The investigation in 2,3'-biquinoline series 26.* Regioselective nitration of 1'-alkyl-1',4'-dihydro-2,3'-biquinolin-4'-ones and 1'-alkyl-1',2'-dihydro-2,3'-biquinolin-2'-ones

The nitration of 1'-alkyl-1',4'-dihydro-2,3'-biquinolin-4'-ones and 1'-alkyl-1',2'-dihydro-2,3'-biquinolin-2'-ones has been investigated. It was shown that the regioselectivity of nitration of the first depends on the acidity of the medium and the order of adding reactants. In strongly acidic medium 1'-alkyl-5,6'-dinitro-1',4'-dihydro-2,3'-biquinolin-4'-ones or mixtures of them with 1'-alkyl-5-nitro-1',4'-dihydro-2,3'-biquinolin-4'-ones are formed. In less acidic media 1'-alkyl-6'-nitro-1',4'-dihydro-2,3'-biquinolin-4'-ones and then 1'-alkyl-6,6'-dinitro-1',4'-dihydro-2,3'-biquinolin-4'-ones are formed. Nitration of 1'-alkyl-1',2'-dihydro-2,3'-biquinolin-2'-ones leads to 1'-alkyl-6'-nitro-1',2'-dihydro-2,3'-biquinolin-2'-one and then 1'-alkyl-6,6',8'-trinitro-1',2'-dihydro-2,3'-biquinolin-2'-one. *For Communication 25 see [1]. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 578-585, April, 2009.