19836-24-9Relevant academic research and scientific papers
Synthesis of 1,3,4-oxadiazoles from 1,2-diacylhydrazines using [Et 2NSF2]BF4 as a practical cyclodehydration agent
Pouliot, Marie-France,Angers, Laetitia,Hamel, Jean-Denys,Paquin, Jean-Francois
supporting information; experimental part, p. 988 - 993 (2012/04/10)
The preparation of 1,3,4-oxadiazoles from 1,2-diacylhydrazines using XtalFluor-E ([Et2NSF2]BF4) as cyclodehydration reagent is described. Various functionalized 1,3,4-oxadiazoles were synthesized and it was found that the use of acetic acid as an additive generally improved the yields.
Oxadiazoles in medicinal chemistry
Bostr?m, Jonas,Hogner, Anders,Llinàs, Antonio,Wellner, Eric,Plowright, Alleyn T.
scheme or table, p. 1817 - 1830 (2012/05/05)
Oxadiazoles are five-membered heteroaromatic rings containing two carbons, two nitrogens, and one oxygen atom, and they exist in different regioisomeric forms. Oxadiazoles are frequently occurring motifs in druglike molecules, and they are often used with the intention of being bioisosteric replacements for ester and amide functionalities. The current study presents a systematic comparison of 1,2,4- and 1,3,4-oxadiazole matched pairs in the AstraZeneca compound collection. In virtually all cases, the 1,3,4-oxadiazole isomer shows an order of magnitude lower lipophilicity (log D), as compared to its isomeric partner. Significant differences are also observed with respect to metabolic stability, hERG inhibition, and aqueous solubil ity, favoring the 1,3,4-oxadiazole isomers. The difference in profile between the 1,2,4 and 1,3,4 regioisomers can be rationalized by their intrinsically different charge distributions (e.g., dipole moments). To facilitate the use of these heteroaromatic rings, novel synthetic routes for ready access of a broad spectrum of 1,3,4-oxadiazoles, under mild conditions, are described.
Mild and convenient one-pot synthesis of 1,3,4-oxadiazoles
Stabile, Paolo,Lamonica, Alessandro,Ribecai, Arianna,Castoldi, Damiano,Guercio, Giuseppe,Curcuruto, Ornella
supporting information; experimental part, p. 4801 - 4805 (2010/10/02)
A mild, general, convenient, and efficient one-pot synthesis of 2-phenyl-5-substituted-1,3,4-oxadiazoles is described. Both (hetero)aryl and alkyl carboxylic acids were efficiently condensed with benzohydrazide in the presence of TBTU to give diacylhydrazine intermediates. The latter underwent a smooth TsCl-mediated cyclodehydration reaction to afford 2-phenyl-5-substituted- 1,3,4-oxadiazoles in good to very good yields.
