Synthesis, Antimicrobial Evaluation, DFT, and Molecular Docking Studies of Pyrano [4,3-b] Pyranone and Pyrano[2,3-b]Pyridinone Systems.

Dehydroacetic acid (DHA) was utilized as a fundamental precursor in the synthesis of novel pyrano [4,3-b] pyran and pyrano [2,3-b] pyridine systems. Whereas, a new series of fused polyheteronuclear systems was achieved through the reaction of DHA with active methylene compounds such as malononitrile and pyrazolone. Whereas, the treatment of DHA 1 with cyclic ketones involving cyclohexanone and cyclododecanone afforded annulated tricyclic system 6 and spiro hybrid molecule 7.

Pyrimido[5,4-c]quinolines: Synthesis from 3,4-Di-functionallized Quinoline, Reactivity and Biological Activities.

Quinoline and pyrimidine moieties are ubiquitous components in both natural and synthetic compounds, showcasing diverse applications. The fusion of these well-known structures into hybrid molecules has garnered attention due to their intriguing biological properties. Particularly in the field of medicinal chemistry, numerous studies in the last decade have focused on pyrimido[5,4-c]quinoline ring systems (PyQs5,4-c).

An Efficient Approach for the Synthesis and Antitumor Evaluation of Novel Azo- and Anil-Linked with 3-Aminopyrazolo[3,4-b]pyridine.

In this project, an effective procedure for constructing a new combination of pyrazolo[3,4-b]pyridine was depicted through the coupling of diazonium salt 2 of heterocyclic amine 1 with active methylene, enamine, and amidine moieties such as 3, 5, 7, and 9 at 0-5 °C in pyridine to afford hydrazinylhydrazonoyl derivatives 4, and diazenylheterocyclic derivatives 6, 8, and 10, respectively. Also, aminopyrazolo[3,4-b]pyridine 1 condensed with different aryl or heteroaryl aldehydes in EtOH/AcOH gave the corresponding aldimine 14, 15, 16. Compound 15 was cyclized via refluxing in DMF for 6 h to afford 18, while the transformation of compound 16 with an alkyl halide afforded 19a, b.

Synthesis of new thienylnicotinamidines: Proapoptotic profile and cell cycle arrest of HepG2 cells.

Fourteen new thienylnicotinamidines and their analogs 5a-5k, 12, 13a, and 13b were prepared and their antiproliferative potential was evaluated against the growth of 60 cancer cell lines. The tested compounds had a strong antiproliferative efficacy against almost all cancer cell lines, with the average GI at ~2.20 µM.

Synthesis of new thienylpicolinamidine derivatives and possible mechanisms of antiproliferative activity.

Three thienylpicolinamidine derivatives 4a-c were prepared from their corresponding picolinonitriles 3a-c on treatment with lithium trimethylsilylamide, LiN(TMS), followed by a de-protection step using ethanol/HCl (gas). DFT calculations were used to optimize the geometric structure of the newly synthesized picolinamidines. The comparison of DFT calculated spectral data with the experimental data (H-NMR and C-NMR) showed a good agreement.

Synthesis, Labeling and Biological Evolution of New Thiopyrano[2,3-b]Pyridine Derivatives as Potential Anticancer Agents.

The new thiopyrano[2,3-b]pyridines 4-9 could be synthesized from the nicotinonitrile derivative 1. The cytotoxicity activity of the selected compounds 5, 6 and 8 was tested against MCF-7 and HCT-116 cell lines. The compound 5 (TP5) exhibited significant inhibitory activity and displayed the most potent activity, more than 6 and 8.

Recent advances in the chemistry of 2-chloroquinoline-3-carbaldehyde and related analogs.

This review highlights the recently cited research data in the literature on the chemistry of 2-chloroquinoline-3-carbaldehyde and related analogs and their applications over the period from 2013 to 2017. It covers: synthesis of quinoline ring systems and reactions adopted to construct fused or binary quinoline-cord heterocyclic systems. The biological evaluation and the synthetic applications of the target compounds were illustrated.

Facile construction of substituted pyrimido[4,5-d]pyrimidones by transformation of enaminouracil.

The reaction of 6-amino-1,3-dimethylpyrimidine-2,4(1H,3H)-dione (1) as a binucleophile with primary aromatic or heterocyclic amines and formaldehyde or aromatic (heterocyclic) aldehydes in a molar ratio (1:1:2) gave the pyrimido[4,5-d]pyrimidin-2,4-dione ring systems 2-5. Treatment of 1 with diamines and formalin in molar ratio (2:1:4) gave the bis-pyrimido[4,5-d]pyrimidin-2,4-diones 6-8. Furthermore, substituted pyrimido[4,5-d]pyrimidin-2,4-diones with uracil derivative 11 or spiro indole 16 were synthesized.

Synthesis, characterization and RHF/ab initio simulations of 2-amino-1,3,4-thiadiazole and its annulated ring junction pyrimidine derivatives.

Michael addition reaction of the 2-amino-1,3,4-thiadiazole to chalcone as biselectrophile afforded 5,7-diphenyl-6-[1,3-diphenylpropan-1-on-3-yl][1,3,4]thiadiazolo[3,2-a]pyrimidine (3) instead of 5,7-diphenyl-5H-[1,3,4]thiadiazolo[3,2-a]pyrimidine (5) via further Michael addition at C5 in pyrimidine moiety. The structure 3 was established through the aspect of ab initio calculations, elemental analysis and spectral data.

Efficient regioselective synthesis and potential antitumor evaluation of isoxazolo[5,4-b]pyridines and related annulated compounds.

The reaction of 5-amino-3-methylisoxazole with appropriate α,β-unsaturated ketones gave the corresponding isoxazolo[5,4-b]pyridines. Treatment of 1 with 2,6-dibenzylidenecyclohexanone or 2-benzylidenedimedone afforded the corresponding isoxazolo[5,4-b]quinoline derivatives. 4,6,8,9-Tetrahydroisoxazolo[5,4-b]quinolin-5-one derivative was also obtained by multicomponent condensation reaction of 1 with dimedone and benzaldehyde.

Synthesis and antioxidant evaluation of some new 3-substituted coumarins.

3-Acetylcoumarin (1) was utilized as a key intermediate for the synthesis of 2-aminothiazole derivative 3 via bromination of 1 to afford acetylbromide 2 followed by treatment with thiourea or via Biginelli reaction of 1. Treatment of 3 with 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde, 2-methyl-4H-benzo[d][1,3]oxazin-4-one, furo[3,4-b]pyrazine-5,7-dione or 2-methyl-5,6,7,8-tetrahydro-4H-benzothieno[2,3-d][1,3]oxazin-4-one afforded diazine derivatives 4-7. Also, pyridopyrimidine 8 was obtained via a one pot reaction of 6-aminothiouracil, p-chlorobenzaldehyde and 3-acetylcoumarin.