6,8-Dibromo-4-chloroquinoline-3-carbaldehyde as a synthon in the development of novel 1,6,8-triaryl-1H-pyrazolo[4,3-c]quinolines

Efficient Synthesis of 1,9-Substituted Benzo[h][1,6]naphthyridin-2(1H)-ones and Evaluation of their Plasmodium falciparum Gametocytocidal Activities

A novel three-component, two-step, one-pot nucleophilic aromatic substitution (S_NAr)-intramolecular cyclization-Suzuki coupling reaction was developed for the synthesis of benzo[h][1,6]naphthyridin-2(1H)-ones (Torins). On the basis of the new efficiently convergent synthetic route, a library of Torin analogs was synthesized. The antimalarial activities of these compounds were evaluated against asexual parasites using a growth inhibition assay and gametocytes using a viability assay.

Crystal structure of 1-(4-chlorophenyl)-6,8-diphenyl-1H-pyrazolo[4,3-c]quinoline, C28H18ClN3

C28H18ClN3, monoclinic, P21/c, (no. 14) a = 5.9519(2) Å, b = 8.0511(3) Å, c = 43.4071(14) Å, β = 90.001(2)°, V =2080.04(12) Å3, Z = 4, Rgt(F) = 0.066, wRref(F2) = 0.190, T = 173 K.

In vitro cytotoxicity of novel 2,5,7-tricarbo-substituted indoles derived from 2-amino-5-bromo-3-iodoacetophenone

A series of novel 2,5,7-tricarbo-substituted indoles were prepared via sequential Sonogashira and Suzuki-Miyaura cross-coupling of 2-amino-5-bromo-3-iodoacetophenone with terminal acetylenes and aryl/styrylboronic acids followed by palladium chloride-mediated heteroannulation of the incipient 5-aryl/styryl-substituted 2-amino-3-(arylalkynyl)acetophenones. These polycarbo-substituted indole derivatives were evaluated for potential in vitro antiproliferative activity against the human breast adenocarcinoma (MCF-7) and human cervical cancer (HeLa) cell lines. Compounds 6f, 6i, 6k, 6m and 6n were found to exhibit significant cytotoxicity and selectivity against the HeLa cells. Compounds 6i and 6m were chosen as representative examples to evaluate their pro-apoptotic efficacy against the HeLa cell line. The compounds induced apoptosis through cell membrane alteration and DNA fragmentation caspase-dependent pathways.

Use of Bromine and Bromo-Organic Compounds in Organic Synthesis

Bromination is one of the most important transformations in organic synthesis and can be carried out using bromine and many other bromo compounds. Use of molecular bromine in organic synthesis is well-known. However, due to the hazardous nature of bromine, enormous growth has been witnessed in the past several decades for the development of solid bromine carriers. This review outlines the use of bromine and different bromo-organic compounds in organic synthesis. The applications of bromine, a total of 107 bromo-organic compounds, 11 other brominating agents, and a few natural bromine sources were incorporated. The scope of these reagents for various organic transformations such as bromination, cohalogenation, oxidation, cyclization, ring-opening reactions, substitution, rearrangement, hydrolysis, catalysis, etc. has been described briefly to highlight important aspects of the bromo-organic compounds in organic synthesis.

Dehydrogenative [2 + 2 + 1] Heteroannulation Using a Methyl Group as a One-Carbon Unit: Access to Pyrazolo[3,4-c]quinolines

A practical and straightforward access to pyrazolo[3,4-c]quinolines by molecular sieve mediated dehydrogenative [2 + 2 + 1] heteroannulation of N-(o-alkenylaryl)imines with aryldiazonium salts is described using a sp(3)-hybrid carbon atom as a one-carbon unit. The reaction enables the formation of three new chemical bonds, a C-C bond and two C-N bonds, in a single reaction and features simple operation and excellent functional group tolerance.

Physicochemical and Critical Micelle Concentration (CMC) of Cationic (CATB) and Anionic (SDS) Surfactants with Environmentally Benign Blue Emitting TTQC Dye

4-(3,4,5-trimethoxyphenyl)-8-methoxy-2-oxo-1,2,5,6 tetrahydrobenzo[h]quinoline-3-carbonitrile (TTQC) dye has synthesized by one-pot multicomponent reactions (MCRs) of 3,4,5-trimethoxybenzaldehyd, ethyl cyanoacetate, 6-methoxy-1,2,3,4-tetrahydro-naphthalin-1-one and ammonium acetate under microwave irradiation. The structures of the synthesized compound was established by spectroscopic (FT-IR, (1)H-NMR, (13)C-NMR, EI-MS) and elemental analyses. In addition, spectroscopic and physicochemical parameters, including electronic absorption, excitation coefficient, Stokes shift, oscillator strength, transition dipole moment and fluorescence quantum yield were investigated in order to explore the analytical potential of synthesized compound. TTQC dye undergoes solubilization in different micelles and may be used as a probe to determine the critical micelle concentration (CMC) of CTAB and SDS.

One-Pot Synthesis, Spectroscopic and Physicochemical Studies of Quinoline Based Blue Emitting Donor-Acceptor Chromophores with Their Biological Application

Blue emitting cyano substituted isoquinoline dyes were synthesized by one-pot multicomponent reactions (MCRs) of aldehydes, malononitrile, 6-methoxy-1,2,3,4-tetrahydro-naphthalin-1-one and ammonium acetate. Results obtained from spectroscopic (FT-IR, (1)H-NMR, (13)C-NMR, EI-MS) and elemental analysis of synthesized compounds was in good agreement with their chemical structures. UV-vis and fluorescence spectroscopy measurements proved that all compounds are good absorbent and fluorescent. Fluorescence polarity study demonstrated that these compounds were sensitive to the polarity of the microenvironment provided by different solvents. In addition, spectroscopic and physicochemical parameters, including electronic absorption, excitation coefficient, stokes shift, oscillator strength, transition dipole moment and fluorescence quantum yield were investigated in order to explore the analytical potential of synthesized compounds. The anti-bacterial activity of these compounds were first studied in vitro by the disk diffusion assay against two Gram-positive and two Gram-negative bacteria then the minimum inhibitory concentration (MIC) was determined with the reference of standard drug chloramphenicol. The results displayed that compound 3 was better inhibitors of both types of the bacteria (Gram-positive and Gram-negative) than chloramphenicol. Graphical Abstract ᅟ.

Novel polycarbo-substituted alkyl (thieno[3,2-c]quinoline)-2-carboxylates: synthesis and cytotoxicity studies

Direct one-pot base-promoted conjugate addition–elimination of 6,8-dibromo-4-chloroquinoline-3-carbaldehyde with methyl mercaptoacetate and subsequent cyclization afforded methyl [(6,8-dibromothieno[3,2-c]quinoline)]-2-carboxylate. The latter undergoes Suzuki-Miyaura cross-coupling with arylboronic acids to yield exclusively the corresponding alkyl [(6,8-diarylthieno[3,2-c]quinoline)]-2-carboxylates,. The cytotoxicity of the prepared compounds was evaluated against the human breast cancer cell line MCF-7 using the MTT assay. The effects of compounds 2, 3c and 4d on cell kinetics were further determined using the xCELLigence Real Time Cell Analysis (RTCA) system. In both the MTT assay and Real Time Cell Analysis, the compounds inhibited cancer cell growth in a dose- and time-dependent manner. Furthermore, on the basis of the calculated LC₅₀ values, the compounds compared favourably with nocodazole, a well-established anticancer drug.

(E)-1-[(5-chloro-3-methyl-1-phenyl-1H-pyrazol-4-yl)methylidene]-2-phenylhydrazine: sheets built from π-stacked hydrogen-bonded chains

The reaction between 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde and phenylhydrazine proceeds via condensation to provide the title compound, C17H15ClN4, (I), rather than via the alternative routes of simple nucleophilic substitution or cyclocondensation. With the exception of the phenyl group bonded directly to the pyrazole ring, the non-H atoms of (I) are nearly coplanar, with an r.m.s. deviation of 0.058 Å. The molecules are linked into C(7) chains by a single N-H···N hydrogen bond, and the chains are linked by π-π stacking interactions to form sheets.

Synthesis and photophysical properties of 2-aryl-6,8-bis(arylethenyl)-4-methoxyquinolines

Iodine-methanol mediated oxidative-aromatization of 2-aryl-6,8-dibromo-2,3-dihydroquinolin-4(1H)-ones afforded the corresponding 2-aryl-6,8-dibromo-4-methoxy-quinolines in high yield and purity. The isomeric 1-(2-amino-3,5-dibromophenyl)-3-aryl-2-propen-1-ones reacted with iodine in methanol afford in a single pot operation the corresponding 2-aryl-6,8-dibromo-4-methoxyquinoline (major) and 2-aryl-6,8-dibromoquinolin-4(1H)-one (minor) products that were separated in sequence by column chromatography on silica gel. Suzuki-Miyaura cross-coupling of the 6,8-dibromo-4-methoxyquinoline derivatives with excess arylvinylboronic acids afforded the corresponding 2-aryl-6,8-bis(2-arylethenyl)-4-methoxyquinolines. The absorption and fluorescence properties of these compounds were also determined.