Carbonic acid tert-butyl 2,4,5-trichlorophenyl ester

Used as reagent for the Boc protection of amino groups; preparation of active esters for peptide synthesis

tert-Butyl 2,4,5-Trichlorophenyl Carbonate is prepared by the reaction between 2,4,5-trichlorophenol and Phosgene in toluene at -10 °C in the  presence of dimethylaniline gives 2,4,5-trichlorophenyl chloroformate. Treatment with t-butanol and  quinoline in CH2Cl2 then affords t-butyl 2,4,5-trichlorophenyl carbonate.

Crystallise the carbonate from a mixture of MeOH (90mL) and water (6mL) using charcoal [Broadbent et al. J Chem Soc (C) 2632 1967, Fieser & Fieser Reagents for Organic Synthesis 2 55 1969].