but if I use ethyl chloroacetate dont I risk a claysen condensation as a sidereaction ?
No, because the Hacac is far more acidic than the ester.Alice - 30-4-2017 at 00:30
A bit more information would be nice. Is it your idea or somewhere from the literature? What solvent do you have in mind?
First, don't overdo it with the base and reflux. Acetyl acetone already has a fairly high equilibrium ratio of enol, but the ratio depends on the
solvent. In water there is even more enol than ketone. So if you feel brave, try the reaction with just as much base as needed to neutralize HCl,
e.g. NaOH, Na2CO3.
1 eq. acetyl acetone + 1.1 eq chloroacetic acid + 0.55 eq. anhydrous Na2CO3 (anhydrous because this way you get the exact amount you want) or 1.1 eq.
NaOH
This means, the base in your reaction mixture will be sodium chloroacetate! Prepare the salt in solution, then add acetyl acetone and stir. If you
plan using ethanol as the solvent do not run the reaction completely anhydrous as it's known for sodium acetate that some equivalents of water enhance
solubility effectively. I think this is true for chloroacetate as well.
Start with a trial at 40 °C or so and concentrated solution. If that's not enough go up to 50 °C and so on. I'd check if water is a suitable
solvent, ethanol or a mixture.
No guarantee this will work and of course this doesn't mean it won't work otherwise.Waffles SS - 30-4-2017 at 07:01
You will get 4,6-DIOXOHEPTANOIC ACID
Synthesis of dioxocarboxylic acids Pendarvis,R.O.; Hampton,K.G.
Journal of Organic Chemistry, 1974 , vol. 39, p. 2289 - 2291
DOI:10.1021/jo00929a035Alice - 30-4-2017 at 08:34
@Waffles. Your literature source displays a special case, which is achieved by generating disodioacetylacetone.Outer - 18-5-2017 at 12:50
You should use twice excess of NaOH, to transform both acetyl-acetone and chloroacetic acid in their Na-salts. Then they will react by the scheme:
(CH3CO)2CHNa + ClCH2COONa = (CH3CO)2CH-CH2COONa + NaCl.
And at the last step the product (Na-salt) should be neutralized by 1 equiv. of an acid (HCl, AcOH etc.) to obtain your product.
