91272-86-5Relevant academic research and scientific papers
Hf(OTf)4-Catalyzed regioselective N -aminomethylation of indoles and related NH-containing heterocycles
Sakai, Norio,Shimamura, Kazuyori,Ikeda, Reiko,Konakahara, Takeo
supporting information; experimental part, p. 3923 - 3926 (2010/07/05)
Figure presented Under Lewis acidic conditions using Hf(OTf)4, the aminomethylation of an indole derivative with a typical N,O-acetal preferentially produced kinetically favored N-aminomethylated indole derivatives instead of thermodynamically favored 3-aminomethylated indoles.
Synthesis of 1-(Dimethylsulfamoyl)-2- and 5-Imidazolecarboxaldehydes. Rearrangement of 1-(Dimethylsulfamoyl)-5-imidazolecarboxaldehyde to the 4-Carboxaldehyde
Kim, Jang-Woo,Abdelaal, Salma M.,Bauer, Ludwig,Heimer, Norman E.
, p. 611 - 620 (2007/10/02)
Lithiation of 1-(dimethylsulfamoyl)imidazole by n-butyllithium, followed by substitution with dimethylformamide provided 1-(dimethylsulfamoyl)-2-imidazolecarboxaldehyde in 19percent yield.When 1-(dimethylsulfamoyl)-2-(tert-butyldimethylsilyl)imidazole was lithiated by sec-butyllithium, followed by methyl formate, there was obtained 1-(dimethylsulfamoyl)-2-(tert-butyldimethylsilyl)-5-imidazolecarboxaldehyde (57percent).Removal of the silyl group by acetic acid yielded 1-(dimethylsulfamoyl)-5-imidazolecarboxaldehyde (11, 96percent) as a gum.Isomerization of 11 took place slowly at room temperature (10 days), or faster in tetrahydrofuran solution containing triethylamine (2 hours) to form crystalline 1-(dimethylsulfamoyl)-4-imidazolecarboxaldehyde (12) in 68percent yield.Proton and carbon-13 nmr spectra were alanyzed to determine the structure of the isomers.However, only X-ray crystallography established the structure of 1-(dimethylsulfamoyl)-4-imidazolecarboxaldehyde, unequivocally.A mechanism for the isomerization of 11 to 12 is proposed.
