Pyridinium Dichromate (PDC)
Pyridinium dichromate is the pyridinium salt of dichromate that can be obtained by addition of pyridine to a solution of chromium trioxide in water.
The orange salt is commercially available and can by conveniently handled and stored; it is non-hygroscopic and soluble in many organic solvents. A similar salt is pyridinium chlorochromate (PCC), which shares the same properties. Both PDC and PCC can convert alcohols into aldehydes and ketones, especially in dichloromethane at room temperature. PDC is less acidic than PCC and is therefore more suitable for the oxidation of acid-sensitive substrates.
A full review of chromium-based reagents can be found in the book written by Tojo and Fernández (Oxidation of Alcohols to Aldehydes and Ketones, Springer Berlin, 2006, 1-97.).
Attention: Chromium (VI) compounds are toxic and must be handled with care.