73306-07-7

Upstream product

• 73306-02-2 4-methyl-2,3-diphenyl-5-p-tolyl-2H-[1,2,6]thiadiazine 1-oxide 
• 78946-69-7 4-Methyl-2,3-diphenyl-5-p-tolyl-2H-[1,2,6]thiadiazine 
• 110-86-1 pyridine 
• 14752-72-8 1,N-Diphenylpropanimine 
• 104-85-8 para-methylbenzonitrile 
• 1227476-15-4 Azobenzene 
• 88039-24-1 [2-Chloro-3-imino-2-methyl-1-phenyl-3-p-tolyl-prop-(E)-ylidene]-phenyl-amine 
• 112253-58-4 (4-Chloro-4-methyl-5-phenyl-3-p-tolyl-4,5-dihydro-isoxazol-5-yl)-phenyl-amine 
• 138356-05-5 3-imino-1,N-diphenyl-2-methyl-3-(p-tolyl)prop-1-enylamine 
• 59-88-1 phenylhydrazine hydrochloride 

Relevant academic research and scientific papers

Multicomponent Pyrazole Synthesis from Alkynes, Nitriles, and Titanium Imido Complexes via Oxidatively Induced N-N Bond Coupling

Pyrazoles are an important class of heterocycles found in a wide range of bioactive compounds and pharmaceuticals. Pyrazole synthesis often requires hydrazine or related reagents where an intact N-N bond is conservatively installed into a pyrazole precursor fragment. Herein, we report the multicomponent oxidative coupling of alkynes, nitriles, and Ti imido complexes for the synthesis of multisubstituted pyrazoles. This modular method avoids potentially hazardous reagents like hydrazine, instead forming the N-N bond in the final step via oxidation-induced coupling on Ti. The mechanism of this transformation has been studied in-depth through stoichiometric reactions of the key diazatitanacyclohexadiene intermediate, which can be accessed via multicomponent coupling of Ti imidos with nitriles and alkynes, ring opening of 2-imino-2H-azirines, or direct metalation of 4-azadiene-1-amine derivatives. The critical transformation in this reaction is the 2-electron oxidation-induced N-N coupling on Ti. This is a rare example of formal N-N coupling on a metal center, which likely occurs through an electrocyclic mechanism analogous to a Nazarov cyclization. Conveniently, these 2-electron-oxidized diazatitanacyclohexadiene intermediates can be accessed via disproportionation of the 1-electron-oxidized species, which allows utilization of weak oxidants such as TEMPO

SYNTHESIS OF 5-AMINO-4-CHLORO-4,5-DIHYDROISOXAZOLES AND 4-CHLOROISOXAZOLES.

4-Chloro-4,5-dihydroisoxazoles (4) and (5) and -isoxazoles (6) were prepared by reaction of chlorodiimines (1) and (2) with hydroxylamine hydrochloride.Basic treatment of (5) gave rise to N-N bond formation yielding pyrazoles (8).

Regiospecific synthesis of pyrazoles from 1-azabutadiene derivatives.

Reaction of 4-amino-1-azabutadienes with different hydrazines leads to pyrazoles.On the other hand, when 4-alkylidene-1-hydrazino-1-azabutadiene derivatives are treated with trifluoroacetic acid, N-alkenylpyrazoles are obtained.

An Unambiguous Synthesis of Pyrazoles by Sulphur Extrusion from 1,2,6-Thiadiazines

Di-imines (1) react with thionyl chloride and sulphur monochloride and dichloride giving different 1,2,6-thiadiazine S-oxides (3) and 1,2,6-thiadiazines (4), respectively.These last two compounds lead, by heating, to pyrazoles (6) via thermal extrusion of