[cofi]

I was thinking about about synthetising malonic acid... something like this:

diethyl-carbonate + ethyl-acetate --(Claisen's reaction)--> diethyl-malonate
diethyl-malonate --(hydrolysis)--> malonic acid

could you tell me how fast would these two reactions go and how could I proove that I got malonic acid as a product... and how much diethyl-carbonate and ethyl-acetate should I use to avoid getting too much ethyl-acethylacetate (product of a competitive reaction between two molecules of ethyl-acetate)?

and, finally, can this diethyl-carbonate be bought somewhere or it's rare and expensive?

[FeLiXe]

the standard way is:

Chloro-acetic-acid + KCN
-> Cyano-acetic-acid

Hydrolisation: malonic acid

[cofi]

I would like to avoid using KCN as it's for educational purposes, and I hate those safety measures and so on...

[movies]

For a Claisen condensation you usually want about 2 or 2.5 equivalents of whatever base you are using (relative to ethyl acetate in this case) and then about 1.25-1.5 equivalents of carbonate.  A convenient base for a reaction like this is NaH.  You can run the reaction in dry THF and it would probably take about 3-12 hours, hard to say for sure.

Diethyl carbonate is a readily available commercial chemical and isn't very expensive.

Of course, malonic acid is also readily available and cheap.

[Mr T]

DONT BOTHER WITH MALONIC ACID SYNTHESIS. IT IS INEXPENSIVE TO BUY. CHECK OUT SIGMA ALDRICH ©www.sigma-aldrich.com