CH (CHa) z CH (CHs) z p-Cymene 2-Monocarboxylic Acid. p-Cymene 3-Monocarboxylic Acid. I. p-Cymene 2-Monocarboxylic Acid.-Paterno and Fileti, in 1875, fused cymene sodium sulfonate with potassium cyanide and saponified the dark colored crude product with alcoholic potassium hydroxide solution, obtaining what was apparently the amide (m. 138- go, corr.) of the cymene 2-carboxylic acid.