Benzyl chloroformate is the benzyl

Benzyl

In organic chemistry, benzyl is the term used to describe the substituent or molecular fragment possessing the structure C6H5CH2-. Benzyl features a benzene ring attached to a CH2 group.-Nomenclature:...

 ester

Ester

Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...

 of chloroformic acid

Chloroformic acid

Chloroformic acid is an unstable chemical compound with the formula ClCO2H. It is the single acyl-halide derivative of carbonic acid . Chloroformic acid is also structurally related to formic acid, which has a hydrogen instead of the chlorine...

. It is also known as benzyl chlorocarbonate is an oily liquid whose color is anywhere from yellow to colorless. It is also known for its pungent odor. When heated, benzyl chloroformate decomposes into phosgene

Phosgene

Phosgene is the chemical compound with the formula COCl2. This colorless gas gained infamy as a chemical weapon during World War I. It is also a valued industrial reagent and building block in synthesis of pharmaceuticals and other organic compounds. In low concentrations, its odor resembles...

 and if it comes in contact with water it produces toxic, corrosive fumes.

Benzyl chloroformate is used in organic synthesis

Organic synthesis

Organic synthesis is a special branch of chemical synthesis and is concerned with the construction of organic compounds via organic reactions. Organic molecules can often contain a higher level of complexity compared to purely inorganic compounds, so the synthesis of organic compounds has...

 for the introduction of the carboxybenzyl

Carboxybenzyl

Carboxybenzyl or Cbz or Z is an amine protecting group in organic synthesis. It is commonly used in peptide synthesis and is formed by reacting an amine with benzyl chloroformate and a weak base:It is used to protect amines from electrophiles...

 (Cbz or Z) protecting group

Protecting group

A protecting group or protective group is introduced into a molecule by chemical modification of a functional group in order to obtain chemoselectivity in a subsequent chemical reaction...

 for amine

Amine

Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines,...

s:

The newly formed Cbz protecting group can be removed under reductive conditions. Typically hydrogen gas and activated palladium on carbon

Palladium on carbon

Palladium on carbon, often referred to as Pd/C, is a form of palladium used for catalysis. It is usually used for catalytic hydrogenations in organic chemistry...

is used.