16600-92-3Relevant articles and documents
Sequential nitration/hydrogenation protocol for the synthesis of triaminophloroglucinol: Safe generation and use of an explosive intermediate under continuous-flow conditions
Cantillo, David,Damm, Markus,Dallinger, Doris,Bauser, Marcus,Berger, Markus,Kappe, C. Oliver
, p. 1360 - 1366 (2014)
A continuous-flow process for the synthesis of triaminophloroglucinol has been developed. The synthetic procedure is based on a sequential nitration/reduction protocol which uses phloroglucinol as an inexpensive substrate. During the initial exothermic nitration step employing a combination of ammonium nitrate and sulfuric acid, the temperature was controlled through the enhanced heat transfer derived from the high surface-to-volume ratio of the utilized capillary tubing. Clogging of the tubing due to precipitation of trinitrophloroglucinol (TNPG) was avoided by immersing the tubular reactor in an ultrasound bath during the process. The nitration mixture was diluted with water and immediately subjected to catalytic hydrogenation of the nitro groups using a commercially available continuous-flow reactor and PtO2 as heterogeneous catalyst, thus avoiding the isolation of the highly unstable and explosive TNPG intermediate.
Optimization of fluorescence property of the 8-oxodGclamp derivative for better selectivity for 8-oxo-2′-deoxyguanosine
Koga, Yohei,Fuchi, Yasufumi,Nakagawa, Osamu,Sasaki, Shigeki
scheme or table, p. 6746 - 6752 (2011/10/04)
2′-Deoxyguanosine (dG) suffers from oxidation by reactive oxygen species (ROS) to form 8-oxo-2′-deoxyguanosine (8-oxo-dG), which is regarded as a marker of oxidative stress in the cells. In our continuous study for the recognition molecule of 8-oxo-dG, 8-oxoGclamp and its derivatives have been identified as the selective fluorescent probe. However, it is an obstacle for further application that dG also forms a complex with 8-oxoGclamp, resulting in fluorescence quenching in less polar solvents. Quenching of the fluorescence of 8-oxoGclamp is thought to involve photo-induced electron transfer in the complex. It was hypothesized that the energy level of the excited state of 8-oxoGclamp and the HOMO energy of dG are the preliminary determinant of the quenching efficiency. Thus, fluorescence properties of the substituted derivatives at the 7-position of the 1,3-diazaphenoxazine part of 8-oxoGclamp were investigated. Among the new derivatives, fluorescence of the 7-phenyl substituted 8-oxoGclamp was not quenched by dG even in the stable complex, exhibiting the highest selectivity for 8-oxo-dG.
Screw Sense Selective Polymerization of Achiral Isocyanides Catalysed by Optically Active Nickel(II) Complexes
Kamer, Paul C. J.,Nolte, Roeland J. M.,Drenth, Wiendelt
, p. 6818 - 6825 (2007/10/02)
Poly(isocyanides), (RN=Cn, can be prepared from isocyanides, , by the catalytic action of nickel(II) compounds.The main chain of these polymers is a rigid helix.This helical conformation results from a restricted rotation around the single bonds that connect the main-chain carbon atoms.Polymerization of achiral isocyanides generally gives a racemic mixture of left- and right-handed helices, whereas polymerization of optically active isocyanides results in helices with an excess of one screw sense.We describe a procedure for obtaining poly(isocyanides) with predominantly one screw sense, starting from an achiral monomer.A catalyst is prepared by adding an optically active amine to a tetrakis(isocyanide)nickel(II) perchlorate complex.Polymerization of various achiral isocyanides with this catalist yields optically active polymers with an enantiomeric excess up to 83percent.
Novel Method for Nitration and Polymerisation of Symmetric Trihydroxybenzene Using Ceric(IV) Ammonium Nitrate
Chaudhuri, Kakoli,Chawla, H. M.
, p. 1184 - 1185 (2007/10/02)
Only symmetric isomer of trihydroxybenzene (phloroglucinol) on treatment with cerium(IV)ammonium nitrate produces 13-acetoxy-1,3,9,11-tetrahydroxy-2,10-dinitrobenzobisbenzodioxin (I) along with 1,3-dihydroxy-5-methoxy-2-nitrobenzene, 1,3,5-trihydroxy-2-nitrobenzene and 1,5-dihydroxy-3-methoxy-2-nitrobenzene, while other isomers undergo very rapid reaction with the formation of polymers which are difficult to separate.
Nitration, Amination, and Halogenation of Di-O-methylphloracetophenone
Acton, John P.,Donnelly, Dorothy J.,Donnelly, John A.
, p. 73 - 80 (2007/10/02)
Chlorination of the title compound gave 5'- and 3'-chloro-2'-hydroxy-4',6'-dimethoxyacetophenone.The nitration of its acetate, followed successively by reduction, diazotization, and reaction with cuprous chloride, gave the 3'-substituted series, 2'-acetoxy-4',6'-dimethoxy-3'-nitroacetophenone, 3'-amino-2'-hydroxy-4',6'-dimethoxyacetophenone, and 3'-chloro-2'-hydroxy-4',6'-methoxyacetophenone, respectively.The orientation of substituents in the products was proved.The amino and chloro members of the isomeric 5'-substituted series were available via 2'-hydroxy-4',6'-dimethoxy-5'-phenylazoacetophenone, the product of the reaction of the title compound with benzenediazonium chloride. - Keywords: Acetophenone; Aromatic substitution; Nuclear regioselectivity
