title: The use of a Mitsunobu reagent for the formation of heterocycles: a simple method for the preparation of 3-alkyl-5-aryl-1,3,4-oxadiazol-2(3H)-ones from carboxylic acids.
abstract: The reaction of carboxylic acids with Mitsunobu reagents, prepared by the reaction of triphenylphosphine with dialkyl azodicarboxylates, followed by heating at 180-190 °C under solvent-free conditions, afforded 3-alkyl-5-aryl-1,3,4-oxadiazol-2(3H)-ones. This facile and convenient method readily provides the 1,3,4-oxadiazolone ring systems in good yields using a one-pot protocol starting from the corresponding carboxylic acids. It was also demonstrated that the presence of a catalytic base facilitates the final ring closure forming the 1,3,4-oxadiazol-2(3H)-one.
authors.affiliation: Laboratory of Organic Chemistry, School of Food and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan. osamu@u-shizuoka-ken.ac.jp.
authors.forename: Osamu
authors.initials: O
authors.lastname: Sugimoto
authors.forename: Tomoyo
authors.initials: T
authors.lastname: Arakaki
authors.forename: Hiroka
authors.initials: H
authors.lastname: Kamio
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Tanji