TMSCl-catalysed condensation of α-diketone compounds with urea/thiourea derivatives under solvent-free conditions

Abstract

An efficient, rapid and green synthesis of glycoluril, imidazolidine-2-one, imidazole-2-one and imidazole-2-thiol derivatives have been accomplished by the reaction of urea/thiourea derivatives and αdiketone at 100 • C in the presence of trimethylsilyl chloride (TMSCl) as Lewis acid catalyst under solvent-free conditions. This approach offers many advantages such as good product yields, various products, short reaction time, easy isolation of products, facile purification and environmentally benign reaction conditions.

Novel Method for the Synthesis of Substituted Imidazothiazolones

“…Note that the melting points and NMR spectra of compounds 8а and 8е are markedly different from those reported earlier by Mobinikhaledi and Amiri. 8 The structure and homogeneity of the compound 8а were confirmed by 1 H and 13 C NMR spectroscopy, elemental analysis, and X-ray diffraction (Figure 3). We can therefore confirm that compounds other than 8а and 8е were obtained by Mobinikhaledi and Amiri.…”

“…We can therefore confirm that compounds other than 8а and 8е were obtained by Mobinikhaledi and Amiri. 8 Imidazolinones 9a-e were prepared by using a simple approach, starting from ureas 10а-e and benzoin (2-hydroxy-1,2-diphenylethanone; 11) (Table 1, entries 1-5). 9 Compounds 9f-h were prepared from the corresponding imidazole oxides 12а-с (entries 6-8).…”

Investigation on the Synthesis, Application and Structural Features of Heteroaryl 1,2-Diketones

“… 5 − 7 Representative reactions for 1,2-diketones are their condensation reactions with bifunctional nucleophiles such as diamines and thioureas to form heterocyclic rings, diamines and diimines ( Scheme 1 ). 8 Additionally, 1,2-diketones have demonstrated some uncommon yet interesting reactions including addition/oxy Cope rearrangement to make 1,6-diketones, and condensation with 1,3-diphenylacetone to make tetraphenylcyclopentadienone ( Scheme 1 ). 9 − 11 By using different heteroaryl substrates, appealing molecular entities can be readily prepared and utilized in many applications, for example pharmaceutical reagents, catalytic ligands and chemical sensors.…”

“…The 1,2-diketones are versatile building blocks and are used as organic intermediates in the total synthesis of natural products, preparation of bioactive molecules, etc. − A well-known 1,2-diketone is benzil or 1,2-diphenylethane-1,2-dione (PhCO) 2 , which can be synthesized from deoxybenzoins, alkynes, aldehydes, or α-oxo acid chloride. − Representative reactions for 1,2-diketones are their condensation reactions with bifunctional nucleophiles such as diamines and thioureas to form heterocyclic rings, diamines and diimines (Scheme ). Additionally, 1,2-diketones have demonstrated some uncommon yet interesting reactions including addition/oxy Cope rearrangement to make 1,6-diketones, and condensation with 1,3-diphenylacetone to make tetraphenylcyclopentadienone (Scheme ). − By using different heteroaryl substrates, appealing molecular entities can be readily prepared and utilized in many applications, for example pharmaceutical reagents, catalytic ligands and chemical sensors …”