Intramolecular cyclization of 5-amino-4-bis (?-chloroethyl)aminopyrimidines

4-R-5,6,7,8,9,10-Hexahydroimidazo [1,2,3-i,j] pteridinium chlorides and 4-R-7-(β-chloroethyl)-7,8-dihydroimidazo[1,2-c]pyrimidinium chlorides were obtained in the reaction of 6-R-5-amino-4-bis(β-hydroxyethyl) aminopyrimidines (R = H, Cl) with SOCl2 or POCl3. The pteridinium chlorides are formed through cyclization of the intermediately formed 4-R-8-(β-chloroethyl)-5,6,7,8-tetrahydropteridines, which, for R = Cl, were obtained independently by reduction of 4-chloro-6-bis-(β-chloroethyl) amino-5-nitropyrimidine. The conditions for the cyclization of imidazopyrimidinium chlorides to give imidazopteridinium chlorides were investigated.