Ethyl acetopyruvate

The stirrer is started and there is added rapidly a cold sulfuric acid solution made by adding enough ice to 200 cc. of concentrated sulfuric acid (sp. g. 1.84) (Note 7) so that some of the ice is not melted. The stirring is continued for five or ten minutes or until the yellow lumps of the sodium salt disappear. The mixture is then extracted with three 600-cc. portions of benzene (Note 8). The benzene is destilled (Note g) from the extracts on a water bath and the residue is transferred to a special 2-I. Claisen flask (Org. Syn. 1, 40) and distilled under diminished pressure. The product boils at i3o-i32°/37 mm. or ii7-iig°/2g mm. A small high-boiling fraction is redistilled to yield 20-30 g. more of the ethyl acetopyruvate. The total yield is 480-520 g. (61-66 per cent of the theoretical amount). 

Ethyl acetopyruvate has been prepared only by the condensation of ethyl oxalate and acetone in the presence of sodium ethylated The method given above is based on that of Claisen and Stylosd... 

As with D-glucose, no positive results have as yet been obtained on attempting to react D-glucosamine with such highly enolizable compounds as diethyl oxalylacetate and ethyl acetopyruvate.26... 

Sodium ethyl acetopyruvate, 6, 40 Sodium ethylate, 6, 40, 48 Sodium formate, 3, 69 Sodium 2-furancarboxylate, 6, 44 Sodium hydrosulfite, 3, 8, 10 Sodium hydroxide, 7, 42, 54, 60, 76 Sodium hydroxide, alcoholic, 7, 89 Sodium p hy[Pg.53]

Ethyl acetopyruvate (37) reacts with 2,3-diaminopyridine in a variety of acidic conditions to yield mainly the 2-acetonyl-3-oxo compound 38. This is readily separated from the much more soluble 2-oxo isomer. 

Dimethylpyridine has been isolated from the basic fraction of coal tar1 and also from the bone oil fraction distilling at i39-i42°.2 It has also been prepared from ethyl acetopyruvate and ethyl (3-aminocrotonate.3... 

---