14248-66-9Relevant articles and documents
A 3, 5 - dimethyl -4 - nitro pyridine - N - oxide synthesis method
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Paragraph 0021; 0022; 0023; 0024; 0025; 0026; 0027-0030, (2017/08/25)
The invention discloses a synthesis method of 3,5-dimethyl-4-nitropyridine-N-oxide, and belongs to the field of chemical industry. The method comprises the following steps: mixing 3,5-dimethyl pyridine-N-oxide with concentrated sulfuric acid so as to form a mixed liquid, dropwise adding a sulfuric acid solution of potassium nitrate to the mixed liquid at 0-60 DEG C, and reacting at 60-120 DEG C for 0.5-12hr so as to obtain 3,5-dimethyl-4-nitropyridine-N-oxide. The synthesis method of the 3,5-dimethyl-4-nitropyridine-N-oxide, by replacing concentrated nitric acid or fuming nitric acid with the potassium nitrate as a nitrating reagent, can be used for greatly shortening reaction time and avoiding the generation of brown smoke during reacting and post-processing, an operating environment is friendly, and the problem of environmental pollution caused by the massive use of nitric acid is relieved; and meanwhile, reaction yield is improved as well; since environmental issue is increasingly emphasized nowadays, the 3,5-dimethyl-4-nitropyridine-N-oxide can be used for better replacing nitric acid as a nitrating reagent to complete a nitrating reaction.
Single-step versus stepwise two-electron reduction of polyarylpyridiniums: Insights from the steric switching of redox potential compression
Fortage, Jerome,Peltier, Cyril,Perruchot, Christian,Takemoto, Yohei,Teki, Yoshio,Bedioui, Fethi,Marvaud, Valerie,Dupeyre, Gregory,Pospisil, Lubomir,Adamo, Carlo,Hromadova, Magdalena,Ciofini, Ilaria,Laine, Philippe P.
supporting information; experimental part, p. 2691 - 2705 (2012/03/22)
Contrary to 4,4′-dipyridinium (i.e., archetypal methyl viologen), which is reduced by two single-electron transfers (stepwise reduction), the 4,1′-dipyridinium isomer (so-called "head-to-tail" isomer) undergoes two electron transfers at apparently the same potential (single-step reduction). A combined theoretical and experimental study has been undertaken to establish that the latter electrochemical behavior, also observed for other polyarylpyridinium electrophores, is due to potential compression originating in a large structural rearrangement. Three series of branched expanded pyridiniums (EPs) were prepared: N-aryl-2,4,6-triphenylpyridiniums (Ar-TP), N-aryl-2,3,4,5,6-pentaphenylpyridiniums (Ar-XP), and N-aryl-3,5-dimethyl-2,4,6- triphenylpyridinium (Ar-DMTP). The intramolecular steric strain was tuned via N-pyridinio aryl group (Ar) phenyl (Ph), 4-pyridyl (Py), and 4-pyridylium (qPy) and their bulky 3,5-dimethyl counterparts, xylyl (Xy), lutidyl (Lu), and lutidylium (qLu), respectively. Ferrocenyl subunits as internal redox references were covalently appended to representative electrophores in order to count the electrons involved in EP-centered reduction processes. Depending on the steric constraint around the N-pyridinio site, the two-electron reduction is single-step (Ar = Ph, Py, qPy) or stepwise (Ar = Xy, Lu, qLu). This steric switching of the potential compression is accurately accounted for by ab initio modeling (Density Functional Theory, DFT) that proposes a mechanism for pyramidalization of the Npyridinio atom coupled with reduction. When the hybridization change of this atom is hindered (Ar = Xy, Lu, qLu), the first reduction is a one-electron process. Theory also reveals that the single-step two-electron reduction involves couples of redox isomers (electromers) displaying both the axial geometry of native EPs and the pyramidalized geometry of doubly reduced EPs. This picture is confirmed by a combined UV-vis-NIR spectroelectrochemical and time-dependent DFT study: comparison of in situ spectroelectrochemical data with the calculated electronic transitions makes it possible to both evidence the distortion and identify the predicted electromers, which play decisive roles in the electron-transfer mechanism. Last, this mechanism is further supported by in-depth analysis of the electronic structures of electrophores in their various reduction states (including electromeric forms).
ANILINOPYRAZOLE DERIVATIVES USEFUL FOR THE TREATMENT OF DIABETES
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Page/Page column 91-92, (2010/11/26)
The present invention relates to anilinopyrazole compounds of formula (1) in which R3 represents an aromatic 5- or 6-membered heteroaromatic ring which is optionally fused to phenyl, said heterocycle or fused heterocycle is optionally substituted, X represents a carboxylic acid, ester or amide, or sulfonamide, and the remaining groups are as defined in the text. It also relates to pharmaceutical compositions containing these materials and, and methods for treating diabetes and related disorders using these materials.
