4-Amino-5-chloro-2,6-dimethylpyrimidine (ACDP) is an aminopyrimidine derivative. Its interaction as an electron donor with a σ-electron acceptor, iodine has been studied. 4-Amino-5-chloro-2,6-dimethylpyrimidine participates in the synthesis of diazino[c]quinolin-5(6H)-one and -isoquinolin-6(5H)-one, diazino[c]naphthyridin-6(5H)- and -5(6H)-one derivatives. 4-Amino-5-chloro-2,6-dimethylpyrimidine is suitable reagent employed as a nucleobase standard in the systematic quantitative structure-retention relationship (QSRR) study on pyrimidines between the molecular descriptors (variables) and their chromatographic retention (experimental unit). 4-Amino-5-chloro-2,6-dimethylpyrimidine (ACDP) is an aminopyrimidine derivative. Its interaction as an electron donor with a σ-electron acceptor, iodine has been studied. 4-Amino-5-chloro-2,6-dimethylpyrimidine participates in the synthesis of diazino[c]quinolin-5(6H)-one and -isoquinolin-6(5H)-one, diazino[c]naphthyridin-6(5H)- and -5(6H)-one derivatives. 4-Amino-5-chloro-2,6-dimethylpyrimidine is suitable reagent employed as a nucleobase standard in the systematic quantitative structure-retention relationship (QSRR) study on pyrimidines between the molecular descriptors (variables) and their chromatographic retention (experimental unit).