- The N-H and O-H bond dissociation energies in 4-hydroxydiphenylamine and its phenoxyl and aminyl radicals
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The N-H and O-H bond dissociation energies in 4-hydroxydiphenylamine Ph-NH-C6H4-OH (DNH= 353.4, DOH=339.3 kJ mol-1) and its semiquinone radicals DNH(Ph-NH-C 6H4-O.) = 273.6, DOH(Ph-N .-C6H4-OH) = 259.5 kJ mol-1 were first estimated using the parabolic model and experimental data (rate constants) on two elementary reactions with participation of N-phenyl-1,4- benzoquinonemonoimine (2). One of the reactions, namely, that of 2 with aromatic amines, was studied in this work using a specially developed method.
- Varlamov
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Read Online
- Construction of diaminobenzoquinone imines via ferrocene-initiated radical reaction of benzoquinone with amines
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A ferrocene-initiated radical reaction of benzoquinone with amines has been successfully developed for the direct access to diaminobenzoquinone imines in high yields, in which the commercially available and cheap ferrocene was employed as a radical initiator and TBHP was used as an oxidant. Moreover, this reaction could be achieved with low loading of ferrocene (0.5 mol%). This protocol is highly efficient with good substrate tolerance and provides a new approach for the construction of benzoquinone imines with potential pharmaceutical interest.
- Feng, Yadong,Liu, Ying,Fu, Qi,Zou, Zhongai,Shen, Jinhai,Cui, Xiuling
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Read Online
- N-H bond dissociation energies in N,N′-diphenyl-1,4-phenylenediamine and its aminyl radical
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The N-H bond dissociation energy (DNH) in the 4-anilinodiphenylaminyl radical formed from N,N′-diphenyl-1,4- phenylenediamine was experimentally determined and calculated by the quantum-chemical method. The experimental DNH value was found from the enthalpy of the reaction of N,N′-diphenyl-1,4-benzoquinonediimine with 4-hydroxydiphenylamine taking into account the bond dissociation energies in 4-hydroxydiphenylamine and its aminyl and phenoxyl radicals, which were determined by the intersecting parabolas method from the kinetic data. The quantum-chemical calculations of DNH used several semiempirical methods by the MOPAC program and the ab initio and DFT methods by the GAUSSIAN 94/98 program. The DNH values, which were closest to the experimental values, were obtained by the B3LYP/6-31+G*method. The results of quantum-chemical calculations of the N-H and O-H bond dissociation energies in 4-hydroxydiphenylamine and its radicals are presented.
- Varlamov,Krisyuk
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Read Online
- Palladium-catalyzed carbonylation of iminoquinones and aryl iodides to access arylp-amino benzoates
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A palladium-catalyzed carbonylation of iminoquinones and aryl iodides has been developed for the construction of arylp-amino benzoates. Using benzene-1,3,5-triyl triformate (TFBen) as the CO source, the reaction proceeded well to give various arylp-amino benzoates in good to excellent yields. Additionally, control experiments were conducted to gain more insights into the reaction mechanism.
- Wang, Siqi,Wu, Xiao-Feng,Yao, Lingyun,Ying, Jun
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supporting information
p. 8246 - 8249
(2021/10/12)
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- Phenoxy-N-phenylaniline derivative and application thereof
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The invention relates to a phenoxy-N-phenylaniline derivative and an application thereof, and belongs to the technical field of novel colorectal cancer drugs. The present invention addresses the problem of providing some novel compounds having c-Myc inhibitory activity. The structural formula of the compound is shown as a formula I in the specification. According to the invention, a series of novel phenoxy-N-phenylaniline derivatives are designed and synthesized, and the compounds can be used as c-Myc inhibitors, have a good inhibition effect on the proliferation of colorectal cancer cells, and provide a new choice for colorectal cancer drugs.
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Paragraph 0064; 0067; 0069; 0071; 0110-0113
(2020/06/05)
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- Ni/Pd-catalyzed Suzuki-Miyaura cross-coupling of alcohols and aldehydes and C-N cross-coupling of nitro and amines: via domino redox reactions: base-free, hydride acceptor-free
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Domino oxidation-Suzuki-Miyaura cross-coupling of benzyl alcohols with phenylboronic acid and domino reduction-C-N cross-coupling of the nitro compounds with aryl halides were carried out using a strong Ni/Pd bimetallic redox catalyst. The catalyst bearing a copolymer with two Ni/Pd coordinated metals in porphyrin (derived from demetalated chlorophyll b) and salen-type ligands, and pyridine moiety as a base functionality all immobilized on magnetite NPs was synthesised and characterized. The domino oxidation cross-coupling reaction was accomplished under molecular O2 in the absence of any hydride acceptor or/and base. Also, the domino reduction C-N cross-coupling reaction was performed in the presence of NaBH4 without the need for any base and co-reductant. This multifunctional catalyst gave moderate to good yields for both coupling reactions with high chemoselectivity. A wide investigation was conducted to determine its mechanism and chemoselectivity.
- Ahmed, Rebin Omer,Kazemnejadi, Milad,Mahmoudi, Boshra
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p. 43962 - 43974
(2020/12/25)
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- Discovery of 4-(3,5-dimethoxy-4-(((4-methoxyphenethyl)amino)methyl)phenoxy)-N-phenylaniline as a novel c-myc inhibitor against colorectal cancer in vitro and in vivo
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Proto-oncogene c-Myc plays an essential role in the development of colorectal cancer (CRC), since downregulation of c-Myc inhibits intestinal polyposis, which is the most cardinal pathological change in the development of CRC. Herein, a series of novel phenoxy-N-phenylaniline derivatives were designed and synthesized. The cytotoxicity activities of all the derivatives were measured by MTT assay in different colon cancer cells, 4-(3,5-dimethoxy-4-(((4-methoxyphenethyl)amino)methyl)phenoxy)-N-phenylaniline (42) was discovered, the lead compound 42 with excellent cytotoxicity activity of IC50 = 0.32 μM, IC50 = 0.51 μM, in HT29 and HCT 15 cells, respectively. Compound 42 had a good inhibitory activity of c-Myc/MAX dimerization and DNA binding. Besides, compound 42 could effectively induce apoptosis and induced G2/M arrest in low concentration and G0/G1 arrest in high concentration to prevent the proliferation and differentiation in colon cancer cells. Western blot analysis confirmed the 42 strongly down-regulated expression of c-Myc. Furthermore, during 30 days treatment 42 exhibited excellent efficacy in HT29 tumor xenograft model without causing significant weight loss and toxicity. Consequently, 42 could be a promising drug candidate for CRC therapy.
- Cao, Chaoguo,Lan, Suke,Li, Rui,Liu, Yuanyuan,Luo, Dan,Luo, Meng,Ma, Xinyu,Shan, Huifang,Yang, Jie,Yu, Su,Zhong, Xinxin
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- Pd-Catalyzed Redox-Neutral C-N Coupling Reaction of Iminoquinones with Electron-Deficient Alkenes without External Oxidants: Access of Tertiary (E)-Enamines and Application to the Synthesis of Indoles and Quinolin-4-ones
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A novel and efficient reductive N-alkenylation of iminoquinones with electron-deficient olefins has been successfully developed by Pd(II)-catalyzed redox-neutral reactions, which provides a synthesis of tertiary (E)-enamines. We further demonstrate that the tertiary enamines can be converted to multifarious N-heterocyclic compounds, indoles, and quinolones in good yields.
- Jillella, Raveendra,Raju, Selvam,Hsiao, Huan-Chang,Hsu, Day-Shin,Chuang, Shih-Ching
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supporting information
p. 6252 - 6256
(2020/08/12)
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- Substituted anilino-benzothiazole-2-thioketone compound as well as preparation method and application thereof
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The invention discloses a substituted anilino-benzothiazole-2-thioketone compound and a preparation method thereof. In addition, the invention also relates to an application of the compound in rubberproducts. The substituted anilino-benzothiazole-2-thioketone compound disclosed by the invention not only can promote rubber vulcanization, but also can prolong the service life of the rubber products.
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Paragraph 0071-0072
(2020/06/05)
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- Enolizable Ketones as Activators of Palladium(II) Precatalysts in Amine Arylation Reactions
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Enolizable ketones have been identified as effective activators for palladium(II) precatalysts in the coupling of aryl bromides and aniline. N-arylation reactions catalyzed by [(DTBNpP)PdCl2]2 (DTBNpP = (bis(tert-butyl)neopentylphosphine) and PEPPSI-IPr precatalysts are activated by the addition of acetone, mesityl oxide, and 3-pentanone. 3-Pentanone was the most effective activator. Mechanistic studies show that acetone, 3-pentanone, and mesityl oxide reduce [(DTBNpP)PdCl2]2 in the presence of NaO-t-Bu to Pd0(DTBNpP)2
- Hu, Huaiyuan,Gilliam, Ashley M.,Qu, Fengrui,Shaughnessy, Kevin H.
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p. 4127 - 4135
(2020/05/05)
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- Method for preparing secondary aromatic amine or tertiary aromatic amine by conducting amination on aryl halide or alkyl halide
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The invention discloses a method for preparing secondary aromatic amine or tertiary aromatic amine by conducting amination on aryl halide or alkyl halide. That is to say, the alkyl halide or the arylhalide and organic amine are mixed according to a certain ratio, and under light irradiation, C-N coupling reaction is carried out, so that a corresponding target product is generated for preparing the secondary amine or the tertiary amine. Compared with existing synthesis technologies, the method has the advantages that the aryl halide or the alkyl halide which is cheap and easy to get is selected as a reaction substrate, the method has good universality for different organic amine separately, moreover, the product selectivity is high, and separation and purification are easy; moreover, the synthesis method does not need to be conducted under severe conditions of high temperature and the like, a green and sustainable light source is adopted as driving force, the atom economy is high, andthe method has wide application prospects.
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Paragraph 0029-0035; 0160; 0064; 0065; 0070; 0071; 0161
(2019/01/14)
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- An Effective Heterogeneous Copper Catalyst System for C-N Coupling and Its Application in the Preparation of 2-Methyl-4-methoxydiphenylamine (MMDPA)
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A ligand-recyclable, environmentally benign heterogeneous catalyst system composed of CuI and polystyrene-supported N (-(4-(aminomethyl)naphthalen-1-yl)- N (-phenyl-1 H -pyrrole-2-carbohydrazide (PSAP) has been established for Ullmann type C-N coupling based on the homogeneous catalyst system N ′, N ′-diphenyl-1 H -pyrrole-2-carbohydrazide/CuI. This heterogeneous catalyst system maintained the catalytic effectiveness of the homogeneous catalyst. A variety of functionalized aryl bromides can be efficiently aminated with aryl amines and aliphatic amines with high selectivity for amines over alcohols. Moreover, a practical application of this catalyst system to promote the reaction of commercially available 4-methoxy-2-methylaniline and bromobenzene in 10 mmol scale, provided 2-methyl-4-methoxydiphenylamine (MMDPA) with 93% yield with the merit of the approach being simple operation for work-up and purification.
- Yi, Zhou,Huang, Manna,Wan, Yiqian,Zhu, Xinhai
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p. 3911 - 3920
(2018/09/29)
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- Synthesis of Di(hetero)arylamines from Nitrosoarenes and Boronic Acids: A General, Mild, and Transition-Metal-Free Coupling
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The synthesis of di(hetero)arylamines by a transition-metal-free cross-coupling between nitrosoarenes and boronic acids is reported. The procedure is experimentally simple, fast, mild, and scalable and has a wide functional group tolerance, including carbonyls, nitro, halogens, free OH and NH groups. It also permits the synthesis of sterically hindered compounds.
- Roscales, Silvia,Csák?, Aurelio G.
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p. 1667 - 1671
(2018/03/23)
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- Palladium-catalyzed amination of aryl sulfoxides
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Amination of diaryl sulfoxides with anilines and alkylamines has been accomplished under palladium/N-heterocyclic carbene (NHC) catalysis. Owing to its electron deficiency, the leaving arenesulfenate anion would be smoothly released from the palladium center to result in uneventful catalyst turnover under milder reaction conditions in comparison with previous C-S bond amination reactions. This amination accommodated a wider range of functional groups such as silyl, boryl, methylsulfanyl, and halogen moieties. Regioselective amination of unsymmetrical diaryl sulfoxides was also executed by means of steric bias.
- Yoshida, Yuto,Otsuka, Shinya,Nogi, Keisuke,Yorimitsu, Hideki
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supporting information
p. 1134 - 1137
(2018/02/23)
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- Chan-Evans-Lam Couplings with Copper Iminoarylsulfonate Complexes: Scope and Mechanism
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Copper(II) pyridyliminoarylsulfonate complexes with chloride or triflate counteranions were employed in Chan-Evans-Lam (CEL) couplings of N-nucleophiles and arylboronic acids. The complexes avoided typical side reactions in CEL couplings, and an excess of boronic acid was not required. Water was tolerated, and addition of neither base nor other additives was necessary. Primary amines, acyclic and cyclic secondary amines, anilines, aminophenol, imidazole, pyrazole, and phenyltetrazole can be quantitatively arylated at either 25 or 50 °C with 2.5 mol % of the catalyst. Reaction kinetics were investigated in detail. Kinetic and spectroscopic studies provide evidence for the formation of unproductive copper-substrate complexes. Formation of an aniline-phenylboronic acid adduct was responsible for the zero-order dependence of reaction rates on phenylboronic acid concentration. Kinetic evidence indicates that the order of reaction steps is transmetalation, nucleophile coordination, and oxidation. Couplings performed poorly with electron-deficient arylboronic acids, due to a slower Cu(II)/Cu(III) oxidation in the catalytic cycle. Photoredox catalysis partially resolved this problem, but addition of copper acetate as an external oxidant proved to be more efficient.
- Hardouin Duparc, Valérie,Bano, Guillaume L.,Schaper, Frank
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p. 7308 - 7325
(2018/07/05)
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- The invention relates to a N, N - disubstituted hydrazide as ligand copper catalysis C - N coupling method (by machine translation)
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The invention discloses a to N, N - disubstituted hydrazide as ligand copper catalysis C - N coupling method, the method uses the aromatic halides with amine compound as a raw material, in order to alcohol compound as the solvent, in order to copper or copper compound as a catalyst, in order to as formula I or formula II as shown by a N, N - disubstituted hydrazide as a ligand, the presence of a base, in the 10 - 130 °C generating C - N coupled reaction for generating N - aryl compound: the invention mild reaction conditions, high chemical selectivity, substrate and wide range of application, simplicity of operation, product is simple and easy to separation and environmental protection, the obtained product yield is higher. Wherein R1, R2 is selected from methyl, phenyl, 4 - methoxyphenyl, 4 - nitro-phenyl, 2 - methylphenyl, 2 - isopropyl phenyl; R3 is hydrogen or methoxy. (by machine translation)
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Paragraph 0145-0147
(2017/07/21)
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- Room-Temperature CuI-Catalyzed Amination of Aryl Iodides and Aryl Bromides
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A general and effective CuI/N′,N′-diaryl-1H-pyrrole-2-carbohydrazide catalyst system was developed for the amination of aryl iodides and bromides at room temperature with good chemoselectivity between -OH and -NH2 groups. Only 5 mol % of CuI and ligands was needed in this protocol to effect the amination of various aryl bromides and aryl iodides with a wide range of aliphatic and aryl amines (1.3 equiv).
- Ding, Xiaomei,Huang, Manna,Yi, Zhou,Du, Dongchen,Zhu, Xinhai,Wan, Yiqian
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p. 5416 - 5423
(2017/05/25)
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- Selective C-N coupling reaction of diaryliodonium salts and dinucleophiles
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N-Aryl-α-amino amides including their chiral isomers have demonstrated important applications as pharmaceutical drugs; however, to date, a one-step synthetic route for them still remains to be developed. Herein, an efficient ligand-free copper-catalyzed selective C-N coupling reaction of diaryliodonium salts and dinucleophiles under mild conditions was realized. Diaryliodonium salts prefer to react with dinucleophiles at the site of stronger alkalic amino groups. Thus, a general aliphatic amino-selective N-arylation of α-amino amides was disclosed. Additionally, copper-catalyzed N-arylation of diaryliodonium salts afforded the same products as obtained via palladium-catalyzed reactions of aryl halides.
- Ma, Chang,Wu, Xufeng,Zeng, Qingle,Zhou, Lihong,Huang, Yi
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supporting information
p. 2873 - 2877
(2017/04/14)
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- Copper(ii)-catalyzed Chan-Lam cross-coupling: chemoselective N-arylation of aminophenols
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Copper(ii)-catalyzed boronic acid promoted chemoselective N-arylation of unprotected aminophenols has been developed. Selective N-arylation of 3-aminophenol is achieved with a Cu(OAc)2/AgOAc combination in MeOH at rt, whereas the chemoselective N-arylated products of 4-aminophenol can be obtained with a Cu(OAc)2/Cs2CO3 system and benzoic acid as an additive. These ligand-free conditions and “open-flask” chemistry are robust and compatible with a wide range of functional groups. The mechanistic investigation for this selective N-arylation has been studied by considering Density Functional Theory (DFT) calculations.
- Siva Reddy,Ranjith Reddy,Nageswar Rao,Jaladanki, Chaitanya K.,Bharatam, Prasad V.,Lam, Patrick Y. S.,Das, Parthasarathi
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supporting information
p. 801 - 806
(2017/02/05)
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- Sulfonato-imino copper(II) complexes: Fast and general Chan-Evans-Lam coupling of amines and anilines
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Sulfonato-imine copper complexes with either chloride or triflate counteranions were prepared in a one-step reaction followed by anion-exchange. They are highly active in Chan-Evans-Lam couplings under mild conditions with a variety of amines or anilines, in particular with sterically hindered substrates. No optimization of reaction conditions other than time and/or temperature is required.
- Hardouin Duparc,Schaper
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supporting information
p. 12766 - 12770
(2017/10/11)
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- Synthesis of polyfunctional secondary amines by the addition of functionalized zinc reagents to nitrosoarenes
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Addition of functionalized aryl, heteroaryl or adamantyl zinc reagents to various nitroso-arenes in the presence of magnesium salts and LiCl in THF produces after a reductive work-up with FeCl2 and NaBH4 in ethanol the corresponding polyfunctional secondary amines in high yields. This journal is
- Dhayalan, Vasudevan,S?mann, Christoph,Knochel, Paul
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supporting information
p. 3239 - 3242
(2015/06/01)
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- Nickel-catalyzed synthesis of diarylamines via oxidatively induced C-N bond formation at room temperature
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A nickel-catalyzed oxidative coupling of zinc amides with organomagnesium compounds selectively produces diarylamines under mild reaction conditions, with tolerance for chloride, bromide, hydroxyl, ester, and ketone groups. A diamine is bis-monoarylated. A bromoaniline undergoes N-arylation followed by Kumada-Tamao-Corriu coupling in one pot. The reaction may proceed via oxidatively induced reductive elimination of a nickel species.
- Ilies, Laurean,Matsubara, Tatsuaki,Nakamura, Eiichi
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supporting information
p. 5570 - 5573,4
(2012/12/12)
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- Copper-catalyzed direct synthesis of di- and triphenylamines: A dramatic accelerating effect of 2-aminophenols
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Utilizing the dramatic accelerating effect of 2-aminophenols, we developed a copper-catalyzed system for the selective synthesis of di- and triphenylamines. In addition, N- and O-arylation could be achieved in coupling reactions between 2-aminophenol and nitroaryl halides. A copper-catalyzed system for the selective synthesis of di- and triphenylamines has been developed. This new protocol provides a direct and efficient way to synthesize o-hydroxy-substituted di- and triphenylamines. Copyright
- Li, Yaming,Wang, Huifeng,Jiang, Linlin,Sun, Fangfang,Fu, Xinmei,Duan, Chunying
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experimental part
p. 6967 - 6973
(2011/02/25)
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- Orthogonal Cu- and Pd-based catalyst systems for the O- and N-arylation of aminophenols
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O- or N-arylated aminophenol products constitute a common structural motif in various potentially useful therapeutic agents and/or drug candidates. We have developed a complementary set of Cu- and Pd-based catalyst systems for the selective O- and N-arylation of unprotected aminophenols using aryl halides. Selective O-arylation of 3- and 4-aminophenols is achieved with copper-catalyzed methods employing picolinic acid or CyDMEDA, trans-N,N′-dimethyl-1,2- cyclohexanediamine, respectively, as the ligand. The selective formation of N-arylated products of 3- and 4-aminophenols can be obtained with BrettPhos precatalyst, a biarylmonophosphine-based palladium catalyst. 2-Aminophenol can be selectively N-arylated with CuI, although no system for the selective O-arylation could be found. Coupling partners with diverse electronic properties and a variety of functional groups can be selectively transformed under these conditions.
- Maiti, Debabrata,Buchwald, Stephen L.
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supporting information; experimental part
p. 17423 - 17429
(2010/03/25)
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- Rate constants of elementary steps of the reversible chain reaction of N-phenyl-1,4-benzoquinonemonoimine with 2,5-dichlorohydroquinone
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The kinetics of reversible chain reactions in quinoneimine-hydroquinone systems has first been studied for the reaction of N-phenyl-1,4- benzoquinonemonoimine with 2,5-dichloro-hydroquinone used as an example. The dependences of the reaction rate on the concentration of the initial reactants, initiator, and each product were studied. The reliable estimates of the rate constants of 11 (of 12) elementary steps of this reaction were obtained from the experimental data using the earlier derived formulas and the method of equal concentrations developed in the present work.
- Antonov,Varlamov
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p. 883 - 889
(2008/09/18)
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- Determination of dissociation energies of N-H bond in the 4-anilinodiphenylaminyl radical and O-H bond in the 2,5-dichloro-4- hydroxyphenoxyl radical from the equilibrium constants of chain reactions in quinoneimine-hydroquinone systems
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The temperature dependences of the equilibrium constants of two chain reversible reactions in quinonediimine (quinonemonoimine)-2,5- dichlorohydroquinone systems in chlorobenzene were studied. The enthalpy of equilibrium of the reversible reaction of quinonediimine with 4-hydroxydiphenylamine was estimated from these data (ΔH = - 14.4±1.6 kJ mol-1) and a more accurate value of the N-H bond dissociation energy in the 4-anilinodiphenylaminyl radical was determined (DNH = 278.6±3.0 kJ mol-1). A chain mechanism was proposed for the reaction between quinonediimine and 2,5-dichlorohydroquinone, and the chain length was estimated (ν = 300 units) at room temperature. Processing of published data on the rate constant of the reaction of styrylperoxy radicals with 2,5-dichlorohydroquinone in the framework of the intersecting parabolas method gave the O-H bond dissociation energy in 2,5-dichlorohydroquinone: DOH = 362.4±0.9 kJ mol-1. Taking into account these data, the O-H bond dissociation energy in the 2,5-dichlorosemiquinone radical was found: DOH = 253.6±1.9 kJ mol-1.
- Antonov,Gadomsky,Varlamov
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p. 1723 - 1728
(2008/02/09)
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- METHOD OF PRODUCING AMINOPHENOL COMPOUNDS
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The present invention provides an industrially advantageous method of producing aminophenol compounds represented by the formula (1) by a simple and easy procedure at a high yield and a high purity. The present invention provides a method of producing an aminophenol compound represented by the formula (1): (wherein each of R1 and R2, which may be the same or different, is a hydrogen atom, a substituted or unsubstituted lower alkyl group or the like; R1 and R2, taken together with the adjacent nitrogen atom, may form a 5- or 6-membered heterocycle with or without other intervening heteroatoms; the heterocycle may be substituted by 1 to 3 substituents selected from the group consisting of a hydroxyl group, a substituted or unsubstituted lower alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryloxy group and the like; and the hydroxyl group in the formula (1) is substituted on the 2- or 4-position to the amino group on the phenyl ring), which comprises allowing a cyclohexanedione compound represented by the formula (2) to react with an amine compound represented by the formula (3) (wherein R1 and R2 are as defined above), under a neutral or basic condition.
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Page/Page column 54-55
(2010/02/14)
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- The chain mechanism of the reaction between 2,5-dimethyl-1,4-hydroquinone and N-Phenyl-1,4-benzoquinonemonoimine
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The kinetic characteristics of the reaction between N-phenyl-1,4- benzoquinonemonoimine and 2,5-dimethyl-1,4-hydroquinone were studied in chlorobenzene at 298.2 K. The reaction was shown to follow a chain mechanism, the chain length being ～102 units. The rate constants for the elementary reaction steps and the effective reaction orders with respect to the components were determined, and the chain lengths at various concentrations were calculated. A comparison of these data with those obtained earlier for a similar reaction between N-phenyl-1,4-benzoquinonemonoimine and 2,5-di-tert-butyl-1,4-hydroquinone led us to conclude that small changes in the nature of hydroquinone substituents strongly influenced the kinetic parameters of this new class of chain reactions.
- Antonov,Varlamov
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p. 721 - 725
(2007/10/03)
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- Hydroxylation of ionized aromatics including carboxylic acid or amine using recombinant Streptomyces lividans cells expressing modified biphenyl dioxygenase genes
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The bphA1(2072)A2A3A4 gene cluster codes for a shuffled biphenyl dioxygenase holoenzyme with broad substrate specificity. These bphA1(2072)A2A3A4 genes were expressed in the actinomycetes Streptomyces lividans using a thiostrepton-inducible promoter PtipA. Biotransformation experiments of various aromatics including carboxylic acid or amine in their molecular structure, such as 1-naphthoic acid, 2-(1-naphthyl)acetic acid, diphenylamine, and 1-benzyl-4-piperidone, were performed using the recombinant S.lividans cells. These ionized aromatics were converted to the corresponding 1,2-dihydrodiol, mono- or tri-hydroxy forms in 48h. The structure of the converted products was determined by their EI-MS, 1H- and 13C NMR analysis, and several products were found to be novel compounds.
- Shindo, Kazutoshi,Nakamura, Ryoko,Chinda, Ikuko,Ohnishi, Yasuo,Horinouchi, Sueharu,Takahashi, Haruko,Iguchi, Kazuo,Harayama, Shigeaki,Furukawa, Kensuke,Misawa, Norihiko
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p. 1895 - 1900
(2007/10/03)
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- Acid-catalysed radical chain reaction of quinoneimine with hydroquinone
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Trichloroacetic acid in as low concentrations as ～10-6 mol dm-3 increased the rate of a chain reaction between N-phenyl-1,4-benzoquinonemonoimine and 2,5-di-tert-butylhydroquinone in chlorobenzene by a factor of 2 to 3.
- Varlamov, Vladimir T.
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- Design, synthesis, and biological evaluation of aryloxyethyl thiocyanate derivatives against Trypanosoma cruzi
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As a continuation of our project aimed at the search for new and safe chemotherapeutic and chemoprophylactic agents against American trypanosomiasis (Chagas' disease), several drugs structurally related to 4-phenoxyphenoxyethyl thiocyanate (4) were designed, synthesized, and evaluated as antiproliferative agents against the parasite responsible for this disease, the hemoflagellated protozoan Trypanosoma cruzi. This thiocyanate derivative was previously shown to be an effective and potent agent against T. cruzi proliferation. Several drugs possessing thiocyanate groups proved to be effective growth inhibitors of T. cruzi growth. Among the designed compounds, it is important to point out the extremely potent activity shown by 11, 23, 38, 53, 90, 99, and 117 against the epimastigote forms of the parasite. All of them exhibited IC50 values in the low micromolar range, and these values were comparable with those presented by our lead drug 4 and ketokonazole, a well-known antiparasitic agent. The activity displayed by the nitrogen-containing derivative 90 was very promising with IC50 values of 3.3 μM. Several other thiocyanate derivatives also proved to be very potent inhibitors of the multiplication of T. cruzi epimastigotes, such as compounds 28, 33, 43, 48, 56, 61, 66, 71, 76, and 124. Compound 43 resulted in being a promising drug because it was also very effective against amastigotes, the clinically more relevant form of the parasite. This compound was 3-fold more potent than 4, while 11 showed nearly the same activity as our lead drug against intracellular T. cruzi. It was very surprising that the experimental juvenoid 124, although fairly devoid of activity against epimastigotes, was very effective against intracellular amastigotes growing in myoblasts. The rest of the designed compounds showed a broad degree of inhibitory action, from moderately active drugs to drugs almost devoid of antiparasitic activity. Compound 43 is an interesting example of an effective antichagasic agent that presents excellent prospectives not only as a lead drug but also to be used for further in vivo studies.
- Elhalem, Eleonora,Bailey, Brian N.,Docampo, Roberto,Ujváry, István,Szajnman, Sergio H.,Rodriguez, Juan B.
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p. 3984 - 3999
(2007/10/03)
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- Reaction product of a rosin acid and an antidegradant
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There is disclosed a reaction product of a rosin acid and a polyfunctional compound having at least one functional group capable of reacting with a carboxylic acid functionality and another functional group having antidegradant properties. The reaction products of this invention can be used as antidegradants in polymeric compositions and lubricating oil compositions.
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- Benzophenone-sensitized Photoreduction of N-Phenyl-p-benzoquinoneimine and Phenothiazine-3-one in Isopropyl Alcohol, Benzhydrol and Ethylene Glycol
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The results of the title investigation show that whereas N-phenyl-p-benzoquinoneimine (PBQ) and phenothiazine-3-one (PT) physically quench triplet benzophenone (3BP) in competition with hydrogen abstraction 3BP from alcohols, these substrates also undergo quantitative reduction to corresponding phenols via the ketyl radicals involving chemical sensitization.The reduced product also quenches the sensitizer through electron transfer at rates comparble to quenching rates by the substrates.The quantum yield data have been rationalised and a reaction scheme consistent with the observations and in close agreement with the kinetic expressions has been presented and various rate constants evaluated.Bulk of evidence is in support of the reduction taking place through hydrogen atom transfer to the carbonyl oxygen rather than to the azomethine nitrogen in these quinoneimines.
- Sidhu, K. S.,Bansal, W. R.,Malhotra, Kamini
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p. 747 - 752
(2007/10/02)
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- Diphenylamino and indolyl substituted pyromellitides
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This invention relates to 3,7-bis(disubstituted aminophenyl- or indolyl)-3,7-bis(diphenylamino)pyromellitides, 3,5-bis(disubstituted aminophenyl- or indolyl)-3,5-bis(diphenylamino)pyromellitides and mixtures thereof useful as color formers, particularly in carbonless duplicating and thermal marking systems, which are prepared by the interaction of 2,5-bis(disubstituted aminophenyl- or indolyl)carbonyl-1,4-benzenedicarboxylic acids or 2,4-bis(disubstituted aminophenyl- or indolyl)carbonyl-1,5-benzenedicarboxylic acids and mixtures thereof with diphenylamines.
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- Process for the preparation of hydroxy-diphenylamines
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A process for the preparation of hydroxy-diphenylamines by condensation of dihydroxybenzene with an excess amount of primary aromatic amine in the presence of a catalytic amount of an acid at elevated temperature is described wherein the excess aromatic amine and, if appropriate, the reaction product is distilled off from the reaction mixture in the presence of a base.
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- Process for preparing p-arylaminophenols with aluminum sulfate or carboxylate
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Process for the preparation of a p-arylaminophenol by reacting hydroquinone with a primary arylamino in the presence of a catalytic amount of aluminum sulfate or an aluminum lower carboxylate.
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- Manufacture of arylamines
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Arylamines are manufactured by reacting alcohols with amines in the presence of phosphorus-III compounds. The arylamines I manufactured by the process of the invention are intermediates for the manufacture of crop protection agents, optical brighteners, especially amino-coumarin derivatives, and dyes, especially of the xanthene, pyronine, rhodamine, oxazine, azo, triphenylmethane and diphenylmethane series.
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