Chloroformate

General chemical structure of chloroformate esters

Not related to the similarly named chloroform (trichloromethane).

Chloroformates are a class of chemical compounds which are esters of chloroformic acid. They are widely used as reagents in organic chemistry. For example, benzyl chloroformate is used to introduce the Cbz protecting group and fluorenylmethyloxycarbonyl chloride is used to introduce the FMOC protecting group. They are gaining popularity in the field of chromatography as versatile derivatization agents. They enable relatively simple transformation of large array of metabolites (aminoacids, amines, carboxylic acids, phenols) for analysis by gas chromatography / mass spectrometry.

Reactions

Chloroformates have similar reactivity to other acyl chlorides, such as:

• Reaction with amines to form carbamates
• Reaction with alcohols to form carbonate esters
• Reaction with carboxylic acids to form mixed anhydrides