Bromo Derivatives Research Articles

On the Halogenation of Tyrosine N‐Oxime Methyl Ester

Efficient syntheses of mono‐, di‐, and heterodihalogenated derivatives of tyrosine N‐oxime methyl ester are reported. Monohalogenation with N‐bromosuccinimide (NBS), N‐chlorosuccinimide (NCS) or N‐iodosuccinimide (NIS) was optimized by addition of acid to suppress dihalogenation, affording bromo, chloro, and iodo derivatives in 71%, 50‐53%, and 78‐80% yields, respectively. Homodihalogenation utilized a two‐step, one‐flask process via a spirocyclic intermediate, yielding dibromo, dichloro, and diiodo analogues, respectively (75‐76%, 54‐56%, 79‐80%). This strategy was extended to synthesize heterodihalogenated bromochloro, bromoiodo, and chloroiodo derivatives from monohalogenated analogues (50‐77%). Key to this approach was the formation of an oxidized spirocyclic intermediate using excess N‐halosuccinimide, followed by Na₂S₂O₄ reduction. This method ensures complete conversion and simplifies purification. Nine halogenated building blocks were prepared. These methods provide practical access to versatile precursors for natural product synthesis and derivatization, offering potential for diverse synthetic applications including regioselective palladium‐catalyzed couplings.

Total Synthesis of (+)-Dixiamycin C via a Late-Stage Ni(II)-Photoredox N-Arylation of Carbazoles.

We report the asymmetric total synthesis of dixiamycin C (1) through the shrewd alliance of the naturally occurring monomer xiamycin A methyl ester (5) and its bromo derivative (31) following a late-stage Buchwald-Macmillan's C-N bond formation via a photoredox electron transfer approach with a less reactive carbazole nitrogen. The key step in the synthesis of monomer xiamycin A methyl ester (5) involves Buchwald's Pd(II)-mediated aerobic dehydrogenative C-N bond formation, Beckmann rearrangement, and ipso-acetylation of an electron-rich aromatic ring of an abietane core.

Diastereoselective Palladaelectro-Catalyzed Construction of Bromomethyl Morpholines as Key Step To Access Morpholino Homonucleosides.

A synthetic protocol for the preparation of a new class of morpholino homonucleosides in enantiopure form starting from readily available 1,2-aminoalcohols or glycidol has been developed. Key intermediates of the synthetic sequence are 2-bromomethyl morpholines, diastereoselectively achieved from the corresponding alkenols by palladaelectro-catalyzed alkoxybromination of unactivated alkenes. The so obtained bromo derivatives are in turn susceptible to functionalization with nucleic bases for easy access to morpholino homonucleosides.

6-Bromo quinazoline derivatives as cytotoxic agents: design, synthesis, molecular docking and MD simulation

Based on unselectively, several side effects and drug resistance of available anticancer agents, the development and research for novel anticancer agents is necessary. In this study, a new series of quinazoline-4(3H)-one derivatives having a thiol group at position 2 of the quinazoline ring (8a-8 h) were designed and synthesized as potential anticancer agents. The Chemical structures of all compounds were characterized by 1H-NMR, 13C-NMR, and Mass spectroscopy. The antiproliferative activity of all derivatives were determined against two cancer cell lines (MCF-7 and SW480) and one normal cell lines (MRC-5) by the MTT method. Cisplatin, Erlotinib and Doxorubicin were used as positive controls. The results of in vitro screening showed that 8a with an aliphatic linker to SH group was the most potent compound with IC50 values of 15.85 ± 3.32 and 17.85 ± 0.92 µM against MCF-7 and SW480 cell lines, respectively. 8a indicated significantly better potency compared to Erlotinib in the MCF-7 cell line. The cytotoxic results obtained from testing compound 8a on the normal cell line, revealing an IC50 value of 84.20 ± 1.72 µM, provide compelling evidence of its selectivity in distinguishing between tumorigenic and non-tumorigenic cell lines. Structure–activity relationship indicated that the variation in the anticancer activities of quinazoline-4(3H)-one derivatives was affected by different substitutions on the SH position. Molecular docking and MD simulation were carried out for consideration of the binding affinity of compounds against EGFR and EGFR-mutated. The binding energy of compounds 8a and 8c were calculated at -6.7 and − 5.3 kcal.mol− 1, respectively. Compounds 8a and 8c were found to establish hydrogen bonds and some other important interactions with key residue. The DFT analysis was also performed at the B3LYP/6–31 + G(d, p) level for compounds 8a, 8c and Erlotinib. Compound 8a was thermodynamically more stable than 8c. Also, the calculated theoretical and experimental data for the IR spectrum were in agreement. The obtained results delineated that the 8a can be considered an appropriate pharmacophore to develop as an anti-proliferative agent.

BM7, a derivative of benzofuran, effectively fights cancer by promoting cancer cell apoptosis and impacting IL-6 levels

The BM7 compound, a bromo derivative of methyl 6-acetyl-5-hydroxy-2-methyl-1-benzofuran-3-carboxylate, was previously identified as cytotoxic to human leukaemia cells (K562 and HL60) and human cervical cancer (HeLa), while showing no toxicity to non-cancerous primary endothelial cells (HUVEC). In this study, we present the first demonstration of BM7's anticancer efficacy in vivo using a mouse chronic myeloid leukaemia xenograft model. Administered intraperitoneally in a mixture of 10% Solutol HS 15/10% ethanol, BM7 exhibited no visible toxicity and significantly reduced tumor weight, comparable to standard drugs imatinib and hydroxyurea. Further supporting its anticancer potential, a multi-model in vitro study involving seven human cancer cell lines revealed the most promising responses in colon cancer (SW480, SW620, HCT116), liver cancer (HEPG2), and breast adenocarcinoma (MDA-MB-231) cells. BM7 demonstrated multifaceted anticancer mechanisms, inducing apoptosis while elevating reactive oxygen species (ROS) levels and suppressing interleukin-6 (IL-6) release in these cell lines. These findings position BM7 as a candidate of significant interest for cancer therapy. Its ability to not only induce apoptosis but also modulate cellular processes such as ROS levels and immune responses, specifically IL-6 suppression, makes BM7 a versatile and promising agent for further exploration in the realm of cancer treatment.

Synthesis and Optical Property Modulation of Substituted [2.2]Paracylophanes through Through‐Space Conjugation

4,16‐para‐substituted [2.2]paracylophane with naphthalene (PCP⎼NAP), anthracene (PCP⎼ANTH), and tetraphenylethylene (PCP⎼TPE), as new through‐space conjugated dimers, were prepared by the Suzuki–Miyaura cross‐coupling reaction of 4,16‐diboryl[2.2]paracyclophane and the corresponding bromo derivative using Pd(PPh3)4 as a catalyst and KOH as a base. The synthesized compounds were fully characterized by NMR and HR‐MS, and their photophysical and electrochemical properties were studied. The photoluminescence quantum yield of PCP⎼NAP, PCP⎼ANTH were determined to be 0.21, 0.50 and for PCP⎼TPE in aggregated state 0.31, respectively. PCP⎼TPE exhibited aggregation‐induced emission characteristics when the water fraction was greater than 50% in THF/water mixtures. PCP⎼ANTH and PCP⎼TPE were also characterized by X‐ray crystallography, and single crystals of PCP⎼ANTH were obtained from the centrosymmetric monoclinic space group C2/c. A single crystal of PCP⎼TPE crystallizes in the centrosymmetric triclinic space group P⎼1, with one molecule residing at the inversion center. The observed properties of these π‐stacked dimers were compared with respect to through‐space conjugation and conjugation length in the structure.

Synthesis and Biofunctional Properties of NaBr/H2O2‐Induced Brominated Uracil Derivatives

AbstractBromouracil derivatives are synthesized using an environmentally acceptable bromination protocol involving NaBr as a promoter. A minimum of 1.5 equivalent NaBr was required to reach the maximum yield. The reactions were conducted in an acidic medium in the presence of H2O2 under ambient conditions. We successfully synthesized ten novel 5‐bromouracil derivatives available in our laboratory and characterized them using various spectroscopic methods such as 1H‐NMR, 13C‐NMR, and SC‐XRD. All the derivatives are screened for anti‐bacterial activities against gram‐positive and gram‐negative bacteria. In particular, compounds 5‐bromo‐4‐chloro‐6‐methylpyrimidin‐2‐amine and 5‐bromo‐6‐chloropyrimidine‐2,4‐diamine exhibited prominent antibacterial activity against gram‐negative E. coli with IC50 values of ~9.8 and ~5.7 μg/mL. The structural‐activity relationship revealed that the presence of the −NH2 group in both the bromo derivatives affirms improving activity. Molecular docking studies also supported the experimental result and showed good binding energy of −4.4 (2 a) and −4.8 (2 b) kcal/mol against E. coli primase.

On the Bromination of Diethyl 3,5-dimethyl-1H-pyrrole-2,4-dicarboxylate: the True Structure of the Halbig’s Product

Pyrrole and its derivatives have attracted the attention of researchers as promising objects of practical importance in various areas of human life. Focusing on Knorr pyrrole as the most readily available pyrrole derivative, our objective was to obtain its bromo derivatives, containing an allyl bromine atom followed by phosphorylation reactions. The reaction involving bromination was carried out with 2 mol of N-bromosuccinimide per 1 mol of Knorr pyrrole 1 in carbon tetrachloride. This reaction was initiated with azobis(isobutyronitrile) and carried out at a boiling point. In acetic acid, the bromination reaction was carried out at a temperature of 38-45°C with a molar ratio of Knorr pyrrole to bromine of 1:4 and another reaction was carried out at 40-50°C with a molar ratio of Knorr pyrrole to bromine of 1:5. The bromination reaction was also performed in chloroform at 27-30°C in the presence of catalytic amounts of aluminum chloride. The same crystalline product was obtained in all cases. X-ray diffraction analysis revealed that the single crystal structure is diethyl 5-(dibromomethyl)-3-methyl-2-oxo-2,3-dihydro-1H-pyrrole-3,4-dicarboxylate 5 with two bromine atoms. This composition is identical to that of the Halbig product. It was found that the bromination of Knorr pyrrole 1 occurs stepwise with excess N-bromosuccinimide and bromine, resulting in the unsaturated lactam 5, commonly known as Halbig’s product. The true structure of product 5 was determined.

Synthesis and evaluation of 2-phenylamino-1,4-naphthoquinones derivatives as potential hypoglycaemic agents.

Due to the severe side effects revealed by most of the currently used antidiabetic medicines, search for finding new and safe drugs to manage diabetes is continued. Naphthoquinones possessing strong antioxidant properties have been employed as candidates for diabetes therapy. Present study is aimed at finding the antioxidant and hypoglycaemic potential of some novel derivatives of 2-phenylamino-1,4-naphthoquinones (PAN) including chloro, nitro, methyl and bromo (5a-d) derivatives synthesized by single pot experiment. Product crystals were purified by TLC and characterized by FT-IR. The antioxidant potential of the compounds was assayed through DPPH radical scavenging and reducing power activities noted as UV-vis. absorbance. The DPPH assay has showed the powerful antioxidant activity of nitro and bromo derivatives, while the nitro derivative showed the significant reduction potential towards FRAP assay. Hypoglycaemic potential of the compounds was studied in rat animal model. All synthesized compounds revealed better hypoglycaemic activity; however, the chloro-derivative exhibited the more potent hypoglycaemic activity showing about 43% reduction in the mean blood glucose levels of the treated animals. As the bioreduction of naphthoquinones may be influenced by changing its redox properties, it has been noticed that the e-donating resonance effect (+R) of 'chloro' group has shown the significant effects on biological activity through stabalization of its imine form which limits the potential of generation of free radicals during bioreduction of quinones and thus has been proposed as the reason of its hypoglycaemic activity. Future studies employing the properties of e-donating groups of PAN may optimize the drug-receptor interaction for better drug designing and drug development strategies against diabetes and also for the clinical trials.

New pyrazole-pyridazine hybrids as selective COX-2 inhibitors: design, synthesis, molecular docking, in silico studies and investigation of their anti-inflammatory potential by evaluation of TNF-α, IL-6, PGE-2 and NO in LPS-induced RAW264.7 macrophages.

Hybrid-based design has gained significant interest in the development of novel active substances with anti-inflammatory properties. In this study, two series of new pyrazole-pyridazine-based hybrids, 5a-f and 6a-f, were designed and synthesized. Molecules containing pyrazole and pyridazine pharmacophores in a single molecule, each with a unique mechanism of action and different pharmacological characteristics, are believed to exert higher biological activity. The cell viability of all compounds was evaluated using MTT assay in LPS-induced RAW264.7 macrophages. In vitro COX-1 and COX-2 inhibition assays were performed for the investigation of the anti-inflammatory activity of target compounds. Trimethoxy derivatives 5f and 6f were the most active candidates, demonstrating higher COX-2 inhibitory action than celecoxib, with IC50 values of 1.50 and 1.15 μM, respectively. Bromo derivative 6e demonstrated a COX-2 inhibitory activity comparable to celecoxib. Further, the ability of compounds 5f, 6e, and 6f to inhibit the generation of specific pro-inflammatory cytokines and mediators, including nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and prostaglandin-E2 (PGE-2), in RAW264.7 macrophages stimulated by LPS was also estimated. Compounds 5f and 6f demonstrated the most potent activity. Morover, according to the investigation using molecular modeling studies, derivatives 5f and 6f showed respectable binding affinity towards the COX-2 active site compared to the reference ligand. Moreover, the ADME parameters, physicochemical characteristics, pharmacokinetic characteristics, and l of the most potent compounds were also computed.

An efficient and high yield protocol for the synthesis of 1,6,9,12-tetrabromo-3,4,9,10-tetracarboxylic acid perylenebisimides and anhydrides using N-bromosuccinamide

Due to the importance of tetrabromo perylene bisimides, in this letter, we report an efficient protocol for the synthesis of various bromo derivatives particularly, 1,6,7,12-tetrabromoperylene-3,4,9,10-tetracarboxylic acid bisimides (perylene bisimides, or PBIs) in high yield with short reaction time using N-bromosuccinimide (NBS) in Conc. H2SO4. By controlling the reaction time, mono, di, tri, and tetrabromo PBI derivatives could be isolated in moderate to good yield. Under the same condition, perylenebisanhydride brominated with NBS afforded tetrabromoperylenebisanhydride quantitatively in a short reaction time.

Synthesis and photothermal conversion properties of sandwich N-fused porphyrin rhodium-μ-dichloride dimer complexes: π-extended analog of pentamethylcyclopentadienyl dirhodium(III)-μ-dichloride dimer

Anionic cyclopentadienyl (Cp) and its pentamethyl-substituted derivative (Cp*) serve as crucial ligands for creating stable π-coordinated materials, including catalysts. From a structural perspective, the π-extended analog of Cp, known as an N-fused porphyrin (NFP), is recognized as an intriguing 18π aromatic chromophore, offering near-infrared (NIR) optical properties that can be fine-tuned through metal complexation. When coordinated with rhodium at the central NFP core, it forms a sandwich binuclear rhodium(III) complex along with terminal and bridging chloride ligands, denoted as Rh-1, and its bromo derivative, Rh-1-Br. In contrast to the bis-NFP complex of iron(II) reported previously by our team, both Rh-1 and Rh-1-Br complexes exhibit strong NIR optical properties and narrow HOMO-LUMO energy gaps, attributed to minimal orbital interactions between the two co-facial NFP ligands. Leveraging these NIR absorption properties, we assessed the photothermal conversion properties of Rh-1 and ligand 1, revealing high conversion efficiency. This suggests their potential application as photothermal agents for use in photothermal therapy.

Synthesis and some properties of new bromo derivatives of isobornylphenols

We determined optimal conditions to brominate various isobornyl phenols with molecular bromine and N -bromosuccinimide as well as studied oxidative bromination of them with KBr-Oxone®. For obtained brominated derivatives, as isobornylphenols, an assessment of erythrotoxicity, membrane-protective and antioxidant activity was performed using in vitro models. Halogen derivatives of isobornylphenols containing a bromine atom in the para -position and an alkyl fragment in the ortho -position relative to the phenolic hydroxyl group showed high antioxidant activity in the model of oxidative hemolysis of erythrocytes.

Synthesis and Some Properties of New Bromo Derivatives of Isobornylphenols

Synthesis and Some Properties of New Bromo Derivatives of Isobornylphenols

Reduction of nicotine and ethanol intake in alcohol-preferring (UChB) female rats by the α4β2 nicotinic acetylcholine receptor partial agonists 5-bromocytisine and cytisine

RationaleNeuronal nicotinic acetylcholine receptors (nAChRs) are implicated in the reinforcing effects of nicotine and ethanol. Previous studies have shown that cytisine and its 5-bromo derivative are partial agonists at the α4β2 nAChRs and that the parent molecule cytisine is effective in reducing both nicotine- and ethanol-self-administration in rats. However, whether 5-bromocytisine affects nicotine or ethanol self-administration was unknown. ObjectivesThe present study compared the effects of 5-bromocytisine and cytisine on nicotine self-administration and further assessed the effect of daily drug injection on voluntary ethanol consumption in alcohol-preferring female rats. Animals were administered a 1.5mg/kg i.p. dose of 5-bromocytisine or cytisine every day for 15–16 days. ResultsThe initial efficacy of 5-bromocytisine and cytisine in reducing nicotine intake was similar (−80%) while for voluntary ethanol intake 5-bromocytisine was a superior inhibitor over cytisine (−78% and −40% respectively). The efficacy of cytisine began to diminish after 10 days of daily administration, which was attributed to tolerance development to its inhibitory effects both on nicotine and ethanol self-administration. Tolerance did not develop for 5-bromocytisine. Conclusion5-Bromocytisine, a weaker α4β2 nAChR partial agonist than cytisine, also produces a sustained inhibition of both nicotine and ethanol self-administration, and unlike cytisine, it does not develop tolerance.

Synthesis and Evaluation of Thioamide and Bromo Derivatives of 1,3-Diphenylpropane-1,3-dione as 5α-Reductase Inhibitors.

1,3-Diphenylpropane-1,3-dione (1) is an acetylacetone β-diketone in which both of the methyl groups have been replaced with phenyl groups. It is a component of licorice root extract (Glycyrrhiza glabra) and has anti-mutagenic and anti-cancer properties. It functions as a metabolite, an anti-mutagen, and an anti-neoplastic agent. It is an aromatic ketone and a β-diketone. 1,3-Diphenylpropane-1,3-dione (1) is primarily used in PVC hard and soft materials, including plates, films, profiles, pipes, and fittings. This research aims to examine the utility of 1,3-diphenylpropane-1,3-dione (1) for the synthesis of a variety of new heterocyclic compounds, such as thioamide, thiazolidine, thiophene-2-carbonitrile, phenylthiazole, thiadiazole-2-carboxylate, 1,3,4-thiadiazole derivatives, 2-bromo-1,3-diphenylpropane-1,3-dione, new substituted benzo[1,4]thiazines, phenylquinoxalines, and imidazo[1,2-b][1,2,4]triazole derivatives of potential biological activity Methods: 1,3-Diphenylpropane-1,3-dione (1) was used as a starting compound for the synthesis of 3-oxo-N,3-diphenyl-2-(phenylcarbonyl)propanethioamide (3) and 2-bromo-1,3-diphenylpropane-1,3-dione (25), which can be used for further preparations. The 5α-reductase inhibitor activity of some of the synthesized compounds was also tested in vivo; the ED50 and LD50 data were established, Results: Using IR, 1H-NMR, mass spectroscopy, and elemental analysis, the structures of all produced compounds were elucidated. Some of these prepared compounds were reported as 5α-reductase inhibitors. New heterocyclic compounds can be formed via 1,3-diphenylpropane-1,3-dione (1), and some of these compounds can act as 5α-reductase inhibitors.

Inhibitory effects of sulfenimides on human and bovine carbonic anhydrase enzymes

A series of sulfenimide derivatives (1a-i) were investigated as inhibitors of human (hCA-I, hCA-II) and bovine (bCA) carbonic anhydrase enzymes. The compounds were synthesised by the reaction of substituted thiophenols with phthalimide by means of an effective, simple and eco-friendly method and the structures were confirmed by IR, 1H NMR, 13C NMR, MS and elemental analysis. All derivatives except for the methyl derivative (1b) exhibited effective inhibitory action at low micromolar concentrations on human isoforms, but only four derivatives (1e, 1f, 1h, 1i) inhibited the bovine enzyme. The bromo derivative (1f) was found to be strongest inhibitor of all three enzymes with KI values of 0.023, 0.044 and 20.57 µM for hCA-I, hCA-II and bCA, respectively. Results of our study will make valuable contributions to carbonic anhydrase inhibition studies for further investigations since inhibitors of this enzyme are important molecules for medicinal chemistry.

Anti-proliferative activity, molecular docking study of novel synthesized ethoxyphenylbenzene sulfonamide with computational calculations

In this elucidation, we synthesized novel benzenesulfonamide and examined its biological evaluation. Firstly, the reaction of 2-allylphenol(1) with 1,2-dibromoethane(2) to afford the corresponding 1-allyl-2-(2-bromoethoxy)benzene(3) which easily isomerized with PdCl2 to afford the (E)-1-(2-bromoethoxy)-2-(prop-1-en-1-yl)benzene (4). Moreover, using the Williamson reaction of compound 4 with o-acetamidophenol gives different acetamide derivatives 6. Furthermore, the acid hydrolysis of compound 6 to afford the corresponding 2-[2-(2-Propenyl-phenoxy)-ethoxy]-phenylamine (8) which reacts with p-toluene sulphonyl chloride to afford the corresponding (E)-4-methyl-N-(2-(2-(2-(prop-1-en-1-yl)phenoxy)ethoxy)phenyl) benzene sulfonamide (10). The reactivity of compound 10 with bromo derivatives utilized microwave irradiation at 100°C to afford the corresponding benzenesulfonamide derivatives 11a-c. The benzenesulfonamide derivatives 11a-c exhibited in-vitro antitumor activity against HepG2 and MCF-7 tumor cells. Additionally, molecular docking simulation on these benzenesulfonamides with (PDB ID: 4hdq) and (PDB ID: 5H38) proteins to know their hydrogen bond interaction with different amino acids and showed the excellent binding affinity energy of compound 11a with -12.621, -10.621kcal/mol and the shortage bond length with 1.32-2.62 Å and attached mostly with different amino acids and this stability revealed to delocalization of benzene rind which attached with two moieties. Furthermore, the computational calculation studies of synthesized compounds were optimized using the DFT/ B3LYP/6-311G(d) basis set to confirm stabilities through physical descriptors, MEP, ESP, and band energy gap.

How to Protect ortho-Carborane from Decapitation—Practical Synthesis of 3,6-Dihalogen Derivatives 3,6-X2-1,2-C2B10H10 (X = Cl, Br, I)

The 3-halogen and 3,6-dihalogen derivatives of ortho-carborane 3-X-1,2-C2B10H11 and 3,6-X2-1,2-C2B10H10 (X = Cl, Br, I) were prepared by Cu-assisted halodeboronation of the corresponding pinacolborate derivatives 3-Bpin-1,2-C2B10H11 and 3,6-(Bpin)2-1,2-C2B10H10. It was shown that decapitation of 3-Cl-1,2-C2B10H11, similarly to the corresponding bromo and iodo derivatives, proceeds regioselectively with the retention of the B-Cl bond. Crystal structures of 3,6-Cl2-1,2-C2B10H10 and Cs [3-Cl-7,8-C2B9H11] were determined by single crystal X-ray diffraction.

Synthesis of novel benzothiophene derivatives as protectors against cranial irradiation-induced neuroinflammation.

Aim: Cranial irradiation results in many deleterious effects to normal tissues, including neuroinflammation. There is a need to explore radioprotective agents that could be safely used to ameliorate these effects. Method: Nine novel benzothiophene derivatives bearing pyrimidinone, pyrazolidinone, triazole and other active moieties were synthesized andevaluated as antioxidants in an in vitro screening experiment. The most potent compounds were then tested as protectors against radiation-induced neuroinflammation and oxidative stress in rat brains following cranial irradiation. Results: The most potent antioxidant compounds were compounds 3-5 and 10 . P-fluro,p- bromo and pyrido benzothiophene derivatives offered good antioxidant and anti-inflammatory effects. Conclusion: Compounds 3-5 may be introduced as nontoxic candidates for adjuvant therapeutic protocols used in head and neck tumorradiotherapeutic management.