Our new procedure involves reaction of 1 equivalent of a carboxylic acid with 4 equivalents of benzotriazole and 1 equivalent of thionyl chloride in CH 2 Cl 2 at room temperature for 2 hours. Success with a wide range of carboxylic acids demonstrates the general applicability of this procedure (Table [1] ). Aliphatic short chain propionic acid, long chain palmitic acid, and alicyclic 1-phenyl-cyclopropanecarboxylic acid gave the corresponding ...
