41126-01-6Relevant articles and documents
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
Sugimoto, Osamu,Arakaki, Tomoyo,Kamio, Hiroka,Tanji, Ken-Ichi
supporting information, p. 7314 - 7317 (2014/07/07)
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.
Syntheses and thermal rearrangements of 2-phenyl-4-alkoxycarbonyl-1,3,4-oxadiazol-5(4H)-ones and related sulfur compounds
Golfier, M.,Guillerez, M. G.
, p. 71 - 80 (2007/10/02)
Syntheses of nine 2-phenyl-4-alkoxycarbonyl-1,3,4-oxadiazol-5(4H)-ones are described.On heating about 200 deg C, these compounds decarboxylate and give 2-phenyl-4-alkyl-1,3,4-oxadiazol-5(4H)-ones.Although many analogies suggest that the rearrangement proceeds through the cyclisation of a 1,5-dipole, arising from the decarboxylation of the heterocycle, no direct evidence for such a mechanism was obtained.On the contrary, the synthesis and the thermal rearrangement of four related sulfur compounds show that such a postulated intermediate cannot explain all the experimental results.
