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. Also, the reaction of DHA 1 with cyanoacetamide derivatives 8 and 11 yielded their corresponding novel pyrano [2,3-b] pyridine-6-carbonitrile frameworks 9 and 12, respectively. Also, in silico predictive theoretical molecular docking studies for bioactive synthesized scaffolds against both HER2 and 6BBP displayed an optimistic result for compounds 2 b, 5, 9, and 12 highlighting their expediency as up-and-coming candidates for future preclinical trials. Additionally, all compounds were assessed as antibacterial agents against various types of four candidates of bacteria in the presence of ampicillin as a reference. Notably, compounds 6, 7, and 12 showed promising antibacterial potential against Bacillus subtilis with activity indexes (69.6, 91.3, and 82.6 %), respectively.

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. The synthesized compounds, explicated by spectral data and elemental analysis, were examined for their antitumor activities. The in vitro cytotoxic activity of new pyrazolo[3,4-b]pyridines against the A2780CP, MCF-7, and HepG-2 cell lines was evaluated using the reference doxorubicin. Compounds 15 and 19a exhibited high reactivity against the A2780CP cell lines, with IC₅₀ values of 35 and 17.9 μM, respectively. Also, compound 28 had the cytotoxic potential for A2780CP and MCF-7 cell lines, with IC₅₀ values of 14.5, and 27.8 μM, respectively.

Intermolecular double Michael reaction to construct 4-benzyl-5-imino-3-phenyl-6-oxa-1-aza-tricyclo[6.2.2.02,7]dodec-2(7)-ene-4-carbonitrile

1-azabicyclo[2.2.2]octan-3-one. HCl (1) reacts with ylidene nitrile through photo- thermal reaction conditions to give 4-benzyl-5-imino-3-phenyl-6-oxa-1-aza-tricyclo[6.2.2.02,7]dodec-2(7)-ene-4-carbonitrile. (3) via intermolecular double Micheal reaction, whereas, 5-imino-3-phenyl-6-oxa-1-azatricyclo[6.2.2.02,7]dodec-2(7)-ene-4-carbonitrile (4) was achieved via thermal conditions only.

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.

Advances in the domain of 4-amino-3-mercapto-1,2,4-triazine-5-ones

This review summarizes results from a literature survey concerning the synthesis and reactions of 4-amino-3-mercapto-1,2,4-triazine-5-ones reported by research groups from 1983 to mid. 2015.

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 of pyrimido[4,5-d]pyrimidin-2,4-diones with different substitution at C-5 and C-7 was achieved to give 13 and 18, respectively.

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.