Continuous, homogeneous and rapid synthesis of 4-bromo-3-methylanisole in a modular microreaction system

4-Bromo-3-methylanisole is mainly used to synthesize black fluorane dye(2-anilino-3-methyl-6-dibutylaminofluorane, ODB-2), which is one of the most important heat and pressure-sensitive dyes in the manufacture of thermal papers. Compared to the industrial heterogeneous batch process, a continuous homogeneous bromination technology in a modular microreaction system has been developed, and 4-bromo-3-methylanisole has been successfully prepared through high-selective mono-bromination of 3-methylanisole with Br2 solution in CHCl3. In optimal conditions, the content of bis-brominated byproducts can be controlled less than 0.5%,which is superior to the industrial standard with 99.5% 3-methylanisole conversion at very short residence time and mild reaction temperature.

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 %.

Room Temperature Phosphorescence of 1-Bromo-4-(bromoacetyl) naphthalene Induced by Sodium Deoxycholate

Sodium deoxycholate (NaDOC) could induce 1-bromo-4-(bromoacetyl) naphthalene (BBAN) to emit strong room temperature phosphorescence (RTP). Measurements of phosphore- scence spectra, peak intensity and polarization were used to investigate the solubilization of BBAN as a function of NaDOC concentration.

Synthesis,Crystal Structure and Anticancer Property of (Z)-N-(4-Bromo-5-ethoxy-3,5-dimethyl-furan-2(5H)-ylidene)-4-methylbenzenesulfonamide

The novel title compound（Z）-N-（4-bromo-5-ethoxy-3,5-dimethylfuran-2（5H）-yli-dene）-4-methylbenzenesulfonamide 1（C15H18BrNO4S） has been unexpectedly synthesized by the aminohalogenation reaction of ethyl 2-methylpenta-2,3-dienoate with TsNBr2,and characterized by mp,IR,1H NMR,EIMS,ESIHRMS and single-crystal X-ray diffraction.It crystallizes in mono-clinic,space group P21/c with a = 11.714（5）,b = 14.106（5）,c = 10.402（4） ,β = 97.298（8）°,V = 1704.9（12） 3,Mr = 388.27,Z = 4,Dc = 1.513 g/cm3,μ（MoKα） = 2.549 mm-1,F（000） = 792,the final R = 0.033 and wR = 0.062 for 3098 observed reflections（Ⅰ 〉 2σ（Ⅰ））.

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.

Coupling reaction mechanism of 2-(2-bromo-4-fluorophenyl)-1-cyclohexen-1-yl trifluoromethane-sulfonate

The detailed mechanism of CuI-catalyzed C-O intramolecular coupling reaction of 2-(2-bromo-4-fluoro-phenyl)-1-cyclohexen-1-yl trifluoromethane–sulfonate was studied with the density functional theory(DFT). The geometries of the reactants,transition states, intermediates and products were optimized at the B3LYP/6-31+G* level. Meanwhile, the single point energy of species involved in gas and solvent at B3LYP/6-311+G* level was individually investigated. Polarizable continuum models(PCM)were applied to the dioxane and water solutions at the same level, respectively. Results show that the rate-limiting step, M3→TS3,does not change in different solutions. However, the activation energy in a dioxane solution is lower than that in water, which explains the previous experimental results. Compared with the non-catalyzed reaction process, the activation energy of the ratelimiting step is reduced by 56.53 kJ mol-1 in gas and 44.84 kJ mol 1in solvent, demonstrating a high catalytic efficiency of CuI.

Synthesis, Structure and Geometrical Calculation of a Novel Co-crystal of {[4-Bromo-2-(benzimidazol-2-yl)phenolato][2-(1-butylbenzimidazol-2-yl)phenolato]zinc(Ⅱ)] and Bis[μ-2-(1-butylbenzimidazol-2-yl)phenolato]-1κN^3:2κO;1κO:2κN^3-bis{[2-(1-butylbe

The title compound has been synthesized and characterized crystallographicaUy. It is a co-crystal consisting of two different neutral zinc（H） complexes with Hbpbm （Hbpbm = 4- bromo-2-（benzimidazol-2-yl）phenol） and Hnpbm （Hnpbm = 2-（1-butylbenzimidazol-2-yl）phenol）. One is a monomeric mixed-ligand complex of [Zn（bpbm）（npbm）] 1 and the other a dimer of [Zn2（npbm）4] 2 with their ratio of 2：1. Thus the overall formula for the title compound is 21.2. Adjacent 1 and 2 are connected to each other by intermolecular hydrogen bonding interactions in the lattice. The crystal data： monoclinic, space group P21/c, a = 15.0141（12）, b = 20.9941（17）, c = 18.4686（15） A, β = 97.445（2）°, V = 5772.4（8） A^3, Mr= 2429.68, Z = 2, Dc = 1.398 g/cm^3,μ = 1.579 -1 mm , F（000） = 2504, R = 0.0637 and wR = 0.1771 for 6464 observed reflections （I 〉 2σ（I））. The geometrical structure for 1 has also been theoretically optimized and compared with the experimental one.

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.

Synthesis and Crystal Structure of N1-(2-(4-Bromo-2-nitrophenoxy)-2-dimethyl acyloxymethyl)-5-fluorouracil

The title compound N1-（2-（4-bromo-2-nitrophenoxy）-2-dimethyl acyloxymethyl）-5-fluorouracil（C15H13BrFN3O7, Mr = 446.19） was synthesized and structurally characterized by ^1H-NMR, -（13）C-NMR, ESI-MS and single-crystal X-ray diffraction. The compound crystallizes in triclinic, space group P1, with a = 8.3325（6）, b = 10.1808（13）, c = 11.8194（16） A, α = 73.194（12）, β= 72.351（9）, γ = 89.509（8）o, V = 911.2（2） A^3, Z = 2, T = 300.79（10） K, μ（Cu Kα） = 3.578 mm^-1, Dc = 1.626 g/cm3, F（000） = 448.0, GOF = 1.060, 5723 reflections measured（8.232≤2θ≤139.592°）, 3339 unique（Rint = 0.0184, Rsigma = 0.0254） which were used in all calculations. The final R = 0.0517（I 〉 2s（I）） and wR = 0.1494（all data）. Hydrogen bonds and π-π interactions together stabilize the structure of the molecule. The preliminary biological test shows that the title compound has good antitumor activity against A549 in vitro and lower toxicity to normal cells.

A selective detection of fluoride ions in DMSO by fluorescent and colorimetry competition assays based on 4-bromo-2,6-bis-(hydroxymethyl)phenol

A novel and very simple colorimetric and fluorometric method for selectively sensing F^- was proposed based on 4-bromo-2,6- bis（hydroxymethyl）phenol（BBHMP）,which is a simple and available phenolic receptor the absence of any special chromophoric function and with over wide range of anions（Cl^-,Br^-,I^-,AcO^-,HSO4^-,NO3^- and BzO^-） in DMSO media.The colorimetric method is described for naked-eye detection of F^- in the presence of the BBHMP.The BBHMP was found to show selective and sensitive fluorescence quenching response toward fluoride over than Cl^-,Br^-,I^-,AcO^-,HSO4^-,NO3^- and BzO^-.

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.

Synthesis,Crystal Structure and DNA-binding Properties of a New Copper(Ⅱ) Schiff Base Complex

A new asymmetric bidentate copper（Ⅱ） complex,CuL 2（HL=2-（（E）-（4-bromophenylimino）methyl）-6-bromo-4-chlorophenol）,has been synthesized and characterized by elemental analyses and single-crystal X-ray diffraction.The complex crystallizes in the monoclinic space group P2 1 /c with a=11.218（3）,b=9.355（3）,c=13.449（4）,β=108.722（4）°,V=1336.8（6）3,Z=2,Dc=2.008 g/cm 3,μ（MoKα）=7.024 mm-1,F（000）=806,S=0.999,the final R=0.0342 and wR=0.0641for2611observed reflections （I〉2σ（I））.The central copper（Ⅱ） is four-coordinate and bonds to two nitrogen and two oxygen atoms from two Schiff base ligands.The complex is linked into a two-dimensional supramolecular structure by weak intermolecular interactions.In addition,DNA-binding properties of the metal complex were investigated using spectrometric titrations and viscosity measurements.The results show that the complex binds with calf-thymus DNA（CT-DNA）,presumably via a partial intercalative mode.The intrinsic binding constant of the Cu（Ⅱ） complex with DNA is 7.335×10 3 M-1.

Synthesis of(R)-(−)-Muscone from(R)-5-Bromo-4-methylpentanoate:A Chiron Approach

A synthesis of(R)-muscone(1),a valuable musk odorant,is presented.The stereogenic center of muscone was introduced from methyl(R)-5-bromo-4-methylpentanoate(5),a chiral pool molecule developed in our group,and the macrocyclic ring was prepared by ring-closing metathesis(RCM)reaction.

Synthesis of 6-Alkylidene-5,6-dihydro-4H-1,3-thiazine Derivatives via the Cyclization of N-3-Bromo-3-alkenylthioamides

By the treatment of N-3-bromo-3-alkenylthioamides with sodium hydroxide in DMF-H2O in the presence of tetra-butylammonium bromide,series of 6-alkylidene-5,6-dihydro-4H-1,3-thiazine derivatives were prepared in moderate to good yields.The cyclization is supposed to proceed via both the intramolecular vinylic nucleophilic substitution and the elimination-addition mechanisms(formation of acetylenic intermediates)in a competitive manner.

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.

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.

Facile One-pot Synthesis of Ethyl 3-Alkyl-4-hydroxy-2-thioxothiazolidine-4-carboxylates

Ethyl 3-alkyl-4-hydroxy-2-thioxothiazolidine-4-carboxylates were prepared in excellent yields from the reaction of corresponding primary amines with carbon disulfide and ethyl 3-bromo-2-oxopropanoate in the presence of anhydrous potassium phosphate in DMF at room temperature within 1 h. The structures of the highly functionalized products were corroborated spectroscopically （IR, ^1H NMR, ^13C NMR, EI-MS） and by elemental analyses. A plausible mechanism for such type of cyclization was proposed.

A Green and Novel Method for the Synthesis of 4,4-Difluoro-3- oxo-2-（triphenylphosphoranylidene） 5-Lactones by Reformatsky Reaction

In the presence of In/CuCl, ethyl 4-bromo-4,4-difluoro-3-oxo-2-（triphenylphosphoranylidene）butanoate reacted with various aldehydes in aqueous medium at room temperature to give the a,a-difluorinated β-hydroxy carbonyl compounds. Furthermore, treating Reformatsky addition compounds with 1 equiv, of sodium hydroxide in the mixture of tetrahydrofuran and water afforded gem-difluoromethylenated 2-triphenylphosphoranylidene δ-lactones in excellent yields.

Synthesis, Structure and Photophysical Properties of Silole-Oxadiazole Copolymers

A new conjugated copolymer （PTST-DyOXD） derived from 1,1-dimethyl-3,4-diphenyl-2,5-bis（5-bromo-2- thienyl）-silole （TST） and 2,5-bis（4-ethynylphenyl）-l,3,4-oxadiazole （DyOXD） was synthesized by Pd（0）-catalyzed Sonogashira coupling reaction. For comparison, another copolymer without acetenyl group （PTST-OXD） was also synthesized by Pd（0）-catalyzed Suzuki coupling reaction. Chemical structures and optoelectronic properties of the copolymers were characterized by IH NMR, 13C NMR, IR, UV-vis absorption, photoluminescence and cyclic voltammetry. The number-average molecular weight （Mn） is 4010 Da for PTST-DyOXD and 3890 Da for PTST-OXD, respectively. The thermogravimetric analysis （TGA） measurements show that they have good thermal stability with decomposition temperature at 312 and 318 ~C, respectively. The optical band gap is 2.21 eV for PTST-DyOXD and 2.10 eV for PTST-OXD based on the absorption onset. CV analysis revealed the LUMO level of PTST-DyOXD is -3.04 eV, lower than that of PTST-OXD （about -2.89 eV）, which is attributed to the introduction of acetylene group in PTST-DyOXD, increasing the system of the conjugate chain length.