120455-06-3Relevant academic research and scientific papers
Metal-free regioselective C-H amination for the synthesis of pyrazole-containing 2H-indazoles
Wang, Kai,Wei, Tingting,Zhang, Yujia,Hou, Jiahao,Bai, Renren,Xie, Yuanyuan
, p. 1787 - 1794 (2021/03/14)
A general and practical regioselective approach for the C-H amination of 2H-indazoles under transition-metal-free conditions was developed. A series of substrates were tested showing eminent functional group tolerance and affording the C-N functionalization products in good to excellent yields. Mechanism studies revealed that a radical process was involved in this transformation.
Efficient synthesis of 2-aryl-2: H -indazoles by base-catalyzed benzyl C-H deprotonation and cyclization
Gao, Wen-Xia,Jin, Guo-Qing,Liu, Miao-Chang,Wu, Hua-Yue,Zhou, Yun-Bing
, p. 14617 - 14620 (2020/12/02)
A straightforward and efficient method for the preparation of 2-aryl-2H-indazoles from ortho-alkyl substituted azoxybenzenes is presented. The reaction proceeds through base-catalyzed benzyl C-H deprotonation and cyclization to afford 2-aryl-2H-indazoles
Tert-Butyl Hydroperoxide-Mediated Oxo-Sulfonylation of 2 H-Indazoles with Sulfinic Acid toward Indazol-3(2 H)-ones
Ghosh, Payel,Mondal, Susmita,Hajra, Alakananda
, p. 1086 - 1090 (2020/02/04)
A new and efficient oxo-sulfonylation protocol has been established for the synthesis of N-sulfonylated indazolones employing sulfinic acid as a sulfonylating agent using tert-butyl hydroperoxide (TBHP) under ambient air. A series of structurally diverse 1-sulfonylindazol-3(2H)-one derivatives were obtained in good yields. A radical reaction mechanism has been proposed for this transformation.
Visible-light-induced regioselective cross-dehydrogenative coupling of 2 H-indazoles with ethers
Singsardar, Mukta,Laru, Sudip,Mondal, Susmita,Hajra, Alakananda
, p. 4543 - 4550 (2019/04/30)
A visible-light-promoted regioselective C(sp2)-H/C(sp3)-H cross-dehydrogenative coupling between 2H-indazoles and ethers has been achieved using a catalytic amount of rose bengal as an organophotoredox-catalyst and tert-butyl hydroperoxide (TBHP) as an oxidant at ambient temperature under aerobic conditions. A variety of C-3 oxyalkylated 2H-indazoles have been synthesized in moderate to good yields. Mechanistic studies suggest a radical pathway of the present reaction.
Mesoporous nitrogen doped nano titania - A green photocatalyst for the effective reductive cleavage of azoxybenzenes to amines or 2-phenyl indazoles in methanol
Selvam,Balachandran,Velmurugan,Swaminathan
experimental part, p. 213 - 222 (2012/03/26)
A new nitrogen precursor, hydrazine hydrate was used in the synthesis of nano-sized, N-doped TiO2 photocatalyst by a simple wet impregnation method. This photocatalyst was characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), High resolution transmission electron microscope (HR-TEM), UV-vis diffuses reflectance spectra (DRS), photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS). XRD patterns show that the crystal structure of N-TiO2 resembles anatase phase of TiO2. The UV-vis spectra indicate an increase in absorption of visible light when compared to TiO2. Furthermore XPS analysis reveals the presence of the N atom as O-Ti-N linkage substituting the O atom in the TiO2 lattice and this causes a decrease in oxygen vacancies. N-TiO2 nanoparticles were used as a green and recyclable heterogeneous photocatalyst for rapid and efficient reductive cleavage of azoxybenzene into their corresponding amines or 2-phenylindazoles with methanol at room temperature under N2 atmosphere. Azoxybenzenes in neat methanol afforded anilines, while in aqueous methanol (20% water-80% methanol) they formed corresponding 2-phenyl indazoles. In both reductive cleavages, nano N-TiO2 is more effective than prepared TiO2, showing that the nitrogen doping could be an excellent choice to improve the photoactivity of TiO2.
Indazole estrogens: Highly selective ligands for the estrogen receptor β
De Angelis, Meri,Stossi, Fabio,Carlson, Kathryn A.,Katzenellenbogen, Benita S.,Katzenellenbogen, John A.
, p. 1132 - 1144 (2007/10/03)
The estrogen receptors, ERα and ERβ, are important pharmaceutical targets. To develop ERβ-selective ligands, we synthesized a series of nonsteroidal compounds having a phenyl-2H-indazole core with different groups at C-3. Several of these show high affinity and good ERβ selectivity, especially those with polar and/or polarizable substituents at this site (halogen, CF3, nitrile); the best compounds have affinities for ERβ comparable to estradiol, with ERβ affinity selectivity >100. This potency and ERβ selectivity is also seen in cell-based transcriptional assays, where several compounds showed ERβ efficacies equivalent to that of estradiol with ERβ potency selectivities of 100. These compounds might prove useful as selective pharmacological probes to study the biological actions of estrogens mediated through ERβ, and they might lead to the development of useful pharmaceuticals. These findings also contribute to an evolving pharmacophore that characterizes certain nonsteroidal ligands having high ERβ subtype affinity and potency selectivity.
Heterogeneous Photocatalytic Reactions of Azobenzenes on Titanium Dioxide Powder in Methanolic Solution
Shibata, Katsuyoshi,Mimura, Tadashi,Matsui, Masaki,Sugiura, Takashi,Minoura, Hideki
, p. 1318 - 1320 (2007/10/02)
Irradiation of a TiO2 powder suspension in a methanolic solution of an azobenzene results in the formation of 1,2,4-triphenyl-1,2,4-triazolidines and a 2-phenylindazole in moderate yields.
