3682-73-3

Upstream product

• 271-44-3 benzimidazole 
• 3076-56-0 p-tolyllead triacetate 
• 70704-41-5 3-chloro-2-(p-tolyl)-2H-indazole 
• 106-38-7 para-bromotoluene 
• 637-60-5 p-tolylhydrazine hydrochloride 
• 16714-25-3 2-azidobenzaldehyde 
• 89-98-5 2-chloro-benzaldehyde 
• 106-49-0 p-toluidine 
• 552-89-6 2-nitro-benzaldehyde 
• 624-31-7 4-tolyl iodide 
• 539-44-6 N-4-methylphenylhydrazine 
• 3433-80-5 1-Bromo-2-bromomethyl-benzene 
• 623-11-0 1-methyl-4-nitrosobenzene 
• 95-53-4 o-toluidine 

Downstream Products

• 1201938-16-0 3-(4-chlorophenyl)-2-p-tolyl-2H-indazole 

Relevant academic research and scientific papers

Metal-free regioselective C-H amination for the synthesis of pyrazole-containing 2H-indazoles

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.

Direct Formation of 2-Substituted 2 H-Indazoles by a Pd-Catalyzed Reaction between 2-Halobenzyl Halides and Arylhydrazines

A direct and operationally simple method for the regioselective synthesis of 2-aryl-substituted 2H-indazoles is reported. The Pd-catalyzed reaction between easily available 2-bromobenzyl bromides and arylhydrazines employing Cs2CO3 as the base and t-Bu3PHBF4 as the ligand in DMSO at 120 °C in a sealed tube delivers the 2-substituted-2H-indazoles in a single synthetic step with yields up to 79%. The new method is based on a regioselective intermolecular N-benzylation followed by intramolecular N-arylation and oxidation.

Manganese-Catalyzed Electrochemical Tandem Azidation-Coarctate Reaction: Easy Access to 2-Azo-benzonitriles

A one-pot cascade transformation consisting of an electrochemically driven azidation of 2H-indazole followed by coarctate fragmentation is developed to synthesize the 2-azo-benzonitrile motif. This manganese-catalyzed transformation is external-chemical-oxidant-free and operates at ambient temperature under air. This methodology exhibits good functional group tolerance, affording a broad range of substrate scopes of up to 89% isolated yield. Diverse derivatization of the 2-azo-benzonitrile product resulted in other valuable scaffolds.

Oxidative cross-dehydrogenative coupling (CDC)viaC(sp2)-H bond functionalization:tert-butyl peroxybenzoate (TBPB)-promoted regioselective direct C-3 acylation/benzoylation of 2H-indazoles with aldehydes/benzyl alcohols/styrenes

An efficient, cost-effective, transition-metal-free, oxidative C(sp2)-H/C(sp2)-H cross-dehydrogenative couplingviaa C(sp2)-H bond functionalization protocol for the regioselective direct C-3 acylation/benzoylation of subst

Direct C3 Carbamoylation of 2H-Indazoles

We developed a novel method for direct C3 carbamoylation of 2H-indazoles using oxamic acids as carbamoyl radical sources. In the presence of ammonium persulfate, carbamoyl radicals were generated from oxamic acids, then used for further reactions with 2H-indazoles to afford the desired products. The reaction proceeds under metal- and catalyst-free conditions. This simple process allows for the efficient synthesis of C3 carbamoylated 2H-indazoles, which are important scaffolds in organic synthesis.

Synthesis method of 2H-indazole and derivatives thereof

The invention discloses a synthetic reaction of 2H-indazole and derivatives thereof under a metal-free condition. The new strategy has the advantages of no metal participation, wide substrate range and good functional group compatibility, and an efficient

Efficient synthesis of 2-aryl-2: H -indazoles by base-catalyzed benzyl C-H deprotonation and cyclization

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

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.

Fe2O3@[proline]–CuMgAl–LDH: A magnetic bifunctional copper and organocatalyst system for one-pot synthesis of quinolines and 2H-indazoles in green media

A novel magnetic core–shell Fe2O3@[proline]–CuMgAl–L(ayered)D(ouble)H(ydroxide) was designed as an efficient bifunctional catalytic system. To this end, Cu (II) was combined with Mg and Al in the LDH structure and l-proline was intercalated between LDH layers in order to perform a straightforward synthesis of quinolines and 2H-indazoles as two important pharmaceutical N-aryl-substituted heterocyclic compounds. In this regard, a facile method was employed through consecutive condensation under a mild conditions in choline azide media, which played the role of a reagent and a solvent to avoid toxic solvents and hazardous azidation reagents. These techniques provided considerable improvement in terms of using green media, reducing starting materials, reaching higher yields and offering a shorter reaction time and lower temperature. In conclusion, it was found that the catalyst could be reused five times with no significant loss of activity.

New yellow-emitting iridium(III) complexes containing 2-phenyl-2H-indazole-based ligands for high efficient OLEDs with EQE over 25%

Six new pidz-based bis-cyclometalated Ir(III) complexes (Ir1-Ir6) have been synthesized and characterized. These complexes contain 2-phenyl-2H-indazole (pidz, 2a), 2-(4-fluorophenyl)–2H-indazole (fpidz, 2b), 2-(p-tolyl)–2H-indazole (ch3pidz, 2c), 2-(4-(trifluoromethyl)phenyl)–2H-indazole (cf3pidz, 2d), 2-(2,4-difluorophenyl)–2H-indazole (2,4-f2pidz, 2e) and 2-(3,5-difluorophenyl)–2H-indazole (3,5-f2pidz, 2f) as cyclometalated (C∧N) ligands, and acetylacetone (acacH) as ancillary ligand. The crystal structure of Ir2 has been determined by X-ray analysis. Different substituents of C∧N ligand in Ir2-Ir6 induce either a bathochromic or hypsochromic shift in the absorption spectra relative to the parent complex Ir1. The phenomenon is further well explained by DFT calculation and electrochemical study. All of the iridium(III) complexes are yellow emissive with quantum yields of 13.1–32.3% and lifetimes of 1.32–1.77 μs in solution at room temperature. We demonstrate that their emission originates from a hybrid 3MLCT/3ILCT/3LLCT excited state on the basis of the experimental and theoretical investigation. The corresponding yellow-emitting devices based on complexes Ir1, Ir2 and Ir4 can produce efficient electrophosphorescence with a luminance efficiency of 35.1–52.2 cd·A-1, a power efficiency of 20.8–32.1 lm·W?1 and an external quantum efficiency of up to 25.6%. All these EL data definitely suggest the bulky –CF3 skeleton in the doped materials could benefit the fabrication of high-efficiency phosphorescent OLEDs.