Anilic acids

Perform the followmg experiment with succinic anhydride. This illustrates the formation of an anilic acid, which is usually an excellent... 

If the anhydride of an unknown acid is being used and the anilic acid does not crystallise after the mixture has been boiled for a short time, cool the solution, wash it with dilute hydrochloric acid to remove the excess of aniline, and evaporate the solvent the anilic acid will then usually crystallise. 

SUCCINIMIDE, N-IODO-, 42, 73 Sulf anilic acid, reaction of the diazonium salt with substituted benzyl alcohols to give aldehydes, 44,. 4 Sulfoacetic acid, 44, 102 Sulfonation of pyridine, 43, 97... 

Dicarboxylic acids are readily converted into cyclic anhydrides when heated alone or in acetic anhydride. Heat 0.5 g of the acid in 2-3 ml of refluxing acetic anhydride for 30 minutes. Remove most of the excess reagent by distillation and crystallise the residual cyclic anhydride from chloroform or toluene. The melting points of aliphatic and aromatic anhydrides are to be found in Tables 10.23 and 10.24 respectively. For conversion of the anhydrides into anilic acids see Section 9.6.16, below. 

Bifurcated hydrogen bonds between dipyridinium cations and coordinated dithiooxalates have been used to assemble tapes [130] with similar geometry to those in which coordinated halides act as acceptors [15]. Replacement of dipyridinium with 4-carboxypiperidinium gave a structure in which the anions are linked by carboxylic acid dimer assembled dications. Similar bifurcated hydrogen bonds were observed in the structures of bipyridinium salts of anilic acids [131]. 

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