57707-15-0

Upstream product

• 94-09-7 p-aminoethylbenzoate 
• 552-89-6 2-nitro-benzaldehyde 
• 23308-83-0 (2-nitrobenzyl)triphenylphosphonium bromide 
• 30806-83-8 p-ethoxycarbonylphenyl isocyanate 
• 51934-41-9 4-iodobenzoic acid ethyl ester 
• 271-44-3 benzimidazole 
• 7182-99-2 4-benzylidenamino-benzoic acid ethyl ester 
• 100-52-7 benzaldehyde 
• 5344-90-1 2-Aminobenzyl alcohol 
• 7476-79-1 4-nitrosobenzoic acid ethyl ester 
• 6630-33-7 ortho-bromobenzaldehyde 
• 57707-09-2 ethyl 4-(2-nitrobenzylideneamino)benzoate 

Downstream Products

• 81265-85-2 4-(2H-indazol-2-yl)benzoic acid 

Relevant academic research and scientific papers

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.

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.

Preparation method 2 - substituted - 222H-indazole compound

The invention provides a preparation method of a 2-substituent-2H-indazole compound. With a cuprous catalyst, a coupling reaction is carried out to substituted 1H-indazole and aryliodonium salt in a low-molecular polar organic solvent to obtain a corresponding 2-substituent-2H-indazole compound, wherein the molar ratio of the 1H-indazole to the aryliodonium salt is 1:1.2. According to the method,the reaction route starts from the 1H-indazole compound which is easy to obtain; with the low-cost cuprous compound as a catalyst, the reaction condition is gentle and yield of produced target compound is high. The method also has good compatibility with various functional groups and can be widely applied to synthesize 2-substituent-2H-indazole compounds having different substituent groups. The method has important application value.

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.

Ultrasound promoted mild and facile onepot, three component synthesis of 2Hindazoles by consecutive condensation, CN and NN bond formations catalysed by copperdoped silica cuprous sulphate (CDSCS) as an efficient heterogeneous nanocatalyst

An ultrasonic promoted facile and convenient one-pot three-component procedure for the synthesis of 2H-indazole derivatives using copper-doped silica cuprous sulphate (CDSCS) as a heterogeneous nano-catalyst has been described. In this approach, ultrasonic mediated reaction of different substituted 2-bromobenzaldehydes, structurally diverse primary amines, and tetrabutylammonium azide (TBAA) as an azide source in the presence of CDSCS in DMSO at room temperature furnishes 2H-indazoles in good to excellent yields. Utilizing ultrasonic irradiation techniques provided the dramatic improvements in terms of higher yields and shorter reaction times compared with conventional heating method.

Consecutive condensation, C-N and N-N bond formations: A copper-catalyzed one-pot three-component synthesis of 2 H -indazole

2H-Indazoles are synthesized using copper-catalyzed, one-pot, three-component reactions of 2-bromobenzaldehydes, primary amines, and sodium azide. A copper catalyst plays the key role in the formation of C-N and N-N bonds. This method has a broad substrate scope with a high tolerance for a variety of functional groups.

Preparation of polyfunctional indazoles and heteroarylazo compounds using highly functionalized zinc reagents

Readily available 2-chloromethylarylzinc reagents react with functionalized aryldiazonlum tetrafluoroborates providing polyfunctional indazoles. Selective metalations of these 2-aryl-2H-indazoles afford new polycyclic aromatlcs. The performance of a chemo

Synthesis of 2-aryl-2H-indazoles by base catalysed reaction of 2-nitrobenzyl triphenylphosphonium bromide and aryl isocyanates

The synthesis of a series of 2-aryl-2H-indazoles is reported. These compounds are obtained in moderate to good yield by reaction of 2-nitrobenzyl triphenylphosphonium bromide with aryl isocyanates, catalysed by sodium hydride or DBU. (C) 2000 Elsevier Science Ltd.