Synthesis of 1,2,4,5‐tetrasubstituted imidazoles and 2,4,5,6‐tetrasubstituted pyrimidines: three‐component, the one‐pot reaction of arylamidines, malononitrile, and arylglyoxals or aryl aldehydes

Abstract

A highly efficient one‐pot synthesis of the 1,2,4,5‐tetrasubstituted imidazoles and 2,4,5,6‐tetrasubstituted pyrimidines through an arylamidine, malononitrile, and carbonyl compound by using Et3N in CH3CN at reflux conditions was developed. The nature of the carbonyl compounds were different; when the carbonyl compound was arylglyoxal or aryl aldehyde, 1,2,4,5‐tetrasubstituted imidazole and 2,4,5,6‐tetrasubstituted pyrimidine were achieved respectively.

Preparation of polysubstituted imidazoles using AC-SO3H/[Urea]7[ZnCl2]2as an efficient catalyst system: a novel method, and α-glucosidase inhibitor activity

“…Polysubstituted imidazoles were produced via ring closure followed by dehydration using AC-SO 3 H as the catalyst. 1 H-NMR, 13 C-NMR, and LC-MS all supported the product structure.…”

“…The solvent was recovered from the ethyl acetate layer, which was then recrystallized with hot ethanol (15 mL) to produce the main product in its pure form. All of the products were veried by using 1 H-NMR, 13 C-NMR, and LC-MS.…”

“…12 H. Mehrabi et al have synthesized polysubstituted imidazoles from arylamidines, malononitrile, and arylglyoxals or aryl aldehydes using Et 3 N in CH 3 CN. 13 The most common method used to synthesize polysubstituted imidazoles was the reaction between aniline, benzil, aldehyde, and ammonium acetate using various catalysts such as Fe 3 O 4 –PEG–Cu, 14 K 5 CoW 12 O 40 ·3H 2 O, 15 PEG-400, 16 DABCO, 17 InCl 3 ·3H 2 O, 18 BF 3 /SiO 2 , 19 silica-bonded propylpiperazine- N -sulfamic acid (SBPPSA), 20 TiCl 4 –SiO 2 , 21 Zr(acac) 2 , 22 polyphosphoric acid impregnated on silica gel (PPA–SiO 2 ), 23 [Hbim]BF 4 , 24 Yb(OTF) 3 , 25 l -proline, 26 MCM-41-SO 3 H, 27 Fe 3 O 4 /SO 3 H@zeolite-Y, 28 nano-Fe 3 O 4 , 29 Brønsted acidic deep eutectic solvent, 30 organocatalyst, 31 dendrimer-PWAn nanoparticles, 32 and another modern method. 32–34 However, the use of acid Lewis as the catalysts and organic solvents used were an environmental impact.…”

Ultrasound‐Assisted Green Synthesis of Pyrrole‐Fused Pyrimidine and Imidazole Rings through a Tandem Pseudo‐Four‐Component Reaction

“…Heterocyclic compounds are one of the hottest research areas in the field of organic synthesis due to their extensive pharmaceutical applications [1] . Among them, nitrogen‐containing five‐ and six‐membered heterocycles, [2] including pyrroles, [1,2,3] imidazoles, [1–2] pyrimidines, [1,2b,4] and their fused derivatives, [5] have received great significance due to their contribution as the key structural moiety in various pharmaceutical compounds and natural products [6] . On the other hand, the mentioned compounds have found extensive applications in the synthesis of pharmaceutical molecules.…”