202344-35-2Relevant articles and documents
N-Picolinamides as ligands for Ullmann-type C-N coupling reactions
Damkaci, Fehmi,Alawaed, Abdulkhaliq,Vik, Erik
supporting information, p. 2197 - 2200 (2016/05/02)
The use of N-phenyl-2-pyridincarboxamide-1-oxide as a ligand with Cu2O in Ullmann type C-N bond formations between aryl halides and N-heteroaryls in common solvents, such as MeCN, DMF, and DMSO at 82-120 °C has been successfully demonstrated. The ligand is effective when only 4% equiv is used relative to the substrate. The reaction provided the corresponding products in coupling of electron-rich, electron poor, and ortho-substituted aryl halides, including ortho aryl-chlorides, in good to very good yields. N-arylation is selectively preferred at the benzyl position when ortho-halide benzyl bromide is reacted with one equivalent of pyrazole. However, di-N-arylation is achieved in very high yields when 2.5 equiv of pyrazole is used, providing a stoichiometric control over the coupling reaction.
Pyrolysis of 1-substituted pyrazoles and chloroform at 550°C: Formation of α-carboline from 1-benzylpyrazoles
Bhatti, Inayat A.,Busby, Reginald E.,Bin Mohamed, Murtedza,Parrick, John,Shaw, C. J. Granville
, p. 3581 - 3585 (2007/10/03)
Pyrolysis of 13CH3 labelled 1-methylpyrazole 8 with chloroform at 550°C in a continuous flow reactor yields unlabelled 2-chloropyrimidine 9 and 2-cyanopyrrole 10 labelled at the cyano group. However, pyrolysis of 1-benzylpyrazole 14 with chloroform under similar conditions gives 9,2-phenylpyrimidine 13 and, as the major product, α-carboline 15. Pyrolysis of several substituted 1-(arylmethyl)pyrazoles and the use of 13C and 15N labelled compounds provides direct evidence by which the positions of 7 atoms of 1-benzylpyrazole can be located in the α-carboline. These data support the mechanisms suggested for the formation of 9, 10, and 15.
