Chemical Properties
Off-white to light beige powder or flakes, melting point 87-89 ℃. Insoluble in water, soluble in organic solvents such as benzene.
Uses
Benzyl carbamate is a reagent used for the nucleophilic introduction of an amino-protected group, Benzyl carbamates can be considered as a benzyloxycarbonyl (otherwise known as carbobenzyloxy, Cbz or Z) protecting group for amino groups. It was introduced as a versatile alternative to the ethoxy carbamate group in peptide synthesis.
Application
Benzyl carbamate is an intermediate in the synthesis of various pharmaceutical compounds. It can be also used as nondeuterated internal standards for the quantitative analysis of carisoprodol in blood.
Preparation
Benzyl carbamate is prepared by reacting benzyl chloroformate with ammonia. Benzyl chloroformate was slowly added to 5 times the volume of cold ammonia water (relative density 0.90) under vigorous stirring, the reaction mixture was placed at room temperature for 30 minutes, the precipitate was filtered out, washed with water and dried to obtain the finished product of benzyl carbamate.
Purification Methods
If it smells of NH3, then dry it in a vacuum desiccator and recrystallise it from 2 volumes of toluene and dry it in a vacuum desiccator again. It forms glistening plates from toluene, and can be recrystallised from H2O [Martell & Herbst J Org Chem 6 878 1941, Carter et al. Org Synth Coll Vol III 168 1955]. [Beilstein 6 IV 2278.]
