A mild and efficient one pot synthesis of 1,3,4-oxadiazoles from carboxylic acids and acyl hydrazides

Synthesis, spectral characteristics and electrochemistry of symmetrically substituted hybrids derived from 2,5-bis(4-bromophenyl)-1,3,4-oxadiazole under Suzuki cross-coupling reaction

“…[5][6][7][8] One of the most widely studied representatives of electron-injection/hole-blocking materials from this class is 2-(4-biphenylyl)-5-(4-tertbutylphenyl)-1,3,4-oxadiazole (PBD), exhibiting high photoluminescence quantum yield and good thermal and chemical stabilities. 9,10 A literature survey revealed some other examples of π-conjugated 1,3,4-oxadiazole hybrids connected directly or indirectly to other [19][20][21][22][23][24][25][26][27] The leading 1,3,4-oxadiazoles are usually prepared from acid hydrazides as cyclocondensation substrates with carboxylic acids, 28 aromatic aldehydes, 29 orthoesters 30 or by transformations involving other rings, such as 1,2,4-oxadiazole. 31 However, the most popular methodology involves reactions of diacylhydrazines with a range of cyclodehydrating agents, just to mention polyphosphoric acid, boron trifluoride-diethyl etherate, thionyl chloride, phosphorus oxychloride or the Burgess reagent.…”

An effective conversion of N'-ethoxymethylene-2-(N-Boc-amino)propionhydrazides into 2-(1-aminoethyl)-1,3,4-oxadiazoles

“…1 A lot of compounds containing such an arrangement demonstrate strong antibacterial, anticonvulsant and anticancer activities; some of them are even used to fight infections involving AIDS. [2][3][4] They also have some industrial applications in agriculture as pesticides, acaricides and nematocides 5,6 or in material science because of their precious electrochemical properties. 7,8 The most popular method to synthesize 1,3,4-oxadiazoles uses acid hydrazides as substrates that undergo reaction with aromatic aldehydes, 9 carboxylic acids 4 and orthoesters.…”

“…[2][3][4] They also have some industrial applications in agriculture as pesticides, acaricides and nematocides 5,6 or in material science because of their precious electrochemical properties. 7,8 The most popular method to synthesize 1,3,4-oxadiazoles uses acid hydrazides as substrates that undergo reaction with aromatic aldehydes, 9 carboxylic acids 4 and orthoesters. 10 Another comprises the reactions of diacylhydrazines with a range of cyclodehydrating agents, for example: polyphosphoric acid, 11 phosphorus oxychloride, 12 thionyl chloride, 13 or boron trifluoride diethyl etherate 14 .…”

Preparation of trichloroacetoamidoxime in aqueous media and application in one pot synthesis of 1,2,4-oxadiazoles

“…In particular, 1,2,4-oxadiazoles represent a class of heterocyclic with a wide variety of biological activities, especially as antiinflamatory, agrochemical and antifungal activities. [1][2][3] Biologically relevant compounds containing the 1,2,4-oxadiazole moiety also include HIV integrase inhibitors, 4 antituberculostatic agents 5 and antikinetoplastid agents. 6 In particular, the introduction of halogens and halogenated groups into organic molecules often confers significant changes in their chemical, physical and pharmacological properties.…”