Reactivity of 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3- carbonitrile towards thioglycolic acid resulted in thiazole derivative 1. The latter reacted with different chemical reagents to give thiazole, pyrano[2,3-d]thiazole and thiazolo[ 4,5-d]thiazole derivatives. Cytotoxicity effects of the newly synthesized products against six cancer cell lines, namely, human gastric cancer (NUGC), human colon cancer (DLD- 1), human liver cancer (HA22T and HEPG-2), human breast cancer (MCF) and nasopharyngeal carcinoma (HONE-1) as well as against a normal fibroblast cell (WI-38) were evaluated. The study showed that the 4,5,6,7 tetrahydrobenzo[ b] thiophene derivatives 6a, 7, 8a,b, 9b and 10b,c w ere t he most active compounds. Their potencies were attributed to the presence of the electron withdrawing groups.

Aim: Aiming to produce pyridine azo disperse dyes with good fastness properties and promising antimicrobial activity, a number of novel systems of polyfunctionalized pyridine azo dyes and their selenium nanoparticles (SeNPs) were synthesized. Materials and methods: The synthesized products were formed by the reaction of diazotized aniline derivatives or diazotized amino antipyrene with any of dibenzoyl methane or benzoyl acetone and cyanoacetamide in boiling ethanolic sodium ethoxide. The structures of the newly synthesized compounds were elucidated by elemental analysis and spectral data. Moreover, (SeNPs) of the pyridine azo disperse dyes were characterized by Ultra-Violet -Visible spectrophotometry, dynamic light scattering , X-ray diffraction, and transmission electron microscope analysis. On the other hand, the synthesized dyes and its (SeNPs) were applied for disperse dyeing of nylon 66 and their fastness properties were measured, such as washing, rubbing, perspiration, and light fastness. In addition, the antimicrobial activities for all the synthesized compounds and for (SeNPs) prepared compounds (2bN, 2cN, 2fN, 2gN, 2hN) were evaluated. Results: Compounds 2bN, 2c, 2cN, 2fN, 2gN, 2h, 2hN, and 2i were the most active compounds against all Gram-positive and Gram-negative bacterial species. While, compounds 2b, 2f, 2g, and 5b were the most active toward some of the bacterial strains (at least two from the selected four strains). Moreover, compounds 2bN, 2cN, 2fN, 2gN, 2h, 2hN showed higher activity toward the fungal strain. Also, the minimal inhibitory concentrations for all the most active compounds were determined. Conclusion: Finally, all the (SeNPs) compounds revealed higher activity against bacterial and fungal strains than the other synthesized compounds.

Aims: The current study aimed to synthesize novel pyrazolo[1,5-a]pyrimidines based on 5- aminopyrazoles 3, evaluate their antimicrobial activity, and study the minimum inhibitory concentration (MIC) for the most active compounds. In addition, molecular docking studies and RNA polymerase inhibitory activity were determined. Background: Starting with our previously reported 5-aminopyrazoles 3, a number of novel pyrazolo[1,5- a]pyrimidines were synthesized. Due to the similarity of pyrazolopyrimidine derivatives with the purine systems, pyrazolopyrimidines are important in many different biological applications, most notably as anti-tumor, antibacterial, and hepatitis C virus inhibitors. The pharmaceutical applications of the pyrazolopyrimidine derivatives were explained in several approved drugs like Indiplon, Zaloplan, and Ocinaplon. Objective: To prepare a novel antimicrobial agent, namely pyrazolo[1,5-a]pyrimidine, reveal their structures using different spectral data, the minimum inhibitory concentration (MIC) for the most active compounds was evaluated, and both the molecular docking and the RNA polymerase inhibitory activity were determined. Methods: A number of different pyrazolopyrimidines namely 2-(phenylamino)-6,11-dihydrobenzo[g]pyrazolo [1,5-a]quinazoline-3-carboxamides (5a-c), (E)-5,7-dimethyl-2-(phenylamino)-6-(phenyldiazenyl)pyrazolo-[1,5- a]pyrimidine-3-carboxamides (7a-c), 7-amino-2-(phenylamino) pyrazolo[1,5-a]pyrimidine-3-carboxamides (11af), 7-amino-2-(phenylamino)-5-(2-thienyl)pyrazolo[1,5-a]pyrimidine-3-carboxamides (14-f) and ethyl 7-amino-3- carbamoyl-2-(phenylamino)-5-(4-pyridyl)pyrazolo[1,5-a]pyrimidine-6-carboxylate derivatives (14g-i) were synthesized through the reaction of 5-aminopyrazoles 3 with a variety of chemical reagents. On the other hand, the evaluation of the antimicrobial activity for all the prepared compounds was screened through different strains as Gram-positive bacteria, such as staphylococcus aureus and Streptococcus mutans, and Gram-negative bacteria, such as Escherichia coli, Pseudomonas aeruginosa, and klebsiella. The antifungal activity was determined by Candids Albicans fungal strain, and the MIC of the most active compounds was measured. The molecular docking was recorded, and the RNA polymerase inhibitory activity was estimated for the high docking score compounds. Results: Compounds 5a, 5b, 5c, 7a, 7b, 7c, 11d, 14b, and 14h were the most active compounds against some of the bacterial and fungal tested strains. MIC was determined for the most active tested compounds. As an antimicrobial agent, compound 7b was the most potent, with a high docking score and RNA polymerase inhibitory activity (IC50= 0.213 μg/ml) compared to Rifampicin (IC50= 0.244 μg/ml). The reactivity of the latter compound was attributed to the presence of 4-Br-C6H4 moiety. The results demonstrated that docking studies on the most active compounds in the RNA polymerase active site were consistent with in vitro assays. Conclusion: The resultant novel bioactive pyrazolo[1,5-a]pyrimidine derivatives were synthesized based on 5- aminopyrazole derivatives 3. The current study evaluated the antimicrobial activity for all the prepared compounds, followed by the determination of the MIC for the most potent active compounds. The molecular docking study was performed, and it was appropriate with the in vitro activity. The RNA polymerase inhibitory activity was assessed for the most active antimicrobial compounds with a high docking score (7b, 7c, 14a, 14b, 14e, 14i). Compound 7b was the most potent compound inhibiting RNA polymerase enzyme compared to the reference drug Rifampicin. Other: The novel prepared heterocyclic systems are extremely important in a variety of domains, especially biological and pharmacological ones.