Trimethylsilyl)ethoxyacetylene, a stable and easy-handling reagent, serves as an excellent dehydrating agent for the synthesis of carboxylic anhydrides and amides from the corresponding carboxylic acids. By means of this reagent, various types of acid-sensitive carboxylic anhydrides and amides were obtained almost in quantitative yields. Twenty-two examples of carboxylic anhydrides and 12 examples of amides were presented.

Using the stable acetylene reagent (II), the carboxylic acids (I), (V), and (VII) are converted to the corresponding anhydrides (III) and (VI) or to the amides (IX).