A convenient protocol for the esterification of carboxylic acids with alcohols in the presence of di-t-butyl dicarbonate

Stoichiometric mixtures of carboxylic acids and primary or secondary alkyl alcohols are cleanly converted into their corresponding esters by treatment with di-t-butyl dicarbonate [(BOC)(2)O] in the presence of catalytic amounts of N,N'-dimethylaminopyridine (DMAP). This convenient procedure provides a general access to a broad variety of esters including those bearing highly sensitive functional groups such as phenol esters or BOC-groups. Purification of the products is particularly easy since the byproducts tBuOH and CO2 are volatile - a great advantage over the standard DCC/DMAP method.