Synthesis of imidazoles via hetero-Cope rearrangements

Solvent-Free Synthesis of 1,2,4,5-Tetrasubstituted Imidazoles Using Nano Fe3O4@SiO2-OSO3H as a Stable and Magnetically Recyclable Heterogeneous Catalyst

“…They can be accessed by cyclization of -(N-acyl-N-alkylamino--ketoamides in refluxing AcOH 16 , hetero-Cope rearrangement 17 , condensation of a 1,2-diketone with an aryl nitrile and primary amine under microwave irradiation 18 , and N-alkylation of trisubstituted imidazoles 19 . Each of these methods has its own merit, however, all of the reported methods (except for the reaction catalyzed by FeCl 3 /montmorillonite K10 under microwave irradiation) require relatively prolonged reaction time.…”

Microwave-assisted synthesis of nitrogen-containing heterocycles

“…The application of imidazoles as 1,3-disubstituted imidazole salts as ionic liquids are also well known [37]. Classically, imidazoles have been synthesized by various methods [38][39][40][41].…”

One-pot synthesis of 2,4,5-trisubstituted imidazole derivatives catalyzed by btppc under solvent-free conditions

“…They have a wide range of biological activities and are well known analgesics, anti-inflammatory, antipar-asitic, anthelmintic, platelet aggregation inhibitors and antiepileptic agents [2]. Several methods such as the hetero-Cope rearrangement [3] and four-component condensation [4] for the synthesis of trisubstituted imidazoles are reported. In recent years, the synthesis of 2,4,5-trisubstituted imidazoles has been catalyzed by I 2 [5], ZrCl 4 [6], ionic liquid [7], L-proline [8], microwave irradiation [9], Yb(OPf) 3 [10] [18], N-methyl-2-pyrrolidone hydrogen sulfate [19], europium triflate [20], sulfated zirconia [21], n-Bu 4 NBr [22], silica-supported Preyssler nanoparticles [23], (NH 4 ) 6 Mo 7 O 24 ⋅4H 2 O [24], nano MgO [25], nano aluminium nitride [26], nano SiO 2 -supported ferric hydrogen sulfate (FHS) [27] and KSF supported 10-molybdo-2-vanadophosphoric acid [28].…”