17064-87-8Relevant academic research and scientific papers
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.
An approach to fused pyrimidine derivatives via Schiff bases of aromatic ortho-nitrocarbaldehydes. An investigation of substituent effects on the reaction course
Ostrowski,Wolniewicz
, p. 705 - 713 (2007/10/03)
The synthesis of fused pyrimidines from the Schiff bases of aromatic ortho-nitrocarbaldehydes is reported. The Schiff bases after selective reduction of the nitro group on 10% Pd/C, followed by condensation of the amines formed with orthoesters, are transformed to the corresponding imidates. Heating of the latter in a sealed tube with an excess of ammonia (or with ammonia in ethanol) gives fused pyrimidines. The influence of various substituents in the aromatic ring of the imine moiety of the Schiff bases on the overall yield of fused pyrimidine derivatives has been investigated. Moderate electron-withdrawing groups gave the best results.
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.
