One-pot Synthesis Of Pyrimido Research Articles

Dual Acidic Ionic Liquid Immobilized on α-Fe2O3–MCM-41 Magnetic Mesoporous Materials as the Hybrid Acidic Nanocatalyst for the Synthesis of Pyrimido[4,5-d]pyrimidine Derivatives

Magnetic α-Fe2O3–MCM-41 mesoporous material functionalized by dual acidic ionic liquid (DAIL) was prepared through a two-step approach as a novel powerful acidic catalyst which provides high ionic media for reactions, by means of post-surface grafting of the mesochannels of α-Fe2O3–MCM-41 materials with 3-sulfobutyl-1-(3-propyltrimethoxysilane)imidazolium hydrogen sulfate as DAIL. Mesoporous MCM-41 was simply packed on the surface of ferric oxide nanoparticles and DAIL was efficiently incorporated into the mesochannels of MCM-41 generating Lewis and Bronsted acidic sites. The catalyst was characterized by FT-IR, X-ray powder diffraction, HRTEM, vibrating sample magnetometer, X-ray energy diffraction spectra, thermogravimetric and differential thermal analyses, and N2 adsorption–desorption measurements. The synthesized hybrid acidic MCM-41 showed good catalytic performance in the one-pot synthesis of pyrimido[4,5-d]pyrimidine derivatives using 6-aminouracil, aldehyde, and urea or thiourea under solvent free conditions. Moreover, it was proved that under this condition, the use of such a hybrid material as a catalyst plays the role of rendering the reactions while neither the α-Fe2O3–MCM-41 nor the 3-methyl-1-(4-sulfonic acid)butylimidazolium hydrogen sulfate were able to promote this reaction.

5-Aminouracil as a Building Block in Heterocyclic Synthesis: Part I. One-pot Synthesis of Pyrimido[5,4-b]quinolin-2,4,9-triones under Microwave Irradiation without Catalyst

A series of 6,7,8,10-tetrahydropyrimido[5,4-b]quinolin-2,4,9-(1H,3H,5H)-triones 6 were synthesized through one-pot condensation of 5-aminouracil, aldehydes and dimedone in DMF under microwave irradiation without catalyst. The products 6a, d were oxidized to the 7,8-dihydro-pyrimido- [5,4-b]quinolin-2,4,9-(1H,3H,6H)-triones 11a, b. Treatment of 6a, d and/or 11a, b with ethyl iodide in the presence of anhydrous potassium carbonate gave the ethylated derivatives 12a, b and 13a, b, respectively. The structures of the products were confirmed by elemental analyses, IR, MS, 1H, and 13C NMR spectra.

Two-component, one-pot synthesis of pyrimido[1,2-b] [1,2,4,5]tetrazines

Derivatives containing the cyclohepta4′,5′thieno[2′,3′:4,5]pyrimido[1,2-b][1,2,4,5]-tetrazin-6-one system were prepared from the reaction of 3-amino-2-thioxo-1,2,3,5,6,7,8,9-octahydro-4H-cyclohepta[4,5]thieno[2,3-d]pyrimidin-4-one (5) or its 2-methylthio derivative 6 with hydrazonoyl chlorides 9. The mechanism of the studied reactions has been discussed and the biological activity of the isolated products has been evaluated.

Microwave-assisted reactions: Part 2Part 1: ref. 1. One-pot synthesis of pyrimido[1,2-a]pyrimidines

A simple route for the synthesis of pyrimido[1,2-a]pyrimidines by condensation of 2-aminopyrimidine 1, aromatic aldehydes 2 and active methylene reagents 3 under microwave irradiation is reported.

A Convenient One-pot Synthesis of Pyrimido[4,5-b]quinolines as 5-Deaza Non-classical Antifolate Inhibitors

A convenient one-pot synthesis of pyrimido[4,5- b]quinolines as non-classical 5-deaza antifolate inhibitors by the reaction of 6-amino-4-oxo-2-thioxotetrahydropyrimidine 1 with aromatic aldehydes and dimedone is reported.

A Convenient One-pot Synthesis of Pyrimido[4,5-b]quinolines as 5-Deaza Non-classical Antifolate Inhibitors

A convenient one-pot synthesis of pyrimido[4,5-b]quinolines as non-classical 5-deaza antifolate inhibitors by the reaction of 6-amino-4-oxo-2-thioxotetrahydropyrimidine 1 with aromatic aldehydes and dimedone is reported.