109772-85-2Relevant academic research and scientific papers
Synthesis, antiprotozoal activity, and cheminformatic analysis of 2-phenyl-2h-indazole derivatives
Aguilera-Perdomo, Jacobo David,Cortés-Benítez, Francisco,Cortés-Gines, Miguel,Del Angel, Kevin Samael Olascoaga,Pérez-Villanueva, Jaime,Palacios-Espinosa, Juan Francisco,Quintana-Salazar, Edgar A.,Rodríguez-Villar, Karen,Soria-Arteche, Olivia,Yépez-Mulia, Lilián
, (2021/05/28)
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.
Facile synthesis of 4-substituted 1,2,4,5-tetrahydro-1,4-benzodiazepin-3-ones by reductive cyclization of 2-chloro-N-(2-nitrobenzyl)acetamides
Sasiambarrena, Leandro D.,Barri, Ivan A.,Fraga, Guido G.,Bravo, Rodolfo D.,Ponzinibbio, Agustín
supporting information, p. 264 - 267 (2019/01/04)
A facile and efficient method was developed for the synthesis of 1,2,4,5-tetrahydro-1,4-benzodiazepine-3-ones from 2-chloro-N-(2-nitrobenzyl)acetamides through a reductive cyclization using iron-ammonium chloride in ethanol–water in good yields. This method provides a simple approach to these benzodiazepine-3-ones which are of high value in the field of medicinal chemistry research.
A Biphilic Phosphetane Catalyzes N-N Bond-Forming Cadogan Heterocyclization via PIII/PV = O Redox Cycling
Nykaza, Trevor V.,Harrison, Tyler S.,Ghosh, Avipsa,Putnik, Rachel A.,Radosevich, Alexander T.
supporting information, p. 6839 - 6842 (2017/05/29)
A small-ring phosphacycle, 1,2,2,3,4,4-hexamethylphosphetane, is found to catalyze deoxygenative N-N bond-forming Cadogan heterocyclization of o-nitrobenzaldimines, o-nitroazobenzenes, and related substrates in the presence of hydrosilane terminal reductant. The reaction provides a chemoselective catalytic synthesis of 2H-indazoles, 2H-benzotriazoles, and related fused heterocyclic systems with good functional group compatibility. On the basis of both stoichiometric and catalytic mechanistic experiments, the reaction is proposed to proceed via catalytic PIII/PV = O cycling, where DFT modeling suggests a turnover-limiting (3+1) cheletropic addition between the phosphetane catalyst and nitroarene substrate. Strain/distortion analysis of the (3+1) transition structure highlights the controlling role of frontier orbital effects underpinning the catalytic performance of the phosphetane.
Microwave-assisted molybdenum-catalyzed reductive cyclization of o -nitrobenzylidene amines to 2-Aryl-2 H -indazoles
Moustafa, Ahmed H.,Malakar, Chandi C.,Aljaar, Nayyef,Merisor, Elena,Conrad, Jürgen,Beifuss, Uwe
supporting information, p. 1573 - 1577 (2013/08/23)
The reductive cyclization of o-nitrobenzylidene amines under microwave conditions employing MoO2Cl2(dmf)2 as catalyst and Ph3P as reducing agent delivers 2-aryl-2H-indazoles with yields ranging from 61-92%. Georg Thieme Verlag Stuttgart. New York.
Microwave-assisted Cadogan reaction for the synthesis of 2-aryl-2H-indazoles, 2-aryl-1H-benzimidazoles, 2-carbonylindoles, carbazole, and phenazine
Creencia, Evelyn Cuevas,Kosaka, Masahiro,Muramatsu, Toshikatsu,Kobayashi, Masashi,Iizuka, Tomohiro,Horaguchi, Takaaki
experimental part, p. 1309 - 1317 (2010/03/23)
(Chemical Equation Presented) The Cadogan reaction, a widely accepted route for the synthesis of nitrogen containing heterocycles, is modified by using microwave radiation as the source of heat instead of the conventional heating by reflux in a nitrogen atmosphere for several hours. Appropriate starting materials were mixed with triethyl phosphite or triphenylphosphine and irradiated with microwaves for several minutes at a specific power to give the desired products. The indazoles were prepared by irradiating N-(2-nitrobenzylidene) anilines with triethyl phosphite at 200 W for 12-14 min to give 85-92% product yields. Irradiation of the mixture of N-benzylidene-2-nitroanilines and triphenylphosphine at 200 W for 3-5 min yielded 93-96% of the benzimidazoles. The carbonylindoles were obtained in 61-68% yields by irradiating 2-nitrochalcone or alkyl 2-nitrocinnamates and triphenylphosphine with microwaves at 80-200 W for 8-11 min. The mixture of 2-nitrobiphenyl and triphenylphosphine yielded 96% of carbazole when irradiated with microwaves at 200 W for 2 min while 75% of phenazine was obtained by irradiating the mixture of 2-nitrodiphenylamine and triphenylphosphine with microwaves at 200 W for 3.5 min. These results show that microwave-assisted Cadogan reactions gave better product yields at shorter reaction times.
o-Nitrobenzylidene Compounds. Part 3. Formation of 4-Arylamino-3-methoxycinnoline 1-Oxides from N-o-Nitrobenzylideneanilines, Cyanide Ion, and Methanol: the Intermediacy of 2-Aryl-3-cyano-2H-indazole 1-Oxides
Johnston, David,Smith, David M.,Shepherd, Thomas,Thompson, David
, p. 495 - 500 (2007/10/02)
The N-o-nitrobenzylidene derivatives of variously substituted anilines (7) have been cyclised by potassium cyanide in methanol, to give 4-arylamino-3-methoxycinnoline 1-oxides (9), the structures of which have been confirmed by independent synthesis of one representative .These cinnoline oxides are the main products (sometimes the only isolated products) when the amine-derived ring in (7) is ortho-substituted; in other cases the cinnoline oxides are minor products formed along with 2-aryl-3-cyano-2H-indazoles (10).In the latter group of reactions, the primary cyclisation products are 2-aryl-3-cyano-2H-indazole 1-oxides (8): these have then either been reduced to the indazoles in the basic methanolic medium, or have undergone ring-opening and recyclisation to give the cinnoline oxides (9).In the other group, where indazole oxides (8) cannot usually be isolated, their intermediacy in cinnoline oxide formation remains a possibility, although other mechanistic pathways can be envisaged.Some 'borderline' cases are identified and discussed.
