Preparation, characterization and application of nano-[Fe3O4@-SiO2@R-NHMe2][H2PO4] as a novel magnetically recoverable catalyst for the synthesis of pyrimido[4,5-b]quinolines

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.…”

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

“…9 A signicant method for the preparation of pyrimido [4,5-b]quinolones is the multi-component reaction of aryl aldehyde, dimedone and 6-amino-1,3-dimethyluracil. 1 Multi-component reactions are one of the most successful methods in organic chemistry to increase the structural diversity and molecular complexity using a simple process without the formation of side-products and save energy, time, solvent and chemical materials and reduce the chemical waste. [10][11][12][13][14][15][16] Multi-component reaction of aryl aldehyde, dimedone and 6-amino-1,3dimethyluracil is carried out by various catalysts including nano-[Fe 3 O 4 @-SiO 2 @R-NHMe 2 ][H 2 PO 4 ], 1 SBA-15/PrN(CH 2 PO 3 -H 2 ) 2 , 17 [TSSECM], 18 Fe 3 O 4 @cellulose sulfuric acid, 19 Agarentrapped sulfonated DABCO, 20 [C 4 (DABCO) 2 ]$2OH, 21 nanocrystalline MgO, 22 [H 2 -DABCO][ClO 4 ] 2 (ref.…”

“…Heterocyclic compounds containing pyrimidine moieties in their structure show an important role in medicinal chemistry. 1 Biological properties of pyrimido[4,5- b ]quinolones give them special activities in medicinal chemistry such as antifungal, 2 anticancer, 3 antimalarial, 4 antiviral, 5 anticancer, 6 anti-inflammatory, 7 antihistaminic, 8 and anti-inflammatory activities. 9 A significant method for the preparation of pyrimido[4,5- b ]quinolones is the multi-component reaction of aryl aldehyde, dimedone and 6-amino-1,3-dimethyluracil.…”

Application of Cyclohexane‐1,3‐diones in the Synthesis of Six‐Membered Nitrogen‐Containing Heterocycles

“…[107] Recently, in 2019 and 2020, similar reports to scheme 4 published in the literature for quinolines synthesis using phosphorous acid affixed En/MIL-100(Cr) as nano-catalyst, SBA-15/PrN(CH 2 PO 3 H 2 ) 2 catalyst in solvent-free conditions and nano-[Fe 3 O 4 @-SiO 2 @R-NHMe 2 ][H 2 PO 4 ] as magnetically recyclable catalyst. [108][109][110][111] New classes of 1,4-dihydropyridine derivatives 5 have also been synthesized in presence of recyclable iron loaded on zirconia (Fe 2 O 3 /ZrO 2 ) catalyst in ethanol solvent at room temperature (Scheme 5). [101] Instead of ethyl ethylacetoacetate, malononitrile can also be used for the synthesis of 1,4-dihydropyridine derivatives.…”