Eco-safe and expeditious approaches for synthesis of quinazoline and pyrimidine-2-amine derivatives using ionic liquids aided with ultrasound or microwave irradiation

Synthesis of Novel Derivatives of 5,6,7,8-Tetrahydroquinazolines Using α-Aminoamidines and In Silico Screening of Their Biological Activity

α-Aminoamidines are promising reagents for the synthesis of a diverse family of pyrimidine ring derivatives. Here, we demonstrate the use of α-aminoamidines for the synthesis of a new series of 5,6,7,8-tetrahydroquinazolines by their reaction with bis-benzylidene cyclohexanones. The reaction occurs in mild conditions and is characterized by excellent yields. It has easy workup, as compared to the existing methods of tetrahydroquinazoline preparation. Newly synthesized derivatives of 5,6,7,8-tetrahydroquinazoline bear protecting groups at the C2-tert-butyl moiety of a quinazoline ring, which can be easily cleaved, opening up further opportunities for their functionalization. Moreover, molecular docking studies indicate that the synthesized compounds reveal high binding affinity toward some essential enzymes of Mycobacterial tuberculosis, such as dihydrofolate reductase (DHFR), pantothenate kinase (MtPanK), and FAD-containing oxidoreductase DprE1 (MtDprE1), so that they may be promising candidates for the molecular design and the development of new antitubercular agents against multidrug-resistant strains of the Tubercle bacillus. Finally, the high inhibition activity of the synthesized compounds was also predicted against β-glucosidase, suggesting a novel tetrahydroquinazoline scaffold for the treatment of diabetes.

One-pot two-step catalytic synthesis of 6-amino-2-pyridone-3,5-dicarbonitriles enabling anti-cancer bioactivity

We report a one-pot two-step synthesis of a bioactive 6-amino-2-pyridone-3,5-dicarbonitrile derivative using natural product catalysts betaine and guanidine carbonate. Anti-cancer bioactivity was observed in specific molecules within the library of 16 derivatives. Out of the compounds, 5o had the most potent anti-cancer activity against glioblastoma cells and was selected for further study. Compound 5o showed anti-cancer properties against liver, breast, lung cancers as well as primary patient-derived glioblastoma cell lines. Furthermore, 5o in combination with specific clinically relevant small molecule inhibitors induced enhanced cytotoxicity in glioblastoma cells. Through our current work, we establish a promising 6-amino-2-pyridone-3,5-dicarbonitrile based lead compound with anti-cancer activity either on its own or in combination with specific clinically relevant small molecule kinase and proteasome inhibitors.

The one-pot synthetic strategy of amino-pyridones with potent anti-cancer activity against breast, brain, liver, and lung cancer cells either alone or in combination with clinically relevant receptor tyrosine kinase and proteasome inhibitors.

Ultrasound-assisted synthesis of pyrimidines and their fused derivatives: A review

The pyrimidine scaffold is present in many bioactive drugs; therefore, efficient synthetic routes that provide shorter reaction times, higher yields, and site-selective reactions are constantly being sought. Ultrasound (US) irradiation has emerged as an alternative energy source in the synthesis of these heterocyclic scaffolds, and over the last ten years there has been a significant increase in the number of publications mentioning US in either the construction or derivatization of the pyrimidine core. This review presents a detailed summary (with 140 references) of the effects of US (synergic or not) on the construction and derivatization of the pyrimidine core through classical reactions (e.g., multicomponent, cyclocondensation, cycloaddition, and alkylation reactions). The main points that were taken into consideration are as follows: chemo- and regioselectivity issues, and the results of conventional heating methods compared to US and mechanistic insights that are also presented and discussed for key reactions.

The Beneficial Sinergy of MW Irradiation and Ionic Liquids in Catalysis of Organic Reactions

The quest for sustainable processes is becoming more and more important, with catalysis playing a major role in improving atom economy and reducing waste. Organic syntheses with less need of protecting/de-protecting steps are highly desirable. The combination of microwave irradiation, as energy source, with ionic liquids, as both solvents and catalysts, offered interesting solutions in recent years. The literature data of the last 15 years concerning selected reactions are presented, highlighting the importance of microwave (MW) technology coupled with ionic liquids.