A series of seventeen 3‐aryl‐1‐heteroarylindeno[1,2‐c]pyrazol‐4(1H)‐ones (4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h, 4i, 4j, 4k, 4l, 4m, 4n, 4o, 4p, 4q) has been synthesized and characterized by spectral (IR, 1H NMR, and mass), X‐ray crystallography and analytical results. All the indenopyrazoles (4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h, 4i, 4j, 4k, 4l, 4m, 4n, 4o, 4p, 4q) were tested for their in vitro antimicrobial activity against two Gram‐positive bacteria viz. Bacillus subtilis (MTCC 441) and Staphylococcus aureus (MTCC 7443), two Gram‐negative bacteria, viz. Escherichia coli (MTCC 42) and Pseudomonas aeruginosa (MTCC 741) and two fungi, viz. Candida albicans (MTCC 183) and Aspergillus niger (MTCC 282) using ceftriaxone and fluconazole as standard references against bacterial and fungal strains, respectively. Among the synthesized derivatives, 4f against B. subtilis and S. aureus, 4e against E. coli, 4g and 4j against P. aeruginosa, 4k and 4l against C. albicans, and 4k against A. niger were found to exhibit appreciable antimicrobial activities. However, 4g (minimum inhibitory concentration, 0.0036 µmol/mL) was found to be more potent than the reference, that is, fluconazole (minimum inhibitory concentration, 0.0050 µmol/mL) against A. niger. Moreover, both antibacterial and antifungal activities were found to be prolific. The radial distribution function parameters were found to be important for description of activities against the modeled strains in quantitative structure–activity relationship studies.

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Experimental detail, Characterization data, and NMR ( 1 H and 13 C) spectra of 4a-4t and 2D-NMR spectra of 4b Contents Experimental detail ……………………………………………………………………….. S2 Characterization data ……………………………………………………………………… S4 General Procedure for antimicrobial activity ……………………………………………… S15 1 H and 13 C NMR Spectra of 4a-4t ……………………….……………………………….. S16 2D-NMR Spectra of 4b……………………………………………………………….....… S56 S2 Experimental DetailCommercial reagents were utilized as received from suppliers without additional purification. 2-Aminothiophenol was purchased from Sigma-Aldrich. All the synthesized compounds were characterized by 1 H NMR, 13 C NMR, IR, ESI-MS and microanalysis. All the melting points (°C) were recorded on electrothermal apparatus in open capillary tubes and are uncorrected. Thin layer chromatography was used for monitoring the progress of the reaction and ascertaining the purity of the synthesized compounds on pre-coated TLC plates (Merck Keiselgel F 254 ) using hexane-ethyl acetate solvent system of different polarity and visualization was achieved by exposure to UV light. Columns were packed as slurry of silica gel (60-120 mesh) in hexane.Initially, compounds were adsorbed on silica gel in appropriate solvent and then loaded on column as slurry in hexane. The FTIR spectra were scanned on IR Affinity-1 FTIR (Shimadzu) spectrophotometer in KBr and wave numbers (ν) are reported in cm -1 . Nuclear Magnetic Resonance spectra ( 1 H at 400 MHz and 13 C at 100 MHz) were recorded on 400 MHz Bruker AVANCE-III spectrometer using CDCl 3 as solvent and tetramethylsilane (TMS) as internal standard. DEPT (Distortionless Enhancement by Polarization Transfer) and 2D-NMR viz. COSY (correlation spectroscopy), HSQC (heteronuclear single-quantum coherence) and HMBC (heteronuclear multiple bond correlation) spectra of compound 4b were also recorded on 400 MHz Bruker AVANCE-III spectrometer. Chemical shifts (δ) are reported in parts per million (ppm) and coupling constants (J) are expressed in Hertz (Hz). Multiplicities in NMR signals are designated as s (singlet), d (doublet), dd (doublet of doublet), t (triplet), q (quartet) and m (multiplet, for unresolved signals). Mass spectra were scanned on Waters Quadrupole Detector (TDQ), Waters gtof micro Mass spectrometer and Agilent 6410B Triple Quard LCMS spectrometer. Microanalyses were performed on Thermo Scientific FLASH-2000 CHN analyser. S3All the synthesized compounds were found in good agreement with the elemental analysis.Analytical results for C, H and N were found to be within ± 0.4 % of the theoretical values.Nomenclature of the compounds was assigned with the help of Chem Draw Ultra 12.0. General procedure for the synthesis of 2-aryl-1H-indene-1,3(2H)-diones (1)Condensation of equimolar quantities of phthalide and appropriate benzaldehyde under the influence of sodium methoxide and ethylacetate led to the formation of 2-aryl-1H-indene-1,3(2H)-diones (1). General procedure for the synthesis of 2-aryl-2-bromo-1H-indene-1,3(2H)-diones (2)The 2-aryl-1H-indene-1,3(2H)-di...

A quantitative structure-activity relationship (QSAR) analysis has been performed on a series of 20 tetracyclic 1,4-benzothiazines (1a-1t) with antimicrobial activity to explain the observed biological activity trend on structural basis. Multiple linear regression (MLR) method was employed to establish statistically significant QSAR models. The developed models are robust, predictive and free from chance correlation with good fitting ability and sufficient generalizability. These studies revealed the dominance of WHIM parameters in describing antimicrobial activity of the title compounds. Further, design of some more active compounds is presented.

Two new series of N‐thiazolyl hydrazones (3a–h) and indenopyrazolones (4a–h) were synthesized by the reaction of various 2‐acyl‐(1H)‐indene‐1,3(2H)‐diones, thiosemicarbazide, and phenacyl bromide/substituted phenacyl bromides. The in vitro antimicrobial activity of these synthesized compounds was assayed against four bacteria, namely, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, and two fungi, namely, Candida albicans and Aspergillus niger, by employing serial dilution method. Ciprofloxacin and fluconazole were used as antibacterial and antifungal reference drugs, respectively. Results of antimicrobial assay showed that the tested compounds have broad range of activity. The compounds 3h and 4a against C. albicans displayed more potency than fluconazole whereas 3b and 3c against B. subtilis showed activity comparable with ciprofloxacin. The synthesized indenopyrazolones (4a–h) were evaluated for their in vitro antioxidant activity by 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging assay using ascorbic acid as reference. Compound 4b exhibited the highest 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging with IC50 value 33.14 μg/mL. The observed results of antimicrobial activity were supported by molecular docking study performed to understand the binding interaction of hydrazones (3a–h) and indenopyrazolones (4a–h) with lanosterol 14α‐demethylase.

In the present study, a series of 20 indane‐based 1,5‐benzothiazepines (5a–t) has been prepared derived from 3‐phenyl‐2,3‐dihydro‐1H‐inden‐1‐one (1). All the synthesized 1,5‐benzothiazepines (5a–t) were screened for their in vitro antimicrobial activities against four bacteria [Bacillus subtilis (MTCC 441), Staphylococcus epidermidis (MTCC 6880), Escherichia coli (MTCC 1652), and Pseudomonas aeruginosa (MTCC 424)] and two fungi [Candida albicans (MTCC 227) and Aspergillus niger (MTCC 8189)]. Among all the tested derivatives, 5n and 5o against E. coli displayed more inhibitory activity than that of the reference drug, ciprofloxacin, while the derivatives 5c, 5m–o, 5s, and 5t against C. albicans, and 5d, 5e, 5n, 5o, 5s, and 5t against A. niger were found to be more potent than the standard drug, that is, fluconazole.

A series of sixteen 1-(4-arylthiazol-2-yl)-1?-(aryl/heteroaryl)-3,3?-dimethyl-[ 4,5?-bi-1H-pyrazol]-5-ols (7a?p) was synthesized starting from dehydroacetic acid (DHA, 1) via the stepwise formation of thiosemicarbazone (2), 3-(1-(2-(4-arylthiazol-2-yl)hydrazono)ethyl)-4-hydroxy-6-methyl-2H-pyran- -2-ones (4a?d) and 1-(1-(4-arylthiazol-2-yl)-5-hydroxy-3-methyl-1H-pyrazol- -4-yl)butane-1,3-diones (5a?d) in high yields. The in vitro antibacterial and antifungal activities of the synthesized bipyrazoles 7a?p were investigated against two Gram-positive bacterial strains, viz. Bacillus subtilis (MTCC 441) and Staphylococcus aureus (MTCC 7443), one Gram-negative bacterial strain, viz. Escherichia coli (MTCC 42), and two fungal strains, viz. Candida albicans (MTCC 183) and Aspergillus niger (MTCC 282). The compounds 7a and 7e were found to exhibit better inhibitory activity against A. niger than the reference fluconazole. Moreover, the antifungal activities of the title compounds were more prolific than their antibacterial activities. Furthermore, in order to study binding interactions, docking simulations of compounds 7a, 7m and 7o were performed into the active site of S. aureus 1,4-dihydroxy-2-naphthoyl- -CoA synthase. Keywords: bipyrazoles; antibacterial; antifungal; docking simulations.

The aim of this review is to collate literature work reported by researchers (from 1994 to 2021) to provide an overview of the available methodologies for the synthesis and diverse pharmacological activities exhibited by pyrazole based molecules. This review highlights recent reports on various routes of synthesis and potential biological evaluation studies viz. anticancer, AT (II) inhibitory, anti-inflammatory activities, HIV-1-RT inhibitory, antihypertensive, herbicidal, antitubercular, insecticidal, antiviral, antimicrobial and COX-2 inhibitory activity, etc. of pyrazole derivatives and also presents recent efforts made on this heterocyclic moiety.