To circumvent these problems, other methods have been reported in which mild reaction conditions were proposed but still using acid chlorides or anhydrides. [4] Recently two methods of in situ generation of mixed anhydrides were reported. The first one employs pivaloyl chloride and triethylamine in toluene, at 80-110 °C, and is especially good for arylacetic acids whereas aliphatic and conjugated acids gave only modest yields. [5] The second one employs diisopropylcarbodiimide ...
