108
Registered: 7-5-2004
Location: Cornworld, Central USA
Member Is Offline

Mood: Enhanced

[*] posted on 31-3-2020 at 11:02


One would add peroxide first, unless small amounts of methanol are needed.



"You're going to be all right, kid...Everything's under control." Yossarian, to Snowden
View user's profile Visit user's homepage View All Posts By User

  Go To Top