Nano-[Fe₃O₄@SiO₂/N-propyl-1-(thiophen-2-yl)ethanimine][ZnCl₂] as a nano magnetite Schiff base complex and heterogeneous catalyst for the synthesis of pyrimido[4,5-b]quinolones

Abstract

Nano-[Fe3O4@SiO2/N-propyl-1-(thiophen-2-yl)ethanimine][ZnCl2] as a nano magnetite Schiff base complex was designed and successfully tested for the synthesis of pyrimido[4,5-b]quinolones.

Synthesis of Novel Pyrimido[4,5-b] Quinolines Containing Benzyloxy and 1,2,3-Triazole Moieties by DABCO as a Basic Catalyst

“…In a mechanism which is supported by the previous literature, − dimedone converts into the enol form by the tautomerization and then DABCO attracted one proton from the hydroxyl group to obtain 5,5-dimethyl-3-oxocyclohex-1-enolate. In the next step, the prepared enolate attacked to aldehyde which is activated by protonated DABCO and lost a molecule of water to generate ( I ) as an intermediate.…”

Synthesis, crystal structure and in silico studies of novel 2,4-dimethoxy-tetrahydropyrimido[4,5-b]quinolin-6(7H)-ones

“…To synthesise novel 2,4-dimethoxy-THPQs, a multi-component strategy was utilised which is used to generate a wide variety of heterocyclic compounds with multifaceted medicinal uses. 24 Previous methods utilised various catalyst such as nano-[Fe 3 O 4 @SiO 2 @R-NHMe 2 ][H 2 PO 4 ], 25 graphene oxide, 26 MIL-100(Cr)/NHEtN(CH 2 PO 3 H 2 ) 2 , 27 choline chloride/oxalic acid, 28 IR-MOF-3-ILOAc-Fe(acac) 3 , 29 N , N -diethyl- N -sulfoethanaminium chloride 30 and nano-[Fe 3 O 4 @SiO 2 / N -propyl-1-(thiophen-2-yl)ethanimine][ZnCl 2 ] 31 to synthesised 2,4-dimethoxy-THPQs. Catalyst-free synthesis of THPQs were also reported using absolute ethanol, 32 acetic acid, 33–35 and electrolysis in presence of alcohol.…”

Silica sulfuric acid coated on SnFe2O4MNPs: synthesis, characterization and catalytic applications in the synthesis of polyhydroquinolines

“… 33 Afterward, its surface was coated with SiO 2 shell according to the previously reported method by our group. 13 Afterward, the sulfuric acid catalytic cites graphed on its surface according to Zolfigol's method: 1.5 mL of chlorosulfuric acid was added dropwise to a dispersed mixture of SnFe 2 O 4 MNPS (1 g) in dry CH 2 Cl 2 (20 mL) and the reaction was cooled in an ice bath, then, the mixture was stirred for 4 h at room temperature. Finally, the obtained SnFe 2 O 4 @silica sulfuric acid MNPs were separated using an external magnet, washed by dry CH 2 Cl 2, and dried at 80 °C in an oven for 12 h ( Scheme 1 ).…”

“…1 Catalysis science is considered as the main center of most key organic reactions such as the named reactions, 10,11 most of the key organic functional group transformations require a catalyst in the reaction media to the selective conversion of the reagents and synthons to the target products with high performance. 9,[12][13][14] In this sense, the utilization of heterogeneous nanomaterials as catalysts has attracted worldwide attention due to their unique role in the conversion of these manufacturing procedures to ecofriendly, greener, economical and viable methods. [15][16][17][18][19][20] During recent decades, acid catalysts have played the main role in the organic functional group transformations especially in multicomponent reactions, despite the widespread use of organic and inorganic acid catalysts, the leaching of hazardous acids into the desired product is one of the negative aspects of employing heterogeneous acid-based catalysts in the sustainable catalysis.…”

“…Catalysis science is considered as the main center of most key organic reactions such as the named reactions, 10,11 most of the key organic functional group transformations require a catalyst in the reaction media to the selective conversion of the reagents and synthons to the target products with high performance. 9,12–14 In this sense, the utilization of heterogeneous nanomaterials as catalysts has attracted worldwide attention due to their unique role in the conversion of these manufacturing procedures to ecofriendly, greener, economical and viable methods. 15–20…”