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

Printable Version  
 Pages:  1  2
Author: Subject: Esterification of Malonic Acid to DiEthyl Malonate
tiger1
Harmless
*




Posts: 8
Registered: 13-4-2008
Location: Left Coast
Member Is Offline

Mood: Mojo Rising

[*] posted on 20-10-2011 at 15:04


Thanks Nicodem, good point on unstable intermediate.
View user's profile View All Posts By User
DJF90
International Hazard
*****




Posts: 2266
Registered: 15-12-2007
Location: At the bench
Member Is Offline

Mood: No Mood

[*] posted on 21-10-2011 at 04:24


If you have access to a dean stark trap, there is a paper utilising Fe2(SO4)3.xH2O as a catalyst for esterification, in toluene and alcohol leading to almost quantitative yields in most cases. Two papers on the same subject, one for aromatic acids, the other for aliphatic.
View user's profile View All Posts By User
Boffis
International Hazard
*****




Posts: 1394
Registered: 1-5-2011
Member Is Offline

Mood: No Mood

[*] posted on 25-10-2011 at 09:27


@DJF90 do you have references for these two papers? They sound interesting on a general prep. level for esters
View user's profile View All Posts By User
DJF90
International Hazard
*****




Posts: 2266
Registered: 15-12-2007
Location: At the bench
Member Is Offline

Mood: No Mood

[*] posted on 25-10-2011 at 16:36


Yes I do, but I'm on a mobile device at the moment. I'll post them in the morning if I remember, otherwise send me a U2U to remind me.

EDIT: As promised...

[Edited on 26-10-2011 by DJF90]

Attachment: Fe2(SO4)3.xH2O catalysed esterification of aromatic acids.pdf (176kB)
This file has been downloaded 729 times

Attachment: High yielding esterification.pdf (135kB)
This file has been downloaded 747 times

View user's profile View All Posts By User
DoctorZET
Harmless
*




Posts: 42
Registered: 25-1-2014
Location: In the lab
Member Is Offline

Mood: tasting a pure sample of madness

[*] posted on 14-4-2014 at 01:23


well, once you have the malonic acid (watch discussion board at ~LINK: http://www.sciencemadness.org/talk/viewthread.php?tid=1600&a... ~), you can try this much more simple way:

HOOC-CH2-COOH + 2 CH3-CH2-OH (with excess) --(traces of H2O, dehydrated CaCl2, HCl bubbles in solution, 70-80*C)--> Et-OOC-CH2-COO-Et ,

where the moisture is absorbed by CaCl2 while some gasos HCl dissolve in solution and protonates the alcohol to form the diethylmalonate ester.

now you have to heat the resulting compounds to 50*C for a while to allow remaining HCl and ethanol to escape from solution, then let the CaCl2 to collect to the bottom and there you have it : pure diethylmalonate ester

If you use instead of HCl and CaCl2 , some H2SO4 ... you will have problems with separating the ester and with the conversion of ethanol to diethyl ether during the reaction.
View user's profile View All Posts By User
AvBaeyer
International Hazard
*****




Posts: 535
Registered: 25-2-2014
Location: CA
Member Is Offline

Mood: No Mood

[*] posted on 14-4-2014 at 18:06


Having looked carefully at the experimental sections for both of the papers cited by DFJ90 above, I find it hard to believe that the ferric sulfate is doing anything for the reported esterification reactions in the absence of data for control reactions without ferric sulfate. The esterifications are being driven by the removal of water, not by any ferric sulfate catalysis.

AvB
View user's profile View All Posts By User
Mush
International Hazard
*****




Posts: 516
Registered: 27-12-2008
Member Is Offline

Mood: No Mood

[*] posted on 7-6-2020 at 16:29


Mechanism of ferric sulphate catalysed esterification

Bioresource Technology 101 (2010) 7338–7343
Ferric sulphate catalysed esterification of free fatty acids in waste cooking oil



Alternative prep. methods

aluminum(III) sulfate, sulfuric acid, T= 100 °C
Kotake; Fujita; Rikagaku Kenkyusho Iho; vol. 1; p. 65

sulfuric acid, toluene, calcium carbide, yield:95,6%
Thielepape; Chemische Berichte; vol. 66; (1933); p. 1460

silver malonate, ethyl iodide, Time= 3h, T= 95 °C
Journal of labelled compounds and radiopharmaceuticals; vol. 47;
11; (2004); p. 779 - 786



Attachment: thielepape 1933 ber 1460 malonic acid carbide toluene sulfuric acid abs etoh.pdf (438kB)
This file has been downloaded 57 times

Attachment: shin2004 ag malonate ethyl iodide.pdf (112kB)
This file has been downloaded 53 times

Attachment: gan2010 Ferric sulphate catalysed esterification of free fatty acids in waste cooking oil.pdf (318kB)
This file has been downloaded 46 times
View user's profile View All Posts By User
Methyl.Magic
Hazard to Others
***




Posts: 139
Registered: 14-5-2007
Member Is Offline

Mood: No Mood

[*] posted on 10-6-2020 at 14:35


Personally I also doubt about the activity of Fe2(SO4)3 for esterficiation. Yes Fe +3 is a lewis acid but ... I don't know I does not 'feel' good.

The most important thing here is to remove water from the reaction to push the equilibrium to the ester buy removing continuously the water formed along to "Lechatelier" Principle.

You can continuously remove water by azeotrope with i.e. toluene but for this reaction the problem is alcohol is also removed by azeotrope and has a lower bp. This reaction use a catalytic amount of TsOH or better my favorite amberlyst-15 resin :cool:

The best option is to stay with H2SO4. Cheap and easy to get. Sulfuric acid is EXTREMELY dehydrating : less than 0.5 eq is way more than enough. If too much is added it can kills malonate by inter-dehydrating it. I bet you can also do the reaction without heating thanks to the dehydrating power of sulfuric acid. After a long reaction time, add water, extract with toluene of suitable solvent, combine the phases, washed the malonate with NaOH solution,dry over MgSO4 then distill the toluene and the malonate. Its just an idea :)

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




Posts: 516
Registered: 27-12-2008
Member Is Offline

Mood: No Mood

[*] posted on 15-8-2020 at 13:37


aluminum(III) sulfate, sulfuric acid, T= 100 °C
Kotake; Fujita; Rikagaku Kenkyusho Iho; vol. 1; p. 65
Chemisches Zentralblatt; vol. 99; no. II; (1928); p. 1545

Chemisches Zentralblatt V.99,  bd 2  (1928)  p.1545_ aluminum(III) sulfate,diethyl malonate.jpg - 363kB

With hydrogen-chloride
Sugasawa; Yakugaku Zasshi/Journal of the Pharmaceutical Society of Japan; (1927); p. 150; Chemisches Zentralblatt; vol. 99; nb. I; (1928); p. 1643

With sulfuric acid
Sugasawa; Yakugaku Zasshi/Journal of the Pharmaceutical Society of Japan; (1927); p. 150; Chemisches Zentralblatt;
vol. 99; nb. I; (1928); p. 1643

Chemisches Zentralblatt vol. 99 nb. I (1928) p. 1643_HCl_diethyl malonate.jpg - 364kB

With phosphoric acid
Lipp, Svetlana V.; Krasnykh, Eugenii L.; Verevkin, Sergey P.; Journal of Chemical and Engineering Data; vol. 56; nb. 4; (2011); p. 800 - 810

Attachment: lipp_2011_phosphoric acid diethyl malonate.pdf (973kB)
This file has been downloaded 28 times

Lipp, S. V.; Krasnykh, E. L.; Levanova, S. V. Retention indicesof symmetric dicarboxylic acid esters.J. Anal. Chem.2008,63, 349–352.

Attachment: Retention indices of symmetric dicarboxylic acid esters.pdf (166kB)
This file has been downloaded 28 times

[Edited on 15-8-2020 by Mush]
View user's profile View All Posts By User
DraconicAcid
International Hazard
*****




Posts: 3400
Registered: 1-2-2013
Location: The tiniest college campus ever....
Member Is Offline

Mood: Semi-victorious.

[*] posted on 15-8-2020 at 15:41


Quote: Originally posted by Methyl.Magic  
After a long reaction time, add water, extract with toluene of suitable solvent, combine the phases, washed the malonate with NaOH solution,dry over MgSO4 then distill the toluene and the malonate.


I would expect sodium hydroxide to rapidly destroy the malonate ester, either by simple hydrolysis, or deprotonation of the central carbon.




Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
View user's profile View All Posts By User
Dr.Bob
International Hazard
*****




Posts: 2200
Registered: 26-1-2011
Location: USA - NC
Member Is Offline

Mood: No Mood

[*] posted on 18-8-2020 at 05:57


Washing with sodium hydroxide solution (or perhaps better sodium bicarbonate or carbonate) should not destroy much of the ester as long as it is a wash for a few minutes, and not a long mixing. After the base wash, wash with brine to remove any remaining base. The basic hydrolysis of an ester is best done with a water miscible organic solvent (not toluene) that will allow the base and ester to contact each other for a long time. So merely washing with base in water, when using a hydrophobic solvent like toluene will not destroy much ester. The hydrolysis and even the deprotonation of diethyl malonate take a long time in the correct solvent mixture.
View user's profile View All Posts By User
 Pages:  1  2

  Go To Top