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Background/Objectives: In this study, the efficacy of benzo[h]chromene derivatives as antiprotozoal and antimycobacterial agents was explored. Methods: A total of twenty compounds, including benzo[h]chromene alkyl diesters and benzo[h]chromene-triazole derivatives, were synthesized and tested against Trypanosoma cruzi, Leishmania braziliensis, L. infantum, and strains of Mycobacterium abscessus and Mycobacterium intracellulare LIID-01. Notably, compounds 1a, 1b, 2a, and 3f exhibited superior activity against Trypanosoma cruzi, with IC50 values of 19.2, 37.3, 68.7, and 24.7 µM, respectively, outperforming the reference drug benznidazole (IC50: 54.7 µM). Results: Compounds 1b and 3f showed excellent selectivity indices against Leishmania braziliensis, with SI values of 19 and 18, respectively, suggesting they could be potential alternatives to the commonly used, but more selective, miltefosine (IC50: 64.0 µM, SI: 43.0). Additionally, compounds 1a, 1b, and 3f were most effective against Leishmania infantum, with IC50 values of 24.9, 30.5, and 46.6 µM, respectively. Compounds 3f and 3h were particularly potent against various Mycobacterium abscessus strains, highlighting their significance given the inherent resistance of these bacteria to standard antimicrobials. Conclusions: The sensitivity of Mycobacterium intracellulare LIID-01 to these compounds also underscored their potential in managing infections by the Mycobacterium avium–intracellulare complex. [ABSTRACT FROM AUTHOR]

Abstract A new series of substituted benzo[h]chromene, benzochromenopyrimidine, and benzochromenotriazolopyrimidine derivatives were synthesized via chemical transformations of iminonitrile, ethoxymethylene amino, and cyanomethylene functionalities. The chemical structures of the synthesized compounds were assured by spectroscopic data and elemental analysis. The larvicidal efficacy of these compounds against Culex pipiens L. larvae was investigated, revealing potent insecticidal activity, particularly for compounds 6, 10, and 16, exceeding that of the standard insecticide chlorpyrifos. The mode of action of these compounds was explored through molecular docking studies, indicating their potential as acetylcholine esterase (AChE) inhibitors and nicotinic acetylcholine receptors (nAChR) blockers. The structure–activity relationship analysis highlighted the influence of substituents and fused heterocyclic rings on larvicidal potency. These findings suggest that the synthesized compounds hold promise as potential candidates for developing novel and effective mosquito control agents.

A new series of substituted benzo[h]chromene, benzochromenopyrimidine, and benzochromenotriazolopyrimidine derivatives were synthesized via chemical transformations of iminonitrile, ethoxymethylene amino, and cyanomethylene functionalities. The chemical structures of the synthesized compounds were assured by spectroscopic data and elemental analysis. The larvicidal efficacy of these compounds against Culex pipiens L. larvae was investigated, revealing potent insecticidal activity, particularly for compounds 6, 10, and 16, exceeding that of the standard insecticide chlorpyrifos. The mode of action of these compounds was explored through molecular docking studies, indicating their potential as acetylcholine esterase (AChE) inhibitors and nicotinic acetylcholine receptors (nAChR) blockers. The structure–activity relationship analysis highlighted the influence of substituents and fused heterocyclic rings on larvicidal potency. These findings suggest that the synthesized compounds hold promise as potential candidates for developing novel and effective mosquito control agents. [ABSTRACT FROM AUTHOR]

We have developed a facile oxidative approach for the synthesis of C‐4 functionalized 2‐oxo‐2H‐benzo[h]chromenes. The required precursors, 4‐(methylthio)‐2‐oxo‐5,6‐dihydro‐benzo[h]chromenes were synthesized by reaction of 1‐tetralones and 2‐cyano‐3,3‐bis(methylthio)acrylate under basic conditions, which can be further aminated with different secondary amines in refluxing ethanol. We have reported the NBS and AIBN mediated oxidation of 5,6‐dihydro‐benzo[h]chromenes to afford 4‐(substituted)‐2‐oxo‐benzo[h]chromenes. The scope of dehydrohalogenation was further extended for the synthesis of thiophene‐fused chromenes. Reactivity of synthesized 4‐(substituted)‐2‐oxo‐benzo[h]chromenes was also explored with C‐ and S‐nucleophiles. [ABSTRACT FROM AUTHOR]

The present study presents easy and rapid methods to synthesize new benzo[ h ]chromene and benzo[ h ] quinoline derivatives. Cytotoxic evaluations of most of the examined compounds indicated that they had significant cytotoxic activities against HepG-2 (human cancer cells) and MCF-7 (breast cancer cells). Compounds 4 and 11 had stronger cytotoxic activity against HepG-2 human cancer cells than the reference drug Doxorubicin. All the examined compounds were significantly active against MCF-7 human cancer cells and were more potent than Doxorubicin. The structures of the new compounds were established from their spectral and elemental data. In addition the structures of benzo[h] chromene 3 and benzo[h]quinoline 7 were recognized by x-ray crystallography. Herein detailed syntheses, spectroscopic information and biological actions of the tested compounds are reported. [ABSTRACT FROM AUTHOR]

• A D-p-A type probe has been developed for detection of ClO−. • The mechanism associated with oxidation breakage of rhodanine moiety was proposed. • The crystal structure of the probe is reported. • The probe has been successfully applied to the imaging of ClO− in cells, plants and zebrafish. Hypochlorite (ClO−) plays an important role in many cellular processes, which is proved to be related to some serious diseases. Given the electron donating and electron withdrawing properties of benzo[ h ]chromene and rhodanine groups, respectively, we developed a Donor (D)-p-Acceptor (A) type probe 1 for the detection of ClO− based on benzo[ h ]chromene (D) and rhodanine (A), whose structure was determined by ESI-MS, NMR and X-ray diffraction. Probe 1 showed a fast (within 20 s), selective and sensitive response toward ClO− via a fluorescent turn-on output. Based-on the spectral change of probe 1 induced by ClO−, the mechanism associated with oxidation breakage of rhodanine moiety was proposed. Due to the excellent biocompatibility and low cytotoxicity, probe 1 can be used for imaging of ClO− in C6 cells, Arabidopsis thaliana, and zebrafish. [Display omitted] [ABSTRACT FROM AUTHOR]

Purpose: To carry out a neat synthesis of 2-amino-5,6-dihydro-8-methoxy-4-phenylbenzo[h]quinoline-3-carbonitrile (compound 2) and 2-amino-5,6-dihydro-8-methoxy-4-phenyl-4H-benzo[h]chromene-3-carbonitrile (compound 3) and evaluate their cytotoxic activity in human glioblastoma cells. Methods: Benzo[h]quinoline and benzo[h]chromene were synthesized by treating 6-methoxy-1-tetralone with benzylidenemalononitrile under microwave irradiation. The structures of compounds 2 and 3 were confirmed by elemental, spectral, and x-ray crystallographic analyses. The cytotoxic activity of compounds 2 and 3 was evaluated using WST-1 assay in U373 human glioblastoma cell line. Results: The molecular structures of compounds 2 and 3 were demonstrated unambiguously from single crystal x-ray measurements and they crystallized in triclinic form, P-1, for both compounds. Invitro cytotoxic activity data for compound 2 in human glioblastoma cell line (U373) indicate that no significant cytotoxicity was observed. On the other hand, compound 3 showed highly significant cytotoxic effects on U373 cells at concentrations starting from 0.1 μg/mL. Conclusion: Compound 3 produces a decrease in cell viability with approximately 80% cell death while compound 2 did not indicate significant cytotoxic activity. This suggests that the chromene moiety of compound 3 may be responsible for its high cytotoxicity. [ABSTRACT FROM AUTHOR]

[Display omitted] • A simple probe has been developed for the "turn-on" fluorescent detection of ClO− based on aggregation-induced emission. • The probe could monitor ClO− with low detection line (246 nM) in semi-aqueous solution. • The probe worked within wide pH rang of 2.0–13.0, and the process of quench completed within 10 s. • The probe has been successfully used for monitoring exogenous and endogenous ClO− in living cells. In this study, we developed a benzo[ h ]chromene-based probe (1) for the detection of hypochlorite (ClO−) based on a typical aggregation-induced emission (AIE) output. Probe 1 shows high selectivity and sensitivity toward ClO−, with a rapid response speed (within 10 s) and a low detection limit (246 nM). Sufficient spectroscopic analyses uphold the oxidation fracture of bridge C=C bond with the aid of ClO−, leading to the change of 1 to 2H-benzo[h]chromene-3-carbaldehyde (1a). In addition, the as-synthesized probe was applied in imaging exogenous and endogenous ClO− in living cells. [ABSTRACT FROM AUTHOR]

Abstract: An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions. [Copyright &y& Elsevier]

Abstract: A benzo[h]chromene derivative, 2-amino-4-phenyl-4H-benzo[h]chromene-3-carbonitrile 1, has been utilized as ‘Turn On’ fluorescence chemosensor for the selective detection of Pb2+. The title compound 1 was synthesized in one step using a multicomponent condensation reaction (MCR), and characterized using various spectroscopic techniques. The selectivity was tested over a range of 17 different metal and non-metal ions. Compound 1 was found to be weak fluorescent (Φ 1 =0.06) because of photoinduced electron transfer (PET). The presence of 2 equiv of Pb2+ showed a significant increase in fluorescence quantum yield ( =0.132). A change in weak blue emission of 1 to a glowing green emission along with a prominent red shift (26nm) in emission band was observed upon addition of Pb2+ to a methanolic solution of 1. The complexation of 1 with Pb2+ was proved by mass spectroscopy and NMR studies. Some of our experimental findings have been supported by theoretical studies. Compound 1 was found to be easily permeable to living cells without causing any harm and ultimately was used to detect effectively Pb2+ in living system. [Copyright &y& Elsevier]

This article describes the thermal rearrangement reactions of aryl geranyl ethers. These reactions depend on the structure of the aryl moiety of the substrate and the reaction conditions used. The naphthyl ethers underwent a [1,3]-alkyl shift, followed by acid-catalyzed intramolecular cyclization. The microwave-assisted rearrangement of isoquinolinyl ether showed a pattern of an abnormal Claisen rearrangement. The multi step rearrangement of the quinolyl ether afforded a spiro compound. These new reactions were used to synthesize novel heterocyclic compounds. [ABSTRACT FROM AUTHOR]

A series of new 2-amino-3-cyano-4-aryl-1,4,5,6-tetrahydrobenzo[h]chromenes derivatives were synthesized by the reaction of malononitrile with 2-arylmethylidene-3, 4-dihydro-1(2H)-naphthalenone in N,N-dimethylformamide(DMF) at 80°C catalyzed by KF-Al2O3. The structure of the product was confirmed by x-ray analysis. [ABSTRACT FROM AUTHOR]

• A simple benzo[ h ]chromene-based probe toward HSO 3 − has been developed. • The crystal structure of the probe is reported. • The probe is aggregation-induced ratiometric emission active. • The probe responses HSO 3 − in almost pure aqueous solution. • The probe could be utilized to detect exogenous HSO 3 − in HeLa cells. Monitoring levels of SO 2 and its derivatives, including sulfite (SO 3 2−) and bisulfite (HSO 3 −) ions, in biological systems is of great importance because their aberrant concentrations in cells may cause several diseases. Aggregation-induced-emission (AIE) active probes are exhibited good photophysical properties in aqueous solution, and have been applied in many fields. Herein, we report benzo[ h ]chromene aldehyde (1) with aggregation-induced ratiometric emission (AIRE) that showed a blue emission in a solution, whereas in an aggregate state, a green emission with 43-nm Stocks shift was observed. Furthermore, this green AIRE was specifically quenched using HSO 3 − under physiological conditions owing to the formation of a water-soluble and non-emissive product after the addition of bisulfite to the aldehyde group of 1. Finally, the imaging experiments indicated that probe 1 could be utilized to detect exogenous HSO 3 − in HeLa cells. [ABSTRACT FROM AUTHOR]

A new series of 2-(4-aryl)-4-ethoxy-4-phenyl-4H-benzo[h]chr- omene derivatives have been synthesized. The procedure involves the multicomponent reaction of 1-naphthol, acetophenone derivatives, and triethyl orthobenzoate catalyzing by efficient bis[7-tert-butyl-2-anilinotropone] Ti complex. [ABSTRACT FROM PUBLISHER]

Background: Benzo[h]chromenes attracted great attention because of their widespread biological activities, including anti-proliferate activity, and the discovery of novel effective anti-cancer agents is imperative., Objective: The main objective was to synthesize new benzo[h]chromene derivatives and some reported derivatives, and then test all of them for their anti-cancer activities., Methods: The structures of the newly synthesized derivatives were confirmed by elemental and spectral analysis (IR, Mass, 1 H-NMR and 13 C-NMR). 35 compounds were selected by the National Cancer Institute (NCI) for single-dose testing against 60 cell lines and 3 active compounds were selected for 5-doses testing. Also, these 3 compounds were tested as EGFR-inhibitors; using sorafenib as standard, and as Tubulin polymerization inhibitors using colchicines as a standard drug. Moreover, molecular docking study for the most active derivative on these 2 enzymes was also carried out., Results: Compounds 1a, 1c and 2b have the highest activities among all 35 tested compounds especially compound 1c., Conclusion: compound 1c has promising anti-cancer activities compared to the used standards and may need further modification and investigations., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)