( 80 ) 
If we decompose the amide by heating it with strong acids or by 
boiling it with dilute alkalis a small quantity of an isomeric ketonic 
acid is produced which proved to be «-ketobutenoic (propionylformic) 
acid CHs. CH3. CO COOH. The statements found in the literature 
on the properties of this acid are mostly somewhat incorrect; the _ 
different authors have, apparently not obtained it in a pure condition, 
or else in too small a quantity and as a liquid. The acid which I 
prepared by decomposing the silver salt with dilute hydrochloric acid 
was purified by distillation in vacuum (b.p. 73°—75° at 15 mm., or 
85° at 21 mm.). The acid is erystallisable, and melts at 31°.5—32°, 
Even when highly diluted, the solution of the acid or of its salts 
yields with phenylhydrazine a compound melting at 143°—144°. 
The ethylester of propionylformic acid was obtained by the action 
of ethyliodide on the silver compound: 66--67° (16 m.m.), m. p. 
of the hydrazone 191°. This ester is also. isomeric with that of 
acetoacetic acid but gives no reaction with FeCls. The oxime of 
propionylformie acid Cy H;.C:N(OH) COOH melts with decompo- 
sition at 154°. 
That the ketonic acid really possesses the said constitution 
was proved by the fact that the CO group cannot occupy the 
(?- or y-position and also by its conversion, by reduction, into 
oxybutyric acid. 
The conversion of @-hydroxybutenoic acid into propionylformic 
(«-ketobutenoie) acid under the influence of acids is not complete; 
very soon we meet with a state of equilibrium in which the e-hydroxy- 
butenoie acid remains for the greater part unchanged (with small 
quantities of lactone-like substances) !). 
The chief product of the action of alkalis is a new acid which 
was also obtained crystalline and has the composition of two mols. 
of «-hydroxybutenoic acid minus one mol. of water. 
A further investigation showed that to this acid must, probably, 
be assigned the constitution: 
H COOH 
A OH 
| COOH 
| A-3-tetrahydro-2-oxyphthalic acid (1,2) 
| 
See 
1) Perhaps a lactone has formed analogous to that recently obtained by Dr. pe Jone 
from pyruvic acid. Rec. 20, 81. 
