- Preparation method of 3,3',4,4'-tetraaminobiphenyl
-
The invention discloses a preparation method of 3,3',4,4'-tetraaminobiphenyl The method comprises the following steps: in the presence of a first catalyst and a second catalyst, carrying out an amino substitution reaction on dichlorobiphenyl diamine and an ammoniation reagent to obtain a crude 3,3',4,4'-tetraaminobiphenyl product; and carrying out post-treatment on the crude 3,3',4,4'-tetraaminobiphenyl product to obtain a purified 3,3',4,4'-tetraaminobiphenyl product, wherein the first catalyst is a mixture of specified amino acid and cuprous salt, and the second catalyst is a phase transfer catalyst. Specific amino acid and the phase transfer catalyst are innovatively introduced to assist a small amount of cuprous salt in forming a new combined catalyst, so the smooth proceeding of the amino substitution reaction can be efficiently promoted, and reaction yield and product purity are improved. The usage of cuprous salt in the catalyst is obviously reduced, so the post-treatment pressure of high-concentration heavy metal salt wastewater is effectively reduced. Reaction temperature and reaction pressure are milder, so energy consumption is reduced, the safety of a process flow is improved, and the method is more suitable for industrial production.
- -
-
Paragraph 0061-0076
(2021/06/09)
-
- Synthesis method of benzidine compound
-
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.
- -
-
Paragraph 0046; 0049; 0055; 0063
(2018/07/30)
-
- A new facile, efficient synthesis and structure peculiarity of quinoxaline derivatives with two benzimidazole fragments
-
A highly efficient and versatile method for the synthesis of quinoxaline derivatives with two benzimidazole fragments have been developed on the basis of the ring contraction of 3-(benzimidazo-2-yl)quinoxalin-2(1H)-one with 1,2-diaminobenzene and its various types of substituted and condensed derivatives. Owing to the inter- and intramolecular processes, involving self association, proton exchange, conformational, and/or tautomeric exchanges between several forms for most of the bis-benzimidazolylquinoxalines signals of bridged and neighboring carbon atoms and the hydrogen atoms of the neighboring carbon atoms of benzimidazole fragments in the NMR spectra are broadened. The conjugation between the benzimidazole fragments and the quinoxaline core of the molecules is increased from the quinoxaline derivative (10c) to its thiadiazol[f]- (17) and pyrrolo[a]-(19) annulated derivatives, resulting in a greater planarity of the molecule as a whole.
- Mamedov, Vakhid A.,Zhukova, Nataliya A.,Syakaev, Victor V.,Gubaidullin, Aidar T.,Beschastnova, Tat'Yana N.,Adgamova, Dil'Bar I.,Samigullina, Aida I.,Latypov, Shamil K.
-
p. 1403 - 1416
(2013/02/23)
-
- Design, synthesis, and anti-tumor evaluation of novel symmetrical bis-benzimidazoles
-
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
-
experimental part
p. 1808 - 1812
(2009/06/28)
-
- METHOD OF MANUFACTURING 3, 3' , 4, 4'-TETRAAMINOBIPHENYL
-
An object of the present invention is to provide an efficient method of manufacturing 3,3′,4,4′-tetraaminobiphenyl with a smaller number of steps. The manufacturing method of 3,3′,4,4′-tetraaminobiphenyl includes reacting the amino groups of a 4-halo-o-phenylenediamine with an inorganic sulfur compound to lead to a 5-halo-2,1,3-benzothiadiazole, subsequently coupling two molecules of the benzothiadiazole together to form a 5,5′-bis(2,1,3-benzothiadiazole) and then deprotecting the amino groups to yield 3,3′,4,4′-tetraaminobiphenyl.
- -
-
Page/Page column 5-6
(2009/06/27)
-
- NaIO4/KI/NaCl: a new reagent system for iodination of activated aromatics through in situ generation of iodine monochloride
-
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
-
p. 4793 - 4796
(2007/10/03)
-
- A NOVEL CATALYTIC PROCESS FOR THE PRODUCTION OF 3,3', 4,4'-TETRAMINOBIPHENYL
-
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.
- -
-
Page/Page column 5; 8
(2010/02/14)
-
- Process for the preparation of high quality 3,3′,4,4′-tetraminobiphenyl
-
The present invention relates to a process for the preparation of pure high quality 3,3′, 4,4′-tetraminobiphenyl (TAB) in high yields. The present invention also discloses a process for the preparation of 3,3′,4,4′ tetraminobiphenyl (TAB) comprising a three step process: (1) oxidation 3,3′-dichloro 4,4′-diaminobiphenyl (DCB) with 50% aq. H2O2, (2) ammonolysis of the resulting 3,3′-dinitro 4,4′-dinitrobiphenyl (DCDNB) and (3) reduction of 3,3′-diamino-4,4′-dinitrobiphenyl (DADNB) with stannous chloride and concentrated hydrochloric acid.
- -
-
Page column 5
(2008/06/13)
-
- A new class of symmetric bisbenzimidazole-based DNA minor groove-binding agents showing antitumor activity
-
The synthesis and evaluation of the novel head-to-head bisbenzimidazole compound 2,2-bis-[4′-(3″-dimethylamino-1″-propyloxy)phenyl]-5,5-bi-1 H-benzimidazole is described. An X-ray crystallographic study of a complex with the DNA dodecanucleotide sequence d(CGCGAAT-TCGCG) shows the compound bound in the A/T minor groove region of a B-DNA duplex and that the head-to-head bisbenzimidazole motif hydrogen-bonds to the edges of all four consecutive A:T base pairs. The compound showed potent growth inhibition with a mean IC50 across an ovarian carcinoma cell line panel of 0.31 μM, with no significant cross-resistance in two acquired cisplatin-resistant cell lines and a low level of cross-resistance in the P-glycoprotein overexpressing acquired doxorubicin-resistant cell line. Studies with the hollow fiber assay and in vivo tumor xenografts showed some evidence of antitumor activity.
- Mann,Baron,Opoku-Boahen,Johansson,Parkinson,Kelland,Neidle
-
p. 138 - 144
(2007/10/03)
-
- Symmetric bis-benzimidazoles: New sequence-selective DNA-binding molecules
-
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.
-
p. 929 - 930
(2007/10/03)
-
- Method for the production of 3,3'4,4'-tetraaminobiphenyl
-
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.
- -
-
-
- Synthesis and Anthelmintic Activity of Bisbenzimidazole-2-carbamates
-
The synthesis of bisbenzimidazole-2-carbamates (1-6) linked directly or by a one-atom bridge (CH2, CO, O, SO2, or S) at the 5 positions is described.Compound (4) shows interesting anthelmintic activity.
- Viswanathan, N.,Joshi, B. S.,Gawad, D. H.,Gokhale, U. B.,Sidhaye, A. R.,Rajasekariah, G. R.
-
p. 730 - 732
(2007/10/02)
-
- Synthesis of pure 3,3'-diaminobenzidine
-
A process for the purification of crude 3,3'-diaminobenzidine comprising contacting it with sulfuric acid. The 3,3'-diaminobenzidine can be produced by the reaction of NH3 and 3,3'-dichlorobenzidine in the presence of various catalysts.
- -
-
-