Abstract-3-Aryl(heteryl)-4-formylpyrazoles were cleanly oxidized by potassium permanganate in water- pyridine medium to afford in high yield 3-aryl(heteryl)pyrazole-4-carboxylic acids, that were further converted into the corresponding chlorides and amides. ... In the series of functionally substituted pyrazoles are important 4-pyrazolecarboxylic acids. On their capability to decarboxylate at elevated temperature is based an extensively used preparation method for pyrazoles ...