One-pot synthesis of novel pyrido[2,3-d]pyrimidines using HAp-encapsulated-γ-Fe2O3 supported sulfonic acid nanocatalyst under solvent-free conditions

One-pot synthesis of novel pyrimido[4,5-b]quinolines and pyrido[2,3-d:6,5d′]dipyrimidines using encapsulated- γ-Fe2O3 nanoparticles

“…3,7-10 we were interested in the synthesis of novel derivatives of pyrimido [4,5−b] The magnetic nanoparticles (γ -Fe 2 O 3 ) were synthesized by a chemical co-precipitation technique using ferric and ferrous ions. Based on the report, 7,8 after coating a layer of hydroxyapatite on the surface of the γ -Fe 2 O 3 nanoparticles, functionalization with a sulfonic acid group was achieved by treatment with chlorosulfonic acid (0.9 mmol g −1 -SO 3 H loading) to furnish [γ -Fe 2 O 3 @HAp-SO 3 H. ] nanocrystallites. The catalyst was characterized by IR, SEM and XRD.…”

“…A few examples can be cited as, designing different Brønsted acids (ClSO 3 H, HClO 4 ,H B F 4 )o n γ -Fe 2 O 3 @SiO 2 [3][4][5][6] and functionalized hydroxyapatiteencapsulated-γ -Fe 2 O 3 magnetic nanoparticles. [7][8][9][10][11] Furthermore, the catalytic properties of Fe 2 O 3 NPs have been nicely exploited in various reactions, 12 such as oxidation of olefins and alcohols using O 2 or hydrogen peroxide, 13 direct borylation of arenes, 14 formation of 2-phenylquinazoline derivatives via condensation of benzylamine with 2-aminoaryl ketones 15 and C-H activation. SiO 2 supported γ -Fe 2 O 3 NPs has also been * For correspondence introduced for drug delivery and magnetic targeting systems.…”

Recent Developments in the MCRs Synthesis of Pyridopyrimidines and Spiro‐Pyridopyrimidines

“…Mohssenimehr et al reported in 2014 sulfonic acid‐functionalized nano‐Fe 2 O 3 particles [γ‐Fe 2 O 3 @HAp‐SO 3 H] as a magnetically Brønsted efficient acid catalyst to synthesis pyridopyrimidines. In this investigation, using Hap‐encapsulated‐γ‐Fe 2 O 3 [γ‐Fe 2 O 3 @HAp‐SO 3 H] catalyzed condensation of 6‐amino‐2‐(methylthio or ethylthio)pyrimidin‐4(3 H )‐one, Meldrum's acid, and aryl aldehydes at 60°C and under solvent‐free conditions to prepare a series of pyrido[2,3‐ d ]pyrimines 59 (Scheme ).…”

Magnetically recoverable copper ferrite catalyzed cascade synthesis of 1,3‐dimethyl‐6‐nitro‐5‐arylpyrido[2,3‐d]pyrimidine‐2,4(1H,3H)‐diones under microwave irradiation and solvent‐less condition

“…So a plethora of reports have been found demonstrating efficient synthetic methodologies for organic molecules containing pyrido[2,3‐ d ]pyrimidine core structure starting from a diverse set of substrates employing homogenous, heterogeneous, and catalyst‐free procedures. [ 21–47 ] Among these, there are a good number of reports that describe excellent use of the diene nature of 6‐[(dimethylamino)methylene‐amino]‐1,3‐dimethyluracil ( 1 ) or related compounds to carry out [4 + 2] cycloaddition reactions with various electron deficient dienophiles for successful synthesis of pyrido[2,3‐ d ]pyrimidine derivatives. [ 21–28 ] Although a few of these reports demonstrate multicomponent methodologies to carry out the transformation in or without presence of homogeneous catalyst, [ 21–23 ] not a single report has been found to employ heterogeneous catalyst system for the purpose.…”