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A series of new coloring materials in nanoscale based on 5-(2-aminothiazol-5-yl) thiazol-2-amine and 5-(4-aminophenyl) thiazol-2-amine were synthesized. The nanoscale pigments were prepared using a grinding high˗energy ball-milling technique. X-ray diffraction and transmission electron microscopy were employed to determine the particle size of the nanoscale pigments (40–80 nm). The synthesized pigments in normal and nanoscale were applied in the printing of polyester fabrics. The fastness and colorimetric properties of the printed samples were carefully studied. Additionally, the synthesized pigments were applied as water-based flexographic ink for paper and carton. The hue of the color pigments L*, a*, b*, glossiness, and fastness to light were measured. The comparison of the new heterocyclic benzidine analogs in normal and nanoscale with commercial benzidine pigments demonstrated better results, particularly for the nanoscale pigments.

Eight azomethine pyrazolone magenta dyes with iminodiethanol groups have been synthesized from 1,3-disubstituted- 1H-pyrazol-5( 4H)-ones in good yield. The newly synthesized dyes were characterized using spectroscopic data and elemental analyses techniques. All dyes have been successfully applied to polyester fabrics as disperse dyes where their dyeing performances have been discussed and evaluated in detail. The shades of these dyes ranged from red violet, purple and dark purple colors with good depth, brightness and good leveling properties. Multifunctional properties such as color representation, colorimetric data (L*, a*, b*, C*, h*, K/S), fastness properties of the dyed samples with respect to washing, perspiration, rubbing and light fastness have been discussed and evaluated in detail. The degree of exhaustion and fixation was also achieved after establishing the optimal dyeing conditions at 130°C, high pressure, 2% shade, and pH ≈5. As well, the influence of the dye bath pH on the K/S percentage and color intensity was estimated and discussed. Furthermore, the dyed fabrics were tested for ultraviolet protection factor and the results showed that these dyes gave excellent ultraviolet protection.

In an effort to discover new imidazolyl nucleus belonging to the family of N-fused heterocyclic compounds which display broad spectrum of biological applications, a series of novel imidazolyl pyrazolopyridines 3a,b–7a,b and imidazolyl pyrazoloquinoxaline 8a–d were synthesized. The structures of all the synthesized compounds were confirmed using spectroscopic data and elemental analyses. The compounds were synthesized using conventional heating besides the environmentally friendly benign techniques and reagents as microwave technique and catalyst under solvent–free conditions and short reaction times by anomeric-based oxidation (ABO) to the products in the final step of the synthetic pathway. Further all the synthesized bioactive molecules are tested for their biological potency: in vitro antimicrobial activity using a disc diffusion technique was performed against various Gram-positive and Gram-negative bacteria as well as fungal strains using Chloramophenicol and Fluconazole as positive controls. Free radical scavenging activity has been investigated using the DPPH scavenging methods. Interestingly, most of the synthesized compounds exhibited good to excellent antibacterial activities against most of bacterial strains and showed the highest antioxidant activity.

3-(Pyridin-3-yl)-1-p-tolyl-1H-pyrazolo[3,4-d]thiazol-5-amine was used as a key synthon for a one-pot two- and three-component synthesis of new fused heterocyclic moieties as pyrazolo[3,4-d]thiazole derivatives containing new fused ring pyrimidines or imidazoles. The compounds were synthesized by using microwave irradiation as an eco-friendly technique besides the conventional heating. All the newly synthesized compounds were characterized on the basis of their physical, spectral and analytical data. Most of the synthesized compounds were evaluated for their in vitro antimicrobial potentialities and antioxidant activities, and the most promising compounds were selected to determine antitumor activity. Molecular docking was performed inside the active site of cathepsin D, and target compounds 5a–c had a good binding energy of − 16.87 to − 11.64 kcal/mol compared to that of original ligand of − 16.02 kcal/mol with different binding interactions, thereby suggesting that these compounds may possibly act as cathepsin D inhibitors and thus may participate in anticancer activity.

A new series of coloring compounds (pigments) based on 5-(2-aminothiazol-5-yl)thiazol-2-amine and 5-(4-aminophenyl)thiazol-2-amine as heterocyclic alternatives for benzidine based on disazo dyestuffs were synthesized. All the newly synthesized pigments are characterized based on their physical, spectral, and analytical data. The antimicrobial activity showed that introducing the heterocyclic analogues thiazole (mono or bis) exhibited less toxic and resisted antimicrobial (five gram-positive strain, three gram-negative, and three fungal species). Thus, derivatives demonstrated moderate to good activity compared with Gentamycin and Ketoconazole. Furthermore, the pigments screened for their in vitro antioxidant properties by the DPPH method, and the newly designed pigments PG4–PG11 with thiazole moiety causes increase antioxidant properties with IC50 values ranged between (0.054–0.192 µM) compared with PG1, PG2, and PG3 (IC50 = 0.712, 0.239, and 0.191 µM) as well as Ascorbic acid (IC50 = 2.532 µM). Further, the synthesized pigments' cytotoxicity activity evaluated against HepG-2 and showed IC50 values ranged between (53.52–94.05 µM) compared with PG1–PG3 (IC50 =216.04–393.58 µM) and doxorubicin (IC50 = 8.17 µM). Molecular docking study concluded that thiazole moiety might be made one or more binding mode as critical hydrogen bonding through the nitrogen of thiazole, as well as arene-cation and/or arene-arene interaction with dihydrofolate reductase (DHFR) active site in 1DLS protein.

Microbial resistance is a big concern worldwide, making the development of new antimicrobial drugs difficult. The thiazole and pyrazole rings are important heterocyclic compounds utilized to produce a variety of antimicrobial medications. As a result, a series of new bis-thiazolyl-pyrazole derivatives 3, 4a-c, 5a, b, and 6a-c was synthesized by reacting bis hydrazonoyl bromide with several active methylene reagents in a one-pot reaction. The assigned structure was characterized entirely based on elemental and spectral analyses. The antimicrobial activity represented by MIC was performed using a resazurin-based turbidimetric (TB) assay. The results exhibited good antimicrobial activity against gram-positive strains, especially S. aureus (ATCC6538) while showing poor to moderate activity against gram-negative and fungal strains. Furthermore, the most active derivatives 3, 4a, 4c, and 5b were evaluated for MIC, MBC, antibiofilm, hemolytic assay, and drug combination testing against two S. aureus (ATCC6538) and MRSA (ACL18) strains. Additionally, bis-thiazolyl pyrazole 3, 4c, and 5b exhibited more potent inhibitory activity for DHFR with IC50 values (6.34 ± 0.26, 7.49 ± 0.28, and 3.81 ± 0.16 µM), respectively, compared with Trimethoprim (8.34 ± 0.11 µM). The bis-1-(substituted-thiazol-2-yl)-1H-pyrazole-4-carbonitrile derivative 5b was the most active member with MIC values ranging from (0.12–0.25 µM) compared to Vancomycin (1–2 µM), and MBC values ranging from (0.5–1 µM) for S. aureus (ATCC6538) and MRSA (ACL18). Surprisingly, compound 5b displayed bactericidal behavior, synergistic effect with three commercial antibiotics, and inhibited DHFR with 2.1 folds higher than Trimethoprim. Finally, good findings were obtained from in silico investigations incorporating toxicity prediction and molecular docking simulation.

Thienopyrazole compound was used as a key synthon for a one- two- and three- pot component synthesis of new fused heterocyclic moieties which are known to have different biological activities. The investigated compounds were previously synthesized by environmentally benign techniques besides the conventional heating. The current study focused on biological evaluation of cytotoxicity, anti-hemolytic and antioxidant activities of some thienopyrazole compounds. The results showed the strongest anti-hemolytic and antioxidant activities are compounds 3a and 14c, respectively. All compounds were examined against normal human lung fibroblast cell line (WI-38) and four human cancer cell lines as human prostate cancer (PC-3), Hepatocellular carcinoma (HEPG-2), Colorectal carcinoma (HCT-116) and Epitheliod carcinoma (Hela). Molecular docking was performed inside the active site of P53 for compounds 1, 2, 11b and 14c. Moreover, quantum chemical calculations were performed on the selected compounds. Both techniques suggested that compound 1 displays high binding affinity in the P53 active site with respect to compound 2 while compound 14c owns a lower affinity with respect to 11b thereby suggesting that compound 11b may possibly act as P53 inhibitor and thus may participate in anticancer activity.

A series of new magenta azomethine reactive disperse dyes were synthesized and applied into polyester/cotton blend fabrics. Various spectroscopic and analytical techniques characterized all the synthesized dyes. The obtained data and theoretical values of all the synthesized molecules were in good agreement with the proposed molecular structure. These dyes have proven their efficiency in dyeing blend fabrics, as they give satisfactory results in fastness properties, colorimetric data and exhaustion, fixation study. Moreover, the dyed fabrics were tested for ultraviolet protection factor and offered high ultraviolet protection. The advantage of synthesizing these dyes is quite facile, and scale-up is feasible, preferring industrial dyeing applications. The designed thiazole azomethine dyes exhibited broad-spectrum antibacterial agents against MDR Gram-positive and Gram-negative bacterial isolates, which will facilitate their rational usage in multiple therapeutic applications. Our findings also demonstrate the possibility of using gamma radiation for sterilization of dyed fabrics and the ability of radiation to intensify their antibacterial activities, thereby inhibiting any bacterial growth on the surface of textiles. The molecular docking study showed good binding as a preferred mode between the dyes and DNA gyrase's active site (2XCT).

Aim and Objective: Pyrazolo pyridine skeleton is an interesting class of heterocycles due to its diverse biological properties including antitumor, antioxidant and antibacterial activities. The objective of this work was established in vitro antiproliferative activities against MCF-7 (breast cancer) human cell lines for of the synthesized compounds IIIa-e. The effect of the molecular and electronic structures on the biological activity was performed to compare the theoretical data with the experimental observations. Materials and Method: The synthesized compounds were prepared by conventional heating and microwave irradiation technique. The structure of the prepared compounds was confirmed by different spectroscopic tools. The compounds IIIa-e was tested for antitumor activity against breast cancer cell line. The quantum chemical, molecular docking and SAR studies were performed for the prepared compounds. Results: The microwave irradiation as a source of energy was used to improve the yield and to reduce the time of the reaction. Under this technique, the reaction time was reduced from 4-8 hours to 15-25 min. The yield of the reactions was increased from 81% to 92%. Also, the obtained products were cleaner. Conclusion: The quantum chemical descriptors confirmed that inhibitor1-(4-methoxyphenyl)-3-(1-methyl-1Himidazol- 4-yl)-6-phenyl-1H-pyrazolo[3,4-b]- pyridine-4-ol (IIIb) is the most potent and reactive among the investigated compounds. This conclusion is congruent with the results obtained experimentally.

A novel series of thiazolopyrimidines, thiazolopyrimidinones, imidazolothiazoles, and 1-thiazole-5-pyrazolone was synthesized under microwave irradiation. Most of the synthesized compounds were screened in vitro antitumor, antioxidant, and antimicrobial activities.

A series of new azomethine dyes based on pyrazolone system have been synthesized via different routes. The solvatochromism for the dyes was evaluated with respect to spectroscopic properties in various solvents. The dyes were applied as disperse dyes on polyester fabrics and gave shade poor to excellent light fastness, washing, perspiration, sublimation, and rubbing fastness properties. Also the position of color in CIELAB coordinates (L*, a*, b*) and K/S value were investigated.

The efficient, facile and green synthesis of 4-bromo pyrazolone by using N-bromo saccharine as valuable green reagent encouraged us to prepare some new fused heterocycles as furopyrazole, pyranopyrazole, imidazopyrazole, pyrazolothiazole, pyrazol thiazolopyrimidine, pyrazolothiazine, oxathinopyrazole, pyrazolobenzooxazine, and pyrazoloquinoxaline. The synthesis was carried out by a basic condensation of bromo pyrazolone 2 and a suitable reagent in a one-pot reaction using chitosan as a green basic catalyst. The reactions were carried out by microwave irradiation technique as a green source of energy as well as the conventional heating. The antioxidant activity of the prepared compounds was studied using 1,1-phenyl-2-picrylhydrazyl (DPPH) assay and their antibacterial activity against Gram-positive, Gram-negative bacteria and antifungal activity was evaluated.

Some new azo dye derivatives having pyrazole and trichlorotriazine moieties were synthesized and were evaluated as reactive dyes for the exhaust dyeing of cotton fiber. The title dyes 5a–c were synthesized from reactions of diazonium salts of 3-substituted-1-phenyl-5-aminopyrazoles 2a–c with 6-amino-7-hydroxy-2-naphthalenesulfonic acid, 4-amino-5-hydroxynaphthalene-2,7-disulfonic acid and/or cyanuric chloride. Other reactive dyes 7a–f were synthesized from reaction of cyanuric chloride and 4-arylazo-3-substituted-1-phenyl-5-aminopyrazoles 6a–f. The synthesized dyes were applied to cotton fiber and their color fastness to light, washing, perspiration, and rubbing were also measured. The dyes showed good to moderate affinity to cotton fiber. The biological screening showed that most of the tested compounds display promising antimicrobial activities against the tested microorganisms.

Three series of mono and disazo disperse dyes were synthesized from 2-amino-4-(pyridin-3-yl) thiazole. The structure of the synthesized dyes was confirmed by elemental analysis, ultraviolet-visible, infrared, proton and carbon nuclear magnetic resonance and mass spectroscopy. The dyeing parameters, perspiration, wash and light fastness of eighteen azo disperse dyes on polyester have been investigated. Application of these dyes on polyester fabric gave yellow to reddish hues for mono azo derivatives and reddish to dark brown hues for disazo derivatives with fair to moderate light fastness and moderate to good wash and perspiration fastness grade. In addition, the synthesized dyes were screened for their antimicrobial activities against some gram positive, gram negative bacteria and fungi. Some of the prepared dyes gave excellent results against most of the tested organisms.

The chemical behavior of 4-(dimethylaminomethylene)-1-phenyl-3-(pyridin-3-yl)-1 H -pyrazol-5(4 H )-one (enaminone) ( 2 ) toward some active methylene reagents has been reported to give pyrazolopyridine derivatives. All the reactions were carried out by conventional heating and microwave irradiation technique. The antioxidant activity of the prepared compounds was studied using 1,1-phenyl-2-picrylhydrazyl (DPPH) assay. Compounds ( 4c ) and ( 4d ) showed the highest activity. The antitumor activity against liver and breast cell lines was tested. Compounds ( 6 ), ( 9 ) and ( 11 ) showed the highest activity for liver cell line while compounds ( 6 ) and ( 9 ) showed the highest activity for breast cell line. Compounds ( 4a – d ) were screened for their antibacterial activity against Gram-positive, Gram-negative bacteria and antifungal activity.

An efficient one-pot synthesis in multi-component system (MRCs) for the preparation of pyrazolo[3,4- b ]pyridine derivatives from the reaction of 5-amino-1-phenyl-3-(pyridin-3-yl)-1 H -pyrazole with 4-anisaldehyde and p -substituted β-ketonitriles or with pyruvic acid and some aromatic aldehydes in acetic acid medium. The reactions were carried out by two different techniques, conventional heating and microwave irradiation. These compounds were screened for their antibacterial activity against Gram-positive bacteria ( Bacillus ), Gram-negative bacteria ( Escherichia coli, Enterobacter cloaca and serratia ) and antifungal activity against Fusarium Oxysporum and Penicillium expansum . Also, among the synthesized compounds 4a – f tested for antitumor activity against liver cell line. Compounds 6-(4-Fluorophenyl)-4-(4-methoxyphenyl)-1-phenyl-3-(pyridin-3-yl)-1H-pyrazolo[3,4- b ]pyridine-5-carbonitrile ( 4e ) and 4-(4-Methoxyphenyl)-1-phenyl-3,6-di(pyridin-3-yl)-1H-pyrazolo[3,4- b ] pyridine-5-carbonitrile ( 4a ) showed the highest activity.

A convenient synthesis of intermediate 4,5-diamino-3-aryl-1-phenylpyrazoles 4a–4c was reported. The different cyclization reactions were carried out with chalcone, 2-mercaptoacetic acid and p-anisialdehyde, ethyl chloroformate, glyoxal and thiourea to afford different N and S containing heterocycles. The reaction conditions were compared by conventional heating and microwave irradiation. The structures of the cyclization products were determined by analytical and spectroscopic data. All the synthesized compounds were screened for antibacterial activities in vitro.

Diazotized aryl amines were coupled with 3-substituted 5-amino pyrazoles to produce a series of novel 3-substituted 5-amino-4-arylazopyrazoles. Also, 3-substituted 5-amino-pyrazoles were diazotized and coupled with different phenols to give the corresponding novel 3-substituted 5-aryl azo pyrazoles. These dyes were characterized by elemental analysis and spectral data, applied to different types of fibres (wool, polyester and a blend of wool/polyester as disperse dyes) and their fastness properties were evaluated.

Coupling of 5-amino-1,3-diaryl-pyrazoles 1a-c with diazonium salts of different aryl amines gave a series of novel1,3-diaryl-5-amino-4-arylazopyrazoles 3a-l . Such compounds could be also obtained by reaction of 5-amino-1,3-diaryl-4-nitroso-1 H -pyrazoles 2a-c with different aryl amines in alkaline medium. Oxidation of azo derivatives 3a-l with cupric acetate, in dimethy lformamide and stream of air, gave 2, 4,6-triaryl-2,4-dihydropyrazolo [4,3- d ]-1,2,3-triazoles 4a-l . and the fluorescence properties of the cyclic triazoles were studied. Diazotization of 5-amino-1,3-diaryl-1 H -pyrazoles 1a-c by sodium nitrite in ortho-phosphoricacid followed by coupling with some aryl amines gave o -aminoazo compounds 5a-f . Cyclisation of compounds 5a-f in pyridine and cupric acetate gave the corresponding triazoles 6a-f . The coupling of compounds 6a-f with different aryl diazonium salts gavecompounds 7a-j . The synthesized dyes were applied to polyesters as disperse dyes and the fastness properties were evaluated.

3-Amino-1-phenyl-4,5-dihydro-1H-pyrazol-5-one (1) was used as starting material for the synthesis of a number of azo compounds 3a–3c and azomethine derivative 4. The deblocking of 3a–3c and 4 gave rise to 5a–5c and 6 in which a free amino was revealed. The diazonium salts of 5a–5c and 6 were coupled with several phenols to produce a number of bis azo compounds 7a–7c and 8a–8c with azomethine in position 4 and azoic group in position 3. The prepared dyes were structurally confirmed by elemental analysis, spectral methods and applied to different fibers (wool, polyester and blend of wool/polyester) as disperse dyes and their fastness properties were measured.

New Mn(II), Ni(II), Co(II) and Cu(II) complexes of an azo dye ligand based on p-phenylenediamine with 5-nitro-8-hydroxyquinoline were synthesized and characterized using elemental analysis, inductive coupled plasma analysis, molar conductance, powder X-ray diffraction, thermogravimetric analysis, magnetic moment measurements, and infrared, 1H NMR, electron ionization mass and UV–visible spectral studies. The spectral and analytical data reveal that the azo dye ligand acts as a monobasic bidentate ligand via deprotonated OH and nitrogen atom of the quinoline ring. The data support the formulation of all complexes with a 2:1 ligand-to-metal ratio, except the Mn(II) complex that has a mononuclear formula. All complexes have an octahedral structure. The molar conductance data reveal that all the metal complexes are non-electrolytic in nature. From the X-ray data, the average particle size of the ligand and its complexes is 0.32–0.64 nm. The colour fastness to light, washing, perspiration, sublimation and rubbing of the prepared ligand and its complexes on polyester fabrics and colorimetric properties were measured. The results reveal that the ligand and its complexes have a good to moderate affinity to polyester fibres.

Benzo[ b]thiophene-5,6-dicarboxaldehyde reacts with dibenzyl ketone, thiodiacetic acid dimethyl ester, hydrazine, p-toluidine, p-aminoacetophenone and nitromethane to give the corresponding seven, six and five-membered rings condensed to benzo[ b]thiophene. Reaction of benzo[ b]thiophene-5,6-dicarboxaldehyde with p-toluidine in the presence of 2-mercaptoethanol gives highly fluorescent compounds. Also, benzo[ b]thiophene-5,6-dicarboxaldehyde was applied to fluorogenic reaction with some amino acids and the obtained data were compared with the reported data in the case of o-phthaldehyde. The synthesised compounds were characterised by their elemental analysis, IR, 1H NMR and mass spectrometry

Most synthesized compounds (IV) and (VI) exhibit antimicrobial activity, while compounds (VIa) and (VIc) show significant activity against HEPG2 human liver cancer cell line.

Compounds (IV), (VIIa), (VIIb), (Xb), (XIb) and (XIc) show significant antibacterial activity against Gram-positive bacteria like Staphylococcus aureus as well as Gram-negative bacteria like Bacillus cereus.

3-Amino-1-phenyl-4,5-dihydro-1H-pyrazol-5-one (1) was used as starting material for the synthesis of a number of azo compounds 3a–3c and azomethine derivative 4. The deblocking of 3a–3c and 4 gave rise to 5a–5c and 6 in which a free amino was revealed. The diazonium salts of 5a–5c and 6 were coupled with several phenols to produce a number of bis azo compounds 7a–7c and 8a–8c with azomethine in position 4 and azoic group in position 3. The prepared dyes were structurally confirmed by elemental analysis, spectral methods and applied to different fibers (wool, polyester and blend of wool/polyester) as disperse dyes and their fastness properties were measured.

Benzo[b]thiophene-5,6-dicarboxaldehyde reacts with dibenzyl ketone, thiodiacetic acid dimethyl ester, hydrazine, p-toluidine, p-aminoacetophenone and nitromethane to give the corresponding seven, six and five-membered rings condensed to benzo[b]thiophene. Reaction of benzo[blthiophene-5,6-dicarboxaldehyde with p-toluidine in the presence of 2-mercaptoethanol gives highly fluorescent compounds. Also, benzo[blthiophene-5,6-dicarboxaldehyde was applied to fluorogenic reaction with some amino acids and the obtained data were compared with the reported data in the case of o-phthaldehyde. The synthesised compounds were characterised by their elemental analysis, IR, 1 H NMR and mass spectrometry.