Versatile synthesis of substituted imidazoles using nano lead (II) nitride as a source of ammonia

The study aims at evaluating the application of nano lead (II) nitride, (Pb3N2), as a suitable source of ammonia for the synthesis of 2, 4, 5-trisubstituted imidazoles. The tests revealed that heating a mixture of a benzaldehyde, a benzyl, and nano lead (II) nitride in methanol leads to the formation of functionalized imidazoles in good to excellent yields [1].Regarding the atom economy, simple reaction design, and the ability to construct compounds of desire by the introduction of several elements in a single chemical event, multicomponent reactions (MCR) have changed to a significant part of the set of methods currently used in combinatorial chemistry. The application of MCR to construct interesting heterocyclic scaffolds is of specific use in the preparation of various chemical libraries of ‘drug-like’ molecules. Imidazoles constitute scaffolds in very important biomolecules, such as histamine, biotin, istidine, pilocarpine alkaloids and other alkaloids, with considerable biological activities like antimicrobial, anticryptococcal or inhibition of nitric oxide synthase, or cytotoxic activities. Ammonia is a common source of nitrogen in organic chemistry, the small scale use of which is limited due to handling issues. Nano Pb3N2 was mentioned to be applicable as a source of ammonia that can be used in organic syntheses, based on the reactions below [2]. In summary, we have shown that the simple method introduced in this work can be effectively used for the synthesis of 2,4,5-three substituted imidazoles based on the application of Nano Pb3N2 as an eco-friendly, inexpensive and efficient source of ammonia, enjoying the advantage of having high yields, and simple and easy work-up operations.