Study of the Toxicity of 1-Bromo-3-Chloro-5,5-Dimethylhydantoin to Zebrafish

Objective 1-Bromo-3-chloro-5,5-dimethylhydantoin （BCDMH） is a solid oxidizing biocide for water disinfection.The objective of this study was to investigate the toxic effect of BCDMH on zebrafish.Methods The developmental toxicity of BCDMH on zebrafish embryos and the dose-effect relationship was determined.The effect of BCDMH exposure on histopathology and tissue antioxidant activity of adult zebrafish were observed over time.Results Exposure to 4 mg/L BCDMH post-fertilization was sufficient to induce a number of developmental malformations,such as edema,axial malformations,and reductions in heart rate and hatching rate.The no observable effects concentration of BCDMH on zebrafish embryo was 0.5 mg/L.After 96 h exposure,the 50% lethal concentration （95% confidence interval （CI）） of BCDMH on zebrafish embryo was 8.10 mg/L （6.15-11.16 mg/L）.The 50% inhibitory concentration （95% CI） of BCDMH on hatching rate was 7.37 mg/L （6.33-8.35 mg/L）.Histopathology showed two types of responses induced by BCDMH,defensive and compensatory.The extreme responses were marked hyperplasia of the gill epithelium with lamellar fusion and epidermal peeling.The histopathologic changes in the gills after 10 days exposure were accompanied by significantly higher catalase activity and lipid peroxidation.Conclusion These results have important implications for studies on the toxicity and use of BCDMH and its analogs.

Synthesis of 1-Bromo-3-methoxy-4-propoxy-5-iodobenzene——A Novel Efficient Process for the Synthesis of Brominated Aromatic Compound

The reaction of aromatic carboxylic acid with oxalyl chloride gives rise to the corres- ponding acid chloride which without purification is treated with the sodium salt of mercapto- pyridine oxide in the presence of 2,2-azo-bisisobutyronitrile (AIBN), radical initiator to give a brominated aromatic compound. After etherification and oxidation, 5-iodovaniline was converted to trisubstituted benzene carboxylic acid which give 1-bromo-3-methoxy-4-propoxy-5-iodo- benzene by this new brominating process with a yield of 74 %.

Synthesis and Anti-influenza Virus Activity of Ethyl 6-Bromo-5-hydroxyindole-3-carboxylate Derivatives

A series of ethyl 6-bromo-5-hydroxyindole-3-carboxylate derivatives were synthesized and their in vitro anti-influenza virus activity was evaluated. All the compounds were characterized by 1H NMR and MS.

Synthesis and Crystal Structure of Methyl 3-(5-Bromo-1-ethyl-1H-indole-3-carbonyl)aminopropionate

Methyl 3-（5-bromo-l-ethyl-lH-indole-3-carbonyl）aminopropionate has been synthesized by the acylation of 5-bromo-3-trichloroacetylindole with β-alanine methyl ester, followed by alkylation with ethyl iodide, in 82.6% yield. Its crystal structure was gotten and determined by X-ray diffraction method. The crystal is of monoclinic, space group P2/c with a = 11.7927（8）, b = 14.9342（8）, c = 9.0060（5） A, β = 101.558（6）°, V = 1553.93（16） A3, Z = 4, Dc= 1.510 g/cm3, 2 = 0.71073 A,μ（MoKa） = 2.656 mm-1, Mr = 353.22 and F（000） = 720. The structure was refined to R = 0.0401 and wR = 0.0825 for 1704 observed reflections with I 〉 2σ（I）. In the crystal structure, intermolecular N（2）-H（2）...O（1） hydrogen bond and weak intermolecular bonds （C（1）-H（1）...O（1） and C（10）-H（10B）-O（2）） are formed, and π-π stacking also exists.

Synthesis, Crystal Structure and Biological Activities of 3-Bromo-5-(4-chlorophenyl)-4-cyanopyrrole-N,N-dimethyl-2-carboxamide

The title compound 3-bromo-5-（4-chlorophenyl）-4-cyanopyrrole-N,N-dimethyl-2-amide（3） was synthesized with 4-bromo-2-（4-chlorophenyl）-5-（trifluoromethyl）-1H-pyrrole-3-carbonitrile（1） and N,N-dimethylformamide（2） by the α-C acylation reaction catalyzed by potassium t-butoxide, and characterized by IR, 1H-NMR and X-ray single-crystal diffraction. It crystallizes in monoclinic, space group P2（1/n）with a = 12.789（2）, b = 13.783（2）, c = 17.980（3） °, β = 109.230（3）°, V = 2992.5 A3, Mr = 352.62, Dc = 1.565 mg/m3, Z = 8, m = 2.924 mm-1, F（000） = 1408, the final R = 0.0424 and w R = 0.0973 for 3518 observed reflections with I 〉 2σ（I）. A total of 23559 reflections were collected, of which 6242 were independent（Rint = 0.0566）. The insecticidal, herbicidal and antibacterial activities of compound 3 were determined, and the experimental results showed that the mortality of 3 at the concentration of 100 ppm on the Fipronil against Linnaeus was 76.6%, the growth inhibition rate of 3 against Cynodon Dactylon under the condition of 100 ppm was 35.8% and the inhibitory activity of 3 at the concentration of 25 ppm against Fusarium graminearum reached 50.9%. Hence, the title compound has the value of further research and application prospect.

Theoretical Study on the Reaction Mechanism of 2-Methoxybenzaldehyde,4-Bromo-indanone,Malononitrile and Ammonium Acetate One-pot to Form 6-(2-Methoxyphenyl)-2-amino-6-bromo-5H-indeno[1,2-b]pyridine-3-carbonitrile

The reaction mechanism of 2-methoxybenzaldehyde, 4-bromo-indanone, malononitrile and ammonium acetate one-pot to form 6-（2-methoxyphenyl）-2-amino-6-bromo-5 Hindeno[1,2-b]pyridine-3-carbonitrile was studied by density functional theory. The geometries of the reactants, transition states, intermediates and products were optimized at the PW91/DNP level. Vibration analysis was carried out to confirm the transition state structure. Reaction pathways were investigated in this study. The result indicates that the reaction Re→ TSB1→IMB1→ TSB2→ IMB2→TSB3→IMB3→TSB4→IMB4→TSB5→IMB5→TSB6→IMB6→TSB7→IMB7→ TSB8→IMB8→TSB9→IMB9→P2 is the main pathway, the activation energy of which is the lowest. The dominant product predicted theoretically is in agreement with the experiment results.

Synthesis and Crystal Structure of 4-Bromo-5-ethoxy-3-methyl-5- (naphthalen-1-yl)-1-tosyl-1H-pyrrol-2(5H)-one

The title compound 4-bromo-5-ethoxy-3-methyl-5-（naphthalen-l-yl）-l-tosyl-lH- pyrrol-2（5H）-one 1 （C24H22BrNO4S, Mr = 500.40） has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/n with a = 8.8562（15）, b = 18.118（3）, c = 14.055（2）A, β = 99.855（3）^o, V= 2221.9（6）A3, Z = 4, Dc = 1.496 g/cm^3,μ= 1.975 mm^-1, 2 = 0.71073A, F（000） = 1024, R = 0.0607 and wR = 0.1371.

A New Poly Brominated Dibenzylphenol from Rhodomela confervoides

A new poly brominated dibenzylphenol named as rhodomevoidin was isolated from Rhodomela confervoides. Its structrue was elucidated as 3-bromo-4, 5-bis (2, 3-dibromo-4, 5- dihydroxybenzyl)pyrocatechol by spectroscopic methods including IR, HRFABMS, 1D and 2D NMR techniques.

Competition of Aromatic Bromination and Nitration in Concentrated Sulfuric Acid

Composition of bromine and nitric acid in concentrated sulfuric acid is effective for bromination of strongly deactivated aromatic compounds and for nitration and bromination of moderately deactivated compounds in one stage. The question why brominating agent is more reactive than nitrating agent in relation to strongly deactivated aromatic compounds and is less reactive in relation to moderate deactivated ones is discussed.

Preconcentration/Separation of Some Metal Ions Using Sodium Dodecyl Sulfate Coated Alumina Modified with Bis（5-bromo- 2-hydroxy-benzaldehyde）-2-methyl-1,5-pentane Diimine （BBHBPDI） Prior to Their Flame-AAS Determination

Preconcentration/separation of Co（II）, Fe（III）, Pb（II）, Cr（IIl）, Cu（II） and Cd（II） ions using bis（5-bromo- 2-hydroxy-benzaldehyde）-2-methy1-1,5-pentane diimine （BBHBPDI） on SDS coated alumina has been reported. The influences of the analytical parameters including pH, ligand and SDS amount, type and concentration of eluent and sample volume on metal ions recoveries were investigated. At optimum values of all variables the relative standard deviation are between 2.5-2.7 and preconcentration factor was 375, while recoveries for all understudy metal ions are higher than 95%, determination limits are between 1.5-2.7. The method has been successfully applied to determination of Co（II）, Fe（III）, Pb（II）, Cr（III）, Cu（II） and Cd（II） ions content in some real samples.

Aromatic Bromination in Concentrated Nitric Acid

Action of bromine in concentrated nitric acid allows carrying out mono- and polybromination of moderately deactivated aromatic compounds. 4-Chloronitrobenzene and isophthalic acid turnes into 3-bromo-4-chloronitrobenzene and 5-bromoisophthalic acid at reaction with bromine in concentrated nitric acid at 20°C whereas in absence of bromine in the same conditions 4-chloro-1, 3-dinitrobenzene and 5-nitroisophthalic acid are formed accordingly. Presence of bromine in concentrated nitric acid changes nitrating capacity to brominating one. Terephthalic acid and phthalic anhydride at heating with bromine in concentrated nitric acid can be transformed to appropriating tetrabromo substituted compounds.

Synthesis of spiro-cyclopropane derivatives containing multiple chiral centers

Tandem asymmetric double Michael addition/internal nucleophilic substitution of the novel chiral source, 5-(l-menthyloxy)-3-bromo-2(5H)-furanone with nucleophilic alcohol compounds has been investigated. The tandem asymmetric reaction can afford four new stereogenic centers with one reaction and give optically pure spiro-cyclopropane derivatives 5a--5d which are difficult to obtain by routine methods. The synthetic method for 5a--5d was studied in detail and the new compounds were identified on the basis of their analytical data and spectroscopic data, such as [α]^(20),IR,~1H NMR,^(13)C NMR, MS and elementary analysis. The absolute configuration of the sprio [5-l-menthyloxy-3-bromo butyrolactocyclopropane-3″, 3′(4′-methyloxy-5′-menthyloxybutyrolactone)] (5a) was established by X-ray crystallography. The work can provide important synthetic strategy in synthesis of some new optically active spiro-cyclopropane analogues and some biologically active molecules with complex structure.