Catalyst-free synthesis of quinazoline derivatives using low melting sugar–urea–salt mixture as a solvent

One-Pot Tandem Synthesis of 2-Arylquinazolines by a Multicomponent Cyclization Reaction

“…No reaction occurred when the procedure was carried out in the absence of copper catalyst (Table 1, entry 18). Finally, we studied the solvent effect and found that CH 3 CN was superior to toluene, THF, PhCl, and DMF (Table 1, entries 12,[19][20][21][22]. In addition, the reaction failed to give the desired product when the procedure was carried out under a N 2 atmosphere.…”

“…Tandem reaction of 2-aminobenzophenones with benzylic amines followed by C-H functionalization has also been reported [15][16][17][18]. Zhang reported a three-component synthesis of quinazoline derivatives using a low melting sugar-urea-salt mixture as a solvent [19]. In 2012, Beifuss and co-workers developed a copper-catalyzed coupling reaction of o-bromobenzylbromides and benzamidines for the synthesis of quinazolines in an aqueous medium [20].…”

Low melting mixtures in organic synthesis – an alternative to ionic liquids?

“…20 Quinazoline derivatives were synthesised in high yields via a one-pot three-component coupling reaction of 2-aminoaryl ketones, aldehydes, and ammonium acetate using maltose-DMU-NH 4 Cl. 70 The use of the sweet solutions is still limited due to their relatively high melting points. Another drawback of the melts is that their components are not chemically inert.…”

Mesoporous silica SBA‐15 functionalized with acidic deep eutectic solvent: A highly active heterogeneous N‐formylation catalyst under solvent‐free conditions

“…Moreover, unlike ionic liquids, these green solvents do not require a preliminary purification step since one only has to mix natural and readily available starting materials. [36][37][38][39][40][41][42] Based on the above information, our research group has been engaged mainly on the development of environmentally friendly organic synthesis in green reaction media such as water and DESs. [43][44][45] In our development efforts towards this important class of DESs, herein we report an alternative, recyclable, mild and highly effective catalytic system based DES that immobilized on nanoporous silica SBA-15 for the N-formylation of amine derivatives with formic acid under solvent-free conditions.…”