14389-13-0Relevant articles and documents
1-Disulfo-[2,2-bipyridine]-1,1-diium chloride ionic liquid as an efficient catalyst for the green synthesis of 5-substituted 1H-tetrazoles
Aali, Elaheh,Gholizadeh, Mostafa,Noroozi-Shad, Nazanin
, (2022)
A simple, green and efficient method has been developed for the synthesis of 5-substituted 1H-tetrazole derivatives through [2+3] cycloaddition reaction in good to excellent yields between various benzonitriles and sodium azide. For this purpose, 1-disulfo-[2,2-bipyridine]-1,1-diium chloride ([BiPy](HSO3)2Cl2) system as an ionic liquid catalyst have been extended for the construction of these valuable products. This procedure has significant advantages, including using ethylene glycol as a green solvent. The other advantages of this method are inexpensive and ease the preparation of the catalyst, mild reaction conditions, green reaction medium, easy workup, short reaction time, and simple experimental process.
The conversion of secondary amides to tetrazoles with trifluoromethanesulfonic anhydride and sodium azide
Thomas
, p. 767 - 768 (1993)
Due to the interest in tetrazoles as medicinal agents, a new, mild one-step method for the conversion of amides to tetrazoles employing triphenylphosphine, diethyl azodicarboxylate, and trimethylsilyl azide was recently introduced. An alternate and equally simple method employing trifluoromethanesulfonic anhydride and sodium azide was devised. This method was used to synthesize a series of 1,5-substituted tetrazoles from readily available secondary amides. A 1H-substituted tetrazole was also synthesized by this method from an amide substituted with a cyanoethyl protecting group.
Batch Versus Flow Lithiation–Substitution of 1,3,4-Oxadiazoles: Exploitation of Unstable Intermediates Using Flow Chemistry
Wong, Jeff Y. F.,Tobin, John M.,Vilela, Filipe,Barker, Graeme
supporting information, p. 12439 - 12445 (2019/09/06)
1,3,4-Oxadiazoles are a common motif in pharmaceutical chemistry, but few convenient methods for their modification exist. A fast, convenient, high yielding and general α-substitution of 1,3,4-oxadiazoles has been developed using a metalation-electrophilic trapping protocol both in batch and under continuous flow conditions in contradiction to previous reports which suggest that α-metalation of this ring system results in ring fragmentation. In batch, lithiation is accomplished at an industrially convenient temperature, ?30 °C, with subsequent trapping giving isolated yields of up to 91 %. Under continuous flow conditions, metalation is carried out at room temperature, and subsequent in flow electrophilic trapping gave up to quantitative isolated yields. Notably, lithiation in batch at room temperature results only in ring fragmentation and we propose that the superior mixing in flow allows interception and exploitation of an unstable intermediate before decomposition can occur.