191349-19-6Relevant academic research and scientific papers
Sequential MCR via Staudinger/Aza-Wittig versus Cycloaddition Reaction to Access Diversely Functionalized 1-Amino-1H-Imidazole-2(3H)-Thiones
Ciccolini, Cecilia,Mari, Giacomo,Favi, Gianfranco,Mantellini, Fabio,de Crescentini, Lucia,Santeusanio, Stefania
, (2019)
A multicomponent reaction (MCR) strategy, alternative to the known cycloaddition reaction, towards variously substituted 1-amino-1H-imidazole-2(3H)-thione derivatives has been successfully developed. The novel approach involves α-halohydrazones whose azidation process followed by tandem Staudinger/aza-Wittig reaction with CS2 in a sequential MCR regioselectively leads to the target compounds avoiding the formation of the regioisomer iminothiazoline heterocycle. The approach can be applied to a range of differently substituted α-halohydrazones bearing also electron-withdrawing groups confirming the wide scope and the substituent tolerance of the process for the synthesis of the target compounds. Interestingly, the concurrent presence of reactive functionalities in the scaffolds so obtained ensures post-modifications in view of N-bridgeheaded heterobicyclic structures.
1-Arylaminoimidazole-2-thiones as intermediates in the synthesis of imidazo[2,1-b][1,3,4]thiadiazines
Neochoritis, Constantinos,Tsoleridis, Constantinos A.,Stephanidou-Stephanatou, Julia
, p. 3527 - 3533 (2008/09/21)
The synthesis of the hitherto unknown imidazo[2,1-b][1,3,4]thiadiazines 7 in good to very good yields (up to 77%) by using suitable imidazole-2-thione precursors 1 has been described, while S-vinylimidazoles 8 and 9 were isolated as by-products. Moreover, the reactivity of the three possible reaction sites of the starting thiones 1 was initially examined by methylation experiments, whereupon the enhanced reactivity of sulfur was proven by the isolation of the methylated derivatives 3 and 4. By prolonged methylation the imidazolinone 6 is finally formed. Theoretical calculations support the experimental results of alkylation products.
Direct synthetic approach to N-substituted 1-amino-2,3-dihydro-1H-imidazole-2-thiones
Schantl, Joachim G.,Lagoja, Irene M.
, p. 691 - 700 (2007/10/03)
In an efficient one-pot procedure, the title compounds (8) were obtained by the reaction of α-halo ketones (1) with potassium thiocyanate and monosubstituted hydrazines (3). The reaction is considered to proceed via the formation of azo-alkenes (5) and th
