What Solid Separates During the Malonic Ester Synthesis Reaction?

[ericvon11]

So I'm performing the reaction using:

urea + diethyl n-butylmalonate ----NaOEt---> n-butylbarbituric acid

My question is, after adding everything, you mix it and heat it, what is the solid that separates during this reaction? I've been thinking it might be diethyl n-butylmalonate but without 1 acid hydrogen due to the NaOEt. Why would this be unreacted though? ANY thoughts or advice would be greatly appreciated

 

[Nemus]

How about the sodium salt of the butylbarbituric acid?

 

[scorpion990]

There is a paper by Arthur W Dox and Lester Yoder called "Alkylbenzene Barbituric Acids." This was published in JACS in 1922. I found the answer in the experimental section. Look up the paper and give it a read.

I'm not trying to make you sweat... If you don't respond by tomorrow, I'll just post it here for completeness :)

EDIT: Didn't realize this was posted so long ago. Anyway... According to the paper, it's ammonium chloride. I assume you're running this reaction in ethanol.

 

[minerva]

It looks like you're talking about the non-professional synthesis of something which is either a controlled substance or pretty darned close to being a controlled substance... which is probably frowned upon by the admins around here.

 

[LudusRex]

The solid that separates during the Malonic Ester Synthesis reaction is likely the sodium salt of the n-butylbarbituric acid. This is formed when the diethyl n-butylmalonate reacts with the sodium ethoxide, resulting in the loss of one acid hydrogen. This salt is not reactive in this reaction and therefore remains unreacted. It is important to note that in any chemical reaction, there will always be some unreacted starting material and by-products formed. This is due to the fact that reactions are never 100% efficient and some of the reactants may not fully participate in the reaction. Additionally, side reactions may also occur, leading to the formation of by-products. Therefore, it is not uncommon to see unreacted starting materials in a reaction.