Magnesia-supported hydroxylamine hydrochloride in the presence of sodium carbonate as an efficient reagent for the synthesis of 1,2,4-oxadiazoles from nitriles

Microwave-Assisted Synthesis of Five-MemberedO,N,N-Heterocycles

“…Reaction of amidoximes and acyl chlorides with magnesium oxide [15] or alumina-supported ammonium fluoride [16] resulted in the formation of 1,2,4-oxadiazole derivatives (Scheme 1). In the other method, the authors used alkyl nitriles, acyl chlorides, and magnesiasupported hydroxyl amine hydrochloride [17] or the same reagent in the presence of potassium fluoride [18] with MW irradiation and obtained the target compounds in good yields (Scheme 2).…”

“…Adib et al [26] reported the one-pot, three-component condensation reaction between nitriles, hydroxylamine, and aldehydes for the synthesis of Kaboudin and Saadati [17] developed the efficient method for the synthesis of 1,2,4-oxadiazoles through one-pot reaction of nitriles with hydroxylamine hydrochloride in the presence of magnesia-supported sodium carbonate followed by reaction with acyl halides under solvent-free conditions using MW irradiation (Scheme 12).…”

Iodine–induced Oxidative Cyclisation of N‐Acyl Amidines: A Rapid Synthesis of 3,5‐Disubstituted‐1,2,4‐Oxadiazoles

“…Many strategies have been reported for the synthesis of 1,2,4‐oxadiazole derivatives. [17] Most of them involve O‐acylation of amidoximes or its precursor nitriles with activated carboxylic acid derivatives such as esters / orthoesters, acid chlorides and anhydrides, followed by intramolecular cyclodehydration (Figure , a‐b) . Very recently, a facile synthesis of 3,5‐disubstituted‐1,2,4‐oxadiazoles via copper‐catalysed‐cascade annulation of amidines and methyl arenes has been reported (Figure , c) …”

Clean one-pot synthesis of 1,2,4-oxadiazoles under solvent-free conditions using microwave irradiation and potassium fluoride as catalyst and solid support

“…23 Also, we knew that for the conversion of nitriles to amidoximes with hydroxylamine hydrochloride, basic media is required because in acidic media the nitrile would undergo hydrolysis to the corresponding amide (Scheme 2). 24 So, for a onepot synthesis of 1,2,4-oxadiazoles using nitrile as starting material we need basic media.…”