Microwave-assisted multicomponent synthesis of antiproliferative 2,4-dimethoxy-tetrahydropyrimido[4,5-]quinolin-6(7)-ones.

In this study, we demonstrate a simple, highly efficient, rapid and convenient series of 2,4-dimethoxy-tetrahydropyrimido[4,5-]quinolin-6(7)-ones 4a-v. Microwave irradiation facilitates the one-pot multicomponent reaction of different aromatic aldehydes, 6-amino-2,4-dimethoxypyrimidine and dimedone using glacial acetic acid. Metal-free multicomponent synthesis, shorter reaction time, higher product yield, easy product purification without column chromatography and outstanding green credential parameters are the key features of this protocol.

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.

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

Herein, acetic acid mediated multicomponent synthesis of novel 2,4-dimethoxy-tetrahydropyrimido[4,5-]quinolin-6(7)-one (2,4-dimethoxy-THPQs) was reported. Single-crystal XRD analysis of four newly developed crystals of 2,4-dimethoxy-THPQs and their DFT study were also reported. The structure of all molecules was optimized using DFT B3LYP/6-31G(d) level and compared with the corresponding single-crystal XRD data.

A novel substrate directed multicomponent reaction for the syntheses of tetrahydro-spiro[pyrazolo[4,3-]quinoline]-8,5'-pyrimidines and tetrahydro-pyrazolo[4,3-]pyrimido[4,5-]quinolines selective multiple C-C bond formation under metal-free conditions.

A versatile and substrate oriented multicomponent reaction for the syntheses of novel highly diastereoselective tetrahydro-1'-spiro[pyrazolo[4,3-]quinoline-8,5'-pyrimidine]-2',4',6'(3')-triones (d.r. up to 20 : 1 ( : )) and tetrahydro-8-pyrazolo[4,3-]pyrimido[4,5-]quinoline-8,10(9)-diones formation of selective multiple C-C bonds under identical reaction conditions ( ethanol as a reaction medium and deep eutectic mixture as a catalyst) is demonstrated.

Impact of an aryl bulky group on a one-pot reaction of aldehyde with malononitrile and -substituted 2-cyanoacetamide.

In this study, we successfully explored the effect of steric hindrance on the one-pot reaction of different aryl aldehydes with malononitrile and -substituted 2-cyanoacetamide in the presence of piperidinium acetate as the catalyst. It involved the Knoevenagel condensation of the aldehyde and malononitrile to produce arylidene malononitrile as an intermediate, which was further treated with -substituted 2-cyanoacetamide to give 6-amino-2-pyridone-3,5-dicarbonitrile derivatives when the less steric bulky group was involved. High steric hindrance changed the earlier reaction route and gave -substituted 2-cyanoacrylamides a slower route.