Esterification Mukaiyama

The formation of esters from carboxylic acids by using Ar-alkyl-2-halopyridinium salts, such as 2-chloro-l-methylpyridine iodide (1) and alcohols, was first reported by Mukaiyama and, thus, the reaction is defined as the Mukaiyama esterification. The active ester (2) forms esters in good yield under mild conditions when subjected to alcohols. 

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