The unprecedented synthesis of novel spiro-1,2,4-triazolidinones

An efficient synthesis of anti-microbial 1,2,4-triazole-3-thiones promoted by acidic ionic liquid

“…In continuation with our interest in the synthesis of 1,2,4-triazolidine-3-thiones, [35][36][37] herein we report an expeditious synthesis of 1,2,4-triazaspiro [4.5]decane-3-thiones from ketones and thiosemicarbazides using catalytic amounts of 1,1 0 -sulfinyldipyridinium bis (hydrogen sulfate) ionic liquid in alcohol at room temperature (Scheme 1). Initial attention was focused on optimization of the reaction conditions in terms of screening of the catalyst for the model reaction of cyclohexanone (1 mmol) and thiosemicarbazide (1 mmol) in ethanol.…”

“…Recently, we have explored three routes for the synthesis of 1,2,4-triazolidine-3-thiones by [C 16 MPy]AlCl 3 Br catalyzed reaction of aldehyde and thiosemicarbazide; glycine nitrate mediated synthesis of spirooxindoles embedded with 1,2,4-triazolidine-3-thione from isatin and thiosemicarbazide and a multicomponent approach for the synthesis of 5-aryl- [1,2,4]triazolidine-3-thiones from aldehydes, hydrazine hydrate, and trimethylsilyl isothiocyanate (TMSNCS) [35][36][37]. There have been sporadic reports on the synthesis of spiro-1,2,4-triazolidinones.…”

“…There have been sporadic reports on the synthesis of spiro-1,2,4-triazolidinones. Earlier, MnO 2 , FeCl 3 , H 2 O 2 and m-chloroperbenzoic acid have been used for synthesis of 1,2,4-triazolidine-4-thiones from steroidal and non-steroidal homocyclic ketone and thiosemicarbazones [36][37][38][39][40][41][42][43]. Recently PEG-assisted synthesis of 5-aryl-1,2,4-triazolidine-3-thiones from aldehydes or cyclic ketones has been reported [44].…”

Synthesis of novel pyrazole‐based triazolidin‐3‐one derivatives by using ZnO/ZrO2 as a reusable catalyst under green conditions

“…Different triazolidine conjugates possessing a large spectrum of activities, including anti‐leishmanial, anti‐convulsant and anti‐cancer activity, have been reported . In fact, some efficient synthetic methods for the assembly of triazolidine rings have been developed, by using catalysts like sulfamic acid, glycine nitrate and [C 16 MPy] AlCl 3 Br . Moreover, green chemistry approaches through catalyst‐free one‐pot synthesis by Rathinam and co‐workers in aqueous medium have also been reported .…”

Thiamine Hydrochloride Catalyzed Synthesis of 1,2,4‐Triazolidine‐3‐thiones in Aqueous Medium

“…In view of the diverse applications of 1,2,4‐triazole and its synthetic congeners, a plethora of methods have been reported for their synthesis . Amongst these, the simplest approach for the synthesis of 1,2,4‐triazolidine‐3‐thiones involves the reaction of aldehydes or ketones with thiosemicarbazides in the presence of catalysts such as sulfamic acid, N,N‐dimethylpyridine‐4‐amine, [C 16 MPy]AlCl 3 Br, [(Py) 2 SO][HSO 4 ], [HMPBSA]HSO 4 , glycine nitrate . Moreover, organic solvents like PEG‐400, glycerol and ethanol endorsing catalyst free conditions have also been reported.…”