pCHCl

pCHCl, also known as phenyl chloroformate, is an organic compound with the chemical formula C6H5OCOCl. It is a colorless liquid with a pungent odor and is an ester of carbonic acid and phenol. Phenyl chloroformate is a derivative of chloroformic acid and phenol, where the hydroxyl group of phenol has been replaced by a chloroformate group. It is typically prepared by the reaction of phenol with phosgene.

This compound serves as a useful reagent in organic synthesis. Its primary application lies in its ability to introduce the benzyloxycarbonyl (Cbz or Z) protecting group onto amines. This protection strategy is widely employed in peptide synthesis and the synthesis of other nitrogen-containing organic molecules. The Cbz group is stable under many reaction conditions but can be readily removed by catalytic hydrogenation or treatment with strong acids. Phenyl chloroformate can also react with alcohols to form carbonates and with thiols to form thiocarbonates. Due to its reactivity, it is handled with care, as it can react with moisture in the air to produce hydrochloric acid and phenol.