[jacy.cn]

Recently，I want to synthesize Ethyl 3-(N,N-dimethylamino)acrylate
The structure is as the following

There are several way to do this
but they are too expensive
Now I think the following way may be feasible in theory
CH₃COOEt [ethyl acetate] + CON(CH₃)₂ [dmf] + Na（H/OH/?）+Dimethylamine hydrochloride--- Ethyl 3-(N,N-dimethylamino)acrylate (I)

because
CH₃CHOOEt [ethyl acetate] + HCOEt [ethyl formate] + Na（H/OH/?）+ Dimethylamine hydrochloride--- Ethyl 3-(N,N-dimethylamino)acrylate(II)
is feasible by our experiment(but the yield is <40% AND ethyl formate is more expensive)。

But when we try the I way, we could not find any product.
the base we try Na,NaH or NaOR.
All of them is the same result.
why?

[orgopete]

While your proposed synthesis seems logical, the chemicals operate by innate reactivity and can ignore your desires. Because amides (DMF) are less susceptible to nucleophilic attack, an alternate reaction can take place, the Claisen condensation. In this instance, with ethoxide as base, there is only very low concentrations of enolate. Ethoxide (ethanol pKa 16) is too weak of a base to generate a very large concentration of enolate (EtOAc pKa 25). So even though you may make some enolate, the bulk of the ester is not ionized and susceptible to nucleophilic attack. 

Re: too expensive
While I cannot tell you when it is cheaper to buy a chemical than make it yourself, you can almost assume that if there are several suppliers, then a high price indicates the actual compound is not readily available. In this case, I can imagine that low demand may also contribute. (I did not search for the existence of any patents though.) It is highly likely that the current route uses a literature preparation and the high price corresponds with low yields and/or expensive starting materials. If you investigate a new route (as you are doing), then it may be possible to prepare the compound cheaply.

I always found it interesting that as I became familiar with the costs of chemicals, that I vicariously learned the basic chemistry of my sophomore organic chemistry class and the need to do the air, fire, and water type of syntheses. Suppliers never sell a product for less than its precursor. You can use that rule to determine what reactions and possible starting materials are used for virtually all starting materials. The more familiar you are with industrial chemicals and their manufacture, the less time it takes to do this type of analysis of cost and chemical efficiency.

[jacy.cn]

Thanks "orgopete" for you message
I found that is very usefull to me
as a nucleophilic reagent
I know "ethyl formate and ethyl acetate" is more easy to attack than "DMF"
But if we can control the reaction detail, for example, temperature,equivalent..
should the reaction be feasible?

At the same time
if we synthesize the product as the II way
I found "ethyl formate" is very easy to hydrogenate in Na(or NaH)
if we make ethyl formate:ethyl acetate(mol)=1~1.5:1
but ethyl formate is disappeared firstly,and this moment ethyl acetate may be left 20~30%
why?
how we can avoid the secondary reaction?

[jacy.cn]

While your proposed synthesis seems logical, the chemicals operate by innate reactivity and can ignore your desires. Because amides (DMF) are less susceptible to nucleophilic attack, an alternate reaction can take place, the Claisen condensation. In this instance, with ethoxide as base, there is only very low concentrations of enolate. Ethoxide (ethanol pKa 16) is too weak of a base to generate a very large concentration of enolate (EtOAc pKa 25). So even though you may make some enolate, the bulk of the ester is not ionized and susceptible to nucleophilic attack. 

Re: too expensive
While I cannot tell you when it is cheaper to buy a chemical than make it yourself, you can almost assume that if there are several suppliers, then a high price indicates the actual compound is not readily available. In this case, I can imagine that low demand may also contribute. (I did not search for the existence of any patents though.) It is highly likely that the current route uses a literature preparation and the high price corresponds with low yields and/or expensive starting materials. If you investigate a new route (as you are doing), then it may be possible to prepare the compound cheaply.

I always found it interesting that as I became familiar with the costs of chemicals, that I vicariously learned the basic chemistry of my sophomore organic chemistry class and the need to do the air, fire, and water type of syntheses. Suppliers never sell a product for less than its precursor. You can use that rule to determine what reactions and possible starting materials are used for virtually all starting materials. The more familiar you are with industrial chemicals and their manufacture, the less time it takes to do this type of analysis of cost and chemical efficiency.

One of the suppliers is very cheap(only RMB 65 per kg, others sell this product > RMB 100)
I analyze this cheapest Product on GC-Ms analysis, found that there are DMF,toluene,ethyl acetate in the product.
toluene may the solvent, and DMF and ethyl acetate maybe the reactant, do you think so?

[orgopete]

I didn't do a search on all of the possible routes, but the impurities are consistent with a Claisen of ethyl acetate and conversion of the enol ether into the vinylogous amide with dimethyl amine. Residual ethyl formate would get converted into DMF.

I suggest you look up a synthesis of your compound and follow that route or just purchase it.

[jacy.cn]

thanks orgopete
"Residual ethyl formate would get converted into DMF"and
may be
"Residual ethyl acetate would get converted into DMAc"

because i found there is DMAc() in the priduct.

so I AM sure the cheapest way may be the II way(react ethyl acetate with ethyl formate)