The acetone dicarboxylic acid, CO(CH 2 CO 2 H) 2, so obtained combines with hydrocyanic acid, and this product yields citric acid on hydrolysis.
PROPIOLIC ACID, CH:C CO 2 H, acetylene mono-carboxylic acid, an unsaturated organic acid prepared by boiling acetylene dicarboxylic acid (obtained by the action of alcoholic potash on dibromsuccinic acid) or its acid potassium salt with water (E.
Such a series of typical compounds are the benzene dicarboxylic acids (phthalic acids), C 6 H 4 (000H) 2.
We may here mention the synthesis of oxyuvitic ester (5-methyl-4-oxy-I-3-benzene dicarboxylic ester) by the condensation of two molecules of sodium acetoacetic ester with one of chloroform (Ann., 1883, 222, p. 249).
Thus ortho-phenylene diamine yields the following products: N H N ./`N; Xn NZ In some cases oxidation of condensed benzenoid-heterocyclic nuclei results in the rupture of the heterocyclic ring with the formation of a benzene dicarboxylic acid; but if the aromatic nucleus be weakened by the introduction of an amino group, then it is the benzenoid nucleus which is destroyed and a dicarboxylic acid of the heterocyclic ring system obtained.