Lithium Hexamethyldisilazane Transformation of Transiently Protected 4-Aza/Benzimidazole Nitriles to Amidines and their Dimethyl Sulfoxide Mediated Imidazole Ring Formation.
Trimethylsilyl-transient protection successfully allowed the use of lithium hexamethyldisilazane to prepare benzimidazole (BI) and 4-azabenzimidazole (azaBI) amidines from nitriles in 58-88% yields. This strategy offers a much better choice to prepare BI/azaBI amidines than the lengthy, low-yielding Pinner reaction. Synthesis of aza/benzimidazole rings from aromatic diamines and aldehydes was affected in dimethyl sulfoxide in 10-15 min, while known procedures require long time and purification. These methods are important for the BI/azaBI-based drug industry and for developing specific DNA binders for expanded therapeutic applications.
Department of Chemistry, Georgia State University , Atlanta, Georgia 30303, United States.|Applied Nucleic Acids Research Center & Chemistry Department, Faculty of Sciences, Zagazig University , Zagazig 44519, Egypt.
Reham A I
RA
Abou-Elkhair
Applied Nucleic Acids Research Center & Chemistry Department, Faculty of Sciences, Zagazig University , Zagazig 44519, Egypt.
Abdalla E A
AE
Hassan
Department of Chemistry, Georgia State University , Atlanta, Georgia 30303, United States.
David W
DW
Boykin
Department of Chemistry, Georgia State University , Atlanta, Georgia 30303, United States.
W David
WD
Wilson
D000578:Amidines / Q000138:chemical synthesis* / Q000737:chemistry; D001372:Aza Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D001562:Benzimidazoles / Q000138:chemical synthesis / Q000737:chemistry*; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D007093:Imidazoles / Q000138:chemical synthesis* / Q000737:chemistry; D018020:Lithium Compounds / Q000737:chemistry*; D015394:Molecular Structure; D009570:Nitriles / Q000138:chemical synthesis / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry*
D000578:Amidines; D001372:Aza Compounds; D001562:Benzimidazoles; D007093:Imidazoles; D018020:Lithium Compounds; D009570:Nitriles; D012821:Silanes; C031000:benzimidazole; C442341:lithium hexamethyldisilazide; D004121:Dimethyl Sulfoxide