57707-17-2

Upstream product

• 95-51-2 o-chloroaniline 
• 6630-33-7 ortho-bromobenzaldehyde 
• 5344-90-1 2-Aminobenzyl alcohol 
• 932-33-2 o-Chloronitrosobenzene 
• 95-53-4 o-toluidine 
• 615-41-8 2-iodochlorobenzene 
• 271-44-3 benzimidazole 
• 552-89-6 2-nitro-benzaldehyde 
• 17099-16-0 (E/Z)-N-(2-nitrobenzylidene)-2-chloroaniline 

Relevant academic research and scientific papers

Synthesis, antiprotozoal activity, and cheminformatic analysis of 2-phenyl-2h-indazole derivatives

Indazole is an important scaffold in medicinal chemistry. At present, the progress on synthetic methodologies has allowed the preparation of several new indazole derivatives with interesting pharmacological properties. Particularly, the antiprotozoal activity of indazole derivatives have been recently reported. Herein, a series of 22 indazole derivatives was synthesized and studied as antiprotozoals. The 2-phenyl-2H-indazole scaffold was accessed by a one-pot procedure, which includes a combination of ultrasound synthesis under neat conditions as well as Cadogan’s cyclization. Moreover, some compounds were derivatized to have an appropriate set to provide structure-activity relationships (SAR) information. Whereas the antiprotozoal activity of six of these compounds against E. histolytica, G. intestinalis, and T. vaginalis had been previously reported, the activity of the additional 16 compounds was evaluated against these same protozoa. The biological assays revealed structural features that favor the antiprotozoal activity against the three protozoans tested, e.g., electron withdrawing groups at the 2-phenyl ring. It is important to mention that the indazole derivatives possess strong antiprotozoal activity and are also characterized by a continuous SAR.

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

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

Room-Temperature, Metal-Free, and One-Pot Preparation of 2H-Indazoles through a Mills Reaction and Cyclization Sequence

The Mills reaction and cyclization of readily available 2-aminobenzyl alcohols and nitrosobenzenes using thionyl bromide provided 2H-indazoles in up to 88 % yields. In the metal-free process, acetic acid played a crucial role for the both Mills reaction and cyclization. A brominated 2H-indazole could also be obtained through the one-pot sequence.

Access to 2-substituted-2: H -indazoles via a copper-catalyzed regioselective cross-coupling reaction

A CuCl catalyzed C-N cross-coupling reaction using commercially available 1H-indazoles with diaryliodonium salts is described. The methodology features ample structural versatility, affording 2-substituted-2H-indazole in good yields and complete N(2)-regiocontrol. Furthermore, the utility of the reaction was demonstrated in the synthesis of a known estrogen receptor β agonist. Mechanistic studies using density functional theory calculations suggested that the complete regioselectivity can be attributed to the only weak base TfO- in our system which could not deprotonate indazoles, and the catalyst oxidation process would be the rate-determining step.

A General One-Pot Synthesis of 2H-Indazoles Using an Organophosphorus–Silane System

A simple and direct approach for the regioselective construction of the privileged 2H-indazole scaffold is described. The developed one-pot strategy involves phospholene-mediated N?N bond formation to access 2H-indazoles. The amount of organophosphorus reagent was minimized by recycling the phospholene oxide with organosilane reductants. Starting from functionalized 2-nitrobenzaldehydes and primary amines, a mild reductive cyclization, involving the use of commercially available phospholene oxide and silanes, delivered a wide variety of substituted 2H-indazoles in good to excellent yields.

Regioselective synthesis of 2 H-indazoles using a mild, one-pot condensation-cadogan reductive cyclization

An operationally simple and efficient one-pot synthesis of 2H-indazoles from commercially available reagents is reported. Ortho-imino-nitrobenzene substrates, generated via condensation, undergo reductive cyclization promoted by tri-n-butylphosophine to afford substituted 2H-indazoles under mild reaction conditions. A variety of electronically diverse ortho-nitrobenzaldehydes and anilines were examined. To further extend the scope of the transformation, aliphatic amines were also employed to form N2-alkyl indazoles selectively under the optimized reaction conditions.

CuII-hydrotalcite catalyzed one-pot three component synthesis of 2H-indazoles by consecutive condensation, C-N and N-N bond formations

An efficient and straightforward synthesis of 2H-indazoles is achieved from 2-bromobenzaldehydes, primary amines and sodium azide through consecutive condensation, C-N and N-N bond formations, catalyzed by a novel heterogeneous CuII-HT catalyst. The recoverable heterogeneous CuII-HT catalyst exhibited an impressive activity for the title reaction without any additives (expensive ligands, etc.). Heterocyclization proceeds through C-N and N-N bond formation, which is the key step to deliver the desired 2H-indazole scaffold. A series of structurally diverse 2H-indazoles were prepared in good to excellent yields from easily accessible starting materials by employing this protocol.