- Synthesis method of benzidine compound
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The invention discloses a synthesis method of a benzidine compound. A compound (I) is subjected to catalytic coupling reaction to obtain a compound (II); the compound (II) is subjected to alkaline oracidic hydrolysis reaction process to obtain a compound (III); the compound (III) is subjected to catalytic hydrogenation reduction reaction in an organic system to obtain a benzidine compound (V); orthe compound (II) is subjected to catalytic hydrogenation reduction reaction in an organic solvent to obtain a compound (V); the compound (V) is subjected to alkaline or acidic hydrolysis reaction toobtain a compound (IV). The method disclosed by the invention overcomes various defects of the existing method; the conventional commercial catalysts are used; the reaction time is greatly shortened;the capacity is improved. Noteworthily, the organic solvent can be recovered and reused; hydroiodic acid or hydrobromide generated through coupling reaction can be smoothly converted into iodides orbromide salts with high economic values through treatment. Therefore, the method disclosed by the invention is an economic easy-to-industrialize green method.
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Paragraph 0046; 0048
(2018/07/30)
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- Design, synthesis, and anti-tumor evaluation of novel symmetrical bis-benzimidazoles
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A novel symmetrical bis-benzimidazole was designed as DNA minor groove binder. Molecular modeling study showed that it could dock into the minor groove of DNA. Several derivatives were synthesized and confirmed by IR, MS, and 1H NMR. All these novel compounds were screened for cytotoxic activity on SKOV-3, HeLa, and BGC-823 cell lines in vitro. Some compounds showed IC50s in the single-digit micromolar range for cytotoxicity in several tumor cell lines.
- Yang, Yan-Hui,Cheng, Mao-Sheng,Wang, Qing-He,Nie, Han,Liao, Na,Wang, Jian,Chen, Hong
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experimental part
p. 1808 - 1812
(2009/06/28)
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- NaIO4/KI/NaCl: a new reagent system for iodination of activated aromatics through in situ generation of iodine monochloride
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A new reagent system consisting of NaIO4/KI/NaCl in aq AcOH has been found to be effective in iodinating a variety of activated aromatic substrates via in situ-generated iodine monochloride, to furnish iodoaromatics in excellent yields. This iodination procedure has been applied successfully for a cost-effective synthesis of 3,3′-diaminobenzidine, a key intermediate for preparing proton conducting membranes for fuel cell applications, with high yield and a purity of 99.7%.
- Emmanuvel, Lourdusamy,Shukla, Ravi Kant,Sudalai, Arumugam,Gurunath, Suryavanshi,Sivaram, Swaminathan
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p. 4793 - 4796
(2007/10/03)
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- A NOVEL CATALYTIC PROCESS FOR THE PRODUCTION OF 3,3', 4,4'-TETRAMINOBIPHENYL
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This invention relates to a process for the production of 3,3’, 4,4’-tetraminobiphenyl (TAB) of formula (1) from non-carcinogenic raw materials, employing Suzuki type biaryl coupling as the key step. sMore particularly, it relates to a three steps process for the production of TAB comprising biaryl aryl coupling of 2-nitro-4-bromoacetanilide (NBA) of formula (2) catalyzed by sulfilimine based palladacycles as catalysts followed by the basic hydrolysis of acetyl group and the reduction of nitro groups with conventional reducing agents.
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Page/Page column 8
(2010/02/14)
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- Symmetric bis-benzimidazoles: New sequence-selective DNA-binding molecules
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A series of bis-benzimidazole compounds with a head-to-head orientation have been designed as sequence-specific DNA binders; crystallographic analysis of oligonucleotide complexes has been combined with DNase I footprinting to confirm that the predicted optimal site for the core bisbenzimidazole motif is the four-base-pair sequence 5'-AATT; this sequence specificity results in inhibition of transcription at A/T sites and may be responsible for the cytotoxic and antitumour effects shown by these head-to-head bis-benzimidazoles.
- Neidle, Stephen,Mann, John,Rayner, Emma L.,Baron, Anne,Opoku-Boahen, Yaw,Simpson, Ian J.,Smith, Nicola J.,Keith R, Fox,Hartley, John A.,Kelland, Lloyd R.
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p. 929 - 930
(2007/10/03)
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- ortho-Substituent effects on the in vitro and in vivo genotoxicity of benzidine derivatives
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Benzidine and its 3,3'-diamino, 3,3'-dimethyl, 3,3'-dimethoxy, 3,3'-difluoro, 3,3'-dichloro, 3,3'-dibromo, 3,3'-dicarbomethoxy and 3,3'-dinitro derivatives together with 2-nitrobenzidine and 3-nitrobenzidine were compared for their in vitro and in vivo genotoxicity. Relative mutagenicity was established with Salmonella strains TA98, TA98/1,8-DNP6 and TA100 with and without S9 activation. All the derivatives in the presence of S9 were more mutagenic than benzidine with 3,3'-dinitro- and 3-nitro-benzidine having the greatest mutagenicity. Mutagenicity in all 3 strains with S9 activation could be correlated to electron-withdrawing ability of substituent groups, as measured by the basicity of the amines. This correlation was explained on the basis that electron-withdrawing groups could favor the stability of the mutagenic intermediate N-hydroxylamine and also enhance the reactivityof the ultimate mutagenic species, the nitrenium ion. Mutagenicity was also correlated to the energy of the lowest unoccupied molecular orbitals (E(LUMO)). Hydrophibicity was found to have very limited effect on the relative mutagenicity of our benzidine derivatives. The in vivo endpoint was chromosomal aberrations in the bone-marrow cells of mice following intraperitoneal administration of benzidine and its derivatives. In contrast to the in vitro results, while all the amines were genotoxic in vivo, only the 3-nitro derivative had a significant increase in toxicity over benzidine.
- You,Brezzell,Das,Espadas-Torre,Hooberman,Sinsheimer
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- Models for intramolecular exchange in organic π-conjugated open-shell systems: A comparison of three non-kekule biphenyldinitrenes
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The important effect of connectivity upon the nature of intramolecular exchange coupling of unpaired electrons by the biphenyl group was investigated by cryogenic matrix photolysis of diazide precursors expected to yield biphenyl-3,4′-dinitrene (1), biphenyl-3,3′-dinitrene (2), and biphenyl-4,4′-dinitrene (3). System 1 was predicted by parity-based qualitative models to exhibit a high-spin ground state. By Curie law analysis of its electron spin resonance (ESR) spectrum at cryogenic temperatures in frozen 2-methyltetrahydrofuran solution, 1 was found to be a quintet ground-state dinitrene with zero field splitting (zfs) parameters of |D/hc| = 0.153 cm-1, |E/hc| = 0.003 cm-1. System 2 was predicted to be disjoint with nearly-degenerate high-spin and low-spin states. Cryogenic frozen solution ESR spectroscopy showed no ESR-active dinitrene 2 upon extended photolysis of its appropriate diazide precursor, although the related mononitrene with zfs of |D/hc| = 0.996 cm-1 was clearly visible. We presume that system 2 was produced in this experiment, but that it acts either as a singlet ground-state dinitrene or as a pair of isolated mononitrenes. A biradical ESR spectrum was found for photolysis of the diazide precursor to 3, with zfs of |D/hc| = 0.189 cm-1 and |E/hc| -1. The thermal dependence of this biradical spectrum shows it to be an excited state, consistent with quinonoidal dinitrene 3 having a singlet ground state and a triplet excited state ca. 0.6 kcal/mol higher in energy. The results for dinitrenes 1-3 were compared to related work on dicarbene molecules described by others, and it was found that the dinitrenes and dicarbenes exhibit similar electron exchange coupling behavior.
- Minato, Masaki,Lahti, Paul M.,Van Willigen, Hans
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p. 4532 - 4539
(2007/10/02)
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- Method for the production of 3,3'4,4'-tetraaminobiphenyl
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A method is provided for the production of 3,3', 4,4'-tetraaminobiphenyl (TAB) from biphenyl comprising the following steps: 1) acetylating the biphenyl in the presence of an appropriate Friedel-Crafts catalyst to obtain 4,4'-diacetylbiphenyl (DAcB); 2) oximating the DAcB to form DAcB dioxime; 3) subjecting the dioxime to a double Beckmann rearrangement to obtain N,N-diacetylbenzidine (DiAcBz); 4) nitrating the DiAcBz to obtain 3,3'-dinitro-N,N-diacetylbenzidine (DNAcBz) 5) removing the acetyl groups of the DNAcBz by basic hydrolysis to form 3,3'-dinitrobenzidine (DNB); and 6) reducing the nitrate groups of the DNB to form TAB.
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- Chemotherapeutically active nitro compounds. I. Nitroanilines
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More than 200 nitro compounds, most of them nitroaniline derivatives substituted with one or more radicals having a basic reaction, were prepared and investigated as to their therapeutic activity against bacteria, fungi, protozoa, helminths, viruses and tumors. Several mono nitrobenzenes with a radical having a basic reaction showed a weak in vitro activity against gram positive bacteria and against Crocker's sarcoma 180; they also showed systemic activity against nematodes (Aspiculuris tetraptera) and viruses. The majority of therapeutically active compounds with pronounced in vitro activity against Trichomonas fetus, Entamoeba histolytica, Schistosoma mansoni, cestodes, nematodes (Ancylostoma caninum), viruses (influenza, MHV, SAV and EMC) and various types of carcinoma (Ehrlich's carcinoma, leukemia 1210, Crocker's sarcoma 180) were dinitrobenzene derivatives with one radical having a basic reaction and electropositive groups or unreactive or reactive chlorine atom, and di nitrobenzene with two equal or two different radicals having a basic reaction. Compound No. 70 revealed a marked in vitro activity against fungi (Trichophyton; Microsporum, Candida albicans). Other nitro compounds such as bis mono and bis dinitrobenzene derivatives likewise showed a systemic action against E. histolytica, viruses and, in particular, carcinoma (Crocker's sarcoma 180, Ridgway's osteosarcoma). Oxygen and sulfur analogue compounds as well as compounds produced by reduction also possessed a distinct activity against E. histolytica and viruses. On the basis of the present results, the dinitrobenzenes substituted with two radicals having a basic reaction include a number which have in common a recognizable structure/activity relationship in respect to E. histolytica, Schistosoma mansoni and different types of viruses. The activity against viruses in this class of compounds is probably due to an increased interferon production in the host animal. Whether the mechanism of action is the same against E. histolytica or Schistosoma mansoni has not been determined so far. A tumorigenic effect was observed mainly in those di nitrobenzenes which are classed as alkylating compounds. Because of the small chemotherapeutic index, the trials were not continued with the most effective compounds mentioned.
- Winkelmann,Raether,Dittmar,et al.
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p. 681 - 708
(2007/10/05)
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