Abstract
The reaction of 9, 10-phenanthrenequinone (PTQ) with cyclohexylguanidine or isopropylguanidine in alkaline aqueous ethanol yielded 1H-phenanthro [9, 10-d] imidazol-2-amine (PIA) as the major product and N-cyclohexyl-PIA or N-isopropyl-PIA, respectively, as a minor product. The same reaction with phenylguanidine or tert-butylguanidine yielded only the corresponding N-substituted PIAs. The yield of N-isopropyl-PIA was increased seven-fold when NaBH4 was added to the reaction mixture of PTQ and isopropylguanidine. N-Substituted PIAs are fluorescent and can be separated from PIA by thin layer chromatography.
